| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Linus Walleij | 3591 | 20.75% | 81 | 17.23% |
| Alexandre Courbot | 1609 | 9.30% | 31 | 6.60% |
| Andy Shevchenko | 1509 | 8.72% | 73 | 15.53% |
| David Brownell | 1306 | 7.54% | 8 | 1.70% |
| Rojhalat Ibrahim | 888 | 5.13% | 3 | 0.64% |
| Bartosz Golaszewski | 879 | 5.08% | 39 | 8.30% |
| Janusz Krzysztofik | 686 | 3.96% | 8 | 1.70% |
| Thierry Reding | 558 | 3.22% | 15 | 3.19% |
| Lukas Wunner | 477 | 2.76% | 1 | 0.21% |
| Dmitry Torokhov | 432 | 2.50% | 6 | 1.28% |
| Hans Verkuil | 426 | 2.46% | 5 | 1.06% |
| Mika Westerberg | 416 | 2.40% | 13 | 2.77% |
| Kent Gibson | 364 | 2.10% | 11 | 2.34% |
| Benoit Parrot | 238 | 1.37% | 1 | 0.21% |
| Geert Uytterhoeven | 235 | 1.36% | 17 | 3.62% |
| Dipen Patel | 188 | 1.09% | 1 | 0.21% |
| Stephen Boyd | 184 | 1.06% | 5 | 1.06% |
| Anton Vorontsov | 177 | 1.02% | 5 | 1.06% |
| Laura Abbott | 164 | 0.95% | 1 | 0.21% |
| Shiraz Hashim | 160 | 0.92% | 1 | 0.21% |
| Laxman Dewangan | 155 | 0.90% | 3 | 0.64% |
| Grant C. Likely | 147 | 0.85% | 2 | 0.43% |
| Christian Ruppert | 136 | 0.79% | 1 | 0.21% |
| Markus Pargmann | 134 | 0.77% | 3 | 0.64% |
| Maulik Shah | 131 | 0.76% | 1 | 0.21% |
| Ricardo Ribalda Delgado | 121 | 0.70% | 6 | 1.28% |
| Marc Zyngier | 107 | 0.62% | 4 | 0.85% |
| Asmaa Mnebhi | 101 | 0.58% | 1 | 0.21% |
| Bamvor Jian Zhang | 96 | 0.55% | 4 | 0.85% |
| Thomas Petazzoni | 94 | 0.54% | 2 | 0.43% |
| Zeng Heng | 88 | 0.51% | 1 | 0.21% |
| Saravana Kannan | 77 | 0.44% | 3 | 0.64% |
| Guenter Roeck | 74 | 0.43% | 3 | 0.64% |
| Rasmus Villemoes | 74 | 0.43% | 1 | 0.21% |
| Brian Masney | 70 | 0.40% | 2 | 0.43% |
| Song Muchun | 69 | 0.40% | 1 | 0.21% |
| Kevin Hao | 67 | 0.39% | 3 | 0.64% |
| Grygorii Strashko | 64 | 0.37% | 6 | 1.28% |
| Uwe Kleine-König | 60 | 0.35% | 3 | 0.64% |
| Johan Hovold | 57 | 0.33% | 9 | 1.91% |
| Sergio Paracuellos | 55 | 0.32% | 1 | 0.21% |
| Charles Keepax | 46 | 0.27% | 1 | 0.21% |
| Shreeya Patel | 41 | 0.24% | 2 | 0.43% |
| Jonas Gorski | 38 | 0.22% | 1 | 0.21% |
| Andrew Lunn | 36 | 0.21% | 1 | 0.21% |
| Nuno Sá | 36 | 0.21% | 1 | 0.21% |
| Jani Nikula | 34 | 0.20% | 2 | 0.43% |
| Russell King | 33 | 0.19% | 1 | 0.21% |
| Andrew Jeffery | 33 | 0.19% | 1 | 0.21% |
| Michał Mirosław | 31 | 0.18% | 2 | 0.43% |
| Felipe Balbi | 31 | 0.18% | 1 | 0.21% |
| Björn Andersson | 27 | 0.16% | 1 | 0.21% |
| Shobhit Kumar | 25 | 0.14% | 1 | 0.21% |
| Philipp Zabel | 22 | 0.13% | 1 | 0.21% |
| Mathias Nyman | 22 | 0.13% | 3 | 0.64% |
| Christophe Leroy | 22 | 0.13% | 3 | 0.64% |
| Peter Rosin | 19 | 0.11% | 1 | 0.21% |
| Mark Brown | 18 | 0.10% | 1 | 0.21% |
| Guennadi Liakhovetski | 18 | 0.10% | 2 | 0.43% |
| Michael Walle | 17 | 0.10% | 2 | 0.43% |
| Biju Das | 16 | 0.09% | 2 | 0.43% |
| Quanyang Wang | 15 | 0.09% | 1 | 0.21% |
| Chris Packham | 15 | 0.09% | 1 | 0.21% |
| Lad Prabhakar | 13 | 0.08% | 1 | 0.21% |
| Drew Fustini | 13 | 0.08% | 1 | 0.21% |
| Axel Lin | 13 | 0.08% | 1 | 0.21% |
| Marco Felsch | 13 | 0.08% | 1 | 0.21% |
| Dmitry Eremin-Solenikov | 13 | 0.08% | 1 | 0.21% |
| Daniel Glöckner | 12 | 0.07% | 1 | 0.21% |
| Anatolij Gustschin | 10 | 0.06% | 1 | 0.21% |
| Andreas Kemnade | 10 | 0.06% | 1 | 0.21% |
| David Gow | 10 | 0.06% | 1 | 0.21% |
| Stephen Warren | 10 | 0.06% | 3 | 0.64% |
| Sudip Mukherjee | 9 | 0.05% | 1 | 0.21% |
| Julien Grossholtz | 9 | 0.05% | 1 | 0.21% |
| Michal Nazarewicz | 7 | 0.04% | 1 | 0.21% |
| Christophe Blaess | 6 | 0.03% | 1 | 0.21% |
| Hans de Goede | 6 | 0.03% | 1 | 0.21% |
| Tomeu Vizoso | 6 | 0.03% | 1 | 0.21% |
| Wei Yongjun | 6 | 0.03% | 1 | 0.21% |
| Kees Cook | 6 | 0.03% | 1 | 0.21% |
| Rafael J. Wysocki | 6 | 0.03% | 2 | 0.43% |
| Nikita Shubin | 6 | 0.03% | 1 | 0.21% |
| Shawn Guo | 6 | 0.03% | 1 | 0.21% |
| Mario Limonciello | 5 | 0.03% | 1 | 0.21% |
| Jiawen Wu | 4 | 0.02% | 1 | 0.21% |
| Jean Delvare | 4 | 0.02% | 1 | 0.21% |
| abdoulaye berthe | 4 | 0.02% | 1 | 0.21% |
| Boris Brezillon | 4 | 0.02% | 1 | 0.21% |
| Colin Cronin | 3 | 0.02% | 1 | 0.21% |
| Kay Sievers | 3 | 0.02% | 1 | 0.21% |
| Vladimir Zapolskiy | 3 | 0.02% | 1 | 0.21% |
| Sachin Kamat | 3 | 0.02% | 1 | 0.21% |
| Wolfram Sang | 3 | 0.02% | 2 | 0.43% |
| Magnus Damm | 2 | 0.01% | 1 | 0.21% |
| Lars-Peter Clausen | 2 | 0.01% | 1 | 0.21% |
| Tejun Heo | 2 | 0.01% | 1 | 0.21% |
| Alexander Stein | 2 | 0.01% | 1 | 0.21% |
| Adrian Hunter | 2 | 0.01% | 1 | 0.21% |
| Trent Piepho | 2 | 0.01% | 1 | 0.21% |
| Marcel Ziswiler | 2 | 0.01% | 1 | 0.21% |
| Zhangfei Gao | 1 | 0.01% | 1 | 0.21% |
| Maxime Ripard | 1 | 0.01% | 1 | 0.21% |
| Masahiro Yamada | 1 | 0.01% | 1 | 0.21% |
| Enrico Weigelt | 1 | 0.01% | 1 | 0.21% |
| Martin Kaiser | 1 | 0.01% | 1 | 0.21% |
| Dan Carpenter | 1 | 0.01% | 1 | 0.21% |
| Haojian Zhuang | 1 | 0.01% | 1 | 0.21% |
| Rahul Bedarkar | 1 | 0.01% | 1 | 0.21% |
| Dongsheng Wang | 1 | 0.01% | 1 | 0.21% |
| Linus Torvalds | 1 | 0.01% | 1 | 0.21% |
| Julia Cartwright | 1 | 0.01% | 1 | 0.21% |
| Total | 17310 | 470 |
// SPDX-License-Identifier: GPL-2.0 #include <linux/acpi.h> #include <linux/bitmap.h> #include <linux/compat.h> #include <linux/debugfs.h> #include <linux/device.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/file.h> #include <linux/fs.h> #include <linux/idr.h> #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/kernel.h> #include <linux/list.h> #include <linux/module.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> #include <linux/seq_file.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/gpio.h> #include <linux/gpio/driver.h> #include <linux/gpio/machine.h> #include <uapi/linux/gpio.h> #include "gpiolib-acpi.h" #include "gpiolib-cdev.h" #include "gpiolib-of.h" #include "gpiolib-swnode.h" #include "gpiolib-sysfs.h" #include "gpiolib.h" #define CREATE_TRACE_POINTS #include <trace/events/gpio.h> /* Implementation infrastructure for GPIO interfaces. * * The GPIO programming interface allows for inlining speed-critical * get/set operations for common cases, so that access to SOC-integrated * GPIOs can sometimes cost only an instruction or two per bit. */ /* When debugging, extend minimal trust to callers and platform code. * Also emit diagnostic messages that may help initial bringup, when * board setup or driver bugs are most common. * * Otherwise, minimize overhead in what may be bitbanging codepaths. */ #ifdef DEBUG #define extra_checks 1 #else #define extra_checks 0 #endif /* Device and char device-related information */ static DEFINE_IDA(gpio_ida); static dev_t gpio_devt; #define GPIO_DEV_MAX 256 /* 256 GPIO chip devices supported */ static int gpio_bus_match(struct device *dev, struct device_driver *drv) { struct fwnode_handle *fwnode = dev_fwnode(dev); /* * Only match if the fwnode doesn't already have a proper struct device * created for it. */ if (fwnode && fwnode->dev != dev) return 0; return 1; } static struct bus_type gpio_bus_type = { .name = "gpio", .match = gpio_bus_match, }; /* * Number of GPIOs to use for the fast path in set array */ #define FASTPATH_NGPIO CONFIG_GPIOLIB_FASTPATH_LIMIT /* gpio_lock prevents conflicts during gpio_desc[] table updates. * While any GPIO is requested, its gpio_chip is not removable; * each GPIO's "requested" flag serves as a lock and refcount. */ DEFINE_SPINLOCK(gpio_lock); static DEFINE_MUTEX(gpio_lookup_lock); static LIST_HEAD(gpio_lookup_list); LIST_HEAD(gpio_devices); static DEFINE_MUTEX(gpio_machine_hogs_mutex); static LIST_HEAD(gpio_machine_hogs); static void gpiochip_free_hogs(struct gpio_chip *gc); static int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, struct lock_class_key *request_key); static void gpiochip_irqchip_remove(struct gpio_chip *gc); static int gpiochip_irqchip_init_hw(struct gpio_chip *gc); static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc); static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc); static bool gpiolib_initialized; static inline void desc_set_label(struct gpio_desc *d, const char *label) { d->label = label; } /** * gpio_to_desc - Convert a GPIO number to its descriptor * @gpio: global GPIO number * * Returns: * The GPIO descriptor associated with the given GPIO, or %NULL if no GPIO * with the given number exists in the system. */ struct gpio_desc *gpio_to_desc(unsigned gpio) { struct gpio_device *gdev; unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) { if (gdev->base <= gpio && gdev->base + gdev->ngpio > gpio) { spin_unlock_irqrestore(&gpio_lock, flags); return &gdev->descs[gpio - gdev->base]; } } spin_unlock_irqrestore(&gpio_lock, flags); if (!gpio_is_valid(gpio)) pr_warn("invalid GPIO %d\n", gpio); return NULL; } EXPORT_SYMBOL_GPL(gpio_to_desc); /* This function is deprecated and will be removed soon, don't use. */ struct gpio_desc *gpiochip_get_desc(struct gpio_chip *gc, unsigned int hwnum) { return gpio_device_get_desc(gc->gpiodev, hwnum); } EXPORT_SYMBOL_GPL(gpiochip_get_desc); /** * gpio_device_get_desc() - get the GPIO descriptor corresponding to the given * hardware number for this GPIO device * @gdev: GPIO device to get the descriptor from * @hwnum: hardware number of the GPIO for this chip * * Returns: * A pointer to the GPIO descriptor or %EINVAL if no GPIO exists in the given * chip for the specified hardware number or %ENODEV if the underlying chip * already vanished. * * The reference count of struct gpio_device is *NOT* increased like when the * GPIO is being requested for exclusive usage. It's up to the caller to make * sure the GPIO device will stay alive together with the descriptor returned * by this function. */ struct gpio_desc * gpio_device_get_desc(struct gpio_device *gdev, unsigned int hwnum) { struct gpio_chip *gc; /* * FIXME: This will be locked once we protect gdev->chip everywhere * with SRCU. */ gc = gdev->chip; if (!gc) return ERR_PTR(-ENODEV); if (hwnum >= gdev->ngpio) return ERR_PTR(-EINVAL); return &gdev->descs[hwnum]; } EXPORT_SYMBOL_GPL(gpio_device_get_desc); /** * desc_to_gpio - convert a GPIO descriptor to the integer namespace * @desc: GPIO descriptor * * This should disappear in the future but is needed since we still * use GPIO numbers for error messages and sysfs nodes. * * Returns: * The global GPIO number for the GPIO specified by its descriptor. */ int desc_to_gpio(const struct gpio_desc *desc) { return desc->gdev->base + (desc - &desc->gdev->descs[0]); } EXPORT_SYMBOL_GPL(desc_to_gpio); /** * gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs * @desc: descriptor to return the chip of */ struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc) { if (!desc || !desc->gdev) return NULL; return desc->gdev->chip; } EXPORT_SYMBOL_GPL(gpiod_to_chip); /** * gpiod_to_gpio_device() - Return the GPIO device to which this descriptor * belongs. * @desc: Descriptor for which to return the GPIO device. * * This *DOES NOT* increase the reference count of the GPIO device as it's * expected that the descriptor is requested and the users already holds a * reference to the device. * * Returns: * Address of the GPIO device owning this descriptor. */ struct gpio_device *gpiod_to_gpio_device(struct gpio_desc *desc) { if (!desc) return NULL; return desc->gdev; } EXPORT_SYMBOL_GPL(gpiod_to_gpio_device); /** * gpio_device_get_base() - Get the base GPIO number allocated by this device * @gdev: GPIO device * * Returns: * First GPIO number in the global GPIO numberspace for this device. */ int gpio_device_get_base(struct gpio_device *gdev) { return gdev->base; } EXPORT_SYMBOL_GPL(gpio_device_get_base); /** * gpio_device_get_chip() - Get the gpio_chip implementation of this GPIO device * @gdev: GPIO device * * Returns: * Address of the GPIO chip backing this device. * * Until we can get rid of all non-driver users of struct gpio_chip, we must * provide a way of retrieving the pointer to it from struct gpio_device. This * is *NOT* safe as the GPIO API is considered to be hot-unpluggable and the * chip can dissapear at any moment (unlike reference-counted struct * gpio_device). * * Use at your own risk. */ struct gpio_chip *gpio_device_get_chip(struct gpio_device *gdev) { return gdev->chip; } EXPORT_SYMBOL_GPL(gpio_device_get_chip); /* dynamic allocation of GPIOs, e.g. on a hotplugged device */ static int gpiochip_find_base(int ngpio) { struct gpio_device *gdev; int base = GPIO_DYNAMIC_BASE; list_for_each_entry(gdev, &gpio_devices, list) { /* found a free space? */ if (gdev->base >= base + ngpio) break; /* nope, check the space right after the chip */ base = gdev->base + gdev->ngpio; if (base < GPIO_DYNAMIC_BASE) base = GPIO_DYNAMIC_BASE; } if (gpio_is_valid(base)) { pr_debug("%s: found new base at %d\n", __func__, base); return base; } else { pr_err("%s: cannot find free range\n", __func__); return -ENOSPC; } } /** * gpiod_get_direction - return the current direction of a GPIO * @desc: GPIO to get the direction of * * Returns 0 for output, 1 for input, or an error code in case of error. * * This function may sleep if gpiod_cansleep() is true. */ int gpiod_get_direction(struct gpio_desc *desc) { struct gpio_chip *gc; unsigned int offset; int ret; gc = gpiod_to_chip(desc); offset = gpio_chip_hwgpio(desc); /* * Open drain emulation using input mode may incorrectly report * input here, fix that up. */ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && test_bit(FLAG_IS_OUT, &desc->flags)) return 0; if (!gc->get_direction) return -ENOTSUPP; ret = gc->get_direction(gc, offset); if (ret < 0) return ret; /* GPIOF_DIR_IN or other positive, otherwise GPIOF_DIR_OUT */ if (ret > 0) ret = 1; assign_bit(FLAG_IS_OUT, &desc->flags, !ret); return ret; } EXPORT_SYMBOL_GPL(gpiod_get_direction); /* * Add a new chip to the global chips list, keeping the list of chips sorted * by range(means [base, base + ngpio - 1]) order. * * Return -EBUSY if the new chip overlaps with some other chip's integer * space. */ static int gpiodev_add_to_list(struct gpio_device *gdev) { struct gpio_device *prev, *next; if (list_empty(&gpio_devices)) { /* initial entry in list */ list_add_tail(&gdev->list, &gpio_devices); return 0; } next = list_first_entry(&gpio_devices, struct gpio_device, list); if (gdev->base + gdev->ngpio <= next->base) { /* add before first entry */ list_add(&gdev->list, &gpio_devices); return 0; } prev = list_last_entry(&gpio_devices, struct gpio_device, list); if (prev->base + prev->ngpio <= gdev->base) { /* add behind last entry */ list_add_tail(&gdev->list, &gpio_devices); return 0; } list_for_each_entry_safe(prev, next, &gpio_devices, list) { /* at the end of the list */ if (&next->list == &gpio_devices) break; /* add between prev and next */ if (prev->base + prev->ngpio <= gdev->base && gdev->base + gdev->ngpio <= next->base) { list_add(&gdev->list, &prev->list); return 0; } } return -EBUSY; } /* * Convert a GPIO name to its descriptor * Note that there is no guarantee that GPIO names are globally unique! * Hence this function will return, if it exists, a reference to the first GPIO * line found that matches the given name. */ static struct gpio_desc *gpio_name_to_desc(const char * const name) { struct gpio_device *gdev; unsigned long flags; if (!name) return NULL; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) { struct gpio_desc *desc; for_each_gpio_desc(gdev->chip, desc) { if (desc->name && !strcmp(desc->name, name)) { spin_unlock_irqrestore(&gpio_lock, flags); return desc; } } } spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } /* * Take the names from gc->names and assign them to their GPIO descriptors. * Warn if a name is already used for a GPIO line on a different GPIO chip. * * Note that: * 1. Non-unique names are still accepted, * 2. Name collisions within the same GPIO chip are not reported. */ static int gpiochip_set_desc_names(struct gpio_chip *gc) { struct gpio_device *gdev = gc->gpiodev; int i; /* First check all names if they are unique */ for (i = 0; i != gc->ngpio; ++i) { struct gpio_desc *gpio; gpio = gpio_name_to_desc(gc->names[i]); if (gpio) dev_warn(&gdev->dev, "Detected name collision for GPIO name '%s'\n", gc->names[i]); } /* Then add all names to the GPIO descriptors */ for (i = 0; i != gc->ngpio; ++i) gdev->descs[i].name = gc->names[i]; return 0; } /* * gpiochip_set_names - Set GPIO line names using device properties * @chip: GPIO chip whose lines should be named, if possible * * Looks for device property "gpio-line-names" and if it exists assigns * GPIO line names for the chip. The memory allocated for the assigned * names belong to the underlying firmware node and should not be released * by the caller. */ static int gpiochip_set_names(struct gpio_chip *chip) { struct gpio_device *gdev = chip->gpiodev; struct device *dev = &gdev->dev; const char **names; int ret, i; int count; count = device_property_string_array_count(dev, "gpio-line-names"); if (count < 0) return 0; /* * When offset is set in the driver side we assume the driver internally * is using more than one gpiochip per the same device. We have to stop * setting friendly names if the specified ones with 'gpio-line-names' * are less than the offset in the device itself. This means all the * lines are not present for every single pin within all the internal * gpiochips. */ if (count <= chip->offset) { dev_warn(dev, "gpio-line-names too short (length %d), cannot map names for the gpiochip at offset %u\n", count, chip->offset); return 0; } names = kcalloc(count, sizeof(*names), GFP_KERNEL); if (!names) return -ENOMEM; ret = device_property_read_string_array(dev, "gpio-line-names", names, count); if (ret < 0) { dev_warn(dev, "failed to read GPIO line names\n"); kfree(names); return ret; } /* * When more that one gpiochip per device is used, 'count' can * contain at most number gpiochips x chip->ngpio. We have to * correctly distribute all defined lines taking into account * chip->offset as starting point from where we will assign * the names to pins from the 'names' array. Since property * 'gpio-line-names' cannot contains gaps, we have to be sure * we only assign those pins that really exists since chip->ngpio * can be different of the chip->offset. */ count = (count > chip->offset) ? count - chip->offset : count; if (count > chip->ngpio) count = chip->ngpio; for (i = 0; i < count; i++) { /* * Allow overriding "fixed" names provided by the GPIO * provider. The "fixed" names are more often than not * generic and less informative than the names given in * device properties. */ if (names[chip->offset + i] && names[chip->offset + i][0]) gdev->descs[i].name = names[chip->offset + i]; } kfree(names); return 0; } static unsigned long *gpiochip_allocate_mask(struct gpio_chip *gc) { unsigned long *p; p = bitmap_alloc(gc->ngpio, GFP_KERNEL); if (!p) return NULL; /* Assume by default all GPIOs are valid */ bitmap_fill(p, gc->ngpio); return p; } static void gpiochip_free_mask(unsigned long **p) { bitmap_free(*p); *p = NULL; } static unsigned int gpiochip_count_reserved_ranges(struct gpio_chip *gc) { struct device *dev = &gc->gpiodev->dev; int size; /* Format is "start, count, ..." */ size = device_property_count_u32(dev, "gpio-reserved-ranges"); if (size > 0 && size % 2 == 0) return size; return 0; } static int gpiochip_apply_reserved_ranges(struct gpio_chip *gc) { struct device *dev = &gc->gpiodev->dev; unsigned int size; u32 *ranges; int ret; size = gpiochip_count_reserved_ranges(gc); if (size == 0) return 0; ranges = kmalloc_array(size, sizeof(*ranges), GFP_KERNEL); if (!ranges) return -ENOMEM; ret = device_property_read_u32_array(dev, "gpio-reserved-ranges", ranges, size); if (ret) { kfree(ranges); return ret; } while (size) { u32 count = ranges[--size]; u32 start = ranges[--size]; if (start >= gc->ngpio || start + count > gc->ngpio) continue; bitmap_clear(gc->valid_mask, start, count); } kfree(ranges); return 0; } static int gpiochip_init_valid_mask(struct gpio_chip *gc) { int ret; if (!(gpiochip_count_reserved_ranges(gc) || gc->init_valid_mask)) return 0; gc->valid_mask = gpiochip_allocate_mask(gc); if (!gc->valid_mask) return -ENOMEM; ret = gpiochip_apply_reserved_ranges(gc); if (ret) return ret; if (gc->init_valid_mask) return gc->init_valid_mask(gc, gc->valid_mask, gc->ngpio); return 0; } static void gpiochip_free_valid_mask(struct gpio_chip *gc) { gpiochip_free_mask(&gc->valid_mask); } static int gpiochip_add_pin_ranges(struct gpio_chip *gc) { /* * Device Tree platforms are supposed to use "gpio-ranges" * property. This check ensures that the ->add_pin_ranges() * won't be called for them. */ if (device_property_present(&gc->gpiodev->dev, "gpio-ranges")) return 0; if (gc->add_pin_ranges) return gc->add_pin_ranges(gc); return 0; } bool gpiochip_line_is_valid(const struct gpio_chip *gc, unsigned int offset) { /* No mask means all valid */ if (likely(!gc->valid_mask)) return true; return test_bit(offset, gc->valid_mask); } EXPORT_SYMBOL_GPL(gpiochip_line_is_valid); static void gpiodev_release(struct device *dev) { struct gpio_device *gdev = to_gpio_device(dev); unsigned long flags; spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); spin_unlock_irqrestore(&gpio_lock, flags); ida_free(&gpio_ida, gdev->id); kfree_const(gdev->label); kfree(gdev->descs); kfree(gdev); } #ifdef CONFIG_GPIO_CDEV #define gcdev_register(gdev, devt) gpiolib_cdev_register((gdev), (devt)) #define gcdev_unregister(gdev) gpiolib_cdev_unregister((gdev)) #else /* * gpiolib_cdev_register() indirectly calls device_add(), which is still * required even when cdev is not selected. */ #define gcdev_register(gdev, devt) device_add(&(gdev)->dev) #define gcdev_unregister(gdev) device_del(&(gdev)->dev) #endif static int gpiochip_setup_dev(struct gpio_device *gdev) { struct fwnode_handle *fwnode = dev_fwnode(&gdev->dev); int ret; /* * If fwnode doesn't belong to another device, it's safe to clear its * initialized flag. */ if (fwnode && !fwnode->dev) fwnode_dev_initialized(fwnode, false); ret = gcdev_register(gdev, gpio_devt); if (ret) return ret; /* From this point, the .release() function cleans up gpio_device */ gdev->dev.release = gpiodev_release; ret = gpiochip_sysfs_register(gdev); if (ret) goto err_remove_device; dev_dbg(&gdev->dev, "registered GPIOs %d to %d on %s\n", gdev->base, gdev->base + gdev->ngpio - 1, gdev->chip->label ? : "generic"); return 0; err_remove_device: gcdev_unregister(gdev); return ret; } static void gpiochip_machine_hog(struct gpio_chip *gc, struct gpiod_hog *hog) { struct gpio_desc *desc; int rv; desc = gpiochip_get_desc(gc, hog->chip_hwnum); if (IS_ERR(desc)) { chip_err(gc, "%s: unable to get GPIO desc: %ld\n", __func__, PTR_ERR(desc)); return; } if (test_bit(FLAG_IS_HOGGED, &desc->flags)) return; rv = gpiod_hog(desc, hog->line_name, hog->lflags, hog->dflags); if (rv) gpiod_err(desc, "%s: unable to hog GPIO line (%s:%u): %d\n", __func__, gc->label, hog->chip_hwnum, rv); } static void machine_gpiochip_add(struct gpio_chip *gc) { struct gpiod_hog *hog; mutex_lock(&gpio_machine_hogs_mutex); list_for_each_entry(hog, &gpio_machine_hogs, list) { if (!strcmp(gc->label, hog->chip_label)) gpiochip_machine_hog(gc, hog); } mutex_unlock(&gpio_machine_hogs_mutex); } static void gpiochip_setup_devs(void) { struct gpio_device *gdev; int ret; list_for_each_entry(gdev, &gpio_devices, list) { ret = gpiochip_setup_dev(gdev); if (ret) dev_err(&gdev->dev, "Failed to initialize gpio device (%d)\n", ret); } } static void gpiochip_set_data(struct gpio_chip *gc, void *data) { gc->gpiodev->data = data; } /** * gpiochip_get_data() - get per-subdriver data for the chip * @gc: GPIO chip * * Returns: * The per-subdriver data for the chip. */ void *gpiochip_get_data(struct gpio_chip *gc) { return gc->gpiodev->data; } EXPORT_SYMBOL_GPL(gpiochip_get_data); int gpiochip_get_ngpios(struct gpio_chip *gc, struct device *dev) { u32 ngpios = gc->ngpio; int ret; if (ngpios == 0) { ret = device_property_read_u32(dev, "ngpios", &ngpios); if (ret == -ENODATA) /* * -ENODATA means that there is no property found and * we want to issue the error message to the user. * Besides that, we want to return different error code * to state that supplied value is not valid. */ ngpios = 0; else if (ret) return ret; gc->ngpio = ngpios; } if (gc->ngpio == 0) { chip_err(gc, "tried to insert a GPIO chip with zero lines\n"); return -EINVAL; } if (gc->ngpio > FASTPATH_NGPIO) chip_warn(gc, "line cnt %u is greater than fast path cnt %u\n", gc->ngpio, FASTPATH_NGPIO); return 0; } EXPORT_SYMBOL_GPL(gpiochip_get_ngpios); int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data, struct lock_class_key *lock_key, struct lock_class_key *request_key) { struct gpio_device *gdev; unsigned long flags; unsigned int i; int base = 0; int ret = 0; /* * First: allocate and populate the internal stat container, and * set up the struct device. */ gdev = kzalloc(sizeof(*gdev), GFP_KERNEL); if (!gdev) return -ENOMEM; gdev->dev.bus = &gpio_bus_type; gdev->dev.parent = gc->parent; gdev->chip = gc; gc->gpiodev = gdev; gpiochip_set_data(gc, data); /* * If the calling driver did not initialize firmware node, * do it here using the parent device, if any. */ if (gc->fwnode) device_set_node(&gdev->dev, gc->fwnode); else if (gc->parent) device_set_node(&gdev->dev, dev_fwnode(gc->parent)); gdev->id = ida_alloc(&gpio_ida, GFP_KERNEL); if (gdev->id < 0) { ret = gdev->id; goto err_free_gdev; } ret = dev_set_name(&gdev->dev, GPIOCHIP_NAME "%d", gdev->id); if (ret) goto err_free_ida; device_initialize(&gdev->dev); if (gc->parent && gc->parent->driver) gdev->owner = gc->parent->driver->owner; else if (gc->owner) /* TODO: remove chip->owner */ gdev->owner = gc->owner; else gdev->owner = THIS_MODULE; ret = gpiochip_get_ngpios(gc, &gdev->dev); if (ret) goto err_free_dev_name; gdev->descs = kcalloc(gc->ngpio, sizeof(*gdev->descs), GFP_KERNEL); if (!gdev->descs) { ret = -ENOMEM; goto err_free_dev_name; } gdev->label = kstrdup_const(gc->label ?: "unknown", GFP_KERNEL); if (!gdev->label) { ret = -ENOMEM; goto err_free_descs; } gdev->ngpio = gc->ngpio; spin_lock_irqsave(&gpio_lock, flags); /* * TODO: this allocates a Linux GPIO number base in the global * GPIO numberspace for this chip. In the long run we want to * get *rid* of this numberspace and use only descriptors, but * it may be a pipe dream. It will not happen before we get rid * of the sysfs interface anyways. */ base = gc->base; if (base < 0) { base = gpiochip_find_base(gc->ngpio); if (base < 0) { spin_unlock_irqrestore(&gpio_lock, flags); ret = base; base = 0; goto err_free_label; } /* * TODO: it should not be necessary to reflect the assigned * base outside of the GPIO subsystem. Go over drivers and * see if anyone makes use of this, else drop this and assign * a poison instead. */ gc->base = base; } else { dev_warn(&gdev->dev, "Static allocation of GPIO base is deprecated, use dynamic allocation.\n"); } gdev->base = base; ret = gpiodev_add_to_list(gdev); if (ret) { spin_unlock_irqrestore(&gpio_lock, flags); chip_err(gc, "GPIO integer space overlap, cannot add chip\n"); goto err_free_label; } for (i = 0; i < gc->ngpio; i++) gdev->descs[i].gdev = gdev; spin_unlock_irqrestore(&gpio_lock, flags); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->line_state_notifier); BLOCKING_INIT_NOTIFIER_HEAD(&gdev->device_notifier); init_rwsem(&gdev->sem); #ifdef CONFIG_PINCTRL INIT_LIST_HEAD(&gdev->pin_ranges); #endif if (gc->names) { ret = gpiochip_set_desc_names(gc); if (ret) goto err_remove_from_list; } ret = gpiochip_set_names(gc); if (ret) goto err_remove_from_list; ret = gpiochip_init_valid_mask(gc); if (ret) goto err_remove_from_list; ret = of_gpiochip_add(gc); if (ret) goto err_free_gpiochip_mask; for (i = 0; i < gc->ngpio; i++) { struct gpio_desc *desc = &gdev->descs[i]; if (gc->get_direction && gpiochip_line_is_valid(gc, i)) { assign_bit(FLAG_IS_OUT, &desc->flags, !gc->get_direction(gc, i)); } else { assign_bit(FLAG_IS_OUT, &desc->flags, !gc->direction_input); } } ret = gpiochip_add_pin_ranges(gc); if (ret) goto err_remove_of_chip; acpi_gpiochip_add(gc); machine_gpiochip_add(gc); ret = gpiochip_irqchip_init_valid_mask(gc); if (ret) goto err_remove_acpi_chip; ret = gpiochip_irqchip_init_hw(gc); if (ret) goto err_remove_acpi_chip; ret = gpiochip_add_irqchip(gc, lock_key, request_key); if (ret) goto err_remove_irqchip_mask; /* * By first adding the chardev, and then adding the device, * we get a device node entry in sysfs under * /sys/bus/gpio/devices/gpiochipN/dev that can be used for * coldplug of device nodes and other udev business. * We can do this only if gpiolib has been initialized. * Otherwise, defer until later. */ if (gpiolib_initialized) { ret = gpiochip_setup_dev(gdev); if (ret) goto err_remove_irqchip; } return 0; err_remove_irqchip: gpiochip_irqchip_remove(gc); err_remove_irqchip_mask: gpiochip_irqchip_free_valid_mask(gc); err_remove_acpi_chip: acpi_gpiochip_remove(gc); err_remove_of_chip: gpiochip_free_hogs(gc); of_gpiochip_remove(gc); err_free_gpiochip_mask: gpiochip_remove_pin_ranges(gc); gpiochip_free_valid_mask(gc); if (gdev->dev.release) { /* release() has been registered by gpiochip_setup_dev() */ gpio_device_put(gdev); goto err_print_message; } err_remove_from_list: spin_lock_irqsave(&gpio_lock, flags); list_del(&gdev->list); spin_unlock_irqrestore(&gpio_lock, flags); err_free_label: kfree_const(gdev->label); err_free_descs: kfree(gdev->descs); err_free_dev_name: kfree(dev_name(&gdev->dev)); err_free_ida: ida_free(&gpio_ida, gdev->id); err_free_gdev: kfree(gdev); err_print_message: /* failures here can mean systems won't boot... */ if (ret != -EPROBE_DEFER) { pr_err("%s: GPIOs %d..%d (%s) failed to register, %d\n", __func__, base, base + (int)gc->ngpio - 1, gc->label ? : "generic", ret); } return ret; } EXPORT_SYMBOL_GPL(gpiochip_add_data_with_key); /** * gpiochip_remove() - unregister a gpio_chip * @gc: the chip to unregister * * A gpio_chip with any GPIOs still requested may not be removed. */ void gpiochip_remove(struct gpio_chip *gc) { struct gpio_device *gdev = gc->gpiodev; unsigned long flags; unsigned int i; down_write(&gdev->sem); /* FIXME: should the legacy sysfs handling be moved to gpio_device? */ gpiochip_sysfs_unregister(gdev); gpiochip_free_hogs(gc); /* Numb the device, cancelling all outstanding operations */ gdev->chip = NULL; gpiochip_irqchip_remove(gc); acpi_gpiochip_remove(gc); of_gpiochip_remove(gc); gpiochip_remove_pin_ranges(gc); gpiochip_free_valid_mask(gc); /* * We accept no more calls into the driver from this point, so * NULL the driver data pointer. */ gpiochip_set_data(gc, NULL); spin_lock_irqsave(&gpio_lock, flags); for (i = 0; i < gdev->ngpio; i++) { if (gpiochip_is_requested(gc, i)) break; } spin_unlock_irqrestore(&gpio_lock, flags); if (i != gdev->ngpio) dev_crit(&gdev->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); /* * The gpiochip side puts its use of the device to rest here: * if there are no userspace clients, the chardev and device will * be removed, else it will be dangling until the last user is * gone. */ gcdev_unregister(gdev); up_write(&gdev->sem); gpio_device_put(gdev); } EXPORT_SYMBOL_GPL(gpiochip_remove); /** * gpio_device_find() - find a specific GPIO device * @data: data to pass to match function * @match: Callback function to check gpio_chip * * Returns: * New reference to struct gpio_device. * * Similar to bus_find_device(). It returns a reference to a gpio_device as * determined by a user supplied @match callback. The callback should return * 0 if the device doesn't match and non-zero if it does. If the callback * returns non-zero, this function will return to the caller and not iterate * over any more gpio_devices. * * The callback takes the GPIO chip structure as argument. During the execution * of the callback function the chip is protected from being freed. TODO: This * actually has yet to be implemented. * * If the function returns non-NULL, the returned reference must be freed by * the caller using gpio_device_put(). */ struct gpio_device *gpio_device_find(void *data, int (*match)(struct gpio_chip *gc, void *data)) { struct gpio_device *gdev; /* * Not yet but in the future the spinlock below will become a mutex. * Annotate this function before anyone tries to use it in interrupt * context like it happened with gpiochip_find(). */ might_sleep(); guard(spinlock_irqsave)(&gpio_lock); list_for_each_entry(gdev, &gpio_devices, list) { if (gdev->chip && match(gdev->chip, data)) return gpio_device_get(gdev); } return NULL; } EXPORT_SYMBOL_GPL(gpio_device_find); static int gpio_chip_match_by_label(struct gpio_chip *gc, void *label) { return gc->label && !strcmp(gc->label, label); } /** * gpio_device_find_by_label() - wrapper around gpio_device_find() finding the * GPIO device by its backing chip's label * @label: Label to lookup * * Returns: * Reference to the GPIO device or NULL. Reference must be released with * gpio_device_put(). */ struct gpio_device *gpio_device_find_by_label(const char *label) { return gpio_device_find((void *)label, gpio_chip_match_by_label); } EXPORT_SYMBOL_GPL(gpio_device_find_by_label); static int gpio_chip_match_by_fwnode(struct gpio_chip *gc, void *fwnode) { return device_match_fwnode(&gc->gpiodev->dev, fwnode); } /** * gpio_device_find_by_fwnode() - wrapper around gpio_device_find() finding * the GPIO device by its fwnode * @fwnode: Firmware node to lookup * * Returns: * Reference to the GPIO device or NULL. Reference must be released with * gpio_device_put(). */ struct gpio_device *gpio_device_find_by_fwnode(const struct fwnode_handle *fwnode) { return gpio_device_find((void *)fwnode, gpio_chip_match_by_fwnode); } EXPORT_SYMBOL_GPL(gpio_device_find_by_fwnode); /** * gpio_device_get() - Increase the reference count of this GPIO device * @gdev: GPIO device to increase the refcount for * * Returns: * Pointer to @gdev. */ struct gpio_device *gpio_device_get(struct gpio_device *gdev) { return to_gpio_device(get_device(&gdev->dev)); } EXPORT_SYMBOL_GPL(gpio_device_get); /** * gpio_device_put() - Decrease the reference count of this GPIO device and * possibly free all resources associated with it. * @gdev: GPIO device to decrease the reference count for */ void gpio_device_put(struct gpio_device *gdev) { put_device(&gdev->dev); } EXPORT_SYMBOL_GPL(gpio_device_put); /** * gpio_device_to_device() - Retrieve the address of the underlying struct * device. * @gdev: GPIO device for which to return the address. * * This does not increase the reference count of the GPIO device nor the * underlying struct device. * * Returns: * Address of struct device backing this GPIO device. */ struct device *gpio_device_to_device(struct gpio_device *gdev) { return &gdev->dev; } EXPORT_SYMBOL_GPL(gpio_device_to_device); #ifdef CONFIG_GPIOLIB_IRQCHIP /* * The following is irqchip helper code for gpiochips. */ static int gpiochip_irqchip_init_hw(struct gpio_chip *gc) { struct gpio_irq_chip *girq = &gc->irq; if (!girq->init_hw) return 0; return girq->init_hw(gc); } static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc) { struct gpio_irq_chip *girq = &gc->irq; if (!girq->init_valid_mask) return 0; girq->valid_mask = gpiochip_allocate_mask(gc); if (!girq->valid_mask) return -ENOMEM; girq->init_valid_mask(gc, girq->valid_mask, gc->ngpio); return 0; } static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) { gpiochip_free_mask(&gc->irq.valid_mask); } bool gpiochip_irqchip_irq_valid(const struct gpio_chip *gc, unsigned int offset) { if (!gpiochip_line_is_valid(gc, offset)) return false; /* No mask means all valid */ if (likely(!gc->irq.valid_mask)) return true; return test_bit(offset, gc->irq.valid_mask); } EXPORT_SYMBOL_GPL(gpiochip_irqchip_irq_valid); #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY /** * gpiochip_set_hierarchical_irqchip() - connects a hierarchical irqchip * to a gpiochip * @gc: the gpiochip to set the irqchip hierarchical handler to * @irqchip: the irqchip to handle this level of the hierarchy, the interrupt * will then percolate up to the parent */ static void gpiochip_set_hierarchical_irqchip(struct gpio_chip *gc, struct irq_chip *irqchip) { /* DT will deal with mapping each IRQ as we go along */ if (is_of_node(gc->irq.fwnode)) return; /* * This is for legacy and boardfile "irqchip" fwnodes: allocate * irqs upfront instead of dynamically since we don't have the * dynamic type of allocation that hardware description languages * provide. Once all GPIO drivers using board files are gone from * the kernel we can delete this code, but for a transitional period * it is necessary to keep this around. */ if (is_fwnode_irqchip(gc->irq.fwnode)) { int i; int ret; for (i = 0; i < gc->ngpio; i++) { struct irq_fwspec fwspec; unsigned int parent_hwirq; unsigned int parent_type; struct gpio_irq_chip *girq = &gc->irq; /* * We call the child to parent translation function * only to check if the child IRQ is valid or not. * Just pick the rising edge type here as that is what * we likely need to support. */ ret = girq->child_to_parent_hwirq(gc, i, IRQ_TYPE_EDGE_RISING, &parent_hwirq, &parent_type); if (ret) { chip_err(gc, "skip set-up on hwirq %d\n", i); continue; } fwspec.fwnode = gc->irq.fwnode; /* This is the hwirq for the GPIO line side of things */ fwspec.param[0] = girq->child_offset_to_irq(gc, i); /* Just pick something */ fwspec.param[1] = IRQ_TYPE_EDGE_RISING; fwspec.param_count = 2; ret = irq_domain_alloc_irqs(gc->irq.domain, 1, NUMA_NO_NODE, &fwspec); if (ret < 0) { chip_err(gc, "can not allocate irq for GPIO line %d parent hwirq %d in hierarchy domain: %d\n", i, parent_hwirq, ret); } } } chip_err(gc, "%s unknown fwnode type proceed anyway\n", __func__); return; } static int gpiochip_hierarchy_irq_domain_translate(struct irq_domain *d, struct irq_fwspec *fwspec, unsigned long *hwirq, unsigned int *type) { /* We support standard DT translation */ if (is_of_node(fwspec->fwnode) && fwspec->param_count == 2) { return irq_domain_translate_twocell(d, fwspec, hwirq, type); } /* This is for board files and others not using DT */ if (is_fwnode_irqchip(fwspec->fwnode)) { int ret; ret = irq_domain_translate_twocell(d, fwspec, hwirq, type); if (ret) return ret; WARN_ON(*type == IRQ_TYPE_NONE); return 0; } return -EINVAL; } static int gpiochip_hierarchy_irq_domain_alloc(struct irq_domain *d, unsigned int irq, unsigned int nr_irqs, void *data) { struct gpio_chip *gc = d->host_data; irq_hw_number_t hwirq; unsigned int type = IRQ_TYPE_NONE; struct irq_fwspec *fwspec = data; union gpio_irq_fwspec gpio_parent_fwspec = {}; unsigned int parent_hwirq; unsigned int parent_type; struct gpio_irq_chip *girq = &gc->irq; int ret; /* * The nr_irqs parameter is always one except for PCI multi-MSI * so this should not happen. */ WARN_ON(nr_irqs != 1); ret = gc->irq.child_irq_domain_ops.translate(d, fwspec, &hwirq, &type); if (ret) return ret; chip_dbg(gc, "allocate IRQ %d, hwirq %lu\n", irq, hwirq); ret = girq->child_to_parent_hwirq(gc, hwirq, type, &parent_hwirq, &parent_type); if (ret) { chip_err(gc, "can't look up hwirq %lu\n", hwirq); return ret; } chip_dbg(gc, "found parent hwirq %u\n", parent_hwirq); /* * We set handle_bad_irq because the .set_type() should * always be invoked and set the right type of handler. */ irq_domain_set_info(d, irq, hwirq, gc->irq.chip, gc, girq->handler, NULL, NULL); irq_set_probe(irq); /* This parent only handles asserted level IRQs */ ret = girq->populate_parent_alloc_arg(gc, &gpio_parent_fwspec, parent_hwirq, parent_type); if (ret) return ret; chip_dbg(gc, "alloc_irqs_parent for %d parent hwirq %d\n", irq, parent_hwirq); irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key); ret = irq_domain_alloc_irqs_parent(d, irq, 1, &gpio_parent_fwspec); /* * If the parent irqdomain is msi, the interrupts have already * been allocated, so the EEXIST is good. */ if (irq_domain_is_msi(d->parent) && (ret == -EEXIST)) ret = 0; if (ret) chip_err(gc, "failed to allocate parent hwirq %d for hwirq %lu\n", parent_hwirq, hwirq); return ret; } static unsigned int gpiochip_child_offset_to_irq_noop(struct gpio_chip *gc, unsigned int offset) { return offset; } static void gpiochip_hierarchy_setup_domain_ops(struct irq_domain_ops *ops) { ops->activate = gpiochip_irq_domain_activate; ops->deactivate = gpiochip_irq_domain_deactivate; ops->alloc = gpiochip_hierarchy_irq_domain_alloc; /* * We only allow overriding the translate() and free() functions for * hierarchical chips, and this should only be done if the user * really need something other than 1:1 translation for translate() * callback and free if user wants to free up any resources which * were allocated during callbacks, for example populate_parent_alloc_arg. */ if (!ops->translate) ops->translate = gpiochip_hierarchy_irq_domain_translate; if (!ops->free) ops->free = irq_domain_free_irqs_common; } static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc) { struct irq_domain *domain; if (!gc->irq.child_to_parent_hwirq || !gc->irq.fwnode) { chip_err(gc, "missing irqdomain vital data\n"); return ERR_PTR(-EINVAL); } if (!gc->irq.child_offset_to_irq) gc->irq.child_offset_to_irq = gpiochip_child_offset_to_irq_noop; if (!gc->irq.populate_parent_alloc_arg) gc->irq.populate_parent_alloc_arg = gpiochip_populate_parent_fwspec_twocell; gpiochip_hierarchy_setup_domain_ops(&gc->irq.child_irq_domain_ops); domain = irq_domain_create_hierarchy( gc->irq.parent_domain, 0, gc->ngpio, gc->irq.fwnode, &gc->irq.child_irq_domain_ops, gc); if (!domain) return ERR_PTR(-ENOMEM); gpiochip_set_hierarchical_irqchip(gc, gc->irq.chip); return domain; } static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc) { return !!gc->irq.parent_domain; } int gpiochip_populate_parent_fwspec_twocell(struct gpio_chip *gc, union gpio_irq_fwspec *gfwspec, unsigned int parent_hwirq, unsigned int parent_type) { struct irq_fwspec *fwspec = &gfwspec->fwspec; fwspec->fwnode = gc->irq.parent_domain->fwnode; fwspec->param_count = 2; fwspec->param[0] = parent_hwirq; fwspec->param[1] = parent_type; return 0; } EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_twocell); int gpiochip_populate_parent_fwspec_fourcell(struct gpio_chip *gc, union gpio_irq_fwspec *gfwspec, unsigned int parent_hwirq, unsigned int parent_type) { struct irq_fwspec *fwspec = &gfwspec->fwspec; fwspec->fwnode = gc->irq.parent_domain->fwnode; fwspec->param_count = 4; fwspec->param[0] = 0; fwspec->param[1] = parent_hwirq; fwspec->param[2] = 0; fwspec->param[3] = parent_type; return 0; } EXPORT_SYMBOL_GPL(gpiochip_populate_parent_fwspec_fourcell); #else static struct irq_domain *gpiochip_hierarchy_create_domain(struct gpio_chip *gc) { return ERR_PTR(-EINVAL); } static bool gpiochip_hierarchy_is_hierarchical(struct gpio_chip *gc) { return false; } #endif /* CONFIG_IRQ_DOMAIN_HIERARCHY */ /** * gpiochip_irq_map() - maps an IRQ into a GPIO irqchip * @d: the irqdomain used by this irqchip * @irq: the global irq number used by this GPIO irqchip irq * @hwirq: the local IRQ/GPIO line offset on this gpiochip * * This function will set up the mapping for a certain IRQ line on a * gpiochip by assigning the gpiochip as chip data, and using the irqchip * stored inside the gpiochip. */ int gpiochip_irq_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) { struct gpio_chip *gc = d->host_data; int ret = 0; if (!gpiochip_irqchip_irq_valid(gc, hwirq)) return -ENXIO; irq_set_chip_data(irq, gc); /* * This lock class tells lockdep that GPIO irqs are in a different * category than their parents, so it won't report false recursion. */ irq_set_lockdep_class(irq, gc->irq.lock_key, gc->irq.request_key); irq_set_chip_and_handler(irq, gc->irq.chip, gc->irq.handler); /* Chips that use nested thread handlers have them marked */ if (gc->irq.threaded) irq_set_nested_thread(irq, 1); irq_set_noprobe(irq); if (gc->irq.num_parents == 1) ret = irq_set_parent(irq, gc->irq.parents[0]); else if (gc->irq.map) ret = irq_set_parent(irq, gc->irq.map[hwirq]); if (ret < 0) return ret; /* * No set-up of the hardware will happen if IRQ_TYPE_NONE * is passed as default type. */ if (gc->irq.default_type != IRQ_TYPE_NONE) irq_set_irq_type(irq, gc->irq.default_type); return 0; } EXPORT_SYMBOL_GPL(gpiochip_irq_map); void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq) { struct gpio_chip *gc = d->host_data; if (gc->irq.threaded) irq_set_nested_thread(irq, 0); irq_set_chip_and_handler(irq, NULL, NULL); irq_set_chip_data(irq, NULL); } EXPORT_SYMBOL_GPL(gpiochip_irq_unmap); static const struct irq_domain_ops gpiochip_domain_ops = { .map = gpiochip_irq_map, .unmap = gpiochip_irq_unmap, /* Virtually all GPIO irqchips are twocell:ed */ .xlate = irq_domain_xlate_twocell, }; static struct irq_domain *gpiochip_simple_create_domain(struct gpio_chip *gc) { struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev); struct irq_domain *domain; domain = irq_domain_create_simple(fwnode, gc->ngpio, gc->irq.first, &gpiochip_domain_ops, gc); if (!domain) return ERR_PTR(-EINVAL); return domain; } /* * TODO: move these activate/deactivate in under the hierarchicial * irqchip implementation as static once SPMI and SSBI (all external * users) are phased over. */ /** * gpiochip_irq_domain_activate() - Lock a GPIO to be used as an IRQ * @domain: The IRQ domain used by this IRQ chip * @data: Outermost irq_data associated with the IRQ * @reserve: If set, only reserve an interrupt vector instead of assigning one * * This function is a wrapper that calls gpiochip_lock_as_irq() and is to be * used as the activate function for the &struct irq_domain_ops. The host_data * for the IRQ domain must be the &struct gpio_chip. */ int gpiochip_irq_domain_activate(struct irq_domain *domain, struct irq_data *data, bool reserve) { struct gpio_chip *gc = domain->host_data; unsigned int hwirq = irqd_to_hwirq(data); return gpiochip_lock_as_irq(gc, hwirq); } EXPORT_SYMBOL_GPL(gpiochip_irq_domain_activate); /** * gpiochip_irq_domain_deactivate() - Unlock a GPIO used as an IRQ * @domain: The IRQ domain used by this IRQ chip * @data: Outermost irq_data associated with the IRQ * * This function is a wrapper that will call gpiochip_unlock_as_irq() and is to * be used as the deactivate function for the &struct irq_domain_ops. The * host_data for the IRQ domain must be the &struct gpio_chip. */ void gpiochip_irq_domain_deactivate(struct irq_domain *domain, struct irq_data *data) { struct gpio_chip *gc = domain->host_data; unsigned int hwirq = irqd_to_hwirq(data); return gpiochip_unlock_as_irq(gc, hwirq); } EXPORT_SYMBOL_GPL(gpiochip_irq_domain_deactivate); static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset) { struct irq_domain *domain = gc->irq.domain; #ifdef CONFIG_GPIOLIB_IRQCHIP /* * Avoid race condition with other code, which tries to lookup * an IRQ before the irqchip has been properly registered, * i.e. while gpiochip is still being brought up. */ if (!gc->irq.initialized) return -EPROBE_DEFER; #endif if (!gpiochip_irqchip_irq_valid(gc, offset)) return -ENXIO; #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY if (irq_domain_is_hierarchy(domain)) { struct irq_fwspec spec; spec.fwnode = domain->fwnode; spec.param_count = 2; spec.param[0] = gc->irq.child_offset_to_irq(gc, offset); spec.param[1] = IRQ_TYPE_NONE; return irq_create_fwspec_mapping(&spec); } #endif return irq_create_mapping(domain, offset); } int gpiochip_irq_reqres(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); unsigned int hwirq = irqd_to_hwirq(d); return gpiochip_reqres_irq(gc, hwirq); } EXPORT_SYMBOL(gpiochip_irq_reqres); void gpiochip_irq_relres(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); unsigned int hwirq = irqd_to_hwirq(d); gpiochip_relres_irq(gc, hwirq); } EXPORT_SYMBOL(gpiochip_irq_relres); static void gpiochip_irq_mask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); unsigned int hwirq = irqd_to_hwirq(d); if (gc->irq.irq_mask) gc->irq.irq_mask(d); gpiochip_disable_irq(gc, hwirq); } static void gpiochip_irq_unmask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); unsigned int hwirq = irqd_to_hwirq(d); gpiochip_enable_irq(gc, hwirq); if (gc->irq.irq_unmask) gc->irq.irq_unmask(d); } static void gpiochip_irq_enable(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); unsigned int hwirq = irqd_to_hwirq(d); gpiochip_enable_irq(gc, hwirq); gc->irq.irq_enable(d); } static void gpiochip_irq_disable(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); unsigned int hwirq = irqd_to_hwirq(d); gc->irq.irq_disable(d); gpiochip_disable_irq(gc, hwirq); } static void gpiochip_set_irq_hooks(struct gpio_chip *gc) { struct irq_chip *irqchip = gc->irq.chip; if (irqchip->flags & IRQCHIP_IMMUTABLE) return; chip_warn(gc, "not an immutable chip, please consider fixing it!\n"); if (!irqchip->irq_request_resources && !irqchip->irq_release_resources) { irqchip->irq_request_resources = gpiochip_irq_reqres; irqchip->irq_release_resources = gpiochip_irq_relres; } if (WARN_ON(gc->irq.irq_enable)) return; /* Check if the irqchip already has this hook... */ if (irqchip->irq_enable == gpiochip_irq_enable || irqchip->irq_mask == gpiochip_irq_mask) { /* * ...and if so, give a gentle warning that this is bad * practice. */ chip_info(gc, "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n"); return; } if (irqchip->irq_disable) { gc->irq.irq_disable = irqchip->irq_disable; irqchip->irq_disable = gpiochip_irq_disable; } else { gc->irq.irq_mask = irqchip->irq_mask; irqchip->irq_mask = gpiochip_irq_mask; } if (irqchip->irq_enable) { gc->irq.irq_enable = irqchip->irq_enable; irqchip->irq_enable = gpiochip_irq_enable; } else { gc->irq.irq_unmask = irqchip->irq_unmask; irqchip->irq_unmask = gpiochip_irq_unmask; } } static int gpiochip_irqchip_add_allocated_domain(struct gpio_chip *gc, struct irq_domain *domain, bool allocated_externally) { if (!domain) return -EINVAL; if (gc->to_irq) chip_warn(gc, "to_irq is redefined in %s and you shouldn't rely on it\n", __func__); gc->to_irq = gpiochip_to_irq; gc->irq.domain = domain; gc->irq.domain_is_allocated_externally = allocated_externally; /* * Using barrier() here to prevent compiler from reordering * gc->irq.initialized before adding irqdomain. */ barrier(); gc->irq.initialized = true; return 0; } /** * gpiochip_add_irqchip() - adds an IRQ chip to a GPIO chip * @gc: the GPIO chip to add the IRQ chip to * @lock_key: lockdep class for IRQ lock * @request_key: lockdep class for IRQ request */ static int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, struct lock_class_key *request_key) { struct fwnode_handle *fwnode = dev_fwnode(&gc->gpiodev->dev); struct irq_chip *irqchip = gc->irq.chip; struct irq_domain *domain; unsigned int type; unsigned int i; int ret; if (!irqchip) return 0; if (gc->irq.parent_handler && gc->can_sleep) { chip_err(gc, "you cannot have chained interrupts on a chip that may sleep\n"); return -EINVAL; } type = gc->irq.default_type; /* * Specifying a default trigger is a terrible idea if DT or ACPI is * used to configure the interrupts, as you may end up with * conflicting triggers. Tell the user, and reset to NONE. */ if (WARN(fwnode && type != IRQ_TYPE_NONE, "%pfw: Ignoring %u default trigger\n", fwnode, type)) type = IRQ_TYPE_NONE; gc->irq.default_type = type; gc->irq.lock_key = lock_key; gc->irq.request_key = request_key; /* If a parent irqdomain is provided, let's build a hierarchy */ if (gpiochip_hierarchy_is_hierarchical(gc)) { domain = gpiochip_hierarchy_create_domain(gc); } else { domain = gpiochip_simple_create_domain(gc); } if (IS_ERR(domain)) return PTR_ERR(domain); if (gc->irq.parent_handler) { for (i = 0; i < gc->irq.num_parents; i++) { void *data; if (gc->irq.per_parent_data) data = gc->irq.parent_handler_data_array[i]; else data = gc->irq.parent_handler_data ?: gc; /* * The parent IRQ chip is already using the chip_data * for this IRQ chip, so our callbacks simply use the * handler_data. */ irq_set_chained_handler_and_data(gc->irq.parents[i], gc->irq.parent_handler, data); } } gpiochip_set_irq_hooks(gc); ret = gpiochip_irqchip_add_allocated_domain(gc, domain, false); if (ret) return ret; acpi_gpiochip_request_interrupts(gc); return 0; } /** * gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip * @gc: the gpiochip to remove the irqchip from * * This is called only from gpiochip_remove() */ static void gpiochip_irqchip_remove(struct gpio_chip *gc) { struct irq_chip *irqchip = gc->irq.chip; unsigned int offset; acpi_gpiochip_free_interrupts(gc); if (irqchip && gc->irq.parent_handler) { struct gpio_irq_chip *irq = &gc->irq; unsigned int i; for (i = 0; i < irq->num_parents; i++) irq_set_chained_handler_and_data(irq->parents[i], NULL, NULL); } /* Remove all IRQ mappings and delete the domain */ if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) { unsigned int irq; for (offset = 0; offset < gc->ngpio; offset++) { if (!gpiochip_irqchip_irq_valid(gc, offset)) continue; irq = irq_find_mapping(gc->irq.domain, offset); irq_dispose_mapping(irq); } irq_domain_remove(gc->irq.domain); } if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) { if (irqchip->irq_request_resources == gpiochip_irq_reqres) { irqchip->irq_request_resources = NULL; irqchip->irq_release_resources = NULL; } if (irqchip->irq_enable == gpiochip_irq_enable) { irqchip->irq_enable = gc->irq.irq_enable; irqchip->irq_disable = gc->irq.irq_disable; } } gc->irq.irq_enable = NULL; gc->irq.irq_disable = NULL; gc->irq.chip = NULL; gpiochip_irqchip_free_valid_mask(gc); } /** * gpiochip_irqchip_add_domain() - adds an irqdomain to a gpiochip * @gc: the gpiochip to add the irqchip to * @domain: the irqdomain to add to the gpiochip * * This function adds an IRQ domain to the gpiochip. */ int gpiochip_irqchip_add_domain(struct gpio_chip *gc, struct irq_domain *domain) { return gpiochip_irqchip_add_allocated_domain(gc, domain, true); } EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain); #else /* CONFIG_GPIOLIB_IRQCHIP */ static inline int gpiochip_add_irqchip(struct gpio_chip *gc, struct lock_class_key *lock_key, struct lock_class_key *request_key) { return 0; } static void gpiochip_irqchip_remove(struct gpio_chip *gc) {} static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gc) { return 0; } static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc) { return 0; } static inline void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gc) { } #endif /* CONFIG_GPIOLIB_IRQCHIP */ /** * gpiochip_generic_request() - request the gpio function for a pin * @gc: the gpiochip owning the GPIO * @offset: the offset of the GPIO to request for GPIO function */ int gpiochip_generic_request(struct gpio_chip *gc, unsigned int offset) { #ifdef CONFIG_PINCTRL if (list_empty(&gc->gpiodev->pin_ranges)) return 0; #endif return pinctrl_gpio_request(gc, offset); } EXPORT_SYMBOL_GPL(gpiochip_generic_request); /** * gpiochip_generic_free() - free the gpio function from a pin * @gc: the gpiochip to request the gpio function for * @offset: the offset of the GPIO to free from GPIO function */ void gpiochip_generic_free(struct gpio_chip *gc, unsigned int offset) { #ifdef CONFIG_PINCTRL if (list_empty(&gc->gpiodev->pin_ranges)) return; #endif pinctrl_gpio_free(gc, offset); } EXPORT_SYMBOL_GPL(gpiochip_generic_free); /** * gpiochip_generic_config() - apply configuration for a pin * @gc: the gpiochip owning the GPIO * @offset: the offset of the GPIO to apply the configuration * @config: the configuration to be applied */ int gpiochip_generic_config(struct gpio_chip *gc, unsigned int offset, unsigned long config) { return pinctrl_gpio_set_config(gc, offset, config); } EXPORT_SYMBOL_GPL(gpiochip_generic_config); #ifdef CONFIG_PINCTRL /** * gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping * @gc: the gpiochip to add the range for * @pctldev: the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_group: name of the pin group inside the pin controller * * Calling this function directly from a DeviceTree-supported * pinctrl driver is DEPRECATED. Please see Section 2.1 of * Documentation/devicetree/bindings/gpio/gpio.txt on how to * bind pinctrl and gpio drivers via the "gpio-ranges" property. */ int gpiochip_add_pingroup_range(struct gpio_chip *gc, struct pinctrl_dev *pctldev, unsigned int gpio_offset, const char *pin_group) { struct gpio_pin_range *pin_range; struct gpio_device *gdev = gc->gpiodev; int ret; pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); if (!pin_range) { chip_err(gc, "failed to allocate pin ranges\n"); return -ENOMEM; } /* Use local offset as range ID */ pin_range->range.id = gpio_offset; pin_range->range.gc = gc; pin_range->range.name = gc->label; pin_range->range.base = gdev->base + gpio_offset; pin_range->pctldev = pctldev; ret = pinctrl_get_group_pins(pctldev, pin_group, &pin_range->range.pins, &pin_range->range.npins); if (ret < 0) { kfree(pin_range); return ret; } pinctrl_add_gpio_range(pctldev, &pin_range->range); chip_dbg(gc, "created GPIO range %d->%d ==> %s PINGRP %s\n", gpio_offset, gpio_offset + pin_range->range.npins - 1, pinctrl_dev_get_devname(pctldev), pin_group); list_add_tail(&pin_range->node, &gdev->pin_ranges); return 0; } EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range); /** * gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping * @gc: the gpiochip to add the range for * @pinctl_name: the dev_name() of the pin controller to map to * @gpio_offset: the start offset in the current gpio_chip number space * @pin_offset: the start offset in the pin controller number space * @npins: the number of pins from the offset of each pin space (GPIO and * pin controller) to accumulate in this range * * Returns: * 0 on success, or a negative error-code on failure. * * Calling this function directly from a DeviceTree-supported * pinctrl driver is DEPRECATED. Please see Section 2.1 of * Documentation/devicetree/bindings/gpio/gpio.txt on how to * bind pinctrl and gpio drivers via the "gpio-ranges" property. */ int gpiochip_add_pin_range(struct gpio_chip *gc, const char *pinctl_name, unsigned int gpio_offset, unsigned int pin_offset, unsigned int npins) { struct gpio_pin_range *pin_range; struct gpio_device *gdev = gc->gpiodev; int ret; pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL); if (!pin_range) { chip_err(gc, "failed to allocate pin ranges\n"); return -ENOMEM; } /* Use local offset as range ID */ pin_range->range.id = gpio_offset; pin_range->range.gc = gc; pin_range->range.name = gc->label; pin_range->range.base = gdev->base + gpio_offset; pin_range->range.pin_base = pin_offset; pin_range->range.npins = npins; pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name, &pin_range->range); if (IS_ERR(pin_range->pctldev)) { ret = PTR_ERR(pin_range->pctldev); chip_err(gc, "could not create pin range\n"); kfree(pin_range); return ret; } chip_dbg(gc, "created GPIO range %d->%d ==> %s PIN %d->%d\n", gpio_offset, gpio_offset + npins - 1, pinctl_name, pin_offset, pin_offset + npins - 1); list_add_tail(&pin_range->node, &gdev->pin_ranges); return 0; } EXPORT_SYMBOL_GPL(gpiochip_add_pin_range); /** * gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings * @gc: the chip to remove all the mappings for */ void gpiochip_remove_pin_ranges(struct gpio_chip *gc) { struct gpio_pin_range *pin_range, *tmp; struct gpio_device *gdev = gc->gpiodev; list_for_each_entry_safe(pin_range, tmp, &gdev->pin_ranges, node) { list_del(&pin_range->node); pinctrl_remove_gpio_range(pin_range->pctldev, &pin_range->range); kfree(pin_range); } } EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges); #endif /* CONFIG_PINCTRL */ /* These "optional" allocation calls help prevent drivers from stomping * on each other, and help provide better diagnostics in debugfs. * They're called even less than the "set direction" calls. */ static int gpiod_request_commit(struct gpio_desc *desc, const char *label) { struct gpio_chip *gc = desc->gdev->chip; int ret; unsigned long flags; unsigned offset; if (label) { label = kstrdup_const(label, GFP_KERNEL); if (!label) return -ENOMEM; } spin_lock_irqsave(&gpio_lock, flags); /* NOTE: gpio_request() can be called in early boot, * before IRQs are enabled, for non-sleeping (SOC) GPIOs. */ if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) { desc_set_label(desc, label ? : "?"); } else { ret = -EBUSY; goto out_free_unlock; } if (gc->request) { /* gc->request may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); offset = gpio_chip_hwgpio(desc); if (gpiochip_line_is_valid(gc, offset)) ret = gc->request(gc, offset); else ret = -EINVAL; spin_lock_irqsave(&gpio_lock, flags); if (ret) { desc_set_label(desc, NULL); clear_bit(FLAG_REQUESTED, &desc->flags); goto out_free_unlock; } } if (gc->get_direction) { /* gc->get_direction may sleep */ spin_unlock_irqrestore(&gpio_lock, flags); gpiod_get_direction(desc); spin_lock_irqsave(&gpio_lock, flags); } spin_unlock_irqrestore(&gpio_lock, flags); return 0; out_free_unlock: spin_unlock_irqrestore(&gpio_lock, flags); kfree_const(label); return ret; } /* * This descriptor validation needs to be inserted verbatim into each * function taking a descriptor, so we need to use a preprocessor * macro to avoid endless duplication. If the desc is NULL it is an * optional GPIO and calls should just bail out. */ static int validate_desc(const struct gpio_desc *desc, const char *func) { if (!desc) return 0; if (IS_ERR(desc)) { pr_warn("%s: invalid GPIO (errorpointer)\n", func); return PTR_ERR(desc); } if (!desc->gdev) { pr_warn("%s: invalid GPIO (no device)\n", func); return -EINVAL; } if (!desc->gdev->chip) { dev_warn(&desc->gdev->dev, "%s: backing chip is gone\n", func); return 0; } return 1; } #define VALIDATE_DESC(desc) do { \ int __valid = validate_desc(desc, __func__); \ if (__valid <= 0) \ return __valid; \ } while (0) #define VALIDATE_DESC_VOID(desc) do { \ int __valid = validate_desc(desc, __func__); \ if (__valid <= 0) \ return; \ } while (0) int gpiod_request(struct gpio_desc *desc, const char *label) { int ret = -EPROBE_DEFER; VALIDATE_DESC(desc); if (try_module_get(desc->gdev->owner)) { ret = gpiod_request_commit(desc, label); if (ret) module_put(desc->gdev->owner); else gpio_device_get(desc->gdev); } if (ret) gpiod_dbg(desc, "%s: status %d\n", __func__, ret); return ret; } static bool gpiod_free_commit(struct gpio_desc *desc) { bool ret = false; unsigned long flags; struct gpio_chip *gc; might_sleep(); spin_lock_irqsave(&gpio_lock, flags); gc = desc->gdev->chip; if (gc && test_bit(FLAG_REQUESTED, &desc->flags)) { if (gc->free) { spin_unlock_irqrestore(&gpio_lock, flags); might_sleep_if(gc->can_sleep); gc->free(gc, gpio_chip_hwgpio(desc)); spin_lock_irqsave(&gpio_lock, flags); } kfree_const(desc->label); desc_set_label(desc, NULL); clear_bit(FLAG_ACTIVE_LOW, &desc->flags); clear_bit(FLAG_REQUESTED, &desc->flags); clear_bit(FLAG_OPEN_DRAIN, &desc->flags); clear_bit(FLAG_OPEN_SOURCE, &desc->flags); clear_bit(FLAG_PULL_UP, &desc->flags); clear_bit(FLAG_PULL_DOWN, &desc->flags); clear_bit(FLAG_BIAS_DISABLE, &desc->flags); clear_bit(FLAG_EDGE_RISING, &desc->flags); clear_bit(FLAG_EDGE_FALLING, &desc->flags); clear_bit(FLAG_IS_HOGGED, &desc->flags); #ifdef CONFIG_OF_DYNAMIC desc->hog = NULL; #endif #ifdef CONFIG_GPIO_CDEV WRITE_ONCE(desc->debounce_period_us, 0); #endif ret = true; } spin_unlock_irqrestore(&gpio_lock, flags); gpiod_line_state_notify(desc, GPIOLINE_CHANGED_RELEASED); return ret; } void gpiod_free(struct gpio_desc *desc) { /* * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip * may already be NULL but we still want to put the references. */ if (!desc) return; if (!gpiod_free_commit(desc)) WARN_ON(extra_checks); module_put(desc->gdev->owner); gpio_device_put(desc->gdev); } /** * gpiochip_is_requested - return string iff signal was requested * @gc: controller managing the signal * @offset: of signal within controller's 0..(ngpio - 1) range * * Returns NULL if the GPIO is not currently requested, else a string. * The string returned is the label passed to gpio_request(); if none has been * passed it is a meaningless, non-NULL constant. * * This function is for use by GPIO controller drivers. The label can * help with diagnostics, and knowing that the signal is used as a GPIO * can help avoid accidentally multiplexing it to another controller. */ const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc; desc = gpiochip_get_desc(gc, offset); if (IS_ERR(desc)) return NULL; if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) return NULL; return desc->label; } EXPORT_SYMBOL_GPL(gpiochip_is_requested); /** * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor * @gc: GPIO chip * @hwnum: hardware number of the GPIO for which to request the descriptor * @label: label for the GPIO * @lflags: lookup flags for this GPIO or 0 if default, this can be used to * specify things like line inversion semantics with the machine flags * such as GPIO_OUT_LOW * @dflags: descriptor request flags for this GPIO or 0 if default, this * can be used to specify consumer semantics such as open drain * * Function allows GPIO chip drivers to request and use their own GPIO * descriptors via gpiolib API. Difference to gpiod_request() is that this * function will not increase reference count of the GPIO chip module. This * allows the GPIO chip module to be unloaded as needed (we assume that the * GPIO chip driver handles freeing the GPIOs it has requested). * * Returns: * A pointer to the GPIO descriptor, or an ERR_PTR()-encoded negative error * code on failure. */ struct gpio_desc *gpiochip_request_own_desc(struct gpio_chip *gc, unsigned int hwnum, const char *label, enum gpio_lookup_flags lflags, enum gpiod_flags dflags) { struct gpio_desc *desc = gpiochip_get_desc(gc, hwnum); int ret; if (IS_ERR(desc)) { chip_err(gc, "failed to get GPIO descriptor\n"); return desc; } ret = gpiod_request_commit(desc, label); if (ret < 0) return ERR_PTR(ret); ret = gpiod_configure_flags(desc, label, lflags, dflags); if (ret) { chip_err(gc, "setup of own GPIO %s failed\n", label); gpiod_free_commit(desc); return ERR_PTR(ret); } return desc; } EXPORT_SYMBOL_GPL(gpiochip_request_own_desc); /** * gpiochip_free_own_desc - Free GPIO requested by the chip driver * @desc: GPIO descriptor to free * * Function frees the given GPIO requested previously with * gpiochip_request_own_desc(). */ void gpiochip_free_own_desc(struct gpio_desc *desc) { if (desc) gpiod_free_commit(desc); } EXPORT_SYMBOL_GPL(gpiochip_free_own_desc); /* * Drivers MUST set GPIO direction before making get/set calls. In * some cases this is done in early boot, before IRQs are enabled. * * As a rule these aren't called more than once (except for drivers * using the open-drain emulation idiom) so these are natural places * to accumulate extra debugging checks. Note that we can't (yet) * rely on gpio_request() having been called beforehand. */ static int gpio_do_set_config(struct gpio_chip *gc, unsigned int offset, unsigned long config) { if (!gc->set_config) return -ENOTSUPP; return gc->set_config(gc, offset, config); } static int gpio_set_config_with_argument(struct gpio_desc *desc, enum pin_config_param mode, u32 argument) { struct gpio_chip *gc = desc->gdev->chip; unsigned long config; config = pinconf_to_config_packed(mode, argument); return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config); } static int gpio_set_config_with_argument_optional(struct gpio_desc *desc, enum pin_config_param mode, u32 argument) { struct device *dev = &desc->gdev->dev; int gpio = gpio_chip_hwgpio(desc); int ret; ret = gpio_set_config_with_argument(desc, mode, argument); if (ret != -ENOTSUPP) return ret; switch (mode) { case PIN_CONFIG_PERSIST_STATE: dev_dbg(dev, "Persistence not supported for GPIO %d\n", gpio); break; default: break; } return 0; } static int gpio_set_config(struct gpio_desc *desc, enum pin_config_param mode) { return gpio_set_config_with_argument(desc, mode, 0); } static int gpio_set_bias(struct gpio_desc *desc) { enum pin_config_param bias; unsigned int arg; if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) bias = PIN_CONFIG_BIAS_DISABLE; else if (test_bit(FLAG_PULL_UP, &desc->flags)) bias = PIN_CONFIG_BIAS_PULL_UP; else if (test_bit(FLAG_PULL_DOWN, &desc->flags)) bias = PIN_CONFIG_BIAS_PULL_DOWN; else return 0; switch (bias) { case PIN_CONFIG_BIAS_PULL_DOWN: case PIN_CONFIG_BIAS_PULL_UP: arg = 1; break; default: arg = 0; break; } return gpio_set_config_with_argument_optional(desc, bias, arg); } /** * gpio_set_debounce_timeout() - Set debounce timeout * @desc: GPIO descriptor to set the debounce timeout * @debounce: Debounce timeout in microseconds * * The function calls the certain GPIO driver to set debounce timeout * in the hardware. * * Returns 0 on success, or negative error code otherwise. */ int gpio_set_debounce_timeout(struct gpio_desc *desc, unsigned int debounce) { return gpio_set_config_with_argument_optional(desc, PIN_CONFIG_INPUT_DEBOUNCE, debounce); } /** * gpiod_direction_input - set the GPIO direction to input * @desc: GPIO to set to input * * Set the direction of the passed GPIO to input, such as gpiod_get_value() can * be called safely on it. * * Return 0 in case of success, else an error code. */ int gpiod_direction_input(struct gpio_desc *desc) { struct gpio_chip *gc; int ret = 0; VALIDATE_DESC(desc); gc = desc->gdev->chip; /* * It is legal to have no .get() and .direction_input() specified if * the chip is output-only, but you can't specify .direction_input() * and not support the .get() operation, that doesn't make sense. */ if (!gc->get && gc->direction_input) { gpiod_warn(desc, "%s: missing get() but have direction_input()\n", __func__); return -EIO; } /* * If we have a .direction_input() callback, things are simple, * just call it. Else we are some input-only chip so try to check the * direction (if .get_direction() is supported) else we silently * assume we are in input mode after this. */ if (gc->direction_input) { ret = gc->direction_input(gc, gpio_chip_hwgpio(desc)); } else if (gc->get_direction && (gc->get_direction(gc, gpio_chip_hwgpio(desc)) != 1)) { gpiod_warn(desc, "%s: missing direction_input() operation and line is output\n", __func__); return -EIO; } if (ret == 0) { clear_bit(FLAG_IS_OUT, &desc->flags); ret = gpio_set_bias(desc); } trace_gpio_direction(desc_to_gpio(desc), 1, ret); return ret; } EXPORT_SYMBOL_GPL(gpiod_direction_input); static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) { struct gpio_chip *gc = desc->gdev->chip; int val = !!value; int ret = 0; /* * It's OK not to specify .direction_output() if the gpiochip is * output-only, but if there is then not even a .set() operation it * is pretty tricky to drive the output line. */ if (!gc->set && !gc->direction_output) { gpiod_warn(desc, "%s: missing set() and direction_output() operations\n", __func__); return -EIO; } if (gc->direction_output) { ret = gc->direction_output(gc, gpio_chip_hwgpio(desc), val); } else { /* Check that we are in output mode if we can */ if (gc->get_direction && gc->get_direction(gc, gpio_chip_hwgpio(desc))) { gpiod_warn(desc, "%s: missing direction_output() operation\n", __func__); return -EIO; } /* * If we can't actively set the direction, we are some * output-only chip, so just drive the output as desired. */ gc->set(gc, gpio_chip_hwgpio(desc), val); } if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); trace_gpio_value(desc_to_gpio(desc), 0, val); trace_gpio_direction(desc_to_gpio(desc), 0, ret); return ret; } /** * gpiod_direction_output_raw - set the GPIO direction to output * @desc: GPIO to set to output * @value: initial output value of the GPIO * * Set the direction of the passed GPIO to output, such as gpiod_set_value() can * be called safely on it. The initial value of the output must be specified * as raw value on the physical line without regard for the ACTIVE_LOW status. * * Return 0 in case of success, else an error code. */ int gpiod_direction_output_raw(struct gpio_desc *desc, int value) { VALIDATE_DESC(desc); return gpiod_direction_output_raw_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); /** * gpiod_direction_output - set the GPIO direction to output * @desc: GPIO to set to output * @value: initial output value of the GPIO * * Set the direction of the passed GPIO to output, such as gpiod_set_value() can * be called safely on it. The initial value of the output must be specified * as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into * account. * * Return 0 in case of success, else an error code. */ int gpiod_direction_output(struct gpio_desc *desc, int value) { int ret; VALIDATE_DESC(desc); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; else value = !!value; /* GPIOs used for enabled IRQs shall not be set as output */ if (test_bit(FLAG_USED_AS_IRQ, &desc->flags) && test_bit(FLAG_IRQ_IS_ENABLED, &desc->flags)) { gpiod_err(desc, "%s: tried to set a GPIO tied to an IRQ as output\n", __func__); return -EIO; } if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { /* First see if we can enable open drain in hardware */ ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_DRAIN); if (!ret) goto set_output_value; /* Emulate open drain by not actively driving the line high */ if (value) { ret = gpiod_direction_input(desc); goto set_output_flag; } } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { ret = gpio_set_config(desc, PIN_CONFIG_DRIVE_OPEN_SOURCE); if (!ret) goto set_output_value; /* Emulate open source by not actively driving the line low */ if (!value) { ret = gpiod_direction_input(desc); goto set_output_flag; } } else { gpio_set_config(desc, PIN_CONFIG_DRIVE_PUSH_PULL); } set_output_value: ret = gpio_set_bias(desc); if (ret) return ret; return gpiod_direction_output_raw_commit(desc, value); set_output_flag: /* * When emulating open-source or open-drain functionalities by not * actively driving the line (setting mode to input) we still need to * set the IS_OUT flag or otherwise we won't be able to set the line * value anymore. */ if (ret == 0) set_bit(FLAG_IS_OUT, &desc->flags); return ret; } EXPORT_SYMBOL_GPL(gpiod_direction_output); /** * gpiod_enable_hw_timestamp_ns - Enable hardware timestamp in nanoseconds. * * @desc: GPIO to enable. * @flags: Flags related to GPIO edge. * * Return 0 in case of success, else negative error code. */ int gpiod_enable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags) { int ret = 0; struct gpio_chip *gc; VALIDATE_DESC(desc); gc = desc->gdev->chip; if (!gc->en_hw_timestamp) { gpiod_warn(desc, "%s: hw ts not supported\n", __func__); return -ENOTSUPP; } ret = gc->en_hw_timestamp(gc, gpio_chip_hwgpio(desc), flags); if (ret) gpiod_warn(desc, "%s: hw ts request failed\n", __func__); return ret; } EXPORT_SYMBOL_GPL(gpiod_enable_hw_timestamp_ns); /** * gpiod_disable_hw_timestamp_ns - Disable hardware timestamp. * * @desc: GPIO to disable. * @flags: Flags related to GPIO edge, same value as used during enable call. * * Return 0 in case of success, else negative error code. */ int gpiod_disable_hw_timestamp_ns(struct gpio_desc *desc, unsigned long flags) { int ret = 0; struct gpio_chip *gc; VALIDATE_DESC(desc); gc = desc->gdev->chip; if (!gc->dis_hw_timestamp) { gpiod_warn(desc, "%s: hw ts not supported\n", __func__); return -ENOTSUPP; } ret = gc->dis_hw_timestamp(gc, gpio_chip_hwgpio(desc), flags); if (ret) gpiod_warn(desc, "%s: hw ts release failed\n", __func__); return ret; } EXPORT_SYMBOL_GPL(gpiod_disable_hw_timestamp_ns); /** * gpiod_set_config - sets @config for a GPIO * @desc: descriptor of the GPIO for which to set the configuration * @config: Same packed config format as generic pinconf * * Returns: * 0 on success, %-ENOTSUPP if the controller doesn't support setting the * configuration. */ int gpiod_set_config(struct gpio_desc *desc, unsigned long config) { struct gpio_chip *gc; VALIDATE_DESC(desc); gc = desc->gdev->chip; return gpio_do_set_config(gc, gpio_chip_hwgpio(desc), config); } EXPORT_SYMBOL_GPL(gpiod_set_config); /** * gpiod_set_debounce - sets @debounce time for a GPIO * @desc: descriptor of the GPIO for which to set debounce time * @debounce: debounce time in microseconds * * Returns: * 0 on success, %-ENOTSUPP if the controller doesn't support setting the * debounce time. */ int gpiod_set_debounce(struct gpio_desc *desc, unsigned int debounce) { unsigned long config; config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce); return gpiod_set_config(desc, config); } EXPORT_SYMBOL_GPL(gpiod_set_debounce); /** * gpiod_set_transitory - Lose or retain GPIO state on suspend or reset * @desc: descriptor of the GPIO for which to configure persistence * @transitory: True to lose state on suspend or reset, false for persistence * * Returns: * 0 on success, otherwise a negative error code. */ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory) { VALIDATE_DESC(desc); /* * Handle FLAG_TRANSITORY first, enabling queries to gpiolib for * persistence state. */ assign_bit(FLAG_TRANSITORY, &desc->flags, transitory); /* If the driver supports it, set the persistence state now */ return gpio_set_config_with_argument_optional(desc, PIN_CONFIG_PERSIST_STATE, !transitory); } /** * gpiod_is_active_low - test whether a GPIO is active-low or not * @desc: the gpio descriptor to test * * Returns 1 if the GPIO is active-low, 0 otherwise. */ int gpiod_is_active_low(const struct gpio_desc *desc) { VALIDATE_DESC(desc); return test_bit(FLAG_ACTIVE_LOW, &desc->flags); } EXPORT_SYMBOL_GPL(gpiod_is_active_low); /** * gpiod_toggle_active_low - toggle whether a GPIO is active-low or not * @desc: the gpio descriptor to change */ void gpiod_toggle_active_low(struct gpio_desc *desc) { VALIDATE_DESC_VOID(desc); change_bit(FLAG_ACTIVE_LOW, &desc->flags); } EXPORT_SYMBOL_GPL(gpiod_toggle_active_low); static int gpio_chip_get_value(struct gpio_chip *gc, const struct gpio_desc *desc) { return gc->get ? gc->get(gc, gpio_chip_hwgpio(desc)) : -EIO; } /* I/O calls are only valid after configuration completed; the relevant * "is this a valid GPIO" error checks should already have been done. * * "Get" operations are often inlinable as reading a pin value register, * and masking the relevant bit in that register. * * When "set" operations are inlinable, they involve writing that mask to * one register to set a low value, or a different register to set it high. * Otherwise locking is needed, so there may be little value to inlining. * *------------------------------------------------------------------------ * * IMPORTANT!!! The hot paths -- get/set value -- assume that callers * have requested the GPIO. That can include implicit requesting by * a direction setting call. Marking a gpio as requested locks its chip * in memory, guaranteeing that these table lookups need no more locking * and that gpiochip_remove() will fail. * * REVISIT when debugging, consider adding some instrumentation to ensure * that the GPIO was actually requested. */ static int gpiod_get_raw_value_commit(const struct gpio_desc *desc) { struct gpio_chip *gc; int value; gc = desc->gdev->chip; value = gpio_chip_get_value(gc, desc); value = value < 0 ? value : !!value; trace_gpio_value(desc_to_gpio(desc), 1, value); return value; } static int gpio_chip_get_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { if (gc->get_multiple) return gc->get_multiple(gc, mask, bits); if (gc->get) { int i, value; for_each_set_bit(i, mask, gc->ngpio) { value = gc->get(gc, i); if (value < 0) return value; __assign_bit(i, bits, value); } return 0; } return -EIO; } int gpiod_get_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { int ret, i = 0; /* * Validate array_info against desc_array and its size. * It should immediately follow desc_array if both * have been obtained from the same gpiod_get_array() call. */ if (array_info && array_info->desc == desc_array && array_size <= array_info->size && (void *)array_info == desc_array + array_info->size) { if (!can_sleep) WARN_ON(array_info->chip->can_sleep); ret = gpio_chip_get_multiple(array_info->chip, array_info->get_mask, value_bitmap); if (ret) return ret; if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) bitmap_xor(value_bitmap, value_bitmap, array_info->invert_mask, array_size); i = find_first_zero_bit(array_info->get_mask, array_size); if (i == array_size) return 0; } else { array_info = NULL; } while (i < array_size) { struct gpio_chip *gc = desc_array[i]->gdev->chip; DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO); DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO); unsigned long *mask, *bits; int first, j; if (likely(gc->ngpio <= FASTPATH_NGPIO)) { mask = fastpath_mask; bits = fastpath_bits; } else { gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC; mask = bitmap_alloc(gc->ngpio, flags); if (!mask) return -ENOMEM; bits = bitmap_alloc(gc->ngpio, flags); if (!bits) { bitmap_free(mask); return -ENOMEM; } } bitmap_zero(mask, gc->ngpio); if (!can_sleep) WARN_ON(gc->can_sleep); /* collect all inputs belonging to the same chip */ first = i; do { const struct gpio_desc *desc = desc_array[i]; int hwgpio = gpio_chip_hwgpio(desc); __set_bit(hwgpio, mask); i++; if (array_info) i = find_next_zero_bit(array_info->get_mask, array_size, i); } while ((i < array_size) && (desc_array[i]->gdev->chip == gc)); ret = gpio_chip_get_multiple(gc, mask, bits); if (ret) { if (mask != fastpath_mask) bitmap_free(mask); if (bits != fastpath_bits) bitmap_free(bits); return ret; } for (j = first; j < i; ) { const struct gpio_desc *desc = desc_array[j]; int hwgpio = gpio_chip_hwgpio(desc); int value = test_bit(hwgpio, bits); if (!raw && test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; __assign_bit(j, value_bitmap, value); trace_gpio_value(desc_to_gpio(desc), 1, value); j++; if (array_info) j = find_next_zero_bit(array_info->get_mask, i, j); } if (mask != fastpath_mask) bitmap_free(mask); if (bits != fastpath_bits) bitmap_free(bits); } return 0; } /** * gpiod_get_raw_value() - return a gpio's raw value * @desc: gpio whose value will be returned * * Return the GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_get_raw_value(const struct gpio_desc *desc) { VALIDATE_DESC(desc); /* Should be using gpiod_get_raw_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); return gpiod_get_raw_value_commit(desc); } EXPORT_SYMBOL_GPL(gpiod_get_raw_value); /** * gpiod_get_value() - return a gpio's value * @desc: gpio whose value will be returned * * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_get_value(const struct gpio_desc *desc) { int value; VALIDATE_DESC(desc); /* Should be using gpiod_get_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); value = gpiod_get_raw_value_commit(desc); if (value < 0) return value; if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; return value; } EXPORT_SYMBOL_GPL(gpiod_get_value); /** * gpiod_get_raw_array_value() - read raw values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. Return 0 in case of success, * else an error code. * * This function can be called from contexts where we cannot sleep, * and it will complain if the GPIO chip functions potentially sleep. */ int gpiod_get_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { if (!desc_array) return -EINVAL; return gpiod_get_array_value_complex(true, false, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value); /** * gpiod_get_array_value() - read values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. Return 0 in case of success, else an error code. * * This function can be called from contexts where we cannot sleep, * and it will complain if the GPIO chip functions potentially sleep. */ int gpiod_get_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { if (!desc_array) return -EINVAL; return gpiod_get_array_value_complex(false, false, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_get_array_value); /* * gpio_set_open_drain_value_commit() - Set the open drain gpio's value. * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherwise it will set to LOW. */ static void gpio_set_open_drain_value_commit(struct gpio_desc *desc, bool value) { int ret = 0; struct gpio_chip *gc = desc->gdev->chip; int offset = gpio_chip_hwgpio(desc); if (value) { ret = gc->direction_input(gc, offset); } else { ret = gc->direction_output(gc, offset, 0); if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); } trace_gpio_direction(desc_to_gpio(desc), value, ret); if (ret < 0) gpiod_err(desc, "%s: Error in set_value for open drain err %d\n", __func__, ret); } /* * _gpio_set_open_source_value() - Set the open source gpio's value. * @desc: gpio descriptor whose state need to be set. * @value: Non-zero for setting it HIGH otherwise it will set to LOW. */ static void gpio_set_open_source_value_commit(struct gpio_desc *desc, bool value) { int ret = 0; struct gpio_chip *gc = desc->gdev->chip; int offset = gpio_chip_hwgpio(desc); if (value) { ret = gc->direction_output(gc, offset, 1); if (!ret) set_bit(FLAG_IS_OUT, &desc->flags); } else { ret = gc->direction_input(gc, offset); } trace_gpio_direction(desc_to_gpio(desc), !value, ret); if (ret < 0) gpiod_err(desc, "%s: Error in set_value for open source err %d\n", __func__, ret); } static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) { struct gpio_chip *gc; gc = desc->gdev->chip; trace_gpio_value(desc_to_gpio(desc), 0, value); gc->set(gc, gpio_chip_hwgpio(desc), value); } /* * set multiple outputs on the same chip; * use the chip's set_multiple function if available; * otherwise set the outputs sequentially; * @chip: the GPIO chip we operate on * @mask: bit mask array; one bit per output; BITS_PER_LONG bits per word * defines which outputs are to be changed * @bits: bit value array; one bit per output; BITS_PER_LONG bits per word * defines the values the outputs specified by mask are to be set to */ static void gpio_chip_set_multiple(struct gpio_chip *gc, unsigned long *mask, unsigned long *bits) { if (gc->set_multiple) { gc->set_multiple(gc, mask, bits); } else { unsigned int i; /* set outputs if the corresponding mask bit is set */ for_each_set_bit(i, mask, gc->ngpio) gc->set(gc, i, test_bit(i, bits)); } } int gpiod_set_array_value_complex(bool raw, bool can_sleep, unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { int i = 0; /* * Validate array_info against desc_array and its size. * It should immediately follow desc_array if both * have been obtained from the same gpiod_get_array() call. */ if (array_info && array_info->desc == desc_array && array_size <= array_info->size && (void *)array_info == desc_array + array_info->size) { if (!can_sleep) WARN_ON(array_info->chip->can_sleep); if (!raw && !bitmap_empty(array_info->invert_mask, array_size)) bitmap_xor(value_bitmap, value_bitmap, array_info->invert_mask, array_size); gpio_chip_set_multiple(array_info->chip, array_info->set_mask, value_bitmap); i = find_first_zero_bit(array_info->set_mask, array_size); if (i == array_size) return 0; } else { array_info = NULL; } while (i < array_size) { struct gpio_chip *gc = desc_array[i]->gdev->chip; DECLARE_BITMAP(fastpath_mask, FASTPATH_NGPIO); DECLARE_BITMAP(fastpath_bits, FASTPATH_NGPIO); unsigned long *mask, *bits; int count = 0; if (likely(gc->ngpio <= FASTPATH_NGPIO)) { mask = fastpath_mask; bits = fastpath_bits; } else { gfp_t flags = can_sleep ? GFP_KERNEL : GFP_ATOMIC; mask = bitmap_alloc(gc->ngpio, flags); if (!mask) return -ENOMEM; bits = bitmap_alloc(gc->ngpio, flags); if (!bits) { bitmap_free(mask); return -ENOMEM; } } bitmap_zero(mask, gc->ngpio); if (!can_sleep) WARN_ON(gc->can_sleep); do { struct gpio_desc *desc = desc_array[i]; int hwgpio = gpio_chip_hwgpio(desc); int value = test_bit(i, value_bitmap); /* * Pins applicable for fast input but not for * fast output processing may have been already * inverted inside the fast path, skip them. */ if (!raw && !(array_info && test_bit(i, array_info->invert_mask)) && test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; trace_gpio_value(desc_to_gpio(desc), 0, value); /* * collect all normal outputs belonging to the same chip * open drain and open source outputs are set individually */ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) { gpio_set_open_drain_value_commit(desc, value); } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) { gpio_set_open_source_value_commit(desc, value); } else { __set_bit(hwgpio, mask); __assign_bit(hwgpio, bits, value); count++; } i++; if (array_info) i = find_next_zero_bit(array_info->set_mask, array_size, i); } while ((i < array_size) && (desc_array[i]->gdev->chip == gc)); /* push collected bits to outputs */ if (count != 0) gpio_chip_set_multiple(gc, mask, bits); if (mask != fastpath_mask) bitmap_free(mask); if (bits != fastpath_bits) bitmap_free(bits); } return 0; } /** * gpiod_set_raw_value() - assign a gpio's raw value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the raw value of the GPIO, i.e. the value of its physical line without * regard for its ACTIVE_LOW status. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_raw_value(struct gpio_desc *desc, int value) { VALIDATE_DESC_VOID(desc); /* Should be using gpiod_set_raw_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); gpiod_set_raw_value_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_raw_value); /** * gpiod_set_value_nocheck() - set a GPIO line value without checking * @desc: the descriptor to set the value on * @value: value to set * * This sets the value of a GPIO line backing a descriptor, applying * different semantic quirks like active low and open drain/source * handling. */ static void gpiod_set_value_nocheck(struct gpio_desc *desc, int value) { if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) gpio_set_open_drain_value_commit(desc, value); else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) gpio_set_open_source_value_commit(desc, value); else gpiod_set_raw_value_commit(desc, value); } /** * gpiod_set_value() - assign a gpio's value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW, * OPEN_DRAIN and OPEN_SOURCE flags into account. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ void gpiod_set_value(struct gpio_desc *desc, int value) { VALIDATE_DESC_VOID(desc); /* Should be using gpiod_set_value_cansleep() */ WARN_ON(desc->gdev->chip->can_sleep); gpiod_set_value_nocheck(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value); /** * gpiod_set_raw_array_value() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_set_raw_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { if (!desc_array) return -EINVAL; return gpiod_set_array_value_complex(true, false, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value); /** * gpiod_set_array_value() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. * * This function can be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. */ int gpiod_set_array_value(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { if (!desc_array) return -EINVAL; return gpiod_set_array_value_complex(false, false, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_set_array_value); /** * gpiod_cansleep() - report whether gpio value access may sleep * @desc: gpio to check * */ int gpiod_cansleep(const struct gpio_desc *desc) { VALIDATE_DESC(desc); return desc->gdev->chip->can_sleep; } EXPORT_SYMBOL_GPL(gpiod_cansleep); /** * gpiod_set_consumer_name() - set the consumer name for the descriptor * @desc: gpio to set the consumer name on * @name: the new consumer name */ int gpiod_set_consumer_name(struct gpio_desc *desc, const char *name) { VALIDATE_DESC(desc); if (name) { name = kstrdup_const(name, GFP_KERNEL); if (!name) return -ENOMEM; } kfree_const(desc->label); desc_set_label(desc, name); return 0; } EXPORT_SYMBOL_GPL(gpiod_set_consumer_name); /** * gpiod_to_irq() - return the IRQ corresponding to a GPIO * @desc: gpio whose IRQ will be returned (already requested) * * Return the IRQ corresponding to the passed GPIO, or an error code in case of * error. */ int gpiod_to_irq(const struct gpio_desc *desc) { struct gpio_chip *gc; int offset; /* * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics * requires this function to not return zero on an invalid descriptor * but rather a negative error number. */ if (!desc || IS_ERR(desc) || !desc->gdev || !desc->gdev->chip) return -EINVAL; gc = desc->gdev->chip; offset = gpio_chip_hwgpio(desc); if (gc->to_irq) { int retirq = gc->to_irq(gc, offset); /* Zero means NO_IRQ */ if (!retirq) return -ENXIO; return retirq; } #ifdef CONFIG_GPIOLIB_IRQCHIP if (gc->irq.chip) { /* * Avoid race condition with other code, which tries to lookup * an IRQ before the irqchip has been properly registered, * i.e. while gpiochip is still being brought up. */ return -EPROBE_DEFER; } #endif return -ENXIO; } EXPORT_SYMBOL_GPL(gpiod_to_irq); /** * gpiochip_lock_as_irq() - lock a GPIO to be used as IRQ * @gc: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to lock down * a certain GPIO line to be used for IRQs. */ int gpiochip_lock_as_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc; desc = gpiochip_get_desc(gc, offset); if (IS_ERR(desc)) return PTR_ERR(desc); /* * If it's fast: flush the direction setting if something changed * behind our back */ if (!gc->can_sleep && gc->get_direction) { int dir = gpiod_get_direction(desc); if (dir < 0) { chip_err(gc, "%s: cannot get GPIO direction\n", __func__); return dir; } } /* To be valid for IRQ the line needs to be input or open drain */ if (test_bit(FLAG_IS_OUT, &desc->flags) && !test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { chip_err(gc, "%s: tried to flag a GPIO set as output for IRQ\n", __func__); return -EIO; } set_bit(FLAG_USED_AS_IRQ, &desc->flags); set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); /* * If the consumer has not set up a label (such as when the * IRQ is referenced from .to_irq()) we set up a label here * so it is clear this is used as an interrupt. */ if (!desc->label) desc_set_label(desc, "interrupt"); return 0; } EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); /** * gpiochip_unlock_as_irq() - unlock a GPIO used as IRQ * @gc: the chip the GPIO to lock belongs to * @offset: the offset of the GPIO to lock as IRQ * * This is used directly by GPIO drivers that want to indicate * that a certain GPIO is no longer used exclusively for IRQ. */ void gpiochip_unlock_as_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc; desc = gpiochip_get_desc(gc, offset); if (IS_ERR(desc)) return; clear_bit(FLAG_USED_AS_IRQ, &desc->flags); clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); /* If we only had this marking, erase it */ if (desc->label && !strcmp(desc->label, "interrupt")) desc_set_label(desc, NULL); } EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq); void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc = gpiochip_get_desc(gc, offset); if (!IS_ERR(desc) && !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); } EXPORT_SYMBOL_GPL(gpiochip_disable_irq); void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset) { struct gpio_desc *desc = gpiochip_get_desc(gc, offset); if (!IS_ERR(desc) && !WARN_ON(!test_bit(FLAG_USED_AS_IRQ, &desc->flags))) { /* * We must not be output when using IRQ UNLESS we are * open drain. */ WARN_ON(test_bit(FLAG_IS_OUT, &desc->flags) && !test_bit(FLAG_OPEN_DRAIN, &desc->flags)); set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); } } EXPORT_SYMBOL_GPL(gpiochip_enable_irq); bool gpiochip_line_is_irq(struct gpio_chip *gc, unsigned int offset) { if (offset >= gc->ngpio) return false; return test_bit(FLAG_USED_AS_IRQ, &gc->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_irq); int gpiochip_reqres_irq(struct gpio_chip *gc, unsigned int offset) { int ret; if (!try_module_get(gc->gpiodev->owner)) return -ENODEV; ret = gpiochip_lock_as_irq(gc, offset); if (ret) { chip_err(gc, "unable to lock HW IRQ %u for IRQ\n", offset); module_put(gc->gpiodev->owner); return ret; } return 0; } EXPORT_SYMBOL_GPL(gpiochip_reqres_irq); void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset) { gpiochip_unlock_as_irq(gc, offset); module_put(gc->gpiodev->owner); } EXPORT_SYMBOL_GPL(gpiochip_relres_irq); bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset) { if (offset >= gc->ngpio) return false; return test_bit(FLAG_OPEN_DRAIN, &gc->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_open_drain); bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset) { if (offset >= gc->ngpio) return false; return test_bit(FLAG_OPEN_SOURCE, &gc->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_open_source); bool gpiochip_line_is_persistent(struct gpio_chip *gc, unsigned int offset) { if (offset >= gc->ngpio) return false; return !test_bit(FLAG_TRANSITORY, &gc->gpiodev->descs[offset].flags); } EXPORT_SYMBOL_GPL(gpiochip_line_is_persistent); /** * gpiod_get_raw_value_cansleep() - return a gpio's raw value * @desc: gpio whose value will be returned * * Return the GPIO's raw value, i.e. the value of the physical line disregarding * its ACTIVE_LOW status, or negative errno on failure. * * This function is to be called from contexts that can sleep. */ int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc) { might_sleep_if(extra_checks); VALIDATE_DESC(desc); return gpiod_get_raw_value_commit(desc); } EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep); /** * gpiod_get_value_cansleep() - return a gpio's value * @desc: gpio whose value will be returned * * Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into * account, or negative errno on failure. * * This function is to be called from contexts that can sleep. */ int gpiod_get_value_cansleep(const struct gpio_desc *desc) { int value; might_sleep_if(extra_checks); VALIDATE_DESC(desc); value = gpiod_get_raw_value_commit(desc); if (value < 0) return value; if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; return value; } EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep); /** * gpiod_get_raw_array_value_cansleep() - read raw values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. Return 0 in case of success, * else an error code. * * This function is to be called from contexts that can sleep. */ int gpiod_get_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { might_sleep_if(extra_checks); if (!desc_array) return -EINVAL; return gpiod_get_array_value_complex(true, true, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_get_raw_array_value_cansleep); /** * gpiod_get_array_value_cansleep() - read values from an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be read * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap to store the read values * * Read the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. Return 0 in case of success, else an error code. * * This function is to be called from contexts that can sleep. */ int gpiod_get_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { might_sleep_if(extra_checks); if (!desc_array) return -EINVAL; return gpiod_get_array_value_complex(false, true, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_get_array_value_cansleep); /** * gpiod_set_raw_value_cansleep() - assign a gpio's raw value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the raw value of the GPIO, i.e. the value of its physical line without * regard for its ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. */ void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value) { might_sleep_if(extra_checks); VALIDATE_DESC_VOID(desc); gpiod_set_raw_value_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep); /** * gpiod_set_value_cansleep() - assign a gpio's value * @desc: gpio whose value will be assigned * @value: value to assign * * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into * account * * This function is to be called from contexts that can sleep. */ void gpiod_set_value_cansleep(struct gpio_desc *desc, int value) { might_sleep_if(extra_checks); VALIDATE_DESC_VOID(desc); gpiod_set_value_nocheck(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep); /** * gpiod_set_raw_array_value_cansleep() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the raw values of the GPIOs, i.e. the values of the physical lines * without regard for their ACTIVE_LOW status. * * This function is to be called from contexts that can sleep. */ int gpiod_set_raw_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { might_sleep_if(extra_checks); if (!desc_array) return -EINVAL; return gpiod_set_array_value_complex(true, true, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_set_raw_array_value_cansleep); /** * gpiod_add_lookup_tables() - register GPIO device consumers * @tables: list of tables of consumers to register * @n: number of tables in the list */ void gpiod_add_lookup_tables(struct gpiod_lookup_table **tables, size_t n) { unsigned int i; mutex_lock(&gpio_lookup_lock); for (i = 0; i < n; i++) list_add_tail(&tables[i]->list, &gpio_lookup_list); mutex_unlock(&gpio_lookup_lock); } /** * gpiod_set_array_value_cansleep() - assign values to an array of GPIOs * @array_size: number of elements in the descriptor array / value bitmap * @desc_array: array of GPIO descriptors whose values will be assigned * @array_info: information on applicability of fast bitmap processing path * @value_bitmap: bitmap of values to assign * * Set the logical values of the GPIOs, i.e. taking their ACTIVE_LOW status * into account. * * This function is to be called from contexts that can sleep. */ int gpiod_set_array_value_cansleep(unsigned int array_size, struct gpio_desc **desc_array, struct gpio_array *array_info, unsigned long *value_bitmap) { might_sleep_if(extra_checks); if (!desc_array) return -EINVAL; return gpiod_set_array_value_complex(false, true, array_size, desc_array, array_info, value_bitmap); } EXPORT_SYMBOL_GPL(gpiod_set_array_value_cansleep); void gpiod_line_state_notify(struct gpio_desc *desc, unsigned long action) { blocking_notifier_call_chain(&desc->gdev->line_state_notifier, action, desc); } /** * gpiod_add_lookup_table() - register GPIO device consumers * @table: table of consumers to register */ void gpiod_add_lookup_table(struct gpiod_lookup_table *table) { gpiod_add_lookup_tables(&table, 1); } EXPORT_SYMBOL_GPL(gpiod_add_lookup_table); /** * gpiod_remove_lookup_table() - unregister GPIO device consumers * @table: table of consumers to unregister */ void gpiod_remove_lookup_table(struct gpiod_lookup_table *table) { /* Nothing to remove */ if (!table) return; mutex_lock(&gpio_lookup_lock); list_del(&table->list); mutex_unlock(&gpio_lookup_lock); } EXPORT_SYMBOL_GPL(gpiod_remove_lookup_table); /** * gpiod_add_hogs() - register a set of GPIO hogs from machine code * @hogs: table of gpio hog entries with a zeroed sentinel at the end */ void gpiod_add_hogs(struct gpiod_hog *hogs) { struct gpiod_hog *hog; mutex_lock(&gpio_machine_hogs_mutex); for (hog = &hogs[0]; hog->chip_label; hog++) { list_add_tail(&hog->list, &gpio_machine_hogs); /* * The chip may have been registered earlier, so check if it * exists and, if so, try to hog the line now. */ struct gpio_device *gdev __free(gpio_device_put) = gpio_device_find_by_label(hog->chip_label); if (gdev) gpiochip_machine_hog(gpio_device_get_chip(gdev), hog); } mutex_unlock(&gpio_machine_hogs_mutex); } EXPORT_SYMBOL_GPL(gpiod_add_hogs); void gpiod_remove_hogs(struct gpiod_hog *hogs) { struct gpiod_hog *hog; mutex_lock(&gpio_machine_hogs_mutex); for (hog = &hogs[0]; hog->chip_label; hog++) list_del(&hog->list); mutex_unlock(&gpio_machine_hogs_mutex); } EXPORT_SYMBOL_GPL(gpiod_remove_hogs); static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev) { const char *dev_id = dev ? dev_name(dev) : NULL; struct gpiod_lookup_table *table; list_for_each_entry(table, &gpio_lookup_list, list) { if (table->dev_id && dev_id) { /* * Valid strings on both ends, must be identical to have * a match */ if (!strcmp(table->dev_id, dev_id)) return table; } else { /* * One of the pointers is NULL, so both must be to have * a match */ if (dev_id == table->dev_id) return table; } } return NULL; } static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id, unsigned int idx, unsigned long *flags) { struct gpio_desc *desc = ERR_PTR(-ENOENT); struct gpiod_lookup_table *table; struct gpiod_lookup *p; struct gpio_chip *gc; guard(mutex)(&gpio_lookup_lock); table = gpiod_find_lookup_table(dev); if (!table) return desc; for (p = &table->table[0]; p->key; p++) { /* idx must always match exactly */ if (p->idx != idx) continue; /* If the lookup entry has a con_id, require exact match */ if (p->con_id && (!con_id || strcmp(p->con_id, con_id))) continue; if (p->chip_hwnum == U16_MAX) { desc = gpio_name_to_desc(p->key); if (desc) { *flags = p->flags; return desc; } dev_warn(dev, "cannot find GPIO line %s, deferring\n", p->key); return ERR_PTR(-EPROBE_DEFER); } struct gpio_device *gdev __free(gpio_device_put) = gpio_device_find_by_label(p->key); if (!gdev) { /* * As the lookup table indicates a chip with * p->key should exist, assume it may * still appear later and let the interested * consumer be probed again or let the Deferred * Probe infrastructure handle the error. */ dev_warn(dev, "cannot find GPIO chip %s, deferring\n", p->key); return ERR_PTR(-EPROBE_DEFER); } gc = gpio_device_get_chip(gdev); if (gc->ngpio <= p->chip_hwnum) { dev_err(dev, "requested GPIO %u (%u) is out of range [0..%u] for chip %s\n", idx, p->chip_hwnum, gc->ngpio - 1, gc->label); return ERR_PTR(-EINVAL); } desc = gpio_device_get_desc(gdev, p->chip_hwnum); *flags = p->flags; return desc; } return desc; } static int platform_gpio_count(struct device *dev, const char *con_id) { struct gpiod_lookup_table *table; struct gpiod_lookup *p; unsigned int count = 0; scoped_guard(mutex, &gpio_lookup_lock) { table = gpiod_find_lookup_table(dev); if (!table) return -ENOENT; for (p = &table->table[0]; p->key; p++) { if ((con_id && p->con_id && !strcmp(con_id, p->con_id)) || (!con_id && !p->con_id)) count++; } } if (!count) return -ENOENT; return count; } static struct gpio_desc *gpiod_find_by_fwnode(struct fwnode_handle *fwnode, struct device *consumer, const char *con_id, unsigned int idx, enum gpiod_flags *flags, unsigned long *lookupflags) { struct gpio_desc *desc = ERR_PTR(-ENOENT); if (is_of_node(fwnode)) { dev_dbg(consumer, "using DT '%pfw' for '%s' GPIO lookup\n", fwnode, con_id); desc = of_find_gpio(to_of_node(fwnode), con_id, idx, lookupflags); } else if (is_acpi_node(fwnode)) { dev_dbg(consumer, "using ACPI '%pfw' for '%s' GPIO lookup\n", fwnode, con_id); desc = acpi_find_gpio(fwnode, con_id, idx, flags, lookupflags); } else if (is_software_node(fwnode)) { dev_dbg(consumer, "using swnode '%pfw' for '%s' GPIO lookup\n", fwnode, con_id); desc = swnode_find_gpio(fwnode, con_id, idx, lookupflags); } return desc; } static struct gpio_desc *gpiod_find_and_request(struct device *consumer, struct fwnode_handle *fwnode, const char *con_id, unsigned int idx, enum gpiod_flags flags, const char *label, bool platform_lookup_allowed) { unsigned long lookupflags = GPIO_LOOKUP_FLAGS_DEFAULT; struct gpio_desc *desc; int ret; desc = gpiod_find_by_fwnode(fwnode, consumer, con_id, idx, &flags, &lookupflags); if (gpiod_not_found(desc) && platform_lookup_allowed) { /* * Either we are not using DT or ACPI, or their lookup did not * return a result. In that case, use platform lookup as a * fallback. */ dev_dbg(consumer, "using lookup tables for GPIO lookup\n"); desc = gpiod_find(consumer, con_id, idx, &lookupflags); } if (IS_ERR(desc)) { dev_dbg(consumer, "No GPIO consumer %s found\n", con_id); return desc; } /* * If a connection label was passed use that, else attempt to use * the device name as label */ ret = gpiod_request(desc, label); if (ret) { if (!(ret == -EBUSY && flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE)) return ERR_PTR(ret); /* * This happens when there are several consumers for * the same GPIO line: we just return here without * further initialization. It is a bit of a hack. * This is necessary to support fixed regulators. * * FIXME: Make this more sane and safe. */ dev_info(consumer, "nonexclusive access to GPIO for %s\n", con_id); return desc; } ret = gpiod_configure_flags(desc, con_id, lookupflags, flags); if (ret < 0) { dev_dbg(consumer, "setup of GPIO %s failed\n", con_id); gpiod_put(desc); return ERR_PTR(ret); } gpiod_line_state_notify(desc, GPIOLINE_CHANGED_REQUESTED); return desc; } /** * fwnode_gpiod_get_index - obtain a GPIO from firmware node * @fwnode: handle of the firmware node * @con_id: function within the GPIO consumer * @index: index of the GPIO to obtain for the consumer * @flags: GPIO initialization flags * @label: label to attach to the requested GPIO * * This function can be used for drivers that get their configuration * from opaque firmware. * * The function properly finds the corresponding GPIO using whatever is the * underlying firmware interface and then makes sure that the GPIO * descriptor is requested before it is returned to the caller. * * Returns: * On successful request the GPIO pin is configured in accordance with * provided @flags. * * In case of error an ERR_PTR() is returned. */ struct gpio_desc *fwnode_gpiod_get_index(struct fwnode_handle *fwnode, const char *con_id, int index, enum gpiod_flags flags, const char *label) { return gpiod_find_and_request(NULL, fwnode, con_id, index, flags, label, false); } EXPORT_SYMBOL_GPL(fwnode_gpiod_get_index); /** * gpiod_count - return the number of GPIOs associated with a device / function * or -ENOENT if no GPIO has been assigned to the requested function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer */ int gpiod_count(struct device *dev, const char *con_id) { const struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; int count = -ENOENT; if (is_of_node(fwnode)) count = of_gpio_get_count(dev, con_id); else if (is_acpi_node(fwnode)) count = acpi_gpio_count(dev, con_id); else if (is_software_node(fwnode)) count = swnode_gpio_count(fwnode, con_id); if (count < 0) count = platform_gpio_count(dev, con_id); return count; } EXPORT_SYMBOL_GPL(gpiod_count); /** * gpiod_get - obtain a GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * Return the GPIO descriptor corresponding to the function con_id of device * dev, -ENOENT if no GPIO has been assigned to the requested function, or * another IS_ERR() code if an error occurred while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id, enum gpiod_flags flags) { return gpiod_get_index(dev, con_id, 0, flags); } EXPORT_SYMBOL_GPL(gpiod_get); /** * gpiod_get_optional - obtain an optional GPIO for a given GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get(), except that when no GPIO was assigned to * the requested function it will return NULL. This is convenient for drivers * that need to handle optional GPIOs. */ struct gpio_desc *__must_check gpiod_get_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) { return gpiod_get_index_optional(dev, con_id, 0, flags); } EXPORT_SYMBOL_GPL(gpiod_get_optional); /** * gpiod_configure_flags - helper function to configure a given GPIO * @desc: gpio whose value will be assigned * @con_id: function within the GPIO consumer * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from * of_find_gpio() or of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags * * Return 0 on success, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ int gpiod_configure_flags(struct gpio_desc *desc, const char *con_id, unsigned long lflags, enum gpiod_flags dflags) { int ret; if (lflags & GPIO_ACTIVE_LOW) set_bit(FLAG_ACTIVE_LOW, &desc->flags); if (lflags & GPIO_OPEN_DRAIN) set_bit(FLAG_OPEN_DRAIN, &desc->flags); else if (dflags & GPIOD_FLAGS_BIT_OPEN_DRAIN) { /* * This enforces open drain mode from the consumer side. * This is necessary for some busses like I2C, but the lookup * should *REALLY* have specified them as open drain in the * first place, so print a little warning here. */ set_bit(FLAG_OPEN_DRAIN, &desc->flags); gpiod_warn(desc, "enforced open drain please flag it properly in DT/ACPI DSDT/board file\n"); } if (lflags & GPIO_OPEN_SOURCE) set_bit(FLAG_OPEN_SOURCE, &desc->flags); if (((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DOWN)) || ((lflags & GPIO_PULL_UP) && (lflags & GPIO_PULL_DISABLE)) || ((lflags & GPIO_PULL_DOWN) && (lflags & GPIO_PULL_DISABLE))) { gpiod_err(desc, "multiple pull-up, pull-down or pull-disable enabled, invalid configuration\n"); return -EINVAL; } if (lflags & GPIO_PULL_UP) set_bit(FLAG_PULL_UP, &desc->flags); else if (lflags & GPIO_PULL_DOWN) set_bit(FLAG_PULL_DOWN, &desc->flags); else if (lflags & GPIO_PULL_DISABLE) set_bit(FLAG_BIAS_DISABLE, &desc->flags); ret = gpiod_set_transitory(desc, (lflags & GPIO_TRANSITORY)); if (ret < 0) return ret; /* No particular flag request, return here... */ if (!(dflags & GPIOD_FLAGS_BIT_DIR_SET)) { gpiod_dbg(desc, "no flags found for %s\n", con_id); return 0; } /* Process flags */ if (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ret = gpiod_direction_output(desc, !!(dflags & GPIOD_FLAGS_BIT_DIR_VAL)); else ret = gpiod_direction_input(desc); return ret; } /** * gpiod_get_index - obtain a GPIO from a multi-index GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @idx: index of the GPIO to obtain in the consumer * @flags: optional GPIO initialization flags * * This variant of gpiod_get() allows to access GPIOs other than the first * defined one for functions that define several GPIOs. * * Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the * requested function and/or index, or another IS_ERR() code if an error * occurred while trying to acquire the GPIO. */ struct gpio_desc *__must_check gpiod_get_index(struct device *dev, const char *con_id, unsigned int idx, enum gpiod_flags flags) { struct fwnode_handle *fwnode = dev ? dev_fwnode(dev) : NULL; const char *devname = dev ? dev_name(dev) : "?"; const char *label = con_id ?: devname; return gpiod_find_and_request(dev, fwnode, con_id, idx, flags, label, true); } EXPORT_SYMBOL_GPL(gpiod_get_index); /** * gpiod_get_index_optional - obtain an optional GPIO from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @index: index of the GPIO to obtain in the consumer * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get_index(), except that when no GPIO with the * specified index was assigned to the requested function it will return NULL. * This is convenient for drivers that need to handle optional GPIOs. */ struct gpio_desc *__must_check gpiod_get_index_optional(struct device *dev, const char *con_id, unsigned int index, enum gpiod_flags flags) { struct gpio_desc *desc; desc = gpiod_get_index(dev, con_id, index, flags); if (gpiod_not_found(desc)) return NULL; return desc; } EXPORT_SYMBOL_GPL(gpiod_get_index_optional); /** * gpiod_hog - Hog the specified GPIO desc given the provided flags * @desc: gpio whose value will be assigned * @name: gpio line name * @lflags: bitmask of gpio_lookup_flags GPIO_* values - returned from * of_find_gpio() or of_get_gpio_hog() * @dflags: gpiod_flags - optional GPIO initialization flags */ int gpiod_hog(struct gpio_desc *desc, const char *name, unsigned long lflags, enum gpiod_flags dflags) { struct gpio_chip *gc; struct gpio_desc *local_desc; int hwnum; int ret; gc = gpiod_to_chip(desc); hwnum = gpio_chip_hwgpio(desc); local_desc = gpiochip_request_own_desc(gc, hwnum, name, lflags, dflags); if (IS_ERR(local_desc)) { ret = PTR_ERR(local_desc); pr_err("requesting hog GPIO %s (chip %s, offset %d) failed, %d\n", name, gc->label, hwnum, ret); return ret; } /* Mark GPIO as hogged so it can be identified and removed later */ set_bit(FLAG_IS_HOGGED, &desc->flags); gpiod_dbg(desc, "hogged as %s%s\n", (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? "output" : "input", (dflags & GPIOD_FLAGS_BIT_DIR_OUT) ? (dflags & GPIOD_FLAGS_BIT_DIR_VAL) ? "/high" : "/low" : ""); return 0; } /** * gpiochip_free_hogs - Scan gpio-controller chip and release GPIO hog * @gc: gpio chip to act on */ static void gpiochip_free_hogs(struct gpio_chip *gc) { struct gpio_desc *desc; for_each_gpio_desc_with_flag(gc, desc, FLAG_IS_HOGGED) gpiochip_free_own_desc(desc); } /** * gpiod_get_array - obtain multiple GPIOs from a multi-index GPIO function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * This function acquires all the GPIOs defined under a given function. * * Return a struct gpio_descs containing an array of descriptors, -ENOENT if * no GPIO has been assigned to the requested function, or another IS_ERR() * code if an error occurred while trying to acquire the GPIOs. */ struct gpio_descs *__must_check gpiod_get_array(struct device *dev, const char *con_id, enum gpiod_flags flags) { struct gpio_desc *desc; struct gpio_descs *descs; struct gpio_array *array_info = NULL; struct gpio_chip *gc; int count, bitmap_size; size_t descs_size; count = gpiod_count(dev, con_id); if (count < 0) return ERR_PTR(count); descs_size = struct_size(descs, desc, count); descs = kzalloc(descs_size, GFP_KERNEL); if (!descs) return ERR_PTR(-ENOMEM); for (descs->ndescs = 0; descs->ndescs < count; descs->ndescs++) { desc = gpiod_get_index(dev, con_id, descs->ndescs, flags); if (IS_ERR(desc)) { gpiod_put_array(descs); return ERR_CAST(desc); } descs->desc[descs->ndescs] = desc; gc = gpiod_to_chip(desc); /* * If pin hardware number of array member 0 is also 0, select * its chip as a candidate for fast bitmap processing path. */ if (descs->ndescs == 0 && gpio_chip_hwgpio(desc) == 0) { struct gpio_descs *array; bitmap_size = BITS_TO_LONGS(gc->ngpio > count ? gc->ngpio : count); array = krealloc(descs, descs_size + struct_size(array_info, invert_mask, 3 * bitmap_size), GFP_KERNEL | __GFP_ZERO); if (!array) { gpiod_put_array(descs); return ERR_PTR(-ENOMEM); } descs = array; array_info = (void *)descs + descs_size; array_info->get_mask = array_info->invert_mask + bitmap_size; array_info->set_mask = array_info->get_mask + bitmap_size; array_info->desc = descs->desc; array_info->size = count; array_info->chip = gc; bitmap_set(array_info->get_mask, descs->ndescs, count - descs->ndescs); bitmap_set(array_info->set_mask, descs->ndescs, count - descs->ndescs); descs->info = array_info; } /* If there is no cache for fast bitmap processing path, continue */ if (!array_info) continue; /* Unmark array members which don't belong to the 'fast' chip */ if (array_info->chip != gc) { __clear_bit(descs->ndescs, array_info->get_mask); __clear_bit(descs->ndescs, array_info->set_mask); } /* * Detect array members which belong to the 'fast' chip * but their pins are not in hardware order. */ else if (gpio_chip_hwgpio(desc) != descs->ndescs) { /* * Don't use fast path if all array members processed so * far belong to the same chip as this one but its pin * hardware number is different from its array index. */ if (bitmap_full(array_info->get_mask, descs->ndescs)) { array_info = NULL; } else { __clear_bit(descs->ndescs, array_info->get_mask); __clear_bit(descs->ndescs, array_info->set_mask); } } else { /* Exclude open drain or open source from fast output */ if (gpiochip_line_is_open_drain(gc, descs->ndescs) || gpiochip_line_is_open_source(gc, descs->ndescs)) __clear_bit(descs->ndescs, array_info->set_mask); /* Identify 'fast' pins which require invertion */ if (gpiod_is_active_low(desc)) __set_bit(descs->ndescs, array_info->invert_mask); } } if (array_info) dev_dbg(dev, "GPIO array info: chip=%s, size=%d, get_mask=%lx, set_mask=%lx, invert_mask=%lx\n", array_info->chip->label, array_info->size, *array_info->get_mask, *array_info->set_mask, *array_info->invert_mask); return descs; } EXPORT_SYMBOL_GPL(gpiod_get_array); /** * gpiod_get_array_optional - obtain multiple GPIOs from a multi-index GPIO * function * @dev: GPIO consumer, can be NULL for system-global GPIOs * @con_id: function within the GPIO consumer * @flags: optional GPIO initialization flags * * This is equivalent to gpiod_get_array(), except that when no GPIO was * assigned to the requested function it will return NULL. */ struct gpio_descs *__must_check gpiod_get_array_optional(struct device *dev, const char *con_id, enum gpiod_flags flags) { struct gpio_descs *descs; descs = gpiod_get_array(dev, con_id, flags); if (gpiod_not_found(descs)) return NULL; return descs; } EXPORT_SYMBOL_GPL(gpiod_get_array_optional); /** * gpiod_put - dispose of a GPIO descriptor * @desc: GPIO descriptor to dispose of * * No descriptor can be used after gpiod_put() has been called on it. */ void gpiod_put(struct gpio_desc *desc) { if (desc) gpiod_free(desc); } EXPORT_SYMBOL_GPL(gpiod_put); /** * gpiod_put_array - dispose of multiple GPIO descriptors * @descs: struct gpio_descs containing an array of descriptors */ void gpiod_put_array(struct gpio_descs *descs) { unsigned int i; for (i = 0; i < descs->ndescs; i++) gpiod_put(descs->desc[i]); kfree(descs); } EXPORT_SYMBOL_GPL(gpiod_put_array); static int gpio_stub_drv_probe(struct device *dev) { /* * The DT node of some GPIO chips have a "compatible" property, but * never have a struct device added and probed by a driver to register * the GPIO chip with gpiolib. In such cases, fw_devlink=on will cause * the consumers of the GPIO chip to get probe deferred forever because * they will be waiting for a device associated with the GPIO chip * firmware node to get added and bound to a driver. * * To allow these consumers to probe, we associate the struct * gpio_device of the GPIO chip with the firmware node and then simply * bind it to this stub driver. */ return 0; } static struct device_driver gpio_stub_drv = { .name = "gpio_stub_drv", .bus = &gpio_bus_type, .probe = gpio_stub_drv_probe, }; static int __init gpiolib_dev_init(void) { int ret; /* Register GPIO sysfs bus */ ret = bus_register(&gpio_bus_type); if (ret < 0) { pr_err("gpiolib: could not register GPIO bus type\n"); return ret; } ret = driver_register(&gpio_stub_drv); if (ret < 0) { pr_err("gpiolib: could not register GPIO stub driver\n"); bus_unregister(&gpio_bus_type); return ret; } ret = alloc_chrdev_region(&gpio_devt, 0, GPIO_DEV_MAX, GPIOCHIP_NAME); if (ret < 0) { pr_err("gpiolib: failed to allocate char dev region\n"); driver_unregister(&gpio_stub_drv); bus_unregister(&gpio_bus_type); return ret; } gpiolib_initialized = true; gpiochip_setup_devs(); #if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO) WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier)); #endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */ return ret; } core_initcall(gpiolib_dev_init); #ifdef CONFIG_DEBUG_FS static void gpiolib_dbg_show(struct seq_file *s, struct gpio_device *gdev) { struct gpio_chip *gc = gdev->chip; struct gpio_desc *desc; unsigned gpio = gdev->base; int value; bool is_out; bool is_irq; bool active_low; for_each_gpio_desc(gc, desc) { if (test_bit(FLAG_REQUESTED, &desc->flags)) { gpiod_get_direction(desc); is_out = test_bit(FLAG_IS_OUT, &desc->flags); value = gpio_chip_get_value(gc, desc); is_irq = test_bit(FLAG_USED_AS_IRQ, &desc->flags); active_low = test_bit(FLAG_ACTIVE_LOW, &desc->flags); seq_printf(s, " gpio-%-3d (%-20.20s|%-20.20s) %s %s %s%s\n", gpio, desc->name ?: "", desc->label, is_out ? "out" : "in ", value >= 0 ? (value ? "hi" : "lo") : "? ", is_irq ? "IRQ " : "", active_low ? "ACTIVE LOW" : ""); } else if (desc->name) { seq_printf(s, " gpio-%-3d (%-20.20s)\n", gpio, desc->name); } gpio++; } } static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos) { unsigned long flags; struct gpio_device *gdev = NULL; loff_t index = *pos; s->private = ""; spin_lock_irqsave(&gpio_lock, flags); list_for_each_entry(gdev, &gpio_devices, list) if (index-- == 0) { spin_unlock_irqrestore(&gpio_lock, flags); return gdev; } spin_unlock_irqrestore(&gpio_lock, flags); return NULL; } static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos) { unsigned long flags; struct gpio_device *gdev = v; void *ret = NULL; spin_lock_irqsave(&gpio_lock, flags); if (list_is_last(&gdev->list, &gpio_devices)) ret = NULL; else ret = list_first_entry(&gdev->list, struct gpio_device, list); spin_unlock_irqrestore(&gpio_lock, flags); s->private = "\n"; ++*pos; return ret; } static void gpiolib_seq_stop(struct seq_file *s, void *v) { } static int gpiolib_seq_show(struct seq_file *s, void *v) { struct gpio_device *gdev = v; struct gpio_chip *gc = gdev->chip; struct device *parent; if (!gc) { seq_printf(s, "%s%s: (dangling chip)", (char *)s->private, dev_name(&gdev->dev)); return 0; } seq_printf(s, "%s%s: GPIOs %d-%d", (char *)s->private, dev_name(&gdev->dev), gdev->base, gdev->base + gdev->ngpio - 1); parent = gc->parent; if (parent) seq_printf(s, ", parent: %s/%s", parent->bus ? parent->bus->name : "no-bus", dev_name(parent)); if (gc->label) seq_printf(s, ", %s", gc->label); if (gc->can_sleep) seq_printf(s, ", can sleep"); seq_printf(s, ":\n"); if (gc->dbg_show) gc->dbg_show(s, gc); else gpiolib_dbg_show(s, gdev); return 0; } static const struct seq_operations gpiolib_sops = { .start = gpiolib_seq_start, .next = gpiolib_seq_next, .stop = gpiolib_seq_stop, .show = gpiolib_seq_show, }; DEFINE_SEQ_ATTRIBUTE(gpiolib); static int __init gpiolib_debugfs_init(void) { /* /sys/kernel/debug/gpio */ debugfs_create_file("gpio", 0444, NULL, NULL, &gpiolib_fops); return 0; } subsys_initcall(gpiolib_debugfs_init); #endif /* DEBUG_FS */
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