diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 1411 |
1 files changed, 1074 insertions, 337 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 0ac2f90ab84..7c7f4b856ba 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -14,42 +14,69 @@ You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ + Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, + MA 02110-1301 USA. */ /* ------------------------------------------------------------------------- */ /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and - Jean Delvare <khali@linux-fr.org> */ + Jean Delvare <jdelvare@suse.de> + Mux support by Rodolfo Giometti <giometti@enneenne.com> and + Michael Lawnick <michael.lawnick.ext@nsn.com> + OF support is copyright (c) 2008 Jochen Friedrich <jochen@scram.de> + (based on a previous patch from Jon Smirl <jonsmirl@gmail.com>) and + (c) 2013 Wolfram Sang <wsa@the-dreams.de> + */ #include <linux/module.h> #include <linux/kernel.h> +#include <linux/delay.h> #include <linux/errno.h> +#include <linux/gpio.h> #include <linux/slab.h> #include <linux/i2c.h> #include <linux/init.h> #include <linux/idr.h> #include <linux/mutex.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> #include <linux/completion.h> #include <linux/hardirq.h> #include <linux/irqflags.h> #include <linux/rwsem.h> +#include <linux/pm_runtime.h> +#include <linux/acpi.h> +#include <linux/jump_label.h> #include <asm/uaccess.h> #include "i2c-core.h" +#define CREATE_TRACE_POINTS +#include <trace/events/i2c.h> -/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees +/* core_lock protects i2c_adapter_idr, and guarantees that device detection, deletion of detected devices, and attach_adapter - and detach_adapter calls are serialized */ + calls are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); -static LIST_HEAD(userspace_devices); static struct device_type i2c_client_type; -static int i2c_check_addr(struct i2c_adapter *adapter, int addr); static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); +static struct static_key i2c_trace_msg = STATIC_KEY_INIT_FALSE; + +void i2c_transfer_trace_reg(void) +{ + static_key_slow_inc(&i2c_trace_msg); +} + +void i2c_transfer_trace_unreg(void) +{ + static_key_slow_dec(&i2c_trace_msg); +} + /* ------------------------------------------------------------------------- */ static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, @@ -71,6 +98,14 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) if (!client) return 0; + /* Attempt an OF style match */ + if (of_driver_match_device(dev, drv)) + return 1; + + /* Then ACPI style match */ + if (acpi_driver_match_device(dev, drv)) + return 1; + driver = to_i2c_driver(drv); /* match on an id table if there is one */ if (driver->id_table) @@ -79,12 +114,16 @@ static int i2c_device_match(struct device *dev, struct device_driver *drv) return 0; } -#ifdef CONFIG_HOTPLUG /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) { struct i2c_client *client = to_i2c_client(dev); + int rc; + + rc = acpi_device_uevent_modalias(dev, env); + if (rc != -ENODEV) + return rc; if (add_uevent_var(env, "MODALIAS=%s%s", I2C_MODULE_PREFIX, client->name)) @@ -93,9 +132,129 @@ static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) return 0; } -#else -#define i2c_device_uevent NULL -#endif /* CONFIG_HOTPLUG */ +/* i2c bus recovery routines */ +static int get_scl_gpio_value(struct i2c_adapter *adap) +{ + return gpio_get_value(adap->bus_recovery_info->scl_gpio); +} + +static void set_scl_gpio_value(struct i2c_adapter *adap, int val) +{ + gpio_set_value(adap->bus_recovery_info->scl_gpio, val); +} + +static int get_sda_gpio_value(struct i2c_adapter *adap) +{ + return gpio_get_value(adap->bus_recovery_info->sda_gpio); +} + +static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) +{ + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; + struct device *dev = &adap->dev; + int ret = 0; + + ret = gpio_request_one(bri->scl_gpio, GPIOF_OPEN_DRAIN | + GPIOF_OUT_INIT_HIGH, "i2c-scl"); + if (ret) { + dev_warn(dev, "Can't get SCL gpio: %d\n", bri->scl_gpio); + return ret; + } + + if (bri->get_sda) { + if (gpio_request_one(bri->sda_gpio, GPIOF_IN, "i2c-sda")) { + /* work without SDA polling */ + dev_warn(dev, "Can't get SDA gpio: %d. Not using SDA polling\n", + bri->sda_gpio); + bri->get_sda = NULL; + } + } + + return ret; +} + +static void i2c_put_gpios_for_recovery(struct i2c_adapter *adap) +{ + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; + + if (bri->get_sda) + gpio_free(bri->sda_gpio); + + gpio_free(bri->scl_gpio); +} + +/* + * 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 + +static int i2c_generic_recovery(struct i2c_adapter *adap) +{ + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; + int i = 0, val = 1, ret = 0; + + if (bri->prepare_recovery) + bri->prepare_recovery(bri); + + /* + * By this time SCL is high, as we need to give 9 falling-rising edges + */ + while (i++ < RECOVERY_CLK_CNT * 2) { + if (val) { + /* Break if SDA is high */ + if (bri->get_sda && bri->get_sda(adap)) + break; + /* 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; + } + } + + val = !val; + bri->set_scl(adap, val); + ndelay(RECOVERY_NDELAY); + } + + if (bri->unprepare_recovery) + bri->unprepare_recovery(bri); + + return ret; +} + +int i2c_generic_scl_recovery(struct i2c_adapter *adap) +{ + adap->bus_recovery_info->set_scl(adap, 1); + return i2c_generic_recovery(adap); +} + +int i2c_generic_gpio_recovery(struct i2c_adapter *adap) +{ + int ret; + + ret = i2c_get_gpios_for_recovery(adap); + if (ret) + return ret; + + ret = i2c_generic_recovery(adap); + i2c_put_gpios_for_recovery(adap); + + return ret; +} + +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); +} static int i2c_device_probe(struct device *dev) { @@ -109,15 +268,17 @@ static int i2c_device_probe(struct device *dev) driver = to_i2c_driver(dev->driver); if (!driver->probe || !driver->id_table) return -ENODEV; - client->driver = driver; + if (!device_can_wakeup(&client->dev)) device_init_wakeup(&client->dev, client->flags & I2C_CLIENT_WAKE); dev_dbg(dev, "probe\n"); + acpi_dev_pm_attach(&client->dev, true); status = driver->probe(client, i2c_match_id(driver->id_table, client)); if (status) - client->driver = NULL; + acpi_dev_pm_detach(&client->dev, true); + return status; } @@ -125,7 +286,7 @@ static int i2c_device_remove(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; - int status; + int status = 0; if (!client || !dev->driver) return 0; @@ -134,12 +295,9 @@ static int i2c_device_remove(struct device *dev) if (driver->remove) { dev_dbg(dev, "remove\n"); status = driver->remove(client); - } else { - dev->driver = NULL; - status = 0; } - if (status == 0) - client->driver = NULL; + + acpi_dev_pm_detach(&client->dev, true); return status; } @@ -155,36 +313,8 @@ static void i2c_device_shutdown(struct device *dev) driver->shutdown(client); } -#ifdef CONFIG_SUSPEND -static int i2c_device_pm_suspend(struct device *dev) -{ - const struct dev_pm_ops *pm; - - if (!dev->driver) - return 0; - pm = dev->driver->pm; - if (!pm || !pm->suspend) - return 0; - return pm->suspend(dev); -} - -static int i2c_device_pm_resume(struct device *dev) -{ - const struct dev_pm_ops *pm; - - if (!dev->driver) - return 0; - pm = dev->driver->pm; - if (!pm || !pm->resume) - return 0; - return pm->resume(dev); -} -#else -#define i2c_device_pm_suspend NULL -#define i2c_device_pm_resume NULL -#endif - -static int i2c_device_suspend(struct device *dev, pm_message_t mesg) +#ifdef CONFIG_PM_SLEEP +static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; @@ -197,7 +327,7 @@ static int i2c_device_suspend(struct device *dev, pm_message_t mesg) return driver->suspend(client, mesg); } -static int i2c_device_resume(struct device *dev) +static int i2c_legacy_resume(struct device *dev) { struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; @@ -210,6 +340,74 @@ static int i2c_device_resume(struct device *dev) return driver->resume(client); } +static int i2c_device_pm_suspend(struct device *dev) +{ + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + + if (pm) + return pm_generic_suspend(dev); + else + return i2c_legacy_suspend(dev, PMSG_SUSPEND); +} + +static int i2c_device_pm_resume(struct device *dev) +{ + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + + if (pm) + return pm_generic_resume(dev); + else + return i2c_legacy_resume(dev); +} + +static int i2c_device_pm_freeze(struct device *dev) +{ + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + + if (pm) + return pm_generic_freeze(dev); + else + return i2c_legacy_suspend(dev, PMSG_FREEZE); +} + +static int i2c_device_pm_thaw(struct device *dev) +{ + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + + if (pm) + return pm_generic_thaw(dev); + else + return i2c_legacy_resume(dev); +} + +static int i2c_device_pm_poweroff(struct device *dev) +{ + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + + if (pm) + return pm_generic_poweroff(dev); + else + return i2c_legacy_suspend(dev, PMSG_HIBERNATE); +} + +static int i2c_device_pm_restore(struct device *dev) +{ + const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; + + if (pm) + return pm_generic_restore(dev); + else + return i2c_legacy_resume(dev); +} +#else /* !CONFIG_PM_SLEEP */ +#define i2c_device_pm_suspend NULL +#define i2c_device_pm_resume NULL +#define i2c_device_pm_freeze NULL +#define i2c_device_pm_thaw NULL +#define i2c_device_pm_poweroff NULL +#define i2c_device_pm_restore NULL +#endif /* !CONFIG_PM_SLEEP */ + static void i2c_client_dev_release(struct device *dev) { kfree(to_i2c_client(dev)); @@ -226,6 +424,12 @@ static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); + int 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); } @@ -248,9 +452,18 @@ static const struct attribute_group *i2c_dev_attr_groups[] = { NULL }; -const static struct dev_pm_ops i2c_device_pm_ops = { +static const struct dev_pm_ops i2c_device_pm_ops = { .suspend = i2c_device_pm_suspend, .resume = i2c_device_pm_resume, + .freeze = i2c_device_pm_freeze, + .thaw = i2c_device_pm_thaw, + .poweroff = i2c_device_pm_poweroff, + .restore = i2c_device_pm_restore, + SET_RUNTIME_PM_OPS( + pm_generic_runtime_suspend, + pm_generic_runtime_resume, + NULL + ) }; struct bus_type i2c_bus_type = { @@ -259,8 +472,6 @@ struct bus_type i2c_bus_type = { .probe = i2c_device_probe, .remove = i2c_device_remove, .shutdown = i2c_device_shutdown, - .suspend = i2c_device_suspend, - .resume = i2c_device_resume, .pm = &i2c_device_pm_ops, }; EXPORT_SYMBOL_GPL(i2c_bus_type); @@ -290,6 +501,157 @@ struct i2c_client *i2c_verify_client(struct device *dev) EXPORT_SYMBOL(i2c_verify_client); +/* 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_client_addr_validity(const struct i2c_client *client) +{ + if (client->flags & I2C_CLIENT_TEN) { + /* 10-bit address, all values are valid */ + if (client->addr > 0x3ff) + return -EINVAL; + } else { + /* 7-bit address, reject the general call address */ + if (client->addr == 0x00 || client->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. */ +static int i2c_check_addr_validity(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 && client->addr == 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_lock_adapter - Get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +void i2c_lock_adapter(struct i2c_adapter *adapter) +{ + struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); + + if (parent) + i2c_lock_adapter(parent); + else + rt_mutex_lock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_lock_adapter); + +/** + * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +static int i2c_trylock_adapter(struct i2c_adapter *adapter) +{ + struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); + + if (parent) + return i2c_trylock_adapter(parent); + else + return rt_mutex_trylock(&adapter->bus_lock); +} + +/** + * i2c_unlock_adapter - Release exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment + */ +void i2c_unlock_adapter(struct i2c_adapter *adapter) +{ + struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); + + if (parent) + i2c_unlock_adapter(parent); + else + rt_mutex_unlock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_unlock_adapter); + +static void i2c_dev_set_name(struct i2c_adapter *adap, + struct i2c_client *client) +{ + struct acpi_device *adev = ACPI_COMPANION(&client->dev); + + if (adev) { + dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); + return; + } + + /* For 10-bit clients, add an arbitrary offset to avoid collisions */ + dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), + client->addr | ((client->flags & I2C_CLIENT_TEN) + ? 0xa000 : 0)); +} + /** * i2c_new_device - instantiate an i2c device * @adap: the adapter managing the device @@ -329,17 +691,26 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) strlcpy(client->name, info->type, sizeof(client->name)); + /* Check for address validity */ + status = i2c_check_client_addr_validity(client); + 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(adap, client->addr); + status = i2c_check_addr_busy(adap, client->addr); 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 = info->of_node; + ACPI_COMPANION_SET(&client->dev, info->acpi_node.companion); - dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), - client->addr); + i2c_dev_set_name(adap, client); status = device_register(&client->dev); if (status) goto out_err; @@ -352,6 +723,7 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) 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 NULL; } @@ -432,6 +804,22 @@ static void i2c_adapter_dev_release(struct device *dev) } /* + * This function is only needed for mutex_lock_nested, so it is never + * called unless locking correctness checking is enabled. Thus we + * make it inline to avoid a compiler warning. That's what gcc ends up + * doing anyway. + */ +static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) +{ + unsigned int depth = 0; + + while ((adapter = i2c_parent_is_i2c_adapter(adapter))) + depth++; + + return 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 @@ -451,8 +839,6 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, char *blank, end; int res; - dev_warn(dev, "The new_device interface is still experimental " - "and may change in a near future\n"); memset(&info, 0, sizeof(struct i2c_board_info)); blank = strchr(buf, ' '); @@ -477,20 +863,14 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EINVAL; } - if (info.addr < 0x03 || info.addr > 0x77) { - dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device", - info.addr); - return -EINVAL; - } - client = i2c_new_device(adap, &info); if (!client) - return -EEXIST; + return -EINVAL; /* Keep track of the added device */ - mutex_lock(&core_lock); - list_add_tail(&client->detected, &userspace_devices); - mutex_unlock(&core_lock); + 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); @@ -529,9 +909,11 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, /* Make sure the device was added through sysfs */ res = -ENOENT; - mutex_lock(&core_lock); - list_for_each_entry_safe(client, next, &userspace_devices, detected) { - if (client->addr == addr && client->adapter == adap) { + mutex_lock_nested(&adap->userspace_clients_lock, + i2c_adapter_depth(adap)); + list_for_each_entry_safe(client, next, &adap->userspace_clients, + detected) { + if (client->addr == addr) { dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", "delete_device", client->name, client->addr); @@ -541,7 +923,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, break; } } - mutex_unlock(&core_lock); + mutex_unlock(&adap->userspace_clients_lock); if (res < 0) dev_err(dev, "%s: Can't find device in list\n", @@ -550,7 +932,8 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); -static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); +static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, + i2c_sysfs_delete_device); static struct attribute *i2c_adapter_attrs[] = { &dev_attr_name.attr, @@ -568,10 +951,28 @@ static const struct attribute_group *i2c_adapter_attr_groups[] = { NULL }; -static struct device_type i2c_adapter_type = { +struct device_type i2c_adapter_type = { .groups = i2c_adapter_attr_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; @@ -593,6 +994,199 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter) up_read(&__i2c_board_lock); } +/* OF support code */ + +#if IS_ENABLED(CONFIG_OF) +static void of_i2c_register_devices(struct i2c_adapter *adap) +{ + void *result; + struct device_node *node; + + /* Only register child devices if the adapter has a node pointer set */ + if (!adap->dev.of_node) + return; + + dev_dbg(&adap->dev, "of_i2c: walking child nodes\n"); + + for_each_available_child_of_node(adap->dev.of_node, node) { + struct i2c_board_info info = {}; + struct dev_archdata dev_ad = {}; + const __be32 *addr; + int len; + + dev_dbg(&adap->dev, "of_i2c: register %s\n", node->full_name); + + if (of_modalias_node(node, info.type, sizeof(info.type)) < 0) { + dev_err(&adap->dev, "of_i2c: modalias failure on %s\n", + node->full_name); + continue; + } + + addr = of_get_property(node, "reg", &len); + if (!addr || (len < sizeof(int))) { + dev_err(&adap->dev, "of_i2c: invalid reg on %s\n", + node->full_name); + continue; + } + + info.addr = be32_to_cpup(addr); + if (info.addr > (1 << 10) - 1) { + dev_err(&adap->dev, "of_i2c: invalid addr=%x on %s\n", + info.addr, node->full_name); + continue; + } + + info.irq = irq_of_parse_and_map(node, 0); + info.of_node = of_node_get(node); + info.archdata = &dev_ad; + + if (of_get_property(node, "wakeup-source", NULL)) + info.flags |= I2C_CLIENT_WAKE; + + request_module("%s%s", I2C_MODULE_PREFIX, info.type); + + result = i2c_new_device(adap, &info); + if (result == NULL) { + dev_err(&adap->dev, "of_i2c: Failure registering %s\n", + node->full_name); + of_node_put(node); + irq_dispose_mapping(info.irq); + continue; + } + } +} + +static int of_dev_node_match(struct device *dev, void *data) +{ + return dev->of_node == data; +} + +/* must call put_device() when done with returned i2c_client device */ +struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) +{ + struct device *dev; + + dev = bus_find_device(&i2c_bus_type, NULL, node, + of_dev_node_match); + if (!dev) + return NULL; + + return i2c_verify_client(dev); +} +EXPORT_SYMBOL(of_find_i2c_device_by_node); + +/* must call put_device() when done with returned i2c_adapter device */ +struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) +{ + struct device *dev; + + dev = bus_find_device(&i2c_bus_type, NULL, node, + of_dev_node_match); + if (!dev) + return NULL; + + return i2c_verify_adapter(dev); +} +EXPORT_SYMBOL(of_find_i2c_adapter_by_node); +#else +static void of_i2c_register_devices(struct i2c_adapter *adap) { } +#endif /* CONFIG_OF */ + +/* ACPI support code */ + +#if IS_ENABLED(CONFIG_ACPI) +static int acpi_i2c_add_resource(struct acpi_resource *ares, void *data) +{ + struct i2c_board_info *info = data; + + if (ares->type == ACPI_RESOURCE_TYPE_SERIAL_BUS) { + struct acpi_resource_i2c_serialbus *sb; + + sb = &ares->data.i2c_serial_bus; + if (sb->type == ACPI_RESOURCE_SERIAL_TYPE_I2C) { + info->addr = sb->slave_address; + if (sb->access_mode == ACPI_I2C_10BIT_MODE) + info->flags |= I2C_CLIENT_TEN; + } + } else if (info->irq < 0) { + struct resource r; + + if (acpi_dev_resource_interrupt(ares, 0, &r)) + info->irq = r.start; + } + + /* Tell the ACPI core to skip this resource */ + return 1; +} + +static acpi_status acpi_i2c_add_device(acpi_handle handle, u32 level, + void *data, void **return_value) +{ + struct i2c_adapter *adapter = data; + struct list_head resource_list; + struct i2c_board_info info; + struct acpi_device *adev; + int ret; + + if (acpi_bus_get_device(handle, &adev)) + return AE_OK; + if (acpi_bus_get_status(adev) || !adev->status.present) + return AE_OK; + + memset(&info, 0, sizeof(info)); + info.acpi_node.companion = adev; + info.irq = -1; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, + acpi_i2c_add_resource, &info); + acpi_dev_free_resource_list(&resource_list); + + if (ret < 0 || !info.addr) + return AE_OK; + + adev->power.flags.ignore_parent = true; + strlcpy(info.type, dev_name(&adev->dev), sizeof(info.type)); + if (!i2c_new_device(adapter, &info)) { + adev->power.flags.ignore_parent = false; + dev_err(&adapter->dev, + "failed to add I2C device %s from ACPI\n", + dev_name(&adev->dev)); + } + + return AE_OK; +} + +/** + * acpi_i2c_register_devices - enumerate I2C slave devices behind adapter + * @adap: pointer to adapter + * + * Enumerate all I2C slave devices behind this adapter by walking the ACPI + * namespace. When a device is found it will be added to the Linux device + * model and bound to the corresponding ACPI handle. + */ +static void acpi_i2c_register_devices(struct i2c_adapter *adap) +{ + acpi_handle handle; + acpi_status status; + + if (!adap->dev.parent) + return; + + handle = ACPI_HANDLE(adap->dev.parent); + if (!handle) + return; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + acpi_i2c_add_device, NULL, + adap, NULL); + if (ACPI_FAILURE(status)) + dev_warn(&adap->dev, "failed to enumerate I2C slaves\n"); +} +#else +static inline void acpi_i2c_register_devices(struct i2c_adapter *adap) {} +#endif /* CONFIG_ACPI */ + static int i2c_do_add_adapter(struct i2c_driver *driver, struct i2c_adapter *adap) { @@ -601,6 +1195,10 @@ static int i2c_do_add_adapter(struct i2c_driver *driver, /* Let legacy drivers scan this bus for matching devices */ if (driver->attach_adapter) { + dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", + driver->driver.name); + dev_warn(&adap->dev, "Please use another way to instantiate " + "your i2c_client\n"); /* We ignore the return code; if it fails, too bad */ driver->attach_adapter(adap); } @@ -614,7 +1212,7 @@ static int __process_new_adapter(struct device_driver *d, void *data) static int i2c_register_adapter(struct i2c_adapter *adap) { - int res = 0, dummy; + int res = 0; /* Can't register until after driver model init */ if (unlikely(WARN_ON(!i2c_bus_type.p))) { @@ -622,7 +1220,21 @@ static int i2c_register_adapter(struct i2c_adapter *adap) goto out_list; } + /* Sanity checks */ + if (unlikely(adap->name[0] == '\0')) { + pr_err("i2c-core: Attempt to register an adapter with " + "no name!\n"); + return -EINVAL; + } + if (unlikely(!adap->algo)) { + pr_err("i2c-core: Attempt to register adapter '%s' with " + "no algo!\n", adap->name); + return -EINVAL; + } + rt_mutex_init(&adap->bus_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) @@ -645,14 +1257,49 @@ static int i2c_register_adapter(struct i2c_adapter *adap) "Failed to create compatibility class link\n"); #endif + /* bus recovery specific initialization */ + if (adap->bus_recovery_info) { + struct i2c_bus_recovery_info *bri = adap->bus_recovery_info; + + if (!bri->recover_bus) { + dev_err(&adap->dev, "No recover_bus() found, not using recovery\n"); + adap->bus_recovery_info = NULL; + goto exit_recovery; + } + + /* Generic GPIO recovery */ + if (bri->recover_bus == i2c_generic_gpio_recovery) { + if (!gpio_is_valid(bri->scl_gpio)) { + dev_err(&adap->dev, "Invalid SCL gpio, not using recovery\n"); + adap->bus_recovery_info = NULL; + goto exit_recovery; + } + + if (gpio_is_valid(bri->sda_gpio)) + bri->get_sda = get_sda_gpio_value; + else + bri->get_sda = NULL; + + bri->get_scl = get_scl_gpio_value; + bri->set_scl = set_scl_gpio_value; + } else if (!bri->set_scl || !bri->get_scl) { + /* Generic SCL recovery */ + dev_err(&adap->dev, "No {get|set}_gpio() found, not using recovery\n"); + adap->bus_recovery_info = NULL; + } + } + +exit_recovery: /* create pre-declared device nodes */ + of_i2c_register_devices(adap); + acpi_i2c_register_devices(adap); + if (adap->nr < __i2c_first_dynamic_bus_num) i2c_scan_static_board_info(adap); /* Notify drivers */ mutex_lock(&core_lock); - dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, - __process_new_adapter); + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); mutex_unlock(&core_lock); return 0; @@ -665,13 +1312,35 @@ out_list: } /** + * __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 (id < 0) + 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. Examples: for I2C adapters dynamically added by - * USB links or PCI plugin cards. + * 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. @@ -679,25 +1348,26 @@ out_list: */ int i2c_add_adapter(struct i2c_adapter *adapter) { - int id, res = 0; + struct device *dev = &adapter->dev; + int id; -retry: - if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) - return -ENOMEM; + 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); - /* "above" here means "above or equal to", sigh */ - res = idr_get_new_above(&i2c_adapter_idr, adapter, - __i2c_first_dynamic_bus_num, &id); + id = idr_alloc(&i2c_adapter_idr, adapter, + __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); mutex_unlock(&core_lock); - - if (res < 0) { - if (res == -EAGAIN) - goto retry; - return res; - } + if (id < 0) + return id; adapter->nr = id; + return i2c_register_adapter(adapter); } EXPORT_SYMBOL(i2c_add_adapter); @@ -712,6 +1382,9 @@ EXPORT_SYMBOL(i2c_add_adapter); * 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. @@ -724,40 +1397,17 @@ EXPORT_SYMBOL(i2c_add_adapter); */ int i2c_add_numbered_adapter(struct i2c_adapter *adap) { - int id; - int status; - - if (adap->nr & ~MAX_ID_MASK) - return -EINVAL; + if (adap->nr == -1) /* -1 means dynamically assign bus id */ + return i2c_add_adapter(adap); -retry: - if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) - return -ENOMEM; - - mutex_lock(&core_lock); - /* "above" here means "above or equal to", sigh; - * we need the "equal to" result to force the result - */ - status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); - if (status == 0 && id != adap->nr) { - status = -EBUSY; - idr_remove(&i2c_adapter_idr, id); - } - mutex_unlock(&core_lock); - if (status == -EAGAIN) - goto retry; - - if (status == 0) - status = i2c_register_adapter(adap); - return status; + return __i2c_add_numbered_adapter(adap); } EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); -static int i2c_do_del_adapter(struct i2c_driver *driver, +static void i2c_do_del_adapter(struct i2c_driver *driver, struct i2c_adapter *adapter) { struct i2c_client *client, *_n; - int res; /* Remove the devices we created ourselves as the result of hardware * probing (using a driver's detect method) */ @@ -769,19 +1419,19 @@ static int i2c_do_del_adapter(struct i2c_driver *driver, i2c_unregister_device(client); } } - - if (!driver->detach_adapter) - return 0; - res = driver->detach_adapter(adapter); - if (res) - dev_err(&adapter->dev, "detach_adapter failed (%d) " - "for driver [%s]\n", res, driver->driver.name); - return res; } 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); if (client) i2c_unregister_device(client); return 0; @@ -789,7 +1439,8 @@ static int __unregister_client(struct device *dev, void *dummy) static int __process_removed_adapter(struct device_driver *d, void *data) { - return i2c_do_del_adapter(to_i2c_driver(d), data); + i2c_do_del_adapter(to_i2c_driver(d), data); + return 0; } /** @@ -800,9 +1451,8 @@ static int __process_removed_adapter(struct device_driver *d, void *data) * This unregisters an I2C adapter which was previously registered * by @i2c_add_adapter or @i2c_add_numbered_adapter. */ -int i2c_del_adapter(struct i2c_adapter *adap) +void i2c_del_adapter(struct i2c_adapter *adap) { - int res = 0; struct i2c_adapter *found; struct i2c_client *client, *next; @@ -813,36 +1463,43 @@ int i2c_del_adapter(struct i2c_adapter *adap) if (found != adap) { pr_debug("i2c-core: attempting to delete unregistered " "adapter [%s]\n", adap->name); - return -EINVAL; + return; } /* Tell drivers about this removal */ mutex_lock(&core_lock); - res = bus_for_each_drv(&i2c_bus_type, NULL, adap, + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_removed_adapter); mutex_unlock(&core_lock); - if (res) - return res; /* Remove devices instantiated from sysfs */ - list_for_each_entry_safe(client, next, &userspace_devices, detected) { - if (client->adapter == adap) { - dev_dbg(&adap->dev, "Removing %s at 0x%x\n", - client->name, client->addr); - list_del(&client->detected); - i2c_unregister_device(client); - } + 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 - checking the returned value. */ - res = device_for_each_child(&adap->dev, NULL, __unregister_client); + * 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); + /* clean up the sysfs representation */ init_completion(&adap->dev_released); device_unregister(&adap->dev); @@ -855,19 +1512,26 @@ int i2c_del_adapter(struct i2c_adapter *adap) idr_remove(&i2c_adapter_idr, adap->nr); mutex_unlock(&core_lock); - dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); - /* Clear the device structure in case this adapter is ever going to be added again */ memset(&adap->dev, 0, sizeof(adap->dev)); - - return 0; } EXPORT_SYMBOL(i2c_del_adapter); - /* ------------------------------------------------------------------------- */ +int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) +{ + 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) @@ -899,13 +1563,19 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver) if (res) return res; + /* Drivers should switch to dev_pm_ops instead. */ + if (driver->suspend) + pr_warn("i2c-core: driver [%s] using legacy suspend method\n", + driver->driver.name); + if (driver->resume) + pr_warn("i2c-core: driver [%s] using legacy resume method\n", + driver->driver.name); + pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); INIT_LIST_HEAD(&driver->clients); /* Walk the adapters that are already present */ - mutex_lock(&core_lock); - bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_new_driver); - mutex_unlock(&core_lock); + i2c_for_each_dev(driver, __process_new_driver); return 0; } @@ -913,9 +1583,9 @@ EXPORT_SYMBOL(i2c_register_driver); static int __process_removed_driver(struct device *dev, void *data) { - if (dev->type != &i2c_adapter_type) - return 0; - return i2c_do_del_adapter(data, to_i2c_adapter(dev)); + if (dev->type == &i2c_adapter_type) + i2c_do_del_adapter(data, to_i2c_adapter(dev)); + return 0; } /** @@ -925,9 +1595,7 @@ static int __process_removed_driver(struct device *dev, void *data) */ void i2c_del_driver(struct i2c_driver *driver) { - mutex_lock(&core_lock); - bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_removed_driver); - mutex_unlock(&core_lock); + i2c_for_each_dev(driver, __process_removed_driver); driver_unregister(&driver->driver); pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); @@ -936,21 +1604,6 @@ EXPORT_SYMBOL(i2c_del_driver); /* ------------------------------------------------------------------------- */ -static int __i2c_check_addr(struct device *dev, void *addrp) -{ - struct i2c_client *client = i2c_verify_client(dev); - int addr = *(int *)addrp; - - if (client && client->addr == addr) - return -EBUSY; - return 0; -} - -static int i2c_check_addr(struct i2c_adapter *adapter, int addr) -{ - return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); -} - /** * i2c_use_client - increments the reference count of the i2c client structure * @client: the client being referenced @@ -992,9 +1645,14 @@ 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->driver && client->driver->command) - client->driver->command(client, arg->cmd, arg->arg); + 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; } @@ -1043,6 +1701,7 @@ static void __exit i2c_exit(void) 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 @@ -1057,6 +1716,58 @@ module_exit(i2c_exit); */ /** + * __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; + + /* i2c_trace_msg 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_key_false(&i2c_trace_msg)) { + 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++) { + ret = adap->algo->master_xfer(adap, msgs, num); + if (ret != -EAGAIN) + break; + if (time_after(jiffies, orig_jiffies + adap->timeout)) + break; + } + + if (static_key_false(&i2c_trace_msg)) { + 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, i, 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 @@ -1070,8 +1781,7 @@ module_exit(i2c_exit); */ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) { - unsigned long orig_jiffies; - int ret, try; + int ret; /* REVISIT the fault reporting model here is weak: * @@ -1101,24 +1811,16 @@ int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) #endif if (in_atomic() || irqs_disabled()) { - ret = rt_mutex_trylock(&adap->bus_lock); + ret = i2c_trylock_adapter(adap); if (!ret) /* I2C activity is ongoing. */ return -EAGAIN; } else { - rt_mutex_lock(&adap->bus_lock); + i2c_lock_adapter(adap); } - /* Retry automatically on arbitration loss */ - orig_jiffies = jiffies; - for (ret = 0, try = 0; try <= adap->retries; try++) { - ret = adap->algo->master_xfer(adap, msgs, num); - if (ret != -EAGAIN) - break; - if (time_after(jiffies, orig_jiffies + adap->timeout)) - break; - } - rt_mutex_unlock(&adap->bus_lock); + ret = __i2c_transfer(adap, msgs, num); + i2c_unlock_adapter(adap); return ret; } else { @@ -1132,14 +1834,14 @@ EXPORT_SYMBOL(i2c_transfer); * i2c_master_send - issue a single I2C message in master transmit mode * @client: Handle to slave device * @buf: Data that will be written to the slave - * @count: How many bytes to write + * @count: How many bytes to write, must be less than 64k since msg.len is u16 * * Returns negative errno, or else the number of bytes written. */ -int i2c_master_send(struct i2c_client *client,const char *buf ,int count) +int i2c_master_send(const struct i2c_client *client, const char *buf, int count) { int ret; - struct i2c_adapter *adap=client->adapter; + struct i2c_adapter *adap = client->adapter; struct i2c_msg msg; msg.addr = client->addr; @@ -1149,8 +1851,10 @@ int i2c_master_send(struct i2c_client *client,const char *buf ,int count) ret = i2c_transfer(adap, &msg, 1); - /* If everything went ok (i.e. 1 msg transmitted), return #bytes - transmitted, else error code. */ + /* + * If everything went ok (i.e. 1 msg transmitted), return #bytes + * transmitted, else error code. + */ return (ret == 1) ? count : ret; } EXPORT_SYMBOL(i2c_master_send); @@ -1159,13 +1863,13 @@ EXPORT_SYMBOL(i2c_master_send); * i2c_master_recv - issue a single I2C message in master receive mode * @client: Handle to slave device * @buf: Where to store data read from slave - * @count: How many bytes to read + * @count: How many bytes to read, must be less than 64k since msg.len is u16 * * Returns negative errno, or else the number of bytes read. */ -int i2c_master_recv(struct i2c_client *client, char *buf ,int count) +int i2c_master_recv(const struct i2c_client *client, char *buf, int count) { - struct i2c_adapter *adap=client->adapter; + struct i2c_adapter *adap = client->adapter; struct i2c_msg msg; int ret; @@ -1177,8 +1881,10 @@ int i2c_master_recv(struct i2c_client *client, char *buf ,int count) ret = i2c_transfer(adap, &msg, 1); - /* If everything went ok (i.e. 1 msg transmitted), return #bytes - transmitted, else error code. */ + /* + * If everything went ok (i.e. 1 msg received), return #bytes received, + * else error code. + */ return (ret == 1) ? count : ret; } EXPORT_SYMBOL(i2c_master_recv); @@ -1189,6 +1895,46 @@ EXPORT_SYMBOL(i2c_master_recv); * ---------------------------------------------------- */ +/* + * 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) { @@ -1198,24 +1944,21 @@ static int i2c_detect_address(struct i2c_client *temp_client, int err; /* Make sure the address is valid */ - if (addr < 0x03 || addr > 0x77) { + err = i2c_check_addr_validity(addr); + if (err) { dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", addr); - return -EINVAL; + return err; } /* Skip if already in use */ - if (i2c_check_addr(adapter, addr)) + if (i2c_check_addr_busy(adapter, addr)) return 0; /* Make sure there is something at this address */ - if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0) + if (!i2c_default_probe(adapter, addr)) return 0; - /* Prevent 24RF08 corruption */ - if ((addr & ~0x0f) == 0x50) - i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL); - /* Finally call the custom detection function */ memset(&info, 0, sizeof(struct i2c_board_info)); info.addr = addr; @@ -1235,6 +1978,13 @@ static int i2c_detect_address(struct i2c_client *temp_client, 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' for details.\n", + info.addr); + dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", info.type, info.addr); client = i2c_new_device(adapter, &info); @@ -1258,92 +2008,65 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) if (!driver->detect || !address_list) 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; - /* Stop here if the classes do not match */ - if (!(adapter->class & driver->class)) - goto exit_free; - - /* Stop here if we can't use SMBUS_QUICK */ - if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { - if (address_list[0] == I2C_CLIENT_END) - goto exit_free; - - dev_warn(&adapter->dev, "SMBus Quick command not supported, " - "can't probe for chips\n"); - err = -EOPNOTSUPP; - goto exit_free; - } - 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 (err) - goto exit_free; + if (unlikely(err)) + break; } - exit_free: 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_probed_device(struct i2c_adapter *adap, struct i2c_board_info *info, - unsigned short const *addr_list) + unsigned short const *addr_list, + int (*probe)(struct i2c_adapter *, unsigned short addr)) { int i; - /* Stop here if the bus doesn't support probing */ - if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { - dev_err(&adap->dev, "Probing not supported\n"); - return NULL; - } + if (!probe) + probe = i2c_default_probe; for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { /* Check address validity */ - if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { + if (i2c_check_addr_validity(addr_list[i]) < 0) { dev_warn(&adap->dev, "Invalid 7-bit address " "0x%02x\n", addr_list[i]); continue; } /* Check address availability */ - if (i2c_check_addr(adap, addr_list[i])) { + 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 - 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 byte - read instead. Also, some bus drivers don't implement - quick write, so we fallback to a byte read it that case - too. */ - if ((addr_list[i] & ~0x07) == 0x30 - || (addr_list[i] & ~0x0f) == 0x50 - || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { - union i2c_smbus_data data; - - if (i2c_smbus_xfer(adap, addr_list[i], 0, - I2C_SMBUS_READ, 0, - I2C_SMBUS_BYTE, &data) >= 0) - break; - } else { - if (i2c_smbus_xfer(adap, addr_list[i], 0, - I2C_SMBUS_WRITE, 0, - I2C_SMBUS_QUICK, NULL) >= 0) - break; - } + /* Test address responsiveness */ + if (probe(adap, addr_list[i])) + break; } if (addr_list[i] == I2C_CLIENT_END) { @@ -1356,12 +2079,12 @@ i2c_new_probed_device(struct i2c_adapter *adap, } EXPORT_SYMBOL_GPL(i2c_new_probed_device); -struct i2c_adapter* i2c_get_adapter(int id) +struct i2c_adapter *i2c_get_adapter(int nr) { struct i2c_adapter *adapter; mutex_lock(&core_lock); - adapter = idr_find(&i2c_adapter_idr, id); + adapter = idr_find(&i2c_adapter_idr, nr); if (adapter && !try_module_get(adapter->owner)) adapter = NULL; @@ -1372,7 +2095,8 @@ EXPORT_SYMBOL(i2c_get_adapter); void i2c_put_adapter(struct i2c_adapter *adap) { - module_put(adap->owner); + if (adap) + module_put(adap->owner); } EXPORT_SYMBOL(i2c_put_adapter); @@ -1383,7 +2107,7 @@ static u8 crc8(u16 data) { int i; - for(i = 0; i < 8; i++) { + for (i = 0; i < 8; i++) { if (data & 0x8000) data = data ^ POLY; data = data << 1; @@ -1396,7 +2120,7 @@ static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) { int i; - for(i = 0; i < count; i++) + for (i = 0; i < count; i++) crc = crc8((crc ^ p[i]) << 8); return crc; } @@ -1444,7 +2168,7 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) * This executes the SMBus "receive byte" protocol, returning negative errno * else the byte received from the device. */ -s32 i2c_smbus_read_byte(struct i2c_client *client) +s32 i2c_smbus_read_byte(const struct i2c_client *client) { union i2c_smbus_data data; int status; @@ -1464,9 +2188,9 @@ EXPORT_SYMBOL(i2c_smbus_read_byte); * This executes the SMBus "send byte" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) +s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) { - return i2c_smbus_xfer(client->adapter,client->addr,client->flags, + return i2c_smbus_xfer(client->adapter, client->addr, client->flags, I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); } EXPORT_SYMBOL(i2c_smbus_write_byte); @@ -1479,7 +2203,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte); * This executes the SMBus "read byte" protocol, returning negative errno * else a data byte received from the device. */ -s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) +s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) { union i2c_smbus_data data; int status; @@ -1500,13 +2224,14 @@ EXPORT_SYMBOL(i2c_smbus_read_byte_data); * This executes the SMBus "write byte" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) +s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, + u8 value) { union i2c_smbus_data data; data.byte = value; - return i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_WRITE,command, - I2C_SMBUS_BYTE_DATA,&data); + return i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, command, + I2C_SMBUS_BYTE_DATA, &data); } EXPORT_SYMBOL(i2c_smbus_write_byte_data); @@ -1518,7 +2243,7 @@ EXPORT_SYMBOL(i2c_smbus_write_byte_data); * This executes the SMBus "read word" protocol, returning negative errno * else a 16-bit unsigned "word" received from the device. */ -s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) +s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) { union i2c_smbus_data data; int status; @@ -1539,39 +2264,18 @@ EXPORT_SYMBOL(i2c_smbus_read_word_data); * This executes the SMBus "write word" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) +s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, + u16 value) { union i2c_smbus_data data; data.word = value; - return i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_WRITE,command, - I2C_SMBUS_WORD_DATA,&data); + return i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, command, + I2C_SMBUS_WORD_DATA, &data); } EXPORT_SYMBOL(i2c_smbus_write_word_data); /** - * i2c_smbus_process_call - SMBus "process call" protocol - * @client: Handle to slave device - * @command: Byte interpreted by slave - * @value: 16-bit "word" being written - * - * This executes the SMBus "process call" protocol, returning negative errno - * else a 16-bit unsigned "word" received from the device. - */ -s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) -{ - union i2c_smbus_data data; - int status; - data.word = value; - - status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, - I2C_SMBUS_WRITE, command, - I2C_SMBUS_PROC_CALL, &data); - return (status < 0) ? status : data.word; -} -EXPORT_SYMBOL(i2c_smbus_process_call); - -/** * i2c_smbus_read_block_data - SMBus "block read" protocol * @client: Handle to slave device * @command: Byte interpreted by slave @@ -1586,7 +2290,7 @@ EXPORT_SYMBOL(i2c_smbus_process_call); * support this; its emulation through I2C messaging relies on a specific * mechanism (I2C_M_RECV_LEN) which may not be implemented. */ -s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, u8 *values) { union i2c_smbus_data data; @@ -1613,7 +2317,7 @@ EXPORT_SYMBOL(i2c_smbus_read_block_data); * This executes the SMBus "block write" protocol, returning negative errno * else zero on success. */ -s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values) { union i2c_smbus_data data; @@ -1622,14 +2326,14 @@ s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, length = I2C_SMBUS_BLOCK_MAX; data.block[0] = length; memcpy(&data.block[1], values, length); - return i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_WRITE,command, - I2C_SMBUS_BLOCK_DATA,&data); + return i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_WRITE, command, + I2C_SMBUS_BLOCK_DATA, &data); } EXPORT_SYMBOL(i2c_smbus_write_block_data); /* Returns the number of read bytes */ -s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, u8 *values) { union i2c_smbus_data data; @@ -1649,7 +2353,7 @@ s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, } EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); -s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, +s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values) { union i2c_smbus_data data; @@ -1666,10 +2370,10 @@ EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); /* Simulate a SMBus command using the i2c protocol No checking of parameters is done! */ -static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, - unsigned short flags, - char read_write, u8 command, int size, - union i2c_smbus_data * data) +static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, + unsigned short flags, + char read_write, u8 command, int size, + union i2c_smbus_data *data) { /* So we need to generate a series of msgs. In the case of writing, we need to use only one message; when reading, we need two. We initialize @@ -1677,16 +2381,26 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, simpler. */ unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; - int num = read_write == I2C_SMBUS_READ?2:1; - struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, - { addr, flags | I2C_M_RD, 0, msgbuf1 } - }; + int num = read_write == I2C_SMBUS_READ ? 2 : 1; int i; u8 partial_pec = 0; int status; + struct i2c_msg msg[2] = { + { + .addr = addr, + .flags = flags, + .len = 1, + .buf = msgbuf0, + }, { + .addr = addr, + .flags = flags | I2C_M_RD, + .len = 0, + .buf = msgbuf1, + }, + }; msgbuf0[0] = command; - switch(size) { + switch (size) { case I2C_SMBUS_QUICK: msg[0].len = 0; /* Special case: The read/write field is used as data */ @@ -1713,7 +2427,7 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, if (read_write == I2C_SMBUS_READ) msg[1].len = 2; else { - msg[0].len=3; + msg[0].len = 3; msgbuf0[1] = data->word & 0xff; msgbuf0[2] = data->word >> 8; } @@ -1806,26 +2520,26 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, } if (read_write == I2C_SMBUS_READ) - switch(size) { - case I2C_SMBUS_BYTE: - data->byte = msgbuf0[0]; - break; - case I2C_SMBUS_BYTE_DATA: - data->byte = msgbuf1[0]; - break; - case I2C_SMBUS_WORD_DATA: - case I2C_SMBUS_PROC_CALL: - data->word = msgbuf1[0] | (msgbuf1[1] << 8); - break; - case I2C_SMBUS_I2C_BLOCK_DATA: - for (i = 0; i < data->block[0]; i++) - data->block[i+1] = msgbuf1[i]; - break; - case I2C_SMBUS_BLOCK_DATA: - case I2C_SMBUS_BLOCK_PROC_CALL: - for (i = 0; i < msgbuf1[0] + 1; i++) - data->block[i] = msgbuf1[i]; - break; + switch (size) { + case I2C_SMBUS_BYTE: + data->byte = msgbuf0[0]; + break; + case I2C_SMBUS_BYTE_DATA: + data->byte = msgbuf1[0]; + break; + case I2C_SMBUS_WORD_DATA: + case I2C_SMBUS_PROC_CALL: + data->word = msgbuf1[0] | (msgbuf1[1] << 8); + break; + case I2C_SMBUS_I2C_BLOCK_DATA: + for (i = 0; i < data->block[0]; i++) + data->block[i+1] = msgbuf1[i]; + break; + case I2C_SMBUS_BLOCK_DATA: + case I2C_SMBUS_BLOCK_PROC_CALL: + for (i = 0; i < msgbuf1[0] + 1; i++) + data->block[i] = msgbuf1[i]; + break; } return 0; } @@ -1851,10 +2565,18 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, int try; s32 res; - flags &= I2C_M_TEN | I2C_CLIENT_PEC; + /* If enabled, the following two tracepoints are conditional on + * read_write and protocol. + */ + trace_smbus_write(adapter, addr, flags, read_write, + command, protocol, data); + trace_smbus_read(adapter, addr, flags, read_write, + command, protocol); + + flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; if (adapter->algo->smbus_xfer) { - rt_mutex_lock(&adapter->bus_lock); + i2c_lock_adapter(adapter); /* Retry automatically on arbitration loss */ orig_jiffies = jiffies; @@ -1868,10 +2590,25 @@ s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, orig_jiffies + adapter->timeout)) break; } - rt_mutex_unlock(&adapter->bus_lock); - } else - res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, - command, protocol, data); + i2c_unlock_adapter(adapter); + + if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) + goto trace; + /* + * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't + * implement native support for the SMBus operation. + */ + } + + res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, + command, protocol, data); + +trace: + /* If enabled, the reply tracepoint is conditional on read_write. */ + trace_smbus_reply(adapter, addr, flags, read_write, + command, protocol, data); + trace_smbus_result(adapter, addr, flags, read_write, + command, protocol, res); return res; } |