| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jean Delvare | 2902 | 31.33% | 51 | 19.84% |
| Wolfram Sang | 1639 | 17.70% | 53 | 20.62% |
| David Brownell | 834 | 9.00% | 13 | 5.06% |
| Dmitry Torokhov | 375 | 4.05% | 5 | 1.95% |
| Benjamin Tissoires | 345 | 3.72% | 1 | 0.39% |
| Viresh Kumar | 311 | 3.36% | 1 | 0.39% |
| Peter Rosin | 242 | 2.61% | 5 | 1.95% |
| Heiner Kallweit | 218 | 2.35% | 2 | 0.78% |
| Linus Torvalds (pre-git) | 209 | 2.26% | 3 | 1.17% |
| Greg Kroah-Hartman | 165 | 1.78% | 10 | 3.89% |
| David Howells | 151 | 1.63% | 1 | 0.39% |
| Michael Lawnick | 136 | 1.47% | 1 | 0.39% |
| Gerd Knorr | 121 | 1.31% | 2 | 0.78% |
| Doug Anderson | 112 | 1.21% | 1 | 0.39% |
| Jean-Michel Hautbois | 102 | 1.10% | 1 | 0.39% |
| Jarkko Nikula | 101 | 1.09% | 3 | 1.17% |
| Andy Shevchenko | 97 | 1.05% | 6 | 2.33% |
| Lee Jones | 72 | 0.78% | 5 | 1.95% |
| Phil Reid | 67 | 0.72% | 4 | 1.56% |
| Pantelis Antoniou | 53 | 0.57% | 3 | 1.17% |
| Octavian Purdila | 53 | 0.57% | 1 | 0.39% |
| Rui Zhang | 48 | 0.52% | 1 | 0.39% |
| Hans de Goede | 47 | 0.51% | 2 | 0.78% |
| Russell King | 45 | 0.49% | 2 | 0.78% |
| Alain Volmat | 44 | 0.48% | 1 | 0.39% |
| Adrian Bunk | 42 | 0.45% | 2 | 0.78% |
| Javier Martinez Canillas | 41 | 0.44% | 2 | 0.78% |
| Yang Ruirui | 38 | 0.41% | 1 | 0.39% |
| Mika Westerberg | 37 | 0.40% | 3 | 1.17% |
| Vladimir Zapolskiy | 36 | 0.39% | 2 | 0.78% |
| Stephen Warren | 35 | 0.38% | 1 | 0.39% |
| Lars-Peter Clausen | 35 | 0.38% | 3 | 1.17% |
| Laurent Pinchart | 31 | 0.33% | 1 | 0.39% |
| Lv Zheng | 27 | 0.29% | 1 | 0.39% |
| Charles Keepax | 24 | 0.26% | 4 | 1.56% |
| Eugen Hristev | 24 | 0.26% | 1 | 0.39% |
| Geert Uytterhoeven | 21 | 0.23% | 2 | 0.78% |
| Faik Uygur | 21 | 0.23% | 1 | 0.39% |
| Grant C. Likely | 21 | 0.23% | 3 | 1.17% |
| Marc Pignat | 19 | 0.21% | 1 | 0.39% |
| Christoph Hellwig | 19 | 0.21% | 2 | 0.78% |
| Sylwester Nawrocki | 19 | 0.21% | 1 | 0.39% |
| Tejun Heo | 17 | 0.18% | 1 | 0.39% |
| Mike Rapoport | 16 | 0.17% | 1 | 0.39% |
| Mark Brown | 15 | 0.16% | 2 | 0.78% |
| Jan Lübbe | 15 | 0.16% | 1 | 0.39% |
| Thadeu Lima de Souza Cascardo | 15 | 0.16% | 1 | 0.39% |
| Ard Biesheuvel | 14 | 0.15% | 1 | 0.39% |
| Bartosz Golaszewski | 14 | 0.15% | 2 | 0.78% |
| Davidlohr Bueso A | 14 | 0.15% | 1 | 0.39% |
| Boris Brezillon | 13 | 0.14% | 1 | 0.39% |
| Ulf Hansson | 11 | 0.12% | 2 | 0.78% |
| Lixin Wang | 11 | 0.12% | 1 | 0.39% |
| Linus Walleij | 10 | 0.11% | 1 | 0.39% |
| Mark M. Hoffman | 9 | 0.10% | 1 | 0.39% |
| Claudio Foellmi | 9 | 0.10% | 1 | 0.39% |
| Lan Tianyu | 8 | 0.09% | 1 | 0.39% |
| Hans Verkuil | 7 | 0.08% | 1 | 0.39% |
| Linus Torvalds | 7 | 0.08% | 2 | 0.78% |
| Arjan van de Ven | 7 | 0.08% | 1 | 0.39% |
| Sudip Mukherjee | 6 | 0.06% | 1 | 0.39% |
| Clifford Wolf | 6 | 0.06% | 1 | 0.39% |
| Rafael J. Wysocki | 6 | 0.06% | 2 | 0.78% |
| Zhenwen Xu | 6 | 0.06% | 1 | 0.39% |
| Jon Smirl | 5 | 0.05% | 1 | 0.39% |
| Laurent Riffard | 5 | 0.05% | 1 | 0.39% |
| Sebastian Hesselbarth | 4 | 0.04% | 1 | 0.39% |
| Steven Rostedt | 4 | 0.04% | 1 | 0.39% |
| Grygorii Strashko | 4 | 0.04% | 2 | 0.78% |
| Andrew Lutomirski | 3 | 0.03% | 1 | 0.39% |
| Rodolfo Giometti | 3 | 0.03% | 1 | 0.39% |
| Kieran Bingham | 3 | 0.03% | 1 | 0.39% |
| Jim Broadus | 3 | 0.03% | 1 | 0.39% |
| Kay Sievers | 2 | 0.02% | 1 | 0.39% |
| Mauro Carvalho Chehab | 2 | 0.02% | 1 | 0.39% |
| Mika Kuoppala | 1 | 0.01% | 1 | 0.39% |
| Lucas De Marchi | 1 | 0.01% | 1 | 0.39% |
| Andreas Schultz | 1 | 0.01% | 1 | 0.39% |
| Alexander Sverdlin | 1 | 0.01% | 1 | 0.39% |
| Shailendra Verma | 1 | 0.01% | 1 | 0.39% |
| Ahbong Chang | 1 | 0.01% | 1 | 0.39% |
| Mickey Stein | 1 | 0.01% | 1 | 0.39% |
| Matthias Kaehlcke | 1 | 0.01% | 1 | 0.39% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.39% |
| Total | 9262 | 257 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * Linux I2C core * * Copyright (C) 1995-99 Simon G. Vogl * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> * Mux support by Rodolfo Giometti <giometti@enneenne.com> and * Michael Lawnick <michael.lawnick.ext@nsn.com> * * Copyright (C) 2013-2017 Wolfram Sang <wsa@kernel.org> */ #define pr_fmt(fmt) "i2c-core: " fmt #include <dt-bindings/i2c/i2c.h> #include <linux/acpi.h> #include <linux/clk/clk-conf.h> #include <linux/completion.h> #include <linux/delay.h> #include <linux/err.h> #include <linux/errno.h> #include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/i2c-smbus.h> #include <linux/idr.h> #include <linux/init.h> #include <linux/irqflags.h> #include <linux/jump_label.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/of_device.h> #include <linux/of.h> #include <linux/of_irq.h> #include <linux/pm_domain.h> #include <linux/pm_runtime.h> #include <linux/pm_wakeirq.h> #include <linux/property.h> #include <linux/rwsem.h> #include <linux/slab.h> #include "i2c-core.h" #define CREATE_TRACE_POINTS #include <trace/events/i2c.h> #define I2C_ADDR_OFFSET_TEN_BIT 0xa000 #define I2C_ADDR_OFFSET_SLAVE 0x1000 #define I2C_ADDR_7BITS_MAX 0x77 #define I2C_ADDR_7BITS_COUNT (I2C_ADDR_7BITS_MAX + 1) #define I2C_ADDR_DEVICE_ID 0x7c /* * core_lock protects i2c_adapter_idr, and guarantees that device detection, * deletion of detected devices are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); static DEFINE_STATIC_KEY_FALSE(i2c_trace_msg_key); static bool is_registered; int i2c_transfer_trace_reg(void) { static_branch_inc(&i2c_trace_msg_key); return 0; } void i2c_transfer_trace_unreg(void) { static_branch_dec(&i2c_trace_msg_key); } const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, const struct i2c_client *client) { if (!(id && client)) return NULL; while (id->name[0]) { if (strcmp(client->name, id->name) == 0) return id; id++; } return NULL; } EXPORT_SYMBOL_GPL(i2c_match_id); static int i2c_device_match(struct device *dev, struct device_driver *drv) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; /* Attempt an OF style match */ if (i2c_of_match_device(drv->of_match_table, client)) return 1; /* Then ACPI style match */ if (acpi_driver_match_device(dev, drv)) return 1; driver = to_i2c_driver(drv); /* Finally an I2C match */ if (i2c_match_id(driver->id_table, client)) return 1; return 0; } static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) { struct i2c_client *client = to_i2c_client(dev); int rc; rc = of_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; rc = acpi_device_uevent_modalias(dev, env); if (rc != -ENODEV) return rc; return add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name); } /* i2c bus recovery routines */ static int get_scl_gpio_value(struct i2c_adapter *adap) { return gpiod_get_value_cansleep(adap->bus_recovery_info->scl_gpiod); } static void set_scl_gpio_value(struct i2c_adapter *adap, int val) { gpiod_set_value_cansleep(adap->bus_recovery_info->scl_gpiod, val); } static int get_sda_gpio_value(struct i2c_adapter *adap) { return gpiod_get_value_cansleep(adap->bus_recovery_info->sda_gpiod); } static void set_sda_gpio_value(struct i2c_adapter *adap, int val) { gpiod_set_value_cansleep(adap->bus_recovery_info->sda_gpiod, val); } static int i2c_generic_bus_free(struct i2c_adapter *adap) { struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; int ret = -EOPNOTSUPP; if (bri->get_bus_free) ret = bri->get_bus_free(adap); else if (bri->get_sda) ret = bri->get_sda(adap); if (ret < 0) return ret; return ret ? 0 : -EBUSY; } /* * We are generating clock pulses. ndelay() determines durating of clk pulses. * We will generate clock with rate 100 KHz and so duration of both clock levels * is: delay in ns = (10^6 / 100) / 2 */ #define RECOVERY_NDELAY 5000 #define RECOVERY_CLK_CNT 9 int i2c_generic_scl_recovery(struct i2c_adapter *adap) { struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; int i = 0, scl = 1, ret = 0; if (bri->prepare_recovery) bri->prepare_recovery(adap); /* * If we can set SDA, we will always create a STOP to ensure additional * pulses will do no harm. This is achieved by letting SDA follow SCL * half a cycle later. Check the 'incomplete_write_byte' fault injector * for details. Note that we must honour tsu:sto, 4us, but lets use 5us * here for simplicity. */ bri->set_scl(adap, scl); ndelay(RECOVERY_NDELAY); if (bri->set_sda) bri->set_sda(adap, scl); ndelay(RECOVERY_NDELAY / 2); /* * By this time SCL is high, as we need to give 9 falling-rising edges */ while (i++ < RECOVERY_CLK_CNT * 2) { if (scl) { /* SCL shouldn't be low here */ if (!bri->get_scl(adap)) { dev_err(&adap->dev, "SCL is stuck low, exit recovery\n"); ret = -EBUSY; break; } } scl = !scl; bri->set_scl(adap, scl); /* Creating STOP again, see above */ if (scl) { /* Honour minimum tsu:sto */ ndelay(RECOVERY_NDELAY); } else { /* Honour minimum tf and thd:dat */ ndelay(RECOVERY_NDELAY / 2); } if (bri->set_sda) bri->set_sda(adap, scl); ndelay(RECOVERY_NDELAY / 2); if (scl) { ret = i2c_generic_bus_free(adap); if (ret == 0) break; } } /* If we can't check bus status, assume recovery worked */ if (ret == -EOPNOTSUPP) ret = 0; if (bri->unprepare_recovery) bri->unprepare_recovery(adap); return ret; } EXPORT_SYMBOL_GPL(i2c_generic_scl_recovery); int i2c_recover_bus(struct i2c_adapter *adap) { if (!adap->bus_recovery_info) return -EOPNOTSUPP; dev_dbg(&adap->dev, "Trying i2c bus recovery\n"); return adap->bus_recovery_info->recover_bus(adap); } EXPORT_SYMBOL_GPL(i2c_recover_bus); static void i2c_init_recovery(struct i2c_adapter *adap) { struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; char *err_str; if (!bri) return; if (!bri->recover_bus) { err_str = "no recover_bus() found"; goto err; } if (bri->scl_gpiod && bri->recover_bus == i2c_generic_scl_recovery) { bri->get_scl = get_scl_gpio_value; bri->set_scl = set_scl_gpio_value; if (bri->sda_gpiod) { bri->get_sda = get_sda_gpio_value; /* FIXME: add proper flag instead of '0' once available */ if (gpiod_get_direction(bri->sda_gpiod) == 0) bri->set_sda = set_sda_gpio_value; } return; } if (bri->recover_bus == i2c_generic_scl_recovery) { /* Generic SCL recovery */ if (!bri->set_scl || !bri->get_scl) { err_str = "no {get|set}_scl() found"; goto err; } if (!bri->set_sda && !bri->get_sda) { err_str = "either get_sda() or set_sda() needed"; goto err; } } return; err: dev_err(&adap->dev, "Not using recovery: %s\n", err_str); adap->bus_recovery_info = NULL; } static int i2c_smbus_host_notify_to_irq(const struct i2c_client *client) { struct i2c_adapter *adap = client->adapter; unsigned int irq; if (!adap->host_notify_domain) return -ENXIO; if (client->flags & I2C_CLIENT_TEN) return -EINVAL; irq = irq_create_mapping(adap->host_notify_domain, client->addr); return irq > 0 ? irq : -ENXIO; } static int i2c_device_probe(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; int status; if (!client) return 0; driver = to_i2c_driver(dev->driver); client->irq = client->init_irq; if (!client->irq && !driver->disable_i2c_core_irq_mapping) { int irq = -ENOENT; if (client->flags & I2C_CLIENT_HOST_NOTIFY) { dev_dbg(dev, "Using Host Notify IRQ\n"); /* Keep adapter active when Host Notify is required */ pm_runtime_get_sync(&client->adapter->dev); irq = i2c_smbus_host_notify_to_irq(client); } else if (dev->of_node) { irq = of_irq_get_byname(dev->of_node, "irq"); if (irq == -EINVAL || irq == -ENODATA) irq = of_irq_get(dev->of_node, 0); } else if (ACPI_COMPANION(dev)) { irq = i2c_acpi_get_irq(client); } if (irq == -EPROBE_DEFER) { status = irq; goto put_sync_adapter; } if (irq < 0) irq = 0; client->irq = irq; } /* * An I2C ID table is not mandatory, if and only if, a suitable OF * or ACPI ID table is supplied for the probing device. */ if (!driver->id_table && !i2c_acpi_match_device(dev->driver->acpi_match_table, client) && !i2c_of_match_device(dev->driver->of_match_table, client)) { status = -ENODEV; goto put_sync_adapter; } if (client->flags & I2C_CLIENT_WAKE) { int wakeirq; wakeirq = of_irq_get_byname(dev->of_node, "wakeup"); if (wakeirq == -EPROBE_DEFER) { status = wakeirq; goto put_sync_adapter; } device_init_wakeup(&client->dev, true); if (wakeirq > 0 && wakeirq != client->irq) status = dev_pm_set_dedicated_wake_irq(dev, wakeirq); else if (client->irq > 0) status = dev_pm_set_wake_irq(dev, client->irq); else status = 0; if (status) dev_warn(&client->dev, "failed to set up wakeup irq\n"); } dev_dbg(dev, "probe\n"); status = of_clk_set_defaults(dev->of_node, false); if (status < 0) goto err_clear_wakeup_irq; status = dev_pm_domain_attach(&client->dev, true); if (status) goto err_clear_wakeup_irq; /* * When there are no more users of probe(), * rename probe_new to probe. */ if (driver->probe_new) status = driver->probe_new(client); else if (driver->probe) status = driver->probe(client, i2c_match_id(driver->id_table, client)); else status = -EINVAL; if (status) goto err_detach_pm_domain; return 0; err_detach_pm_domain: dev_pm_domain_detach(&client->dev, true); err_clear_wakeup_irq: dev_pm_clear_wake_irq(&client->dev); device_init_wakeup(&client->dev, false); put_sync_adapter: if (client->flags & I2C_CLIENT_HOST_NOTIFY) pm_runtime_put_sync(&client->adapter->dev); return status; } static int i2c_device_remove(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; int status = 0; if (!client || !dev->driver) return 0; driver = to_i2c_driver(dev->driver); if (driver->remove) { dev_dbg(dev, "remove\n"); status = driver->remove(client); } dev_pm_domain_detach(&client->dev, true); dev_pm_clear_wake_irq(&client->dev); device_init_wakeup(&client->dev, false); client->irq = 0; if (client->flags & I2C_CLIENT_HOST_NOTIFY) pm_runtime_put(&client->adapter->dev); return status; } static void i2c_device_shutdown(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; if (!client || !dev->driver) return; driver = to_i2c_driver(dev->driver); if (driver->shutdown) driver->shutdown(client); } static void i2c_client_dev_release(struct device *dev) { kfree(to_i2c_client(dev)); } static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf) { return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); } static DEVICE_ATTR_RO(name); static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); int len; len = of_device_modalias(dev, buf, PAGE_SIZE); if (len != -ENODEV) return len; len = acpi_device_modalias(dev, buf, PAGE_SIZE -1); if (len != -ENODEV) return len; return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); } static DEVICE_ATTR_RO(modalias); static struct attribute *i2c_dev_attrs[] = { &dev_attr_name.attr, /* modalias helps coldplug: modprobe $(cat .../modalias) */ &dev_attr_modalias.attr, NULL }; ATTRIBUTE_GROUPS(i2c_dev); struct bus_type i2c_bus_type = { .name = "i2c", .match = i2c_device_match, .probe = i2c_device_probe, .remove = i2c_device_remove, .shutdown = i2c_device_shutdown, }; EXPORT_SYMBOL_GPL(i2c_bus_type); struct device_type i2c_client_type = { .groups = i2c_dev_groups, .uevent = i2c_device_uevent, .release = i2c_client_dev_release, }; EXPORT_SYMBOL_GPL(i2c_client_type); /** * i2c_verify_client - return parameter as i2c_client, or NULL * @dev: device, probably from some driver model iterator * * When traversing the driver model tree, perhaps using driver model * iterators like @device_for_each_child(), you can't assume very much * about the nodes you find. Use this function to avoid oopses caused * by wrongly treating some non-I2C device as an i2c_client. */ struct i2c_client *i2c_verify_client(struct device *dev) { return (dev->type == &i2c_client_type) ? to_i2c_client(dev) : NULL; } EXPORT_SYMBOL(i2c_verify_client); /* Return a unique address which takes the flags of the client into account */ static unsigned short i2c_encode_flags_to_addr(struct i2c_client *client) { unsigned short addr = client->addr; /* For some client flags, add an arbitrary offset to avoid collisions */ if (client->flags & I2C_CLIENT_TEN) addr |= I2C_ADDR_OFFSET_TEN_BIT; if (client->flags & I2C_CLIENT_SLAVE) addr |= I2C_ADDR_OFFSET_SLAVE; return addr; } /* This is a permissive address validity check, I2C address map constraints * are purposely not enforced, except for the general call address. */ static int i2c_check_addr_validity(unsigned int addr, unsigned short flags) { if (flags & I2C_CLIENT_TEN) { /* 10-bit address, all values are valid */ if (addr > 0x3ff) return -EINVAL; } else { /* 7-bit address, reject the general call address */ if (addr == 0x00 || addr > 0x7f) return -EINVAL; } return 0; } /* And this is a strict address validity check, used when probing. If a * device uses a reserved address, then it shouldn't be probed. 7-bit * addressing is assumed, 10-bit address devices are rare and should be * explicitly enumerated. */ int i2c_check_7bit_addr_validity_strict(unsigned short addr) { /* * Reserved addresses per I2C specification: * 0x00 General call address / START byte * 0x01 CBUS address * 0x02 Reserved for different bus format * 0x03 Reserved for future purposes * 0x04-0x07 Hs-mode master code * 0x78-0x7b 10-bit slave addressing * 0x7c-0x7f Reserved for future purposes */ if (addr < 0x08 || addr > 0x77) return -EINVAL; return 0; } static int __i2c_check_addr_busy(struct device *dev, void *addrp) { struct i2c_client *client = i2c_verify_client(dev); int addr = *(int *)addrp; if (client && i2c_encode_flags_to_addr(client) == addr) return -EBUSY; return 0; } /* walk up mux tree */ static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) { struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); int result; result = device_for_each_child(&adapter->dev, &addr, __i2c_check_addr_busy); if (!result && parent) result = i2c_check_mux_parents(parent, addr); return result; } /* recurse down mux tree */ static int i2c_check_mux_children(struct device *dev, void *addrp) { int result; if (dev->type == &i2c_adapter_type) result = device_for_each_child(dev, addrp, i2c_check_mux_children); else result = __i2c_check_addr_busy(dev, addrp); return result; } static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) { struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); int result = 0; if (parent) result = i2c_check_mux_parents(parent, addr); if (!result) result = device_for_each_child(&adapter->dev, &addr, i2c_check_mux_children); return result; } /** * i2c_adapter_lock_bus - Get exclusive access to an I2C bus segment * @adapter: Target I2C bus segment * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT * locks only this branch in the adapter tree */ static void i2c_adapter_lock_bus(struct i2c_adapter *adapter, unsigned int flags) { rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter)); } /** * i2c_adapter_trylock_bus - Try to get exclusive access to an I2C bus segment * @adapter: Target I2C bus segment * @flags: I2C_LOCK_ROOT_ADAPTER trylocks the root i2c adapter, I2C_LOCK_SEGMENT * trylocks only this branch in the adapter tree */ static int i2c_adapter_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) { return rt_mutex_trylock(&adapter->bus_lock); } /** * i2c_adapter_unlock_bus - Release exclusive access to an I2C bus segment * @adapter: Target I2C bus segment * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT * unlocks only this branch in the adapter tree */ static void i2c_adapter_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) { rt_mutex_unlock(&adapter->bus_lock); } static void i2c_dev_set_name(struct i2c_adapter *adap, struct i2c_client *client, struct i2c_board_info const *info) { struct acpi_device *adev = ACPI_COMPANION(&client->dev); if (info && info->dev_name) { dev_set_name(&client->dev, "i2c-%s", info->dev_name); return; } if (adev) { dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); return; } dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), i2c_encode_flags_to_addr(client)); } int i2c_dev_irq_from_resources(const struct resource *resources, unsigned int num_resources) { struct irq_data *irqd; int i; for (i = 0; i < num_resources; i++) { const struct resource *r = &resources[i]; if (resource_type(r) != IORESOURCE_IRQ) continue; if (r->flags & IORESOURCE_BITS) { irqd = irq_get_irq_data(r->start); if (!irqd) break; irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); } return r->start; } return 0; } /** * i2c_new_client_device - instantiate an i2c device * @adap: the adapter managing the device * @info: describes one I2C device; bus_num is ignored * Context: can sleep * * Create an i2c device. Binding is handled through driver model * probe()/remove() methods. A driver may be bound to this device when we * return from this function, or any later moment (e.g. maybe hotplugging will * load the driver module). This call is not appropriate for use by mainboard * initialization logic, which usually runs during an arch_initcall() long * before any i2c_adapter could exist. * * This returns the new i2c client, which may be saved for later use with * i2c_unregister_device(); or an ERR_PTR to describe the error. */ struct i2c_client * i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info) { struct i2c_client *client; int status; client = kzalloc(sizeof *client, GFP_KERNEL); if (!client) return ERR_PTR(-ENOMEM); client->adapter = adap; client->dev.platform_data = info->platform_data; client->flags = info->flags; client->addr = info->addr; client->init_irq = info->irq; if (!client->init_irq) client->init_irq = i2c_dev_irq_from_resources(info->resources, info->num_resources); strlcpy(client->name, info->type, sizeof(client->name)); status = i2c_check_addr_validity(client->addr, client->flags); if (status) { dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); goto out_err_silent; } /* Check for address business */ status = i2c_check_addr_busy(adap, i2c_encode_flags_to_addr(client)); if (status) goto out_err; client->dev.parent = &client->adapter->dev; client->dev.bus = &i2c_bus_type; client->dev.type = &i2c_client_type; client->dev.of_node = of_node_get(info->of_node); client->dev.fwnode = info->fwnode; i2c_dev_set_name(adap, client, info); if (info->properties) { status = device_add_properties(&client->dev, info->properties); if (status) { dev_err(&adap->dev, "Failed to add properties to client %s: %d\n", client->name, status); goto out_err_put_of_node; } } status = device_register(&client->dev); if (status) goto out_free_props; dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", client->name, dev_name(&client->dev)); return client; out_free_props: if (info->properties) device_remove_properties(&client->dev); out_err_put_of_node: of_node_put(info->of_node); out_err: dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x (%d)\n", client->name, client->addr, status); out_err_silent: kfree(client); return ERR_PTR(status); } EXPORT_SYMBOL_GPL(i2c_new_client_device); /** * i2c_new_device - instantiate an i2c device * @adap: the adapter managing the device * @info: describes one I2C device; bus_num is ignored * Context: can sleep * * This deprecated function has the same functionality as * @i2c_new_client_device, it just returns NULL instead of an ERR_PTR in case of * an error for compatibility with current I2C API. It will be removed once all * users are converted. * * This returns the new i2c client, which may be saved for later use with * i2c_unregister_device(); or NULL to indicate an error. */ struct i2c_client * i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) { struct i2c_client *ret; ret = i2c_new_client_device(adap, info); return IS_ERR(ret) ? NULL : ret; } EXPORT_SYMBOL_GPL(i2c_new_device); /** * i2c_unregister_device - reverse effect of i2c_new_*_device() * @client: value returned from i2c_new_*_device() * Context: can sleep */ void i2c_unregister_device(struct i2c_client *client) { if (IS_ERR_OR_NULL(client)) return; if (client->dev.of_node) { of_node_clear_flag(client->dev.of_node, OF_POPULATED); of_node_put(client->dev.of_node); } if (ACPI_COMPANION(&client->dev)) acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev)); device_unregister(&client->dev); } EXPORT_SYMBOL_GPL(i2c_unregister_device); static const struct i2c_device_id dummy_id[] = { { "dummy", 0 }, { }, }; static int dummy_probe(struct i2c_client *client, const struct i2c_device_id *id) { return 0; } static int dummy_remove(struct i2c_client *client) { return 0; } static struct i2c_driver dummy_driver = { .driver.name = "dummy", .probe = dummy_probe, .remove = dummy_remove, .id_table = dummy_id, }; /** * i2c_new_dummy_device - return a new i2c device bound to a dummy driver * @adapter: the adapter managing the device * @address: seven bit address to be used * Context: can sleep * * This returns an I2C client bound to the "dummy" driver, intended for use * with devices that consume multiple addresses. Examples of such chips * include various EEPROMS (like 24c04 and 24c08 models). * * These dummy devices have two main uses. First, most I2C and SMBus calls * except i2c_transfer() need a client handle; the dummy will be that handle. * And second, this prevents the specified address from being bound to a * different driver. * * This returns the new i2c client, which should be saved for later use with * i2c_unregister_device(); or an ERR_PTR to describe the error. */ struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address) { struct i2c_board_info info = { I2C_BOARD_INFO("dummy", address), }; return i2c_new_client_device(adapter, &info); } EXPORT_SYMBOL_GPL(i2c_new_dummy_device); struct i2c_dummy_devres { struct i2c_client *client; }; static void devm_i2c_release_dummy(struct device *dev, void *res) { struct i2c_dummy_devres *this = res; i2c_unregister_device(this->client); } /** * devm_i2c_new_dummy_device - return a new i2c device bound to a dummy driver * @dev: device the managed resource is bound to * @adapter: the adapter managing the device * @address: seven bit address to be used * Context: can sleep * * This is the device-managed version of @i2c_new_dummy_device. It returns the * new i2c client or an ERR_PTR in case of an error. */ struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adapter, u16 address) { struct i2c_dummy_devres *dr; struct i2c_client *client; dr = devres_alloc(devm_i2c_release_dummy, sizeof(*dr), GFP_KERNEL); if (!dr) return ERR_PTR(-ENOMEM); client = i2c_new_dummy_device(adapter, address); if (IS_ERR(client)) { devres_free(dr); } else { dr->client = client; devres_add(dev, dr); } return client; } EXPORT_SYMBOL_GPL(devm_i2c_new_dummy_device); /** * i2c_new_ancillary_device - Helper to get the instantiated secondary address * and create the associated device * @client: Handle to the primary client * @name: Handle to specify which secondary address to get * @default_addr: Used as a fallback if no secondary address was specified * Context: can sleep * * I2C clients can be composed of multiple I2C slaves bound together in a single * component. The I2C client driver then binds to the master I2C slave and needs * to create I2C dummy clients to communicate with all the other slaves. * * This function creates and returns an I2C dummy client whose I2C address is * retrieved from the platform firmware based on the given slave name. If no * address is specified by the firmware default_addr is used. * * On DT-based platforms the address is retrieved from the "reg" property entry * cell whose "reg-names" value matches the slave name. * * This returns the new i2c client, which should be saved for later use with * i2c_unregister_device(); or an ERR_PTR to describe the error. */ struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, const char *name, u16 default_addr) { struct device_node *np = client->dev.of_node; u32 addr = default_addr; int i; if (np) { i = of_property_match_string(np, "reg-names", name); if (i >= 0) of_property_read_u32_index(np, "reg", i, &addr); } dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); return i2c_new_dummy_device(client->adapter, addr); } EXPORT_SYMBOL_GPL(i2c_new_ancillary_device); /* ------------------------------------------------------------------------- */ /* I2C bus adapters -- one roots each I2C or SMBUS segment */ static void i2c_adapter_dev_release(struct device *dev) { struct i2c_adapter *adap = to_i2c_adapter(dev); complete(&adap->dev_released); } unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) { unsigned int depth = 0; while ((adapter = i2c_parent_is_i2c_adapter(adapter))) depth++; WARN_ONCE(depth >= MAX_LOCKDEP_SUBCLASSES, "adapter depth exceeds lockdep subclass limit\n"); return depth; } EXPORT_SYMBOL_GPL(i2c_adapter_depth); /* * Let users instantiate I2C devices through sysfs. This can be used when * platform initialization code doesn't contain the proper data for * whatever reason. Also useful for drivers that do device detection and * detection fails, either because the device uses an unexpected address, * or this is a compatible device with different ID register values. * * Parameter checking may look overzealous, but we really don't want * the user to provide incorrect parameters. */ static ssize_t new_device_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_adapter *adap = to_i2c_adapter(dev); struct i2c_board_info info; struct i2c_client *client; char *blank, end; int res; memset(&info, 0, sizeof(struct i2c_board_info)); blank = strchr(buf, ' '); if (!blank) { dev_err(dev, "%s: Missing parameters\n", "new_device"); return -EINVAL; } if (blank - buf > I2C_NAME_SIZE - 1) { dev_err(dev, "%s: Invalid device name\n", "new_device"); return -EINVAL; } memcpy(info.type, buf, blank - buf); /* Parse remaining parameters, reject extra parameters */ res = sscanf(++blank, "%hi%c", &info.addr, &end); if (res < 1) { dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); return -EINVAL; } if (res > 1 && end != '\n') { dev_err(dev, "%s: Extra parameters\n", "new_device"); return -EINVAL; } if ((info.addr & I2C_ADDR_OFFSET_TEN_BIT) == I2C_ADDR_OFFSET_TEN_BIT) { info.addr &= ~I2C_ADDR_OFFSET_TEN_BIT; info.flags |= I2C_CLIENT_TEN; } if (info.addr & I2C_ADDR_OFFSET_SLAVE) { info.addr &= ~I2C_ADDR_OFFSET_SLAVE; info.flags |= I2C_CLIENT_SLAVE; } client = i2c_new_client_device(adap, &info); if (IS_ERR(client)) return PTR_ERR(client); /* Keep track of the added device */ mutex_lock(&adap->userspace_clients_lock); list_add_tail(&client->detected, &adap->userspace_clients); mutex_unlock(&adap->userspace_clients_lock); dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", info.type, info.addr); return count; } static DEVICE_ATTR_WO(new_device); /* * And of course let the users delete the devices they instantiated, if * they got it wrong. This interface can only be used to delete devices * instantiated by i2c_sysfs_new_device above. This guarantees that we * don't delete devices to which some kernel code still has references. * * Parameter checking may look overzealous, but we really don't want * the user to delete the wrong device. */ static ssize_t delete_device_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_adapter *adap = to_i2c_adapter(dev); struct i2c_client *client, *next; unsigned short addr; char end; int res; /* Parse parameters, reject extra parameters */ res = sscanf(buf, "%hi%c", &addr, &end); if (res < 1) { dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); return -EINVAL; } if (res > 1 && end != '\n') { dev_err(dev, "%s: Extra parameters\n", "delete_device"); return -EINVAL; } /* Make sure the device was added through sysfs */ res = -ENOENT; mutex_lock_nested(&adap->userspace_clients_lock, i2c_adapter_depth(adap)); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { if (i2c_encode_flags_to_addr(client) == addr) { dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", "delete_device", client->name, client->addr); list_del(&client->detected); i2c_unregister_device(client); res = count; break; } } mutex_unlock(&adap->userspace_clients_lock); if (res < 0) dev_err(dev, "%s: Can't find device in list\n", "delete_device"); return res; } static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, delete_device_store); static struct attribute *i2c_adapter_attrs[] = { &dev_attr_name.attr, &dev_attr_new_device.attr, &dev_attr_delete_device.attr, NULL }; ATTRIBUTE_GROUPS(i2c_adapter); struct device_type i2c_adapter_type = { .groups = i2c_adapter_groups, .release = i2c_adapter_dev_release, }; EXPORT_SYMBOL_GPL(i2c_adapter_type); /** * i2c_verify_adapter - return parameter as i2c_adapter or NULL * @dev: device, probably from some driver model iterator * * When traversing the driver model tree, perhaps using driver model * iterators like @device_for_each_child(), you can't assume very much * about the nodes you find. Use this function to avoid oopses caused * by wrongly treating some non-I2C device as an i2c_adapter. */ struct i2c_adapter *i2c_verify_adapter(struct device *dev) { return (dev->type == &i2c_adapter_type) ? to_i2c_adapter(dev) : NULL; } EXPORT_SYMBOL(i2c_verify_adapter); #ifdef CONFIG_I2C_COMPAT static struct class_compat *i2c_adapter_compat_class; #endif static void i2c_scan_static_board_info(struct i2c_adapter *adapter) { struct i2c_devinfo *devinfo; down_read(&__i2c_board_lock); list_for_each_entry(devinfo, &__i2c_board_list, list) { if (devinfo->busnum == adapter->nr && IS_ERR(i2c_new_client_device(adapter, &devinfo->board_info))) dev_err(&adapter->dev, "Can't create device at 0x%02x\n", devinfo->board_info.addr); } up_read(&__i2c_board_lock); } static int i2c_do_add_adapter(struct i2c_driver *driver, struct i2c_adapter *adap) { /* Detect supported devices on that bus, and instantiate them */ i2c_detect(adap, driver); return 0; } static int __process_new_adapter(struct device_driver *d, void *data) { return i2c_do_add_adapter(to_i2c_driver(d), data); } static const struct i2c_lock_operations i2c_adapter_lock_ops = { .lock_bus = i2c_adapter_lock_bus, .trylock_bus = i2c_adapter_trylock_bus, .unlock_bus = i2c_adapter_unlock_bus, }; static void i2c_host_notify_irq_teardown(struct i2c_adapter *adap) { struct irq_domain *domain = adap->host_notify_domain; irq_hw_number_t hwirq; if (!domain) return; for (hwirq = 0 ; hwirq < I2C_ADDR_7BITS_COUNT ; hwirq++) irq_dispose_mapping(irq_find_mapping(domain, hwirq)); irq_domain_remove(domain); adap->host_notify_domain = NULL; } static int i2c_host_notify_irq_map(struct irq_domain *h, unsigned int virq, irq_hw_number_t hw_irq_num) { irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); return 0; } static const struct irq_domain_ops i2c_host_notify_irq_ops = { .map = i2c_host_notify_irq_map, }; static int i2c_setup_host_notify_irq_domain(struct i2c_adapter *adap) { struct irq_domain *domain; if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_HOST_NOTIFY)) return 0; domain = irq_domain_create_linear(adap->dev.fwnode, I2C_ADDR_7BITS_COUNT, &i2c_host_notify_irq_ops, adap); if (!domain) return -ENOMEM; adap->host_notify_domain = domain; return 0; } /** * i2c_handle_smbus_host_notify - Forward a Host Notify event to the correct * I2C client. * @adap: the adapter * @addr: the I2C address of the notifying device * Context: can't sleep * * Helper function to be called from an I2C bus driver's interrupt * handler. It will schedule the Host Notify IRQ. */ int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr) { int irq; if (!adap) return -EINVAL; irq = irq_find_mapping(adap->host_notify_domain, addr); if (irq <= 0) return -ENXIO; generic_handle_irq(irq); return 0; } EXPORT_SYMBOL_GPL(i2c_handle_smbus_host_notify); static int i2c_register_adapter(struct i2c_adapter *adap) { int res = -EINVAL; /* Can't register until after driver model init */ if (WARN_ON(!is_registered)) { res = -EAGAIN; goto out_list; } /* Sanity checks */ if (WARN(!adap->name[0], "i2c adapter has no name")) goto out_list; if (!adap->algo) { pr_err("adapter '%s': no algo supplied!\n", adap->name); goto out_list; } if (!adap->lock_ops) adap->lock_ops = &i2c_adapter_lock_ops; adap->locked_flags = 0; rt_mutex_init(&adap->bus_lock); rt_mutex_init(&adap->mux_lock); mutex_init(&adap->userspace_clients_lock); INIT_LIST_HEAD(&adap->userspace_clients); /* Set default timeout to 1 second if not already set */ if (adap->timeout == 0) adap->timeout = HZ; /* register soft irqs for Host Notify */ res = i2c_setup_host_notify_irq_domain(adap); if (res) { pr_err("adapter '%s': can't create Host Notify IRQs (%d)\n", adap->name, res); goto out_list; } dev_set_name(&adap->dev, "i2c-%d", adap->nr); adap->dev.bus = &i2c_bus_type; adap->dev.type = &i2c_adapter_type; res = device_register(&adap->dev); if (res) { pr_err("adapter '%s': can't register device (%d)\n", adap->name, res); goto out_list; } res = of_i2c_setup_smbus_alert(adap); if (res) goto out_reg; dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); pm_runtime_no_callbacks(&adap->dev); pm_suspend_ignore_children(&adap->dev, true); pm_runtime_enable(&adap->dev); #ifdef CONFIG_I2C_COMPAT res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, adap->dev.parent); if (res) dev_warn(&adap->dev, "Failed to create compatibility class link\n"); #endif i2c_init_recovery(adap); /* create pre-declared device nodes */ of_i2c_register_devices(adap); i2c_acpi_register_devices(adap); i2c_acpi_install_space_handler(adap); if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); /* Notify drivers */ mutex_lock(&core_lock); bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); mutex_unlock(&core_lock); return 0; out_reg: init_completion(&adap->dev_released); device_unregister(&adap->dev); wait_for_completion(&adap->dev_released); out_list: mutex_lock(&core_lock); idr_remove(&i2c_adapter_idr, adap->nr); mutex_unlock(&core_lock); return res; } /** * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 * @adap: the adapter to register (with adap->nr initialized) * Context: can sleep * * See i2c_add_numbered_adapter() for details. */ static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) { int id; mutex_lock(&core_lock); id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, GFP_KERNEL); mutex_unlock(&core_lock); if (WARN(id < 0, "couldn't get idr")) return id == -ENOSPC ? -EBUSY : id; return i2c_register_adapter(adap); } /** * i2c_add_adapter - declare i2c adapter, use dynamic bus number * @adapter: the adapter to add * Context: can sleep * * This routine is used to declare an I2C adapter when its bus number * doesn't matter or when its bus number is specified by an dt alias. * Examples of bases when the bus number doesn't matter: I2C adapters * dynamically added by USB links or PCI plugin cards. * * When this returns zero, a new bus number was allocated and stored * in adap->nr, and the specified adapter became available for clients. * Otherwise, a negative errno value is returned. */ int i2c_add_adapter(struct i2c_adapter *adapter) { struct device *dev = &adapter->dev; int id; if (dev->of_node) { id = of_alias_get_id(dev->of_node, "i2c"); if (id >= 0) { adapter->nr = id; return __i2c_add_numbered_adapter(adapter); } } mutex_lock(&core_lock); id = idr_alloc(&i2c_adapter_idr, adapter, __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); mutex_unlock(&core_lock); if (WARN(id < 0, "couldn't get idr")) return id; adapter->nr = id; return i2c_register_adapter(adapter); } EXPORT_SYMBOL(i2c_add_adapter); /** * i2c_add_numbered_adapter - declare i2c adapter, use static bus number * @adap: the adapter to register (with adap->nr initialized) * Context: can sleep * * This routine is used to declare an I2C adapter when its bus number * matters. For example, use it for I2C adapters from system-on-chip CPUs, * or otherwise built in to the system's mainboard, and where i2c_board_info * is used to properly configure I2C devices. * * If the requested bus number is set to -1, then this function will behave * identically to i2c_add_adapter, and will dynamically assign a bus number. * * If no devices have pre-been declared for this bus, then be sure to * register the adapter before any dynamically allocated ones. Otherwise * the required bus ID may not be available. * * When this returns zero, the specified adapter became available for * clients using the bus number provided in adap->nr. Also, the table * of I2C devices pre-declared using i2c_register_board_info() is scanned, * and the appropriate driver model device nodes are created. Otherwise, a * negative errno value is returned. */ int i2c_add_numbered_adapter(struct i2c_adapter *adap) { if (adap->nr == -1) /* -1 means dynamically assign bus id */ return i2c_add_adapter(adap); return __i2c_add_numbered_adapter(adap); } EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); static void i2c_do_del_adapter(struct i2c_driver *driver, struct i2c_adapter *adapter) { struct i2c_client *client, *_n; /* Remove the devices we created ourselves as the result of hardware * probing (using a driver's detect method) */ list_for_each_entry_safe(client, _n, &driver->clients, detected) { if (client->adapter == adapter) { dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", client->name, client->addr); list_del(&client->detected); i2c_unregister_device(client); } } } static int __unregister_client(struct device *dev, void *dummy) { struct i2c_client *client = i2c_verify_client(dev); if (client && strcmp(client->name, "dummy")) i2c_unregister_device(client); return 0; } static int __unregister_dummy(struct device *dev, void *dummy) { struct i2c_client *client = i2c_verify_client(dev); i2c_unregister_device(client); return 0; } static int __process_removed_adapter(struct device_driver *d, void *data) { i2c_do_del_adapter(to_i2c_driver(d), data); return 0; } /** * i2c_del_adapter - unregister I2C adapter * @adap: the adapter being unregistered * Context: can sleep * * This unregisters an I2C adapter which was previously registered * by @i2c_add_adapter or @i2c_add_numbered_adapter. */ void i2c_del_adapter(struct i2c_adapter *adap) { struct i2c_adapter *found; struct i2c_client *client, *next; /* First make sure that this adapter was ever added */ mutex_lock(&core_lock); found = idr_find(&i2c_adapter_idr, adap->nr); mutex_unlock(&core_lock); if (found != adap) { pr_debug("attempting to delete unregistered adapter [%s]\n", adap->name); return; } i2c_acpi_remove_space_handler(adap); /* Tell drivers about this removal */ mutex_lock(&core_lock); bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_removed_adapter); mutex_unlock(&core_lock); /* Remove devices instantiated from sysfs */ mutex_lock_nested(&adap->userspace_clients_lock, i2c_adapter_depth(adap)); list_for_each_entry_safe(client, next, &adap->userspace_clients, detected) { dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, client->addr); list_del(&client->detected); i2c_unregister_device(client); } mutex_unlock(&adap->userspace_clients_lock); /* Detach any active clients. This can't fail, thus we do not * check the returned value. This is a two-pass process, because * we can't remove the dummy devices during the first pass: they * could have been instantiated by real devices wishing to clean * them up properly, so we give them a chance to do that first. */ device_for_each_child(&adap->dev, NULL, __unregister_client); device_for_each_child(&adap->dev, NULL, __unregister_dummy); #ifdef CONFIG_I2C_COMPAT class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, adap->dev.parent); #endif /* device name is gone after device_unregister */ dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); pm_runtime_disable(&adap->dev); i2c_host_notify_irq_teardown(adap); /* wait until all references to the device are gone * * FIXME: This is old code and should ideally be replaced by an * alternative which results in decoupling the lifetime of the struct * device from the i2c_adapter, like spi or netdev do. Any solution * should be thoroughly tested with DEBUG_KOBJECT_RELEASE enabled! */ init_completion(&adap->dev_released); device_unregister(&adap->dev); wait_for_completion(&adap->dev_released); /* free bus id */ mutex_lock(&core_lock); idr_remove(&i2c_adapter_idr, adap->nr); mutex_unlock(&core_lock); /* Clear the device structure in case this adapter is ever going to be added again */ memset(&adap->dev, 0, sizeof(adap->dev)); } EXPORT_SYMBOL(i2c_del_adapter); /** * i2c_parse_fw_timings - get I2C related timing parameters from firmware * @dev: The device to scan for I2C timing properties * @t: the i2c_timings struct to be filled with values * @use_defaults: bool to use sane defaults derived from the I2C specification * when properties are not found, otherwise don't update * * Scan the device for the generic I2C properties describing timing parameters * for the signal and fill the given struct with the results. If a property was * not found and use_defaults was true, then maximum timings are assumed which * are derived from the I2C specification. If use_defaults is not used, the * results will be as before, so drivers can apply their own defaults before * calling this helper. The latter is mainly intended for avoiding regressions * of existing drivers which want to switch to this function. New drivers * almost always should use the defaults. */ void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults) { int ret; ret = device_property_read_u32(dev, "clock-frequency", &t->bus_freq_hz); if (ret && use_defaults) t->bus_freq_hz = I2C_MAX_STANDARD_MODE_FREQ; ret = device_property_read_u32(dev, "i2c-scl-rising-time-ns", &t->scl_rise_ns); if (ret && use_defaults) { if (t->bus_freq_hz <= I2C_MAX_STANDARD_MODE_FREQ) t->scl_rise_ns = 1000; else if (t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ) t->scl_rise_ns = 300; else t->scl_rise_ns = 120; } ret = device_property_read_u32(dev, "i2c-scl-falling-time-ns", &t->scl_fall_ns); if (ret && use_defaults) { if (t->bus_freq_hz <= I2C_MAX_FAST_MODE_FREQ) t->scl_fall_ns = 300; else t->scl_fall_ns = 120; } ret = device_property_read_u32(dev, "i2c-scl-internal-delay-ns", &t->scl_int_delay_ns); if (ret && use_defaults) t->scl_int_delay_ns = 0; ret = device_property_read_u32(dev, "i2c-sda-falling-time-ns", &t->sda_fall_ns); if (ret && use_defaults) t->sda_fall_ns = t->scl_fall_ns; ret = device_property_read_u32(dev, "i2c-sda-hold-time-ns", &t->sda_hold_ns); if (ret && use_defaults) t->sda_hold_ns = 0; ret = device_property_read_u32(dev, "i2c-digital-filter-width-ns", &t->digital_filter_width_ns); if (ret && use_defaults) t->digital_filter_width_ns = 0; ret = device_property_read_u32(dev, "i2c-analog-filter-cutoff-frequency", &t->analog_filter_cutoff_freq_hz); if (ret && use_defaults) t->analog_filter_cutoff_freq_hz = 0; } EXPORT_SYMBOL_GPL(i2c_parse_fw_timings); /* ------------------------------------------------------------------------- */ int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data)) { int res; mutex_lock(&core_lock); res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); mutex_unlock(&core_lock); return res; } EXPORT_SYMBOL_GPL(i2c_for_each_dev); static int __process_new_driver(struct device *dev, void *data) { if (dev->type != &i2c_adapter_type) return 0; return i2c_do_add_adapter(data, to_i2c_adapter(dev)); } /* * An i2c_driver is used with one or more i2c_client (device) nodes to access * i2c slave chips, on a bus instance associated with some i2c_adapter. */ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) { int res; /* Can't register until after driver model init */ if (WARN_ON(!is_registered)) return -EAGAIN; /* add the driver to the list of i2c drivers in the driver core */ driver->driver.owner = owner; driver->driver.bus = &i2c_bus_type; INIT_LIST_HEAD(&driver->clients); /* When registration returns, the driver core * will have called probe() for all matching-but-unbound devices. */ res = driver_register(&driver->driver); if (res) return res; pr_debug("driver [%s] registered\n", driver->driver.name); /* Walk the adapters that are already present */ i2c_for_each_dev(driver, __process_new_driver); return 0; } EXPORT_SYMBOL(i2c_register_driver); static int __process_removed_driver(struct device *dev, void *data) { if (dev->type == &i2c_adapter_type) i2c_do_del_adapter(data, to_i2c_adapter(dev)); return 0; } /** * i2c_del_driver - unregister I2C driver * @driver: the driver being unregistered * Context: can sleep */ void i2c_del_driver(struct i2c_driver *driver) { i2c_for_each_dev(driver, __process_removed_driver); driver_unregister(&driver->driver); pr_debug("driver [%s] unregistered\n", driver->driver.name); } EXPORT_SYMBOL(i2c_del_driver); /* ------------------------------------------------------------------------- */ struct i2c_cmd_arg { unsigned cmd; void *arg; }; static int i2c_cmd(struct device *dev, void *_arg) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_cmd_arg *arg = _arg; struct i2c_driver *driver; if (!client || !client->dev.driver) return 0; driver = to_i2c_driver(client->dev.driver); if (driver->command) driver->command(client, arg->cmd, arg->arg); return 0; } void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) { struct i2c_cmd_arg cmd_arg; cmd_arg.cmd = cmd; cmd_arg.arg = arg; device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); } EXPORT_SYMBOL(i2c_clients_command); static int __init i2c_init(void) { int retval; retval = of_alias_get_highest_id("i2c"); down_write(&__i2c_board_lock); if (retval >= __i2c_first_dynamic_bus_num) __i2c_first_dynamic_bus_num = retval + 1; up_write(&__i2c_board_lock); retval = bus_register(&i2c_bus_type); if (retval) return retval; is_registered = true; #ifdef CONFIG_I2C_COMPAT i2c_adapter_compat_class = class_compat_register("i2c-adapter"); if (!i2c_adapter_compat_class) { retval = -ENOMEM; goto bus_err; } #endif retval = i2c_add_driver(&dummy_driver); if (retval) goto class_err; if (IS_ENABLED(CONFIG_OF_DYNAMIC)) WARN_ON(of_reconfig_notifier_register(&i2c_of_notifier)); if (IS_ENABLED(CONFIG_ACPI)) WARN_ON(acpi_reconfig_notifier_register(&i2c_acpi_notifier)); return 0; class_err: #ifdef CONFIG_I2C_COMPAT class_compat_unregister(i2c_adapter_compat_class); bus_err: #endif is_registered = false; bus_unregister(&i2c_bus_type); return retval; } static void __exit i2c_exit(void) { if (IS_ENABLED(CONFIG_ACPI)) WARN_ON(acpi_reconfig_notifier_unregister(&i2c_acpi_notifier)); if (IS_ENABLED(CONFIG_OF_DYNAMIC)) WARN_ON(of_reconfig_notifier_unregister(&i2c_of_notifier)); i2c_del_driver(&dummy_driver); #ifdef CONFIG_I2C_COMPAT class_compat_unregister(i2c_adapter_compat_class); #endif bus_unregister(&i2c_bus_type); tracepoint_synchronize_unregister(); } /* We must initialize early, because some subsystems register i2c drivers * in subsys_initcall() code, but are linked (and initialized) before i2c. */ postcore_initcall(i2c_init); module_exit(i2c_exit); /* ---------------------------------------------------- * the functional interface to the i2c busses. * ---------------------------------------------------- */ /* Check if val is exceeding the quirk IFF quirk is non 0 */ #define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk))) static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char *err_msg) { dev_err_ratelimited(&adap->dev, "adapter quirk: %s (addr 0x%04x, size %u, %s)\n", err_msg, msg->addr, msg->len, msg->flags & I2C_M_RD ? "read" : "write"); return -EOPNOTSUPP; } static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { const struct i2c_adapter_quirks *q = adap->quirks; int max_num = q->max_num_msgs, i; bool do_len_check = true; if (q->flags & I2C_AQ_COMB) { max_num = 2; /* special checks for combined messages */ if (num == 2) { if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags & I2C_M_RD) return i2c_quirk_error(adap, &msgs[0], "1st comb msg must be write"); if (q->flags & I2C_AQ_COMB_READ_SECOND && !(msgs[1].flags & I2C_M_RD)) return i2c_quirk_error(adap, &msgs[1], "2nd comb msg must be read"); if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr) return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr"); if (i2c_quirk_exceeded(msgs[0].len, q->max_comb_1st_msg_len)) return i2c_quirk_error(adap, &msgs[0], "msg too long"); if (i2c_quirk_exceeded(msgs[1].len, q->max_comb_2nd_msg_len)) return i2c_quirk_error(adap, &msgs[1], "msg too long"); do_len_check = false; } } if (i2c_quirk_exceeded(num, max_num)) return i2c_quirk_error(adap, &msgs[0], "too many messages"); for (i = 0; i < num; i++) { u16 len = msgs[i].len; if (msgs[i].flags & I2C_M_RD) { if (do_len_check && i2c_quirk_exceeded(len, q->max_read_len)) return i2c_quirk_error(adap, &msgs[i], "msg too long"); if (q->flags & I2C_AQ_NO_ZERO_LEN_READ && len == 0) return i2c_quirk_error(adap, &msgs[i], "no zero length"); } else { if (do_len_check && i2c_quirk_exceeded(len, q->max_write_len)) return i2c_quirk_error(adap, &msgs[i], "msg too long"); if (q->flags & I2C_AQ_NO_ZERO_LEN_WRITE && len == 0) return i2c_quirk_error(adap, &msgs[i], "no zero length"); } } return 0; } /** * __i2c_transfer - unlocked flavor of i2c_transfer * @adap: Handle to I2C bus * @msgs: One or more messages to execute before STOP is issued to * terminate the operation; each message begins with a START. * @num: Number of messages to be executed. * * Returns negative errno, else the number of messages executed. * * Adapter lock must be held when calling this function. No debug logging * takes place. adap->algo->master_xfer existence isn't checked. */ int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { unsigned long orig_jiffies; int ret, try; if (WARN_ON(!msgs || num < 1)) return -EINVAL; ret = __i2c_check_suspended(adap); if (ret) return ret; if (adap->quirks && i2c_check_for_quirks(adap, msgs, num)) return -EOPNOTSUPP; /* * i2c_trace_msg_key gets enabled when tracepoint i2c_transfer gets * enabled. This is an efficient way of keeping the for-loop from * being executed when not needed. */ if (static_branch_unlikely(&i2c_trace_msg_key)) { int i; for (i = 0; i < num; i++) if (msgs[i].flags & I2C_M_RD) trace_i2c_read(adap, &msgs[i], i); else trace_i2c_write(adap, &msgs[i], i); } /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; for (ret = 0, try = 0; try <= adap->retries; try++) { if (i2c_in_atomic_xfer_mode() && adap->algo->master_xfer_atomic) ret = adap->algo->master_xfer_atomic(adap, msgs, num); else ret = adap->algo->master_xfer(adap, msgs, num); if (ret != -EAGAIN) break; if (time_after(jiffies, orig_jiffies + adap->timeout)) break; } if (static_branch_unlikely(&i2c_trace_msg_key)) { int i; for (i = 0; i < ret; i++) if (msgs[i].flags & I2C_M_RD) trace_i2c_reply(adap, &msgs[i], i); trace_i2c_result(adap, num, ret); } return ret; } EXPORT_SYMBOL(__i2c_transfer); /** * i2c_transfer - execute a single or combined I2C message * @adap: Handle to I2C bus * @msgs: One or more messages to execute before STOP is issued to * terminate the operation; each message begins with a START. * @num: Number of messages to be executed. * * Returns negative errno, else the number of messages executed. * * Note that there is no requirement that each message be sent to * the same slave address, although that is the most common model. */ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { int ret; if (!adap->algo->master_xfer) { dev_dbg(&adap->dev, "I2C level transfers not supported\n"); return -EOPNOTSUPP; } /* REVISIT the fault reporting model here is weak: * * - When we get an error after receiving N bytes from a slave, * there is no way to report "N". * * - When we get a NAK after transmitting N bytes to a slave, * there is no way to report "N" ... or to let the master * continue executing the rest of this combined message, if * that's the appropriate response. * * - When for example "num" is two and we successfully complete * the first message but get an error part way through the * second, it's unclear whether that should be reported as * one (discarding status on the second message) or errno * (discarding status on the first one). */ ret = __i2c_lock_bus_helper(adap); if (ret) return ret; ret = __i2c_transfer(adap, msgs, num); i2c_unlock_bus(adap, I2C_LOCK_SEGMENT); return ret; } EXPORT_SYMBOL(i2c_transfer); /** * i2c_transfer_buffer_flags - issue a single I2C message transferring data * to/from a buffer * @client: Handle to slave device * @buf: Where the data is stored * @count: How many bytes to transfer, must be less than 64k since msg.len is u16 * @flags: The flags to be used for the message, e.g. I2C_M_RD for reads * * Returns negative errno, or else the number of bytes transferred. */ int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, int count, u16 flags) { int ret; struct i2c_msg msg = { .addr = client->addr, .flags = flags | (client->flags & I2C_M_TEN), .len = count, .buf = buf, }; ret = i2c_transfer(client->adapter, &msg, 1); /* * If everything went ok (i.e. 1 msg transferred), return #bytes * transferred, else error code. */ return (ret == 1) ? count : ret; } EXPORT_SYMBOL(i2c_transfer_buffer_flags); /** * i2c_get_device_id - get manufacturer, part id and die revision of a device * @client: The device to query * @id: The queried information * * Returns negative errno on error, zero on success. */ int i2c_get_device_id(const struct i2c_client *client, struct i2c_device_identity *id) { struct i2c_adapter *adap = client->adapter; union i2c_smbus_data raw_id; int ret; if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) return -EOPNOTSUPP; raw_id.block[0] = 3; ret = i2c_smbus_xfer(adap, I2C_ADDR_DEVICE_ID, 0, I2C_SMBUS_READ, client->addr << 1, I2C_SMBUS_I2C_BLOCK_DATA, &raw_id); if (ret) return ret; id->manufacturer_id = (raw_id.block[1] << 4) | (raw_id.block[2] >> 4); id->part_id = ((raw_id.block[2] & 0xf) << 5) | (raw_id.block[3] >> 3); id->die_revision = raw_id.block[3] & 0x7; return 0; } EXPORT_SYMBOL_GPL(i2c_get_device_id); /* ---------------------------------------------------- * the i2c address scanning function * Will not work for 10-bit addresses! * ---------------------------------------------------- */ /* * Legacy default probe function, mostly relevant for SMBus. The default * probe method is a quick write, but it is known to corrupt the 24RF08 * EEPROMs due to a state machine bug, and could also irreversibly * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, * we use a short byte read instead. Also, some bus drivers don't implement * quick write, so we fallback to a byte read in that case too. * On x86, there is another special case for FSC hardware monitoring chips, * which want regular byte reads (address 0x73.) Fortunately, these are the * only known chips using this I2C address on PC hardware. * Returns 1 if probe succeeded, 0 if not. */ static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) { int err; union i2c_smbus_data dummy; #ifdef CONFIG_X86 if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE_DATA, &dummy); else #endif if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, I2C_SMBUS_QUICK, NULL); else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy); else { dev_warn(&adap->dev, "No suitable probing method supported for address 0x%02X\n", addr); err = -EOPNOTSUPP; } return err >= 0; } static int i2c_detect_address(struct i2c_client *temp_client, struct i2c_driver *driver) { struct i2c_board_info info; struct i2c_adapter *adapter = temp_client->adapter; int addr = temp_client->addr; int err; /* Make sure the address is valid */ err = i2c_check_7bit_addr_validity_strict(addr); if (err) { dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", addr); return err; } /* Skip if already in use (7 bit, no need to encode flags) */ if (i2c_check_addr_busy(adapter, addr)) return 0; /* Make sure there is something at this address */ if (!i2c_default_probe(adapter, addr)) return 0; /* Finally call the custom detection function */ memset(&info, 0, sizeof(struct i2c_board_info)); info.addr = addr; err = driver->detect(temp_client, &info); if (err) { /* -ENODEV is returned if the detection fails. We catch it here as this isn't an error. */ return err == -ENODEV ? 0 : err; } /* Consistency check */ if (info.type[0] == '\0') { dev_err(&adapter->dev, "%s detection function provided no name for 0x%x\n", driver->driver.name, addr); } else { struct i2c_client *client; /* Detection succeeded, instantiate the device */ if (adapter->class & I2C_CLASS_DEPRECATED) dev_warn(&adapter->dev, "This adapter will soon drop class based instantiation of devices. " "Please make sure client 0x%02x gets instantiated by other means. " "Check 'Documentation/i2c/instantiating-devices.rst' for details.\n", info.addr); dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", info.type, info.addr); client = i2c_new_client_device(adapter, &info); if (!IS_ERR(client)) list_add_tail(&client->detected, &driver->clients); else dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", info.type, info.addr); } return 0; } static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) { const unsigned short *address_list; struct i2c_client *temp_client; int i, err = 0; int adap_id = i2c_adapter_id(adapter); address_list = driver->address_list; if (!driver->detect || !address_list) return 0; /* Warn that the adapter lost class based instantiation */ if (adapter->class == I2C_CLASS_DEPRECATED) { dev_dbg(&adapter->dev, "This adapter dropped support for I2C classes and won't auto-detect %s devices anymore. " "If you need it, check 'Documentation/i2c/instantiating-devices.rst' for alternatives.\n", driver->driver.name); return 0; } /* Stop here if the classes do not match */ if (!(adapter->class & driver->class)) return 0; /* Set up a temporary client to help detect callback */ temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); if (!temp_client) return -ENOMEM; temp_client->adapter = adapter; for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { dev_dbg(&adapter->dev, "found normal entry for adapter %d, addr 0x%02x\n", adap_id, address_list[i]); temp_client->addr = address_list[i]; err = i2c_detect_address(temp_client, driver); if (unlikely(err)) break; } kfree(temp_client); return err; } int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) { return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, I2C_SMBUS_QUICK, NULL) >= 0; } EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); struct i2c_client * i2c_new_scanned_device(struct i2c_adapter *adap, struct i2c_board_info *info, unsigned short const *addr_list, int (*probe)(struct i2c_adapter *adap, unsigned short addr)) { int i; if (!probe) probe = i2c_default_probe; for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { /* Check address validity */ if (i2c_check_7bit_addr_validity_strict(addr_list[i]) < 0) { dev_warn(&adap->dev, "Invalid 7-bit address 0x%02x\n", addr_list[i]); continue; } /* Check address availability (7 bit, no need to encode flags) */ if (i2c_check_addr_busy(adap, addr_list[i])) { dev_dbg(&adap->dev, "Address 0x%02x already in use, not probing\n", addr_list[i]); continue; } /* Test address responsiveness */ if (probe(adap, addr_list[i])) break; } if (addr_list[i] == I2C_CLIENT_END) { dev_dbg(&adap->dev, "Probing failed, no device found\n"); return ERR_PTR(-ENODEV); } info->addr = addr_list[i]; return i2c_new_client_device(adap, info); } EXPORT_SYMBOL_GPL(i2c_new_scanned_device); struct i2c_adapter *i2c_get_adapter(int nr) { struct i2c_adapter *adapter; mutex_lock(&core_lock); adapter = idr_find(&i2c_adapter_idr, nr); if (!adapter) goto exit; if (try_module_get(adapter->owner)) get_device(&adapter->dev); else adapter = NULL; exit: mutex_unlock(&core_lock); return adapter; } EXPORT_SYMBOL(i2c_get_adapter); void i2c_put_adapter(struct i2c_adapter *adap) { if (!adap) return; put_device(&adap->dev); module_put(adap->owner); } EXPORT_SYMBOL(i2c_put_adapter); /** * i2c_get_dma_safe_msg_buf() - get a DMA safe buffer for the given i2c_msg * @msg: the message to be checked * @threshold: the minimum number of bytes for which using DMA makes sense. * Should at least be 1. * * Return: NULL if a DMA safe buffer was not obtained. Use msg->buf with PIO. * Or a valid pointer to be used with DMA. After use, release it by * calling i2c_put_dma_safe_msg_buf(). * * This function must only be called from process context! */ u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold) { /* also skip 0-length msgs for bogus thresholds of 0 */ if (!threshold) pr_debug("DMA buffer for addr=0x%02x with length 0 is bogus\n", msg->addr); if (msg->len < threshold || msg->len == 0) return NULL; if (msg->flags & I2C_M_DMA_SAFE) return msg->buf; pr_debug("using bounce buffer for addr=0x%02x, len=%d\n", msg->addr, msg->len); if (msg->flags & I2C_M_RD) return kzalloc(msg->len, GFP_KERNEL); else return kmemdup(msg->buf, msg->len, GFP_KERNEL); } EXPORT_SYMBOL_GPL(i2c_get_dma_safe_msg_buf); /** * i2c_put_dma_safe_msg_buf - release DMA safe buffer and sync with i2c_msg * @buf: the buffer obtained from i2c_get_dma_safe_msg_buf(). May be NULL. * @msg: the message which the buffer corresponds to * @xferred: bool saying if the message was transferred */ void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred) { if (!buf || buf == msg->buf) return; if (xferred && msg->flags & I2C_M_RD) memcpy(msg->buf, buf, msg->len); kfree(buf); } EXPORT_SYMBOL_GPL(i2c_put_dma_safe_msg_buf); MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); MODULE_DESCRIPTION("I2C-Bus main module"); MODULE_LICENSE("GPL");
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