| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Kent Gibson | 9890 | 80.64% | 34 | 37.78% |
| Dipen Patel | 785 | 6.40% | 1 | 1.11% |
| Bartosz Golaszewski | 688 | 5.61% | 7 | 7.78% |
| Linus Walleij | 424 | 3.46% | 12 | 13.33% |
| David Brownell | 133 | 1.08% | 1 | 1.11% |
| Andy Shevchenko | 125 | 1.02% | 9 | 10.00% |
| Russell King | 61 | 0.50% | 1 | 1.11% |
| Alexandre Courbot | 53 | 0.43% | 4 | 4.44% |
| Gabriel Knezek | 13 | 0.11% | 1 | 1.11% |
| Marc Zyngier | 10 | 0.08% | 1 | 1.11% |
| Linus Torvalds | 10 | 0.08% | 1 | 1.11% |
| Thierry Reding | 9 | 0.07% | 2 | 2.22% |
| Lukas Wunner | 9 | 0.07% | 1 | 1.11% |
| Janusz Krzysztofik | 7 | 0.06% | 3 | 3.33% |
| Anton Vorontsov | 7 | 0.06% | 1 | 1.11% |
| Meng Li | 6 | 0.05% | 1 | 1.11% |
| Lars-Peter Clausen | 5 | 0.04% | 1 | 1.11% |
| Grant C. Likely | 5 | 0.04% | 1 | 1.11% |
| Shiraz Hashim | 5 | 0.04% | 1 | 1.11% |
| Kees Cook | 4 | 0.03% | 1 | 1.11% |
| Rojhalat Ibrahim | 4 | 0.03% | 1 | 1.11% |
| Benoit Parrot | 4 | 0.03% | 1 | 1.11% |
| Alexey Dobriyan | 2 | 0.02% | 1 | 1.11% |
| Drew Fustini | 2 | 0.02% | 1 | 1.11% |
| Al Viro | 2 | 0.02% | 1 | 1.11% |
| Mika Westerberg | 1 | 0.01% | 1 | 1.11% |
| Total | 12264 | 90 |
// SPDX-License-Identifier: GPL-2.0 #include <linux/anon_inodes.h> #include <linux/atomic.h> #include <linux/bitmap.h> #include <linux/build_bug.h> #include <linux/cdev.h> #include <linux/compat.h> #include <linux/compiler.h> #include <linux/device.h> #include <linux/err.h> #include <linux/file.h> #include <linux/gpio.h> #include <linux/gpio/driver.h> #include <linux/hte.h> #include <linux/interrupt.h> #include <linux/irqreturn.h> #include <linux/kernel.h> #include <linux/kfifo.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/pinctrl/consumer.h> #include <linux/poll.h> #include <linux/seq_file.h> #include <linux/spinlock.h> #include <linux/timekeeping.h> #include <linux/uaccess.h> #include <linux/workqueue.h> #include <uapi/linux/gpio.h> #include "gpiolib.h" #include "gpiolib-cdev.h" /* * Array sizes must ensure 64-bit alignment and not create holes in the * struct packing. */ static_assert(IS_ALIGNED(GPIO_V2_LINES_MAX, 2)); static_assert(IS_ALIGNED(GPIO_MAX_NAME_SIZE, 8)); /* * Check that uAPI structs are 64-bit aligned for 32/64-bit compatibility */ static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_attribute), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config_attribute), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_config), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_request), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_info_changed), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_event), 8)); static_assert(IS_ALIGNED(sizeof(struct gpio_v2_line_values), 8)); /* Character device interface to GPIO. * * The GPIO character device, /dev/gpiochipN, provides userspace an * interface to gpiolib GPIOs via ioctl()s. */ typedef __poll_t (*poll_fn)(struct file *, struct poll_table_struct *); typedef long (*ioctl_fn)(struct file *, unsigned int, unsigned long); typedef ssize_t (*read_fn)(struct file *, char __user *, size_t count, loff_t *); static __poll_t call_poll_locked(struct file *file, struct poll_table_struct *wait, struct gpio_device *gdev, poll_fn func) { __poll_t ret; down_read(&gdev->sem); ret = func(file, wait); up_read(&gdev->sem); return ret; } static long call_ioctl_locked(struct file *file, unsigned int cmd, unsigned long arg, struct gpio_device *gdev, ioctl_fn func) { long ret; down_read(&gdev->sem); ret = func(file, cmd, arg); up_read(&gdev->sem); return ret; } static ssize_t call_read_locked(struct file *file, char __user *buf, size_t count, loff_t *f_ps, struct gpio_device *gdev, read_fn func) { ssize_t ret; down_read(&gdev->sem); ret = func(file, buf, count, f_ps); up_read(&gdev->sem); return ret; } /* * GPIO line handle management */ #ifdef CONFIG_GPIO_CDEV_V1 /** * struct linehandle_state - contains the state of a userspace handle * @gdev: the GPIO device the handle pertains to * @label: consumer label used to tag descriptors * @descs: the GPIO descriptors held by this handle * @num_descs: the number of descriptors held in the descs array */ struct linehandle_state { struct gpio_device *gdev; const char *label; struct gpio_desc *descs[GPIOHANDLES_MAX]; u32 num_descs; }; #define GPIOHANDLE_REQUEST_VALID_FLAGS \ (GPIOHANDLE_REQUEST_INPUT | \ GPIOHANDLE_REQUEST_OUTPUT | \ GPIOHANDLE_REQUEST_ACTIVE_LOW | \ GPIOHANDLE_REQUEST_BIAS_PULL_UP | \ GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | \ GPIOHANDLE_REQUEST_BIAS_DISABLE | \ GPIOHANDLE_REQUEST_OPEN_DRAIN | \ GPIOHANDLE_REQUEST_OPEN_SOURCE) static int linehandle_validate_flags(u32 flags) { /* Return an error if an unknown flag is set */ if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) return -EINVAL; /* * Do not allow both INPUT & OUTPUT flags to be set as they are * contradictory. */ if ((flags & GPIOHANDLE_REQUEST_INPUT) && (flags & GPIOHANDLE_REQUEST_OUTPUT)) return -EINVAL; /* * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If * the hardware actually supports enabling both at the same time the * electrical result would be disastrous. */ if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) && (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) return -EINVAL; /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */ if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) && ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))) return -EINVAL; /* Bias flags only allowed for input or output mode. */ if (!((flags & GPIOHANDLE_REQUEST_INPUT) || (flags & GPIOHANDLE_REQUEST_OUTPUT)) && ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) || (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) || (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN))) return -EINVAL; /* Only one bias flag can be set. */ if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) return -EINVAL; return 0; } static void linehandle_flags_to_desc_flags(u32 lflags, unsigned long *flagsp) { assign_bit(FLAG_ACTIVE_LOW, flagsp, lflags & GPIOHANDLE_REQUEST_ACTIVE_LOW); assign_bit(FLAG_OPEN_DRAIN, flagsp, lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN); assign_bit(FLAG_OPEN_SOURCE, flagsp, lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE); assign_bit(FLAG_PULL_UP, flagsp, lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP); assign_bit(FLAG_PULL_DOWN, flagsp, lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN); assign_bit(FLAG_BIAS_DISABLE, flagsp, lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE); } static long linehandle_set_config(struct linehandle_state *lh, void __user *ip) { struct gpiohandle_config gcnf; struct gpio_desc *desc; int i, ret; u32 lflags; if (copy_from_user(&gcnf, ip, sizeof(gcnf))) return -EFAULT; lflags = gcnf.flags; ret = linehandle_validate_flags(lflags); if (ret) return ret; for (i = 0; i < lh->num_descs; i++) { desc = lh->descs[i]; linehandle_flags_to_desc_flags(gcnf.flags, &desc->flags); /* * Lines have to be requested explicitly for input * or output, else the line will be treated "as is". */ if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { int val = !!gcnf.default_values[i]; ret = gpiod_direction_output(desc, val); if (ret) return ret; } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { ret = gpiod_direction_input(desc); if (ret) return ret; } blocking_notifier_call_chain(&desc->gdev->notifier, GPIO_V2_LINE_CHANGED_CONFIG, desc); } return 0; } static long linehandle_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned long arg) { struct linehandle_state *lh = file->private_data; void __user *ip = (void __user *)arg; struct gpiohandle_data ghd; DECLARE_BITMAP(vals, GPIOHANDLES_MAX); unsigned int i; int ret; if (!lh->gdev->chip) return -ENODEV; switch (cmd) { case GPIOHANDLE_GET_LINE_VALUES_IOCTL: /* NOTE: It's okay to read values of output lines */ ret = gpiod_get_array_value_complex(false, true, lh->num_descs, lh->descs, NULL, vals); if (ret) return ret; memset(&ghd, 0, sizeof(ghd)); for (i = 0; i < lh->num_descs; i++) ghd.values[i] = test_bit(i, vals); if (copy_to_user(ip, &ghd, sizeof(ghd))) return -EFAULT; return 0; case GPIOHANDLE_SET_LINE_VALUES_IOCTL: /* * All line descriptors were created at once with the same * flags so just check if the first one is really output. */ if (!test_bit(FLAG_IS_OUT, &lh->descs[0]->flags)) return -EPERM; if (copy_from_user(&ghd, ip, sizeof(ghd))) return -EFAULT; /* Clamp all values to [0,1] */ for (i = 0; i < lh->num_descs; i++) __assign_bit(i, vals, ghd.values[i]); /* Reuse the array setting function */ return gpiod_set_array_value_complex(false, true, lh->num_descs, lh->descs, NULL, vals); case GPIOHANDLE_SET_CONFIG_IOCTL: return linehandle_set_config(lh, ip); default: return -EINVAL; } } static long linehandle_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct linehandle_state *lh = file->private_data; return call_ioctl_locked(file, cmd, arg, lh->gdev, linehandle_ioctl_unlocked); } #ifdef CONFIG_COMPAT static long linehandle_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) { return linehandle_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); } #endif static void linehandle_free(struct linehandle_state *lh) { int i; for (i = 0; i < lh->num_descs; i++) if (lh->descs[i]) gpiod_free(lh->descs[i]); kfree(lh->label); put_device(&lh->gdev->dev); kfree(lh); } static int linehandle_release(struct inode *inode, struct file *file) { linehandle_free(file->private_data); return 0; } static const struct file_operations linehandle_fileops = { .release = linehandle_release, .owner = THIS_MODULE, .llseek = noop_llseek, .unlocked_ioctl = linehandle_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = linehandle_ioctl_compat, #endif }; static int linehandle_create(struct gpio_device *gdev, void __user *ip) { struct gpiohandle_request handlereq; struct linehandle_state *lh; struct file *file; int fd, i, ret; u32 lflags; if (copy_from_user(&handlereq, ip, sizeof(handlereq))) return -EFAULT; if ((handlereq.lines == 0) || (handlereq.lines > GPIOHANDLES_MAX)) return -EINVAL; lflags = handlereq.flags; ret = linehandle_validate_flags(lflags); if (ret) return ret; lh = kzalloc(sizeof(*lh), GFP_KERNEL); if (!lh) return -ENOMEM; lh->gdev = gdev; get_device(&gdev->dev); if (handlereq.consumer_label[0] != '\0') { /* label is only initialized if consumer_label is set */ lh->label = kstrndup(handlereq.consumer_label, sizeof(handlereq.consumer_label) - 1, GFP_KERNEL); if (!lh->label) { ret = -ENOMEM; goto out_free_lh; } } lh->num_descs = handlereq.lines; /* Request each GPIO */ for (i = 0; i < handlereq.lines; i++) { u32 offset = handlereq.lineoffsets[i]; struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); if (IS_ERR(desc)) { ret = PTR_ERR(desc); goto out_free_lh; } ret = gpiod_request_user(desc, lh->label); if (ret) goto out_free_lh; lh->descs[i] = desc; linehandle_flags_to_desc_flags(handlereq.flags, &desc->flags); ret = gpiod_set_transitory(desc, false); if (ret < 0) goto out_free_lh; /* * Lines have to be requested explicitly for input * or output, else the line will be treated "as is". */ if (lflags & GPIOHANDLE_REQUEST_OUTPUT) { int val = !!handlereq.default_values[i]; ret = gpiod_direction_output(desc, val); if (ret) goto out_free_lh; } else if (lflags & GPIOHANDLE_REQUEST_INPUT) { ret = gpiod_direction_input(desc); if (ret) goto out_free_lh; } blocking_notifier_call_chain(&desc->gdev->notifier, GPIO_V2_LINE_CHANGED_REQUESTED, desc); dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", offset); } fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); if (fd < 0) { ret = fd; goto out_free_lh; } file = anon_inode_getfile("gpio-linehandle", &linehandle_fileops, lh, O_RDONLY | O_CLOEXEC); if (IS_ERR(file)) { ret = PTR_ERR(file); goto out_put_unused_fd; } handlereq.fd = fd; if (copy_to_user(ip, &handlereq, sizeof(handlereq))) { /* * fput() will trigger the release() callback, so do not go onto * the regular error cleanup path here. */ fput(file); put_unused_fd(fd); return -EFAULT; } fd_install(fd, file); dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", lh->num_descs); return 0; out_put_unused_fd: put_unused_fd(fd); out_free_lh: linehandle_free(lh); return ret; } #endif /* CONFIG_GPIO_CDEV_V1 */ /** * struct line - contains the state of a requested line * @desc: the GPIO descriptor for this line. * @req: the corresponding line request * @irq: the interrupt triggered in response to events on this GPIO * @edflags: the edge flags, GPIO_V2_LINE_FLAG_EDGE_RISING and/or * GPIO_V2_LINE_FLAG_EDGE_FALLING, indicating the edge detection applied * @timestamp_ns: cache for the timestamp storing it between hardirq and * IRQ thread, used to bring the timestamp close to the actual event * @req_seqno: the seqno for the current edge event in the sequence of * events for the corresponding line request. This is drawn from the @req. * @line_seqno: the seqno for the current edge event in the sequence of * events for this line. * @work: the worker that implements software debouncing * @sw_debounced: flag indicating if the software debouncer is active * @level: the current debounced physical level of the line * @hdesc: the Hardware Timestamp Engine (HTE) descriptor * @raw_level: the line level at the time of event * @total_discard_seq: the running counter of the discarded events * @last_seqno: the last sequence number before debounce period expires */ struct line { struct gpio_desc *desc; /* * -- edge detector specific fields -- */ struct linereq *req; unsigned int irq; /* * The flags for the active edge detector configuration. * * edflags is set by linereq_create(), linereq_free(), and * linereq_set_config_unlocked(), which are themselves mutually * exclusive, and is accessed by edge_irq_thread(), * process_hw_ts_thread() and debounce_work_func(), * which can all live with a slightly stale value. */ u64 edflags; /* * timestamp_ns and req_seqno are accessed only by * edge_irq_handler() and edge_irq_thread(), which are themselves * mutually exclusive, so no additional protection is necessary. */ u64 timestamp_ns; u32 req_seqno; /* * line_seqno is accessed by either edge_irq_thread() or * debounce_work_func(), which are themselves mutually exclusive, * so no additional protection is necessary. */ u32 line_seqno; /* * -- debouncer specific fields -- */ struct delayed_work work; /* * sw_debounce is accessed by linereq_set_config(), which is the * only setter, and linereq_get_values(), which can live with a * slightly stale value. */ unsigned int sw_debounced; /* * level is accessed by debounce_work_func(), which is the only * setter, and linereq_get_values() which can live with a slightly * stale value. */ unsigned int level; #ifdef CONFIG_HTE struct hte_ts_desc hdesc; /* * HTE provider sets line level at the time of event. The valid * value is 0 or 1 and negative value for an error. */ int raw_level; /* * when sw_debounce is set on HTE enabled line, this is running * counter of the discarded events. */ u32 total_discard_seq; /* * when sw_debounce is set on HTE enabled line, this variable records * last sequence number before debounce period expires. */ u32 last_seqno; #endif /* CONFIG_HTE */ }; /** * struct linereq - contains the state of a userspace line request * @gdev: the GPIO device the line request pertains to * @label: consumer label used to tag GPIO descriptors * @num_lines: the number of lines in the lines array * @wait: wait queue that handles blocking reads of events * @event_buffer_size: the number of elements allocated in @events * @events: KFIFO for the GPIO events * @seqno: the sequence number for edge events generated on all lines in * this line request. Note that this is not used when @num_lines is 1, as * the line_seqno is then the same and is cheaper to calculate. * @config_mutex: mutex for serializing ioctl() calls to ensure consistency * of configuration, particularly multi-step accesses to desc flags. * @lines: the lines held by this line request, with @num_lines elements. */ struct linereq { struct gpio_device *gdev; const char *label; u32 num_lines; wait_queue_head_t wait; u32 event_buffer_size; DECLARE_KFIFO_PTR(events, struct gpio_v2_line_event); atomic_t seqno; struct mutex config_mutex; struct line lines[]; }; #define GPIO_V2_LINE_BIAS_FLAGS \ (GPIO_V2_LINE_FLAG_BIAS_PULL_UP | \ GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | \ GPIO_V2_LINE_FLAG_BIAS_DISABLED) #define GPIO_V2_LINE_DIRECTION_FLAGS \ (GPIO_V2_LINE_FLAG_INPUT | \ GPIO_V2_LINE_FLAG_OUTPUT) #define GPIO_V2_LINE_DRIVE_FLAGS \ (GPIO_V2_LINE_FLAG_OPEN_DRAIN | \ GPIO_V2_LINE_FLAG_OPEN_SOURCE) #define GPIO_V2_LINE_EDGE_FLAGS \ (GPIO_V2_LINE_FLAG_EDGE_RISING | \ GPIO_V2_LINE_FLAG_EDGE_FALLING) #define GPIO_V2_LINE_FLAG_EDGE_BOTH GPIO_V2_LINE_EDGE_FLAGS #define GPIO_V2_LINE_VALID_FLAGS \ (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ GPIO_V2_LINE_DIRECTION_FLAGS | \ GPIO_V2_LINE_DRIVE_FLAGS | \ GPIO_V2_LINE_EDGE_FLAGS | \ GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME | \ GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ GPIO_V2_LINE_BIAS_FLAGS) /* subset of flags relevant for edge detector configuration */ #define GPIO_V2_LINE_EDGE_DETECTOR_FLAGS \ (GPIO_V2_LINE_FLAG_ACTIVE_LOW | \ GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE | \ GPIO_V2_LINE_EDGE_FLAGS) static void linereq_put_event(struct linereq *lr, struct gpio_v2_line_event *le) { bool overflow = false; spin_lock(&lr->wait.lock); if (kfifo_is_full(&lr->events)) { overflow = true; kfifo_skip(&lr->events); } kfifo_in(&lr->events, le, 1); spin_unlock(&lr->wait.lock); if (!overflow) wake_up_poll(&lr->wait, EPOLLIN); else pr_debug_ratelimited("event FIFO is full - event dropped\n"); } static u64 line_event_timestamp(struct line *line) { if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &line->desc->flags)) return ktime_get_real_ns(); else if (IS_ENABLED(CONFIG_HTE) && test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags)) return line->timestamp_ns; return ktime_get_ns(); } static u32 line_event_id(int level) { return level ? GPIO_V2_LINE_EVENT_RISING_EDGE : GPIO_V2_LINE_EVENT_FALLING_EDGE; } #ifdef CONFIG_HTE static enum hte_return process_hw_ts_thread(void *p) { struct line *line; struct linereq *lr; struct gpio_v2_line_event le; u64 edflags; int level; if (!p) return HTE_CB_HANDLED; line = p; lr = line->req; memset(&le, 0, sizeof(le)); le.timestamp_ns = line->timestamp_ns; edflags = READ_ONCE(line->edflags); switch (edflags & GPIO_V2_LINE_EDGE_FLAGS) { case GPIO_V2_LINE_FLAG_EDGE_BOTH: level = (line->raw_level >= 0) ? line->raw_level : gpiod_get_raw_value_cansleep(line->desc); if (edflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) level = !level; le.id = line_event_id(level); break; case GPIO_V2_LINE_FLAG_EDGE_RISING: le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; break; case GPIO_V2_LINE_FLAG_EDGE_FALLING: le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; break; default: return HTE_CB_HANDLED; } le.line_seqno = line->line_seqno; le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; le.offset = gpio_chip_hwgpio(line->desc); linereq_put_event(lr, &le); return HTE_CB_HANDLED; } static enum hte_return process_hw_ts(struct hte_ts_data *ts, void *p) { struct line *line; struct linereq *lr; int diff_seqno = 0; if (!ts || !p) return HTE_CB_HANDLED; line = p; line->timestamp_ns = ts->tsc; line->raw_level = ts->raw_level; lr = line->req; if (READ_ONCE(line->sw_debounced)) { line->total_discard_seq++; line->last_seqno = ts->seq; mod_delayed_work(system_wq, &line->work, usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); } else { if (unlikely(ts->seq < line->line_seqno)) return HTE_CB_HANDLED; diff_seqno = ts->seq - line->line_seqno; line->line_seqno = ts->seq; if (lr->num_lines != 1) line->req_seqno = atomic_add_return(diff_seqno, &lr->seqno); return HTE_RUN_SECOND_CB; } return HTE_CB_HANDLED; } static int hte_edge_setup(struct line *line, u64 eflags) { int ret; unsigned long flags = 0; struct hte_ts_desc *hdesc = &line->hdesc; if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? HTE_FALLING_EDGE_TS : HTE_RISING_EDGE_TS; if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) flags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? HTE_RISING_EDGE_TS : HTE_FALLING_EDGE_TS; line->total_discard_seq = 0; hte_init_line_attr(hdesc, desc_to_gpio(line->desc), flags, NULL, line->desc); ret = hte_ts_get(NULL, hdesc, 0); if (ret) return ret; return hte_request_ts_ns(hdesc, process_hw_ts, process_hw_ts_thread, line); } #else static int hte_edge_setup(struct line *line, u64 eflags) { return 0; } #endif /* CONFIG_HTE */ static irqreturn_t edge_irq_thread(int irq, void *p) { struct line *line = p; struct linereq *lr = line->req; struct gpio_v2_line_event le; /* Do not leak kernel stack to userspace */ memset(&le, 0, sizeof(le)); if (line->timestamp_ns) { le.timestamp_ns = line->timestamp_ns; } else { /* * We may be running from a nested threaded interrupt in * which case we didn't get the timestamp from * edge_irq_handler(). */ le.timestamp_ns = line_event_timestamp(line); if (lr->num_lines != 1) line->req_seqno = atomic_inc_return(&lr->seqno); } line->timestamp_ns = 0; switch (READ_ONCE(line->edflags) & GPIO_V2_LINE_EDGE_FLAGS) { case GPIO_V2_LINE_FLAG_EDGE_BOTH: le.id = line_event_id(gpiod_get_value_cansleep(line->desc)); break; case GPIO_V2_LINE_FLAG_EDGE_RISING: le.id = GPIO_V2_LINE_EVENT_RISING_EDGE; break; case GPIO_V2_LINE_FLAG_EDGE_FALLING: le.id = GPIO_V2_LINE_EVENT_FALLING_EDGE; break; default: return IRQ_NONE; } line->line_seqno++; le.line_seqno = line->line_seqno; le.seqno = (lr->num_lines == 1) ? le.line_seqno : line->req_seqno; le.offset = gpio_chip_hwgpio(line->desc); linereq_put_event(lr, &le); return IRQ_HANDLED; } static irqreturn_t edge_irq_handler(int irq, void *p) { struct line *line = p; struct linereq *lr = line->req; /* * Just store the timestamp in hardirq context so we get it as * close in time as possible to the actual event. */ line->timestamp_ns = line_event_timestamp(line); if (lr->num_lines != 1) line->req_seqno = atomic_inc_return(&lr->seqno); return IRQ_WAKE_THREAD; } /* * returns the current debounced logical value. */ static bool debounced_value(struct line *line) { bool value; /* * minor race - debouncer may be stopped here, so edge_detector_stop() * must leave the value unchanged so the following will read the level * from when the debouncer was last running. */ value = READ_ONCE(line->level); if (test_bit(FLAG_ACTIVE_LOW, &line->desc->flags)) value = !value; return value; } static irqreturn_t debounce_irq_handler(int irq, void *p) { struct line *line = p; mod_delayed_work(system_wq, &line->work, usecs_to_jiffies(READ_ONCE(line->desc->debounce_period_us))); return IRQ_HANDLED; } static void debounce_work_func(struct work_struct *work) { struct gpio_v2_line_event le; struct line *line = container_of(work, struct line, work.work); struct linereq *lr; u64 eflags, edflags = READ_ONCE(line->edflags); int level = -1; #ifdef CONFIG_HTE int diff_seqno; if (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) level = line->raw_level; #endif if (level < 0) level = gpiod_get_raw_value_cansleep(line->desc); if (level < 0) { pr_debug_ratelimited("debouncer failed to read line value\n"); return; } if (READ_ONCE(line->level) == level) return; WRITE_ONCE(line->level, level); /* -- edge detection -- */ eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; if (!eflags) return; /* switch from physical level to logical - if they differ */ if (edflags & GPIO_V2_LINE_FLAG_ACTIVE_LOW) level = !level; /* ignore edges that are not being monitored */ if (((eflags == GPIO_V2_LINE_FLAG_EDGE_RISING) && !level) || ((eflags == GPIO_V2_LINE_FLAG_EDGE_FALLING) && level)) return; /* Do not leak kernel stack to userspace */ memset(&le, 0, sizeof(le)); lr = line->req; le.timestamp_ns = line_event_timestamp(line); le.offset = gpio_chip_hwgpio(line->desc); #ifdef CONFIG_HTE if (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) { /* discard events except the last one */ line->total_discard_seq -= 1; diff_seqno = line->last_seqno - line->total_discard_seq - line->line_seqno; line->line_seqno = line->last_seqno - line->total_discard_seq; le.line_seqno = line->line_seqno; le.seqno = (lr->num_lines == 1) ? le.line_seqno : atomic_add_return(diff_seqno, &lr->seqno); } else #endif /* CONFIG_HTE */ { line->line_seqno++; le.line_seqno = line->line_seqno; le.seqno = (lr->num_lines == 1) ? le.line_seqno : atomic_inc_return(&lr->seqno); } le.id = line_event_id(level); linereq_put_event(lr, &le); } static int debounce_setup(struct line *line, unsigned int debounce_period_us) { unsigned long irqflags; int ret, level, irq; /* try hardware */ ret = gpiod_set_debounce(line->desc, debounce_period_us); if (!ret) { WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); return ret; } if (ret != -ENOTSUPP) return ret; if (debounce_period_us) { /* setup software debounce */ level = gpiod_get_raw_value_cansleep(line->desc); if (level < 0) return level; if (!(IS_ENABLED(CONFIG_HTE) && test_bit(FLAG_EVENT_CLOCK_HTE, &line->desc->flags))) { irq = gpiod_to_irq(line->desc); if (irq < 0) return -ENXIO; irqflags = IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING; ret = request_irq(irq, debounce_irq_handler, irqflags, line->req->label, line); if (ret) return ret; line->irq = irq; } else { ret = hte_edge_setup(line, GPIO_V2_LINE_FLAG_EDGE_BOTH); if (ret) return ret; } WRITE_ONCE(line->level, level); WRITE_ONCE(line->sw_debounced, 1); } return 0; } static bool gpio_v2_line_config_debounced(struct gpio_v2_line_config *lc, unsigned int line_idx) { unsigned int i; u64 mask = BIT_ULL(line_idx); for (i = 0; i < lc->num_attrs; i++) { if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && (lc->attrs[i].mask & mask)) return true; } return false; } static u32 gpio_v2_line_config_debounce_period(struct gpio_v2_line_config *lc, unsigned int line_idx) { unsigned int i; u64 mask = BIT_ULL(line_idx); for (i = 0; i < lc->num_attrs; i++) { if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_DEBOUNCE) && (lc->attrs[i].mask & mask)) return lc->attrs[i].attr.debounce_period_us; } return 0; } static void edge_detector_stop(struct line *line) { if (line->irq) { free_irq(line->irq, line); line->irq = 0; } #ifdef CONFIG_HTE if (READ_ONCE(line->edflags) & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) hte_ts_put(&line->hdesc); #endif cancel_delayed_work_sync(&line->work); WRITE_ONCE(line->sw_debounced, 0); WRITE_ONCE(line->edflags, 0); if (line->desc) WRITE_ONCE(line->desc->debounce_period_us, 0); /* do not change line->level - see comment in debounced_value() */ } static int edge_detector_setup(struct line *line, struct gpio_v2_line_config *lc, unsigned int line_idx, u64 edflags) { u32 debounce_period_us; unsigned long irqflags = 0; u64 eflags; int irq, ret; eflags = edflags & GPIO_V2_LINE_EDGE_FLAGS; if (eflags && !kfifo_initialized(&line->req->events)) { ret = kfifo_alloc(&line->req->events, line->req->event_buffer_size, GFP_KERNEL); if (ret) return ret; } if (gpio_v2_line_config_debounced(lc, line_idx)) { debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); ret = debounce_setup(line, debounce_period_us); if (ret) return ret; WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); } /* detection disabled or sw debouncer will provide edge detection */ if (!eflags || READ_ONCE(line->sw_debounced)) return 0; if (IS_ENABLED(CONFIG_HTE) && (edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) return hte_edge_setup(line, edflags); irq = gpiod_to_irq(line->desc); if (irq < 0) return -ENXIO; if (eflags & GPIO_V2_LINE_FLAG_EDGE_RISING) irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; if (eflags & GPIO_V2_LINE_FLAG_EDGE_FALLING) irqflags |= test_bit(FLAG_ACTIVE_LOW, &line->desc->flags) ? IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; irqflags |= IRQF_ONESHOT; /* Request a thread to read the events */ ret = request_threaded_irq(irq, edge_irq_handler, edge_irq_thread, irqflags, line->req->label, line); if (ret) return ret; line->irq = irq; return 0; } static int edge_detector_update(struct line *line, struct gpio_v2_line_config *lc, unsigned int line_idx, u64 edflags) { u64 active_edflags = READ_ONCE(line->edflags); unsigned int debounce_period_us = gpio_v2_line_config_debounce_period(lc, line_idx); if ((active_edflags == edflags) && (READ_ONCE(line->desc->debounce_period_us) == debounce_period_us)) return 0; /* sw debounced and still will be...*/ if (debounce_period_us && READ_ONCE(line->sw_debounced)) { WRITE_ONCE(line->desc->debounce_period_us, debounce_period_us); return 0; } /* reconfiguring edge detection or sw debounce being disabled */ if ((line->irq && !READ_ONCE(line->sw_debounced)) || (active_edflags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE) || (!debounce_period_us && READ_ONCE(line->sw_debounced))) edge_detector_stop(line); return edge_detector_setup(line, lc, line_idx, edflags); } static u64 gpio_v2_line_config_flags(struct gpio_v2_line_config *lc, unsigned int line_idx) { unsigned int i; u64 mask = BIT_ULL(line_idx); for (i = 0; i < lc->num_attrs; i++) { if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_FLAGS) && (lc->attrs[i].mask & mask)) return lc->attrs[i].attr.flags; } return lc->flags; } static int gpio_v2_line_config_output_value(struct gpio_v2_line_config *lc, unsigned int line_idx) { unsigned int i; u64 mask = BIT_ULL(line_idx); for (i = 0; i < lc->num_attrs; i++) { if ((lc->attrs[i].attr.id == GPIO_V2_LINE_ATTR_ID_OUTPUT_VALUES) && (lc->attrs[i].mask & mask)) return !!(lc->attrs[i].attr.values & mask); } return 0; } static int gpio_v2_line_flags_validate(u64 flags) { /* Return an error if an unknown flag is set */ if (flags & ~GPIO_V2_LINE_VALID_FLAGS) return -EINVAL; if (!IS_ENABLED(CONFIG_HTE) && (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) return -EOPNOTSUPP; /* * Do not allow both INPUT and OUTPUT flags to be set as they are * contradictory. */ if ((flags & GPIO_V2_LINE_FLAG_INPUT) && (flags & GPIO_V2_LINE_FLAG_OUTPUT)) return -EINVAL; /* Only allow one event clock source */ if (IS_ENABLED(CONFIG_HTE) && (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME) && (flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE)) return -EINVAL; /* Edge detection requires explicit input. */ if ((flags & GPIO_V2_LINE_EDGE_FLAGS) && !(flags & GPIO_V2_LINE_FLAG_INPUT)) return -EINVAL; /* * Do not allow OPEN_SOURCE and OPEN_DRAIN flags in a single * request. If the hardware actually supports enabling both at the * same time the electrical result would be disastrous. */ if ((flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN) && (flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE)) return -EINVAL; /* Drive requires explicit output direction. */ if ((flags & GPIO_V2_LINE_DRIVE_FLAGS) && !(flags & GPIO_V2_LINE_FLAG_OUTPUT)) return -EINVAL; /* Bias requires explicit direction. */ if ((flags & GPIO_V2_LINE_BIAS_FLAGS) && !(flags & GPIO_V2_LINE_DIRECTION_FLAGS)) return -EINVAL; /* Only one bias flag can be set. */ if (((flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED) && (flags & (GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN | GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) || ((flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) && (flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP))) return -EINVAL; return 0; } static int gpio_v2_line_config_validate(struct gpio_v2_line_config *lc, unsigned int num_lines) { unsigned int i; u64 flags; int ret; if (lc->num_attrs > GPIO_V2_LINE_NUM_ATTRS_MAX) return -EINVAL; if (memchr_inv(lc->padding, 0, sizeof(lc->padding))) return -EINVAL; for (i = 0; i < num_lines; i++) { flags = gpio_v2_line_config_flags(lc, i); ret = gpio_v2_line_flags_validate(flags); if (ret) return ret; /* debounce requires explicit input */ if (gpio_v2_line_config_debounced(lc, i) && !(flags & GPIO_V2_LINE_FLAG_INPUT)) return -EINVAL; } return 0; } static void gpio_v2_line_config_flags_to_desc_flags(u64 flags, unsigned long *flagsp) { assign_bit(FLAG_ACTIVE_LOW, flagsp, flags & GPIO_V2_LINE_FLAG_ACTIVE_LOW); if (flags & GPIO_V2_LINE_FLAG_OUTPUT) set_bit(FLAG_IS_OUT, flagsp); else if (flags & GPIO_V2_LINE_FLAG_INPUT) clear_bit(FLAG_IS_OUT, flagsp); assign_bit(FLAG_EDGE_RISING, flagsp, flags & GPIO_V2_LINE_FLAG_EDGE_RISING); assign_bit(FLAG_EDGE_FALLING, flagsp, flags & GPIO_V2_LINE_FLAG_EDGE_FALLING); assign_bit(FLAG_OPEN_DRAIN, flagsp, flags & GPIO_V2_LINE_FLAG_OPEN_DRAIN); assign_bit(FLAG_OPEN_SOURCE, flagsp, flags & GPIO_V2_LINE_FLAG_OPEN_SOURCE); assign_bit(FLAG_PULL_UP, flagsp, flags & GPIO_V2_LINE_FLAG_BIAS_PULL_UP); assign_bit(FLAG_PULL_DOWN, flagsp, flags & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN); assign_bit(FLAG_BIAS_DISABLE, flagsp, flags & GPIO_V2_LINE_FLAG_BIAS_DISABLED); assign_bit(FLAG_EVENT_CLOCK_REALTIME, flagsp, flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME); assign_bit(FLAG_EVENT_CLOCK_HTE, flagsp, flags & GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE); } static long linereq_get_values(struct linereq *lr, void __user *ip) { struct gpio_v2_line_values lv; DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); struct gpio_desc **descs; unsigned int i, didx, num_get; bool val; int ret; /* NOTE: It's ok to read values of output lines. */ if (copy_from_user(&lv, ip, sizeof(lv))) return -EFAULT; for (num_get = 0, i = 0; i < lr->num_lines; i++) { if (lv.mask & BIT_ULL(i)) { num_get++; descs = &lr->lines[i].desc; } } if (num_get == 0) return -EINVAL; if (num_get != 1) { descs = kmalloc_array(num_get, sizeof(*descs), GFP_KERNEL); if (!descs) return -ENOMEM; for (didx = 0, i = 0; i < lr->num_lines; i++) { if (lv.mask & BIT_ULL(i)) { descs[didx] = lr->lines[i].desc; didx++; } } } ret = gpiod_get_array_value_complex(false, true, num_get, descs, NULL, vals); if (num_get != 1) kfree(descs); if (ret) return ret; lv.bits = 0; for (didx = 0, i = 0; i < lr->num_lines; i++) { if (lv.mask & BIT_ULL(i)) { if (lr->lines[i].sw_debounced) val = debounced_value(&lr->lines[i]); else val = test_bit(didx, vals); if (val) lv.bits |= BIT_ULL(i); didx++; } } if (copy_to_user(ip, &lv, sizeof(lv))) return -EFAULT; return 0; } static long linereq_set_values_unlocked(struct linereq *lr, struct gpio_v2_line_values *lv) { DECLARE_BITMAP(vals, GPIO_V2_LINES_MAX); struct gpio_desc **descs; unsigned int i, didx, num_set; int ret; bitmap_zero(vals, GPIO_V2_LINES_MAX); for (num_set = 0, i = 0; i < lr->num_lines; i++) { if (lv->mask & BIT_ULL(i)) { if (!test_bit(FLAG_IS_OUT, &lr->lines[i].desc->flags)) return -EPERM; if (lv->bits & BIT_ULL(i)) __set_bit(num_set, vals); num_set++; descs = &lr->lines[i].desc; } } if (num_set == 0) return -EINVAL; if (num_set != 1) { /* build compacted desc array and values */ descs = kmalloc_array(num_set, sizeof(*descs), GFP_KERNEL); if (!descs) return -ENOMEM; for (didx = 0, i = 0; i < lr->num_lines; i++) { if (lv->mask & BIT_ULL(i)) { descs[didx] = lr->lines[i].desc; didx++; } } } ret = gpiod_set_array_value_complex(false, true, num_set, descs, NULL, vals); if (num_set != 1) kfree(descs); return ret; } static long linereq_set_values(struct linereq *lr, void __user *ip) { struct gpio_v2_line_values lv; int ret; if (copy_from_user(&lv, ip, sizeof(lv))) return -EFAULT; mutex_lock(&lr->config_mutex); ret = linereq_set_values_unlocked(lr, &lv); mutex_unlock(&lr->config_mutex); return ret; } static long linereq_set_config_unlocked(struct linereq *lr, struct gpio_v2_line_config *lc) { struct gpio_desc *desc; struct line *line; unsigned int i; u64 flags, edflags; int ret; for (i = 0; i < lr->num_lines; i++) { line = &lr->lines[i]; desc = lr->lines[i].desc; flags = gpio_v2_line_config_flags(lc, i); gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS; /* * Lines have to be requested explicitly for input * or output, else the line will be treated "as is". */ if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { int val = gpio_v2_line_config_output_value(lc, i); edge_detector_stop(line); ret = gpiod_direction_output(desc, val); if (ret) return ret; } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { ret = gpiod_direction_input(desc); if (ret) return ret; ret = edge_detector_update(line, lc, i, edflags); if (ret) return ret; } WRITE_ONCE(line->edflags, edflags); blocking_notifier_call_chain(&desc->gdev->notifier, GPIO_V2_LINE_CHANGED_CONFIG, desc); } return 0; } static long linereq_set_config(struct linereq *lr, void __user *ip) { struct gpio_v2_line_config lc; int ret; if (copy_from_user(&lc, ip, sizeof(lc))) return -EFAULT; ret = gpio_v2_line_config_validate(&lc, lr->num_lines); if (ret) return ret; mutex_lock(&lr->config_mutex); ret = linereq_set_config_unlocked(lr, &lc); mutex_unlock(&lr->config_mutex); return ret; } static long linereq_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned long arg) { struct linereq *lr = file->private_data; void __user *ip = (void __user *)arg; if (!lr->gdev->chip) return -ENODEV; switch (cmd) { case GPIO_V2_LINE_GET_VALUES_IOCTL: return linereq_get_values(lr, ip); case GPIO_V2_LINE_SET_VALUES_IOCTL: return linereq_set_values(lr, ip); case GPIO_V2_LINE_SET_CONFIG_IOCTL: return linereq_set_config(lr, ip); default: return -EINVAL; } } static long linereq_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct linereq *lr = file->private_data; return call_ioctl_locked(file, cmd, arg, lr->gdev, linereq_ioctl_unlocked); } #ifdef CONFIG_COMPAT static long linereq_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) { return linereq_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); } #endif static __poll_t linereq_poll_unlocked(struct file *file, struct poll_table_struct *wait) { struct linereq *lr = file->private_data; __poll_t events = 0; if (!lr->gdev->chip) return EPOLLHUP | EPOLLERR; poll_wait(file, &lr->wait, wait); if (!kfifo_is_empty_spinlocked_noirqsave(&lr->events, &lr->wait.lock)) events = EPOLLIN | EPOLLRDNORM; return events; } static __poll_t linereq_poll(struct file *file, struct poll_table_struct *wait) { struct linereq *lr = file->private_data; return call_poll_locked(file, wait, lr->gdev, linereq_poll_unlocked); } static ssize_t linereq_read_unlocked(struct file *file, char __user *buf, size_t count, loff_t *f_ps) { struct linereq *lr = file->private_data; struct gpio_v2_line_event le; ssize_t bytes_read = 0; int ret; if (!lr->gdev->chip) return -ENODEV; if (count < sizeof(le)) return -EINVAL; do { spin_lock(&lr->wait.lock); if (kfifo_is_empty(&lr->events)) { if (bytes_read) { spin_unlock(&lr->wait.lock); return bytes_read; } if (file->f_flags & O_NONBLOCK) { spin_unlock(&lr->wait.lock); return -EAGAIN; } ret = wait_event_interruptible_locked(lr->wait, !kfifo_is_empty(&lr->events)); if (ret) { spin_unlock(&lr->wait.lock); return ret; } } ret = kfifo_out(&lr->events, &le, 1); spin_unlock(&lr->wait.lock); if (ret != 1) { /* * This should never happen - we were holding the * lock from the moment we learned the fifo is no * longer empty until now. */ ret = -EIO; break; } if (copy_to_user(buf + bytes_read, &le, sizeof(le))) return -EFAULT; bytes_read += sizeof(le); } while (count >= bytes_read + sizeof(le)); return bytes_read; } static ssize_t linereq_read(struct file *file, char __user *buf, size_t count, loff_t *f_ps) { struct linereq *lr = file->private_data; return call_read_locked(file, buf, count, f_ps, lr->gdev, linereq_read_unlocked); } static void linereq_free(struct linereq *lr) { unsigned int i; for (i = 0; i < lr->num_lines; i++) { if (lr->lines[i].desc) { edge_detector_stop(&lr->lines[i]); gpiod_free(lr->lines[i].desc); } } kfifo_free(&lr->events); kfree(lr->label); put_device(&lr->gdev->dev); kfree(lr); } static int linereq_release(struct inode *inode, struct file *file) { struct linereq *lr = file->private_data; linereq_free(lr); return 0; } #ifdef CONFIG_PROC_FS static void linereq_show_fdinfo(struct seq_file *out, struct file *file) { struct linereq *lr = file->private_data; struct device *dev = &lr->gdev->dev; u16 i; seq_printf(out, "gpio-chip:\t%s\n", dev_name(dev)); for (i = 0; i < lr->num_lines; i++) seq_printf(out, "gpio-line:\t%d\n", gpio_chip_hwgpio(lr->lines[i].desc)); } #endif static const struct file_operations line_fileops = { .release = linereq_release, .read = linereq_read, .poll = linereq_poll, .owner = THIS_MODULE, .llseek = noop_llseek, .unlocked_ioctl = linereq_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = linereq_ioctl_compat, #endif #ifdef CONFIG_PROC_FS .show_fdinfo = linereq_show_fdinfo, #endif }; static int linereq_create(struct gpio_device *gdev, void __user *ip) { struct gpio_v2_line_request ulr; struct gpio_v2_line_config *lc; struct linereq *lr; struct file *file; u64 flags, edflags; unsigned int i; int fd, ret; if (copy_from_user(&ulr, ip, sizeof(ulr))) return -EFAULT; if ((ulr.num_lines == 0) || (ulr.num_lines > GPIO_V2_LINES_MAX)) return -EINVAL; if (memchr_inv(ulr.padding, 0, sizeof(ulr.padding))) return -EINVAL; lc = &ulr.config; ret = gpio_v2_line_config_validate(lc, ulr.num_lines); if (ret) return ret; lr = kzalloc(struct_size(lr, lines, ulr.num_lines), GFP_KERNEL); if (!lr) return -ENOMEM; lr->gdev = gdev; get_device(&gdev->dev); for (i = 0; i < ulr.num_lines; i++) { lr->lines[i].req = lr; WRITE_ONCE(lr->lines[i].sw_debounced, 0); INIT_DELAYED_WORK(&lr->lines[i].work, debounce_work_func); } if (ulr.consumer[0] != '\0') { /* label is only initialized if consumer is set */ lr->label = kstrndup(ulr.consumer, sizeof(ulr.consumer) - 1, GFP_KERNEL); if (!lr->label) { ret = -ENOMEM; goto out_free_linereq; } } mutex_init(&lr->config_mutex); init_waitqueue_head(&lr->wait); lr->event_buffer_size = ulr.event_buffer_size; if (lr->event_buffer_size == 0) lr->event_buffer_size = ulr.num_lines * 16; else if (lr->event_buffer_size > GPIO_V2_LINES_MAX * 16) lr->event_buffer_size = GPIO_V2_LINES_MAX * 16; atomic_set(&lr->seqno, 0); lr->num_lines = ulr.num_lines; /* Request each GPIO */ for (i = 0; i < ulr.num_lines; i++) { u32 offset = ulr.offsets[i]; struct gpio_desc *desc = gpiochip_get_desc(gdev->chip, offset); if (IS_ERR(desc)) { ret = PTR_ERR(desc); goto out_free_linereq; } ret = gpiod_request_user(desc, lr->label); if (ret) goto out_free_linereq; lr->lines[i].desc = desc; flags = gpio_v2_line_config_flags(lc, i); gpio_v2_line_config_flags_to_desc_flags(flags, &desc->flags); ret = gpiod_set_transitory(desc, false); if (ret < 0) goto out_free_linereq; edflags = flags & GPIO_V2_LINE_EDGE_DETECTOR_FLAGS; /* * Lines have to be requested explicitly for input * or output, else the line will be treated "as is". */ if (flags & GPIO_V2_LINE_FLAG_OUTPUT) { int val = gpio_v2_line_config_output_value(lc, i); ret = gpiod_direction_output(desc, val); if (ret) goto out_free_linereq; } else if (flags & GPIO_V2_LINE_FLAG_INPUT) { ret = gpiod_direction_input(desc); if (ret) goto out_free_linereq; ret = edge_detector_setup(&lr->lines[i], lc, i, edflags); if (ret) goto out_free_linereq; } lr->lines[i].edflags = edflags; blocking_notifier_call_chain(&desc->gdev->notifier, GPIO_V2_LINE_CHANGED_REQUESTED, desc); dev_dbg(&gdev->dev, "registered chardev handle for line %d\n", offset); } fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); if (fd < 0) { ret = fd; goto out_free_linereq; } file = anon_inode_getfile("gpio-line", &line_fileops, lr, O_RDONLY | O_CLOEXEC); if (IS_ERR(file)) { ret = PTR_ERR(file); goto out_put_unused_fd; } ulr.fd = fd; if (copy_to_user(ip, &ulr, sizeof(ulr))) { /* * fput() will trigger the release() callback, so do not go onto * the regular error cleanup path here. */ fput(file); put_unused_fd(fd); return -EFAULT; } fd_install(fd, file); dev_dbg(&gdev->dev, "registered chardev handle for %d lines\n", lr->num_lines); return 0; out_put_unused_fd: put_unused_fd(fd); out_free_linereq: linereq_free(lr); return ret; } #ifdef CONFIG_GPIO_CDEV_V1 /* * GPIO line event management */ /** * struct lineevent_state - contains the state of a userspace event * @gdev: the GPIO device the event pertains to * @label: consumer label used to tag descriptors * @desc: the GPIO descriptor held by this event * @eflags: the event flags this line was requested with * @irq: the interrupt that trigger in response to events on this GPIO * @wait: wait queue that handles blocking reads of events * @events: KFIFO for the GPIO events * @timestamp: cache for the timestamp storing it between hardirq * and IRQ thread, used to bring the timestamp close to the actual * event */ struct lineevent_state { struct gpio_device *gdev; const char *label; struct gpio_desc *desc; u32 eflags; int irq; wait_queue_head_t wait; DECLARE_KFIFO(events, struct gpioevent_data, 16); u64 timestamp; }; #define GPIOEVENT_REQUEST_VALID_FLAGS \ (GPIOEVENT_REQUEST_RISING_EDGE | \ GPIOEVENT_REQUEST_FALLING_EDGE) static __poll_t lineevent_poll_unlocked(struct file *file, struct poll_table_struct *wait) { struct lineevent_state *le = file->private_data; __poll_t events = 0; if (!le->gdev->chip) return EPOLLHUP | EPOLLERR; poll_wait(file, &le->wait, wait); if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock)) events = EPOLLIN | EPOLLRDNORM; return events; } static __poll_t lineevent_poll(struct file *file, struct poll_table_struct *wait) { struct lineevent_state *le = file->private_data; return call_poll_locked(file, wait, le->gdev, lineevent_poll_unlocked); } struct compat_gpioeevent_data { compat_u64 timestamp; u32 id; }; static ssize_t lineevent_read_unlocked(struct file *file, char __user *buf, size_t count, loff_t *f_ps) { struct lineevent_state *le = file->private_data; struct gpioevent_data ge; ssize_t bytes_read = 0; ssize_t ge_size; int ret; if (!le->gdev->chip) return -ENODEV; /* * When compatible system call is being used the struct gpioevent_data, * in case of at least ia32, has different size due to the alignment * differences. Because we have first member 64 bits followed by one of * 32 bits there is no gap between them. The only difference is the * padding at the end of the data structure. Hence, we calculate the * actual sizeof() and pass this as an argument to copy_to_user() to * drop unneeded bytes from the output. */ if (compat_need_64bit_alignment_fixup()) ge_size = sizeof(struct compat_gpioeevent_data); else ge_size = sizeof(struct gpioevent_data); if (count < ge_size) return -EINVAL; do { spin_lock(&le->wait.lock); if (kfifo_is_empty(&le->events)) { if (bytes_read) { spin_unlock(&le->wait.lock); return bytes_read; } if (file->f_flags & O_NONBLOCK) { spin_unlock(&le->wait.lock); return -EAGAIN; } ret = wait_event_interruptible_locked(le->wait, !kfifo_is_empty(&le->events)); if (ret) { spin_unlock(&le->wait.lock); return ret; } } ret = kfifo_out(&le->events, &ge, 1); spin_unlock(&le->wait.lock); if (ret != 1) { /* * This should never happen - we were holding the lock * from the moment we learned the fifo is no longer * empty until now. */ ret = -EIO; break; } if (copy_to_user(buf + bytes_read, &ge, ge_size)) return -EFAULT; bytes_read += ge_size; } while (count >= bytes_read + ge_size); return bytes_read; } static ssize_t lineevent_read(struct file *file, char __user *buf, size_t count, loff_t *f_ps) { struct lineevent_state *le = file->private_data; return call_read_locked(file, buf, count, f_ps, le->gdev, lineevent_read_unlocked); } static void lineevent_free(struct lineevent_state *le) { if (le->irq) free_irq(le->irq, le); if (le->desc) gpiod_free(le->desc); kfree(le->label); put_device(&le->gdev->dev); kfree(le); } static int lineevent_release(struct inode *inode, struct file *file) { lineevent_free(file->private_data); return 0; } static long lineevent_ioctl_unlocked(struct file *file, unsigned int cmd, unsigned long arg) { struct lineevent_state *le = file->private_data; void __user *ip = (void __user *)arg; struct gpiohandle_data ghd; if (!le->gdev->chip) return -ENODEV; /* * We can get the value for an event line but not set it, * because it is input by definition. */ if (cmd == GPIOHANDLE_GET_LINE_VALUES_IOCTL) { int val; memset(&ghd, 0, sizeof(ghd)); val = gpiod_get_value_cansleep(le->desc); if (val < 0) return val; ghd.values[0] = val; if (copy_to_user(ip, &ghd, sizeof(ghd))) return -EFAULT; return 0; } return -EINVAL; } static long lineevent_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct lineevent_state *le = file->private_data; return call_ioctl_locked(file, cmd, arg, le->gdev, lineevent_ioctl_unlocked); } #ifdef CONFIG_COMPAT static long lineevent_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) { return lineevent_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); } #endif static const struct file_operations lineevent_fileops = { .release = lineevent_release, .read = lineevent_read, .poll = lineevent_poll, .owner = THIS_MODULE, .llseek = noop_llseek, .unlocked_ioctl = lineevent_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = lineevent_ioctl_compat, #endif }; static irqreturn_t lineevent_irq_thread(int irq, void *p) { struct lineevent_state *le = p; struct gpioevent_data ge; int ret; /* Do not leak kernel stack to userspace */ memset(&ge, 0, sizeof(ge)); /* * We may be running from a nested threaded interrupt in which case * we didn't get the timestamp from lineevent_irq_handler(). */ if (!le->timestamp) ge.timestamp = ktime_get_ns(); else ge.timestamp = le->timestamp; if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE && le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { int level = gpiod_get_value_cansleep(le->desc); if (level) /* Emit low-to-high event */ ge.id = GPIOEVENT_EVENT_RISING_EDGE; else /* Emit high-to-low event */ ge.id = GPIOEVENT_EVENT_FALLING_EDGE; } else if (le->eflags & GPIOEVENT_REQUEST_RISING_EDGE) { /* Emit low-to-high event */ ge.id = GPIOEVENT_EVENT_RISING_EDGE; } else if (le->eflags & GPIOEVENT_REQUEST_FALLING_EDGE) { /* Emit high-to-low event */ ge.id = GPIOEVENT_EVENT_FALLING_EDGE; } else { return IRQ_NONE; } ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge, 1, &le->wait.lock); if (ret) wake_up_poll(&le->wait, EPOLLIN); else pr_debug_ratelimited("event FIFO is full - event dropped\n"); return IRQ_HANDLED; } static irqreturn_t lineevent_irq_handler(int irq, void *p) { struct lineevent_state *le = p; /* * Just store the timestamp in hardirq context so we get it as * close in time as possible to the actual event. */ le->timestamp = ktime_get_ns(); return IRQ_WAKE_THREAD; } static int lineevent_create(struct gpio_device *gdev, void __user *ip) { struct gpioevent_request eventreq; struct lineevent_state *le; struct gpio_desc *desc; struct file *file; u32 offset; u32 lflags; u32 eflags; int fd; int ret; int irq, irqflags = 0; if (copy_from_user(&eventreq, ip, sizeof(eventreq))) return -EFAULT; offset = eventreq.lineoffset; lflags = eventreq.handleflags; eflags = eventreq.eventflags; desc = gpiochip_get_desc(gdev->chip, offset); if (IS_ERR(desc)) return PTR_ERR(desc); /* Return an error if a unknown flag is set */ if ((lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS) || (eflags & ~GPIOEVENT_REQUEST_VALID_FLAGS)) return -EINVAL; /* This is just wrong: we don't look for events on output lines */ if ((lflags & GPIOHANDLE_REQUEST_OUTPUT) || (lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) || (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)) return -EINVAL; /* Only one bias flag can be set. */ if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) && (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN | GPIOHANDLE_REQUEST_BIAS_PULL_UP))) || ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) && (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP))) return -EINVAL; le = kzalloc(sizeof(*le), GFP_KERNEL); if (!le) return -ENOMEM; le->gdev = gdev; get_device(&gdev->dev); if (eventreq.consumer_label[0] != '\0') { /* label is only initialized if consumer_label is set */ le->label = kstrndup(eventreq.consumer_label, sizeof(eventreq.consumer_label) - 1, GFP_KERNEL); if (!le->label) { ret = -ENOMEM; goto out_free_le; } } ret = gpiod_request_user(desc, le->label); if (ret) goto out_free_le; le->desc = desc; le->eflags = eflags; linehandle_flags_to_desc_flags(lflags, &desc->flags); ret = gpiod_direction_input(desc); if (ret) goto out_free_le; blocking_notifier_call_chain(&desc->gdev->notifier, GPIO_V2_LINE_CHANGED_REQUESTED, desc); irq = gpiod_to_irq(desc); if (irq <= 0) { ret = -ENODEV; goto out_free_le; } if (eflags & GPIOEVENT_REQUEST_RISING_EDGE) irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING; if (eflags & GPIOEVENT_REQUEST_FALLING_EDGE) irqflags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ? IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING; irqflags |= IRQF_ONESHOT; INIT_KFIFO(le->events); init_waitqueue_head(&le->wait); /* Request a thread to read the events */ ret = request_threaded_irq(irq, lineevent_irq_handler, lineevent_irq_thread, irqflags, le->label, le); if (ret) goto out_free_le; le->irq = irq; fd = get_unused_fd_flags(O_RDONLY | O_CLOEXEC); if (fd < 0) { ret = fd; goto out_free_le; } file = anon_inode_getfile("gpio-event", &lineevent_fileops, le, O_RDONLY | O_CLOEXEC); if (IS_ERR(file)) { ret = PTR_ERR(file); goto out_put_unused_fd; } eventreq.fd = fd; if (copy_to_user(ip, &eventreq, sizeof(eventreq))) { /* * fput() will trigger the release() callback, so do not go onto * the regular error cleanup path here. */ fput(file); put_unused_fd(fd); return -EFAULT; } fd_install(fd, file); return 0; out_put_unused_fd: put_unused_fd(fd); out_free_le: lineevent_free(le); return ret; } static void gpio_v2_line_info_to_v1(struct gpio_v2_line_info *info_v2, struct gpioline_info *info_v1) { u64 flagsv2 = info_v2->flags; memcpy(info_v1->name, info_v2->name, sizeof(info_v1->name)); memcpy(info_v1->consumer, info_v2->consumer, sizeof(info_v1->consumer)); info_v1->line_offset = info_v2->offset; info_v1->flags = 0; if (flagsv2 & GPIO_V2_LINE_FLAG_USED) info_v1->flags |= GPIOLINE_FLAG_KERNEL; if (flagsv2 & GPIO_V2_LINE_FLAG_OUTPUT) info_v1->flags |= GPIOLINE_FLAG_IS_OUT; if (flagsv2 & GPIO_V2_LINE_FLAG_ACTIVE_LOW) info_v1->flags |= GPIOLINE_FLAG_ACTIVE_LOW; if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_DRAIN) info_v1->flags |= GPIOLINE_FLAG_OPEN_DRAIN; if (flagsv2 & GPIO_V2_LINE_FLAG_OPEN_SOURCE) info_v1->flags |= GPIOLINE_FLAG_OPEN_SOURCE; if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_UP) info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_UP; if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN) info_v1->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN; if (flagsv2 & GPIO_V2_LINE_FLAG_BIAS_DISABLED) info_v1->flags |= GPIOLINE_FLAG_BIAS_DISABLE; } static void gpio_v2_line_info_changed_to_v1( struct gpio_v2_line_info_changed *lic_v2, struct gpioline_info_changed *lic_v1) { memset(lic_v1, 0, sizeof(*lic_v1)); gpio_v2_line_info_to_v1(&lic_v2->info, &lic_v1->info); lic_v1->timestamp = lic_v2->timestamp_ns; lic_v1->event_type = lic_v2->event_type; } #endif /* CONFIG_GPIO_CDEV_V1 */ static void gpio_desc_to_lineinfo(struct gpio_desc *desc, struct gpio_v2_line_info *info) { struct gpio_chip *gc = desc->gdev->chip; bool ok_for_pinctrl; unsigned long flags; u32 debounce_period_us; unsigned int num_attrs = 0; memset(info, 0, sizeof(*info)); info->offset = gpio_chip_hwgpio(desc); /* * This function takes a mutex so we must check this before taking * the spinlock. * * FIXME: find a non-racy way to retrieve this information. Maybe a * lock common to both frameworks? */ ok_for_pinctrl = pinctrl_gpio_can_use_line(gc->base + info->offset); spin_lock_irqsave(&gpio_lock, flags); if (desc->name) strscpy(info->name, desc->name, sizeof(info->name)); if (desc->label) strscpy(info->consumer, desc->label, sizeof(info->consumer)); /* * Userspace only need to know that the kernel is using this GPIO so * it can't use it. */ info->flags = 0; if (test_bit(FLAG_REQUESTED, &desc->flags) || test_bit(FLAG_IS_HOGGED, &desc->flags) || test_bit(FLAG_USED_AS_IRQ, &desc->flags) || test_bit(FLAG_EXPORT, &desc->flags) || test_bit(FLAG_SYSFS, &desc->flags) || !gpiochip_line_is_valid(gc, info->offset) || !ok_for_pinctrl) info->flags |= GPIO_V2_LINE_FLAG_USED; if (test_bit(FLAG_IS_OUT, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_OUTPUT; else info->flags |= GPIO_V2_LINE_FLAG_INPUT; if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_ACTIVE_LOW; if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_OPEN_DRAIN; if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_OPEN_SOURCE; if (test_bit(FLAG_BIAS_DISABLE, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_BIAS_DISABLED; if (test_bit(FLAG_PULL_DOWN, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_DOWN; if (test_bit(FLAG_PULL_UP, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_BIAS_PULL_UP; if (test_bit(FLAG_EDGE_RISING, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_EDGE_RISING; if (test_bit(FLAG_EDGE_FALLING, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_EDGE_FALLING; if (test_bit(FLAG_EVENT_CLOCK_REALTIME, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_REALTIME; else if (test_bit(FLAG_EVENT_CLOCK_HTE, &desc->flags)) info->flags |= GPIO_V2_LINE_FLAG_EVENT_CLOCK_HTE; debounce_period_us = READ_ONCE(desc->debounce_period_us); if (debounce_period_us) { info->attrs[num_attrs].id = GPIO_V2_LINE_ATTR_ID_DEBOUNCE; info->attrs[num_attrs].debounce_period_us = debounce_period_us; num_attrs++; } info->num_attrs = num_attrs; spin_unlock_irqrestore(&gpio_lock, flags); } struct gpio_chardev_data { struct gpio_device *gdev; wait_queue_head_t wait; DECLARE_KFIFO(events, struct gpio_v2_line_info_changed, 32); struct notifier_block lineinfo_changed_nb; unsigned long *watched_lines; #ifdef CONFIG_GPIO_CDEV_V1 atomic_t watch_abi_version; #endif }; static int chipinfo_get(struct gpio_chardev_data *cdev, void __user *ip) { struct gpio_device *gdev = cdev->gdev; struct gpiochip_info chipinfo; memset(&chipinfo, 0, sizeof(chipinfo)); strscpy(chipinfo.name, dev_name(&gdev->dev), sizeof(chipinfo.name)); strscpy(chipinfo.label, gdev->label, sizeof(chipinfo.label)); chipinfo.lines = gdev->ngpio; if (copy_to_user(ip, &chipinfo, sizeof(chipinfo))) return -EFAULT; return 0; } #ifdef CONFIG_GPIO_CDEV_V1 /* * returns 0 if the versions match, else the previously selected ABI version */ static int lineinfo_ensure_abi_version(struct gpio_chardev_data *cdata, unsigned int version) { int abiv = atomic_cmpxchg(&cdata->watch_abi_version, 0, version); if (abiv == version) return 0; return abiv; } static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip, bool watch) { struct gpio_desc *desc; struct gpioline_info lineinfo; struct gpio_v2_line_info lineinfo_v2; if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; /* this doubles as a range check on line_offset */ desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.line_offset); if (IS_ERR(desc)) return PTR_ERR(desc); if (watch) { if (lineinfo_ensure_abi_version(cdev, 1)) return -EPERM; if (test_and_set_bit(lineinfo.line_offset, cdev->watched_lines)) return -EBUSY; } gpio_desc_to_lineinfo(desc, &lineinfo_v2); gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { if (watch) clear_bit(lineinfo.line_offset, cdev->watched_lines); return -EFAULT; } return 0; } #endif static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip, bool watch) { struct gpio_desc *desc; struct gpio_v2_line_info lineinfo; if (copy_from_user(&lineinfo, ip, sizeof(lineinfo))) return -EFAULT; if (memchr_inv(lineinfo.padding, 0, sizeof(lineinfo.padding))) return -EINVAL; desc = gpiochip_get_desc(cdev->gdev->chip, lineinfo.offset); if (IS_ERR(desc)) return PTR_ERR(desc); if (watch) { #ifdef CONFIG_GPIO_CDEV_V1 if (lineinfo_ensure_abi_version(cdev, 2)) return -EPERM; #endif if (test_and_set_bit(lineinfo.offset, cdev->watched_lines)) return -EBUSY; } gpio_desc_to_lineinfo(desc, &lineinfo); if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) { if (watch) clear_bit(lineinfo.offset, cdev->watched_lines); return -EFAULT; } return 0; } static int lineinfo_unwatch(struct gpio_chardev_data *cdev, void __user *ip) { __u32 offset; if (copy_from_user(&offset, ip, sizeof(offset))) return -EFAULT; if (offset >= cdev->gdev->ngpio) return -EINVAL; if (!test_and_clear_bit(offset, cdev->watched_lines)) return -EBUSY; return 0; } /* * gpio_ioctl() - ioctl handler for the GPIO chardev */ static long gpio_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { struct gpio_chardev_data *cdev = file->private_data; struct gpio_device *gdev = cdev->gdev; void __user *ip = (void __user *)arg; /* We fail any subsequent ioctl():s when the chip is gone */ if (!gdev->chip) return -ENODEV; /* Fill in the struct and pass to userspace */ switch (cmd) { case GPIO_GET_CHIPINFO_IOCTL: return chipinfo_get(cdev, ip); #ifdef CONFIG_GPIO_CDEV_V1 case GPIO_GET_LINEHANDLE_IOCTL: return linehandle_create(gdev, ip); case GPIO_GET_LINEEVENT_IOCTL: return lineevent_create(gdev, ip); case GPIO_GET_LINEINFO_IOCTL: return lineinfo_get_v1(cdev, ip, false); case GPIO_GET_LINEINFO_WATCH_IOCTL: return lineinfo_get_v1(cdev, ip, true); #endif /* CONFIG_GPIO_CDEV_V1 */ case GPIO_V2_GET_LINEINFO_IOCTL: return lineinfo_get(cdev, ip, false); case GPIO_V2_GET_LINEINFO_WATCH_IOCTL: return lineinfo_get(cdev, ip, true); case GPIO_V2_GET_LINE_IOCTL: return linereq_create(gdev, ip); case GPIO_GET_LINEINFO_UNWATCH_IOCTL: return lineinfo_unwatch(cdev, ip); default: return -EINVAL; } } #ifdef CONFIG_COMPAT static long gpio_ioctl_compat(struct file *file, unsigned int cmd, unsigned long arg) { return gpio_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); } #endif static struct gpio_chardev_data * to_gpio_chardev_data(struct notifier_block *nb) { return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb); } static int lineinfo_changed_notify(struct notifier_block *nb, unsigned long action, void *data) { struct gpio_chardev_data *cdev = to_gpio_chardev_data(nb); struct gpio_v2_line_info_changed chg; struct gpio_desc *desc = data; int ret; if (!test_bit(gpio_chip_hwgpio(desc), cdev->watched_lines)) return NOTIFY_DONE; memset(&chg, 0, sizeof(chg)); chg.event_type = action; chg.timestamp_ns = ktime_get_ns(); gpio_desc_to_lineinfo(desc, &chg.info); ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock); if (ret) wake_up_poll(&cdev->wait, EPOLLIN); else pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n"); return NOTIFY_OK; } static __poll_t lineinfo_watch_poll_unlocked(struct file *file, struct poll_table_struct *pollt) { struct gpio_chardev_data *cdev = file->private_data; __poll_t events = 0; if (!cdev->gdev->chip) return EPOLLHUP | EPOLLERR; poll_wait(file, &cdev->wait, pollt); if (!kfifo_is_empty_spinlocked_noirqsave(&cdev->events, &cdev->wait.lock)) events = EPOLLIN | EPOLLRDNORM; return events; } static __poll_t lineinfo_watch_poll(struct file *file, struct poll_table_struct *pollt) { struct gpio_chardev_data *cdev = file->private_data; return call_poll_locked(file, pollt, cdev->gdev, lineinfo_watch_poll_unlocked); } static ssize_t lineinfo_watch_read_unlocked(struct file *file, char __user *buf, size_t count, loff_t *off) { struct gpio_chardev_data *cdev = file->private_data; struct gpio_v2_line_info_changed event; ssize_t bytes_read = 0; int ret; size_t event_size; if (!cdev->gdev->chip) return -ENODEV; #ifndef CONFIG_GPIO_CDEV_V1 event_size = sizeof(struct gpio_v2_line_info_changed); if (count < event_size) return -EINVAL; #endif do { spin_lock(&cdev->wait.lock); if (kfifo_is_empty(&cdev->events)) { if (bytes_read) { spin_unlock(&cdev->wait.lock); return bytes_read; } if (file->f_flags & O_NONBLOCK) { spin_unlock(&cdev->wait.lock); return -EAGAIN; } ret = wait_event_interruptible_locked(cdev->wait, !kfifo_is_empty(&cdev->events)); if (ret) { spin_unlock(&cdev->wait.lock); return ret; } } #ifdef CONFIG_GPIO_CDEV_V1 /* must be after kfifo check so watch_abi_version is set */ if (atomic_read(&cdev->watch_abi_version) == 2) event_size = sizeof(struct gpio_v2_line_info_changed); else event_size = sizeof(struct gpioline_info_changed); if (count < event_size) { spin_unlock(&cdev->wait.lock); return -EINVAL; } #endif ret = kfifo_out(&cdev->events, &event, 1); spin_unlock(&cdev->wait.lock); if (ret != 1) { ret = -EIO; break; /* We should never get here. See lineevent_read(). */ } #ifdef CONFIG_GPIO_CDEV_V1 if (event_size == sizeof(struct gpio_v2_line_info_changed)) { if (copy_to_user(buf + bytes_read, &event, event_size)) return -EFAULT; } else { struct gpioline_info_changed event_v1; gpio_v2_line_info_changed_to_v1(&event, &event_v1); if (copy_to_user(buf + bytes_read, &event_v1, event_size)) return -EFAULT; } #else if (copy_to_user(buf + bytes_read, &event, event_size)) return -EFAULT; #endif bytes_read += event_size; } while (count >= bytes_read + sizeof(event)); return bytes_read; } static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, size_t count, loff_t *off) { struct gpio_chardev_data *cdev = file->private_data; return call_read_locked(file, buf, count, off, cdev->gdev, lineinfo_watch_read_unlocked); } /** * gpio_chrdev_open() - open the chardev for ioctl operations * @inode: inode for this chardev * @file: file struct for storing private data * Returns 0 on success */ static int gpio_chrdev_open(struct inode *inode, struct file *file) { struct gpio_device *gdev = container_of(inode->i_cdev, struct gpio_device, chrdev); struct gpio_chardev_data *cdev; int ret = -ENOMEM; down_read(&gdev->sem); /* Fail on open if the backing gpiochip is gone */ if (!gdev->chip) { ret = -ENODEV; goto out_unlock; } cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); if (!cdev) goto out_unlock; cdev->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL); if (!cdev->watched_lines) goto out_free_cdev; init_waitqueue_head(&cdev->wait); INIT_KFIFO(cdev->events); cdev->gdev = gdev; cdev->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify; ret = blocking_notifier_chain_register(&gdev->notifier, &cdev->lineinfo_changed_nb); if (ret) goto out_free_bitmap; get_device(&gdev->dev); file->private_data = cdev; ret = nonseekable_open(inode, file); if (ret) goto out_unregister_notifier; up_read(&gdev->sem); return ret; out_unregister_notifier: blocking_notifier_chain_unregister(&gdev->notifier, &cdev->lineinfo_changed_nb); out_free_bitmap: bitmap_free(cdev->watched_lines); out_free_cdev: kfree(cdev); out_unlock: up_read(&gdev->sem); return ret; } /** * gpio_chrdev_release() - close chardev after ioctl operations * @inode: inode for this chardev * @file: file struct for storing private data * Returns 0 on success */ static int gpio_chrdev_release(struct inode *inode, struct file *file) { struct gpio_chardev_data *cdev = file->private_data; struct gpio_device *gdev = cdev->gdev; bitmap_free(cdev->watched_lines); blocking_notifier_chain_unregister(&gdev->notifier, &cdev->lineinfo_changed_nb); put_device(&gdev->dev); kfree(cdev); return 0; } static const struct file_operations gpio_fileops = { .release = gpio_chrdev_release, .open = gpio_chrdev_open, .poll = lineinfo_watch_poll, .read = lineinfo_watch_read, .owner = THIS_MODULE, .llseek = no_llseek, .unlocked_ioctl = gpio_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = gpio_ioctl_compat, #endif }; int gpiolib_cdev_register(struct gpio_device *gdev, dev_t devt) { int ret; cdev_init(&gdev->chrdev, &gpio_fileops); gdev->chrdev.owner = THIS_MODULE; gdev->dev.devt = MKDEV(MAJOR(devt), gdev->id); ret = cdev_device_add(&gdev->chrdev, &gdev->dev); if (ret) return ret; chip_dbg(gdev->chip, "added GPIO chardev (%d:%d)\n", MAJOR(devt), gdev->id); return 0; } void gpiolib_cdev_unregister(struct gpio_device *gdev) { cdev_device_del(&gdev->chrdev, &gdev->dev); }
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