diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 2377 |
1 files changed, 1691 insertions, 686 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 8b645c6b2cb..7c7f4b856ba 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -14,193 +14,472 @@ 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/seq_file.h> -#include <linux/platform_device.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 <asm/semaphore.h> #include "i2c-core.h" +#define CREATE_TRACE_POINTS +#include <trace/events/i2c.h> +/* core_lock protects i2c_adapter_idr, and guarantees + that device detection, deletion of detected devices, and attach_adapter + calls are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); -#define is_newstyle_driver(d) ((d)->probe || (d)->remove) +static struct device_type i2c_client_type; +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, + const struct i2c_client *client) +{ + while (id->name[0]) { + if (strcmp(client->name, id->name) == 0) + return id; + id++; + } + return NULL; +} + static int i2c_device_match(struct device *dev, struct device_driver *drv) { - struct i2c_client *client = to_i2c_client(dev); - struct i2c_driver *driver = to_i2c_driver(drv); + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; - /* make legacy i2c drivers bypass driver model probing entirely; - * such drivers scan each i2c adapter/bus themselves. - */ - if (!is_newstyle_driver(driver)) + if (!client) return 0; - /* new style drivers use the same kind of driver matching policy - * as platform devices or SPI: compare device and driver IDs. - */ - return strcmp(client->driver_name, drv->name) == 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) + return i2c_match_id(driver->id_table, client) != NULL; + + 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; - /* by definition, legacy drivers can't hotplug */ - if (dev->driver || !client->driver_name) - return 0; + rc = acpi_device_uevent_modalias(dev, env); + if (rc != -ENODEV) + return rc; - if (add_uevent_var(env, "MODALIAS=%s", client->driver_name)) + if (add_uevent_var(env, "MODALIAS=%s%s", + I2C_MODULE_PREFIX, client->name)) return -ENOMEM; dev_dbg(dev, "uevent\n"); 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) { - struct i2c_client *client = to_i2c_client(dev); - struct i2c_driver *driver = to_i2c_driver(dev->driver); + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; int status; - if (!driver->probe) + if (!client) + return 0; + + 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"); - status = driver->probe(client); + + 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; } static int i2c_device_remove(struct device *dev) { - struct i2c_client *client = to_i2c_client(dev); + struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; - int status; + int status = 0; - if (!dev->driver) + if (!client || !dev->driver) return 0; driver = to_i2c_driver(dev->driver); 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; } static void i2c_device_shutdown(struct device *dev) { + struct i2c_client *client = i2c_verify_client(dev); struct i2c_driver *driver; - if (!dev->driver) + if (!client || !dev->driver) return; driver = to_i2c_driver(dev->driver); if (driver->shutdown) - driver->shutdown(to_i2c_client(dev)); + driver->shutdown(client); } -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; - if (!dev->driver) + if (!client || !dev->driver) return 0; driver = to_i2c_driver(dev->driver); if (!driver->suspend) return 0; - return driver->suspend(to_i2c_client(dev), 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; - if (!dev->driver) + if (!client || !dev->driver) return 0; driver = to_i2c_driver(dev->driver); if (!driver->resume) return 0; - return driver->resume(to_i2c_client(dev)); + return driver->resume(client); } -static void i2c_client_release(struct device *dev) +static int i2c_device_pm_suspend(struct device *dev) { - struct i2c_client *client = to_i2c_client(dev); - complete(&client->released); + 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)); } -static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t +show_name(struct device *dev, struct device_attribute *attr, char *buf) { - struct i2c_client *client = to_i2c_client(dev); - return sprintf(buf, "%s\n", client->name); + return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? + to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); } -static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t +show_modalias(struct device *dev, struct device_attribute *attr, char *buf) { struct i2c_client *client = to_i2c_client(dev); - return client->driver_name - ? sprintf(buf, "%s\n", client->driver_name) - : 0; + 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); } -static struct device_attribute i2c_dev_attrs[] = { - __ATTR(name, S_IRUGO, show_client_name, NULL), +static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); +static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); + +static struct attribute *i2c_dev_attrs[] = { + &dev_attr_name.attr, /* modalias helps coldplug: modprobe $(cat .../modalias) */ - __ATTR(modalias, S_IRUGO, show_modalias, NULL), - { }, + &dev_attr_modalias.attr, + NULL +}; + +static struct attribute_group i2c_dev_attr_group = { + .attrs = i2c_dev_attrs, +}; + +static const struct attribute_group *i2c_dev_attr_groups[] = { + &i2c_dev_attr_group, + NULL }; -static struct bus_type i2c_bus_type = { +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 = { .name = "i2c", - .dev_attrs = i2c_dev_attrs, .match = i2c_device_match, - .uevent = i2c_device_uevent, .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); + +static struct device_type i2c_client_type = { + .groups = i2c_dev_attr_groups, + .uevent = i2c_device_uevent, + .release = i2c_client_dev_release, }; @@ -215,23 +494,176 @@ static struct bus_type i2c_bus_type = { */ struct i2c_client *i2c_verify_client(struct device *dev) { - return (dev->bus == &i2c_bus_type) + return (dev->type == &i2c_client_type) ? to_i2c_client(dev) : NULL; } 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 for use with a new style driver + * 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 * - * Create a device to work with a new style i2c driver, where binding is - * handled through driver model probe()/remove() methods. This call is not - * appropriate for use by mainboad initialization logic, which usually runs - * during an arch_initcall() long before any i2c_adapter could exist. + * 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 NULL to indicate an error. @@ -249,27 +681,51 @@ i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) client->adapter = adap; client->dev.platform_data = info->platform_data; - device_init_wakeup(&client->dev, info->flags & I2C_CLIENT_WAKE); - client->flags = info->flags & ~I2C_CLIENT_WAKE; + if (info->archdata) + client->dev.archdata = *info->archdata; + + client->flags = info->flags; client->addr = info->addr; client->irq = info->irq; - strlcpy(client->driver_name, info->driver_name, - sizeof(client->driver_name)); strlcpy(client->name, info->type, sizeof(client->name)); - /* a new style 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). and the device - * refcount model is the standard driver model one. - */ - status = i2c_attach_client(client); - if (status < 0) { - kfree(client); - client = NULL; + /* 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_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); + + i2c_dev_set_name(adap, client); + status = device_register(&client->dev); + if (status) + goto out_err; + + dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", + client->name, dev_name(&client->dev)); + return client; + +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; } EXPORT_SYMBOL_GPL(i2c_new_device); @@ -281,41 +737,38 @@ EXPORT_SYMBOL_GPL(i2c_new_device); */ void i2c_unregister_device(struct i2c_client *client) { - struct i2c_adapter *adapter = client->adapter; - struct i2c_driver *driver = client->driver; - - if (driver && !is_newstyle_driver(driver)) { - dev_err(&client->dev, "can't unregister devices " - "with legacy drivers\n"); - WARN_ON(1); - return; - } - - mutex_lock(&adapter->clist_lock); - list_del(&client->list); - mutex_unlock(&adapter->clist_lock); - device_unregister(&client->dev); } EXPORT_SYMBOL_GPL(i2c_unregister_device); -static int dummy_nop(struct i2c_client *client) +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_nop, - .remove = dummy_nop, + .probe = dummy_probe, + .remove = dummy_remove, + .id_table = dummy_id, }; /** * i2c_new_dummy - return a new i2c device bound to a dummy driver * @adapter: the adapter managing the device * @address: seven bit address to be used - * @type: optional label used for i2c_client.name * Context: can sleep * * This returns an I2C client bound to the "dummy" driver, intended for use @@ -330,16 +783,12 @@ static struct i2c_driver dummy_driver = { * This returns the new i2c client, which should be saved for later use with * i2c_unregister_device(); or NULL to indicate an error. */ -struct i2c_client * -i2c_new_dummy(struct i2c_adapter *adapter, u16 address, const char *type) +struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) { struct i2c_board_info info = { - .driver_name = "dummy", - .addr = address, + I2C_BOARD_INFO("dummy", address), }; - if (type) - strlcpy(info.type, type, sizeof info.type); return i2c_new_device(adapter, &info); } EXPORT_SYMBOL_GPL(i2c_new_dummy); @@ -354,95 +803,533 @@ static void i2c_adapter_dev_release(struct device *dev) complete(&adap->dev_released); } +/* + * 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 + * 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 -show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) +i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) { struct i2c_adapter *adap = to_i2c_adapter(dev); - return sprintf(buf, "%s\n", adap->name); + 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; + } + + client = i2c_new_device(adap, &info); + if (!client) + return -EINVAL; + + /* 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 struct device_attribute i2c_adapter_attrs[] = { - __ATTR(name, S_IRUGO, show_adapter_name, NULL), - { }, +/* + * 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 +i2c_sysfs_delete_device(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 (client->addr == 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(new_device, S_IWUSR, NULL, i2c_sysfs_new_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, + &dev_attr_new_device.attr, + &dev_attr_delete_device.attr, + NULL }; -static struct class i2c_adapter_class = { - .owner = THIS_MODULE, - .name = "i2c-adapter", - .dev_attrs = i2c_adapter_attrs, +static struct attribute_group i2c_adapter_attr_group = { + .attrs = i2c_adapter_attrs, }; +static const struct attribute_group *i2c_adapter_attr_groups[] = { + &i2c_adapter_attr_group, + NULL +}; + +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; +#endif + static void i2c_scan_static_board_info(struct i2c_adapter *adapter) { struct i2c_devinfo *devinfo; - mutex_lock(&__i2c_board_lock); + down_read(&__i2c_board_lock); list_for_each_entry(devinfo, &__i2c_board_list, list) { if (devinfo->busnum == adapter->nr && !i2c_new_device(adapter, &devinfo->board_info)) - printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n", - i2c_adapter_id(adapter), + dev_err(&adapter->dev, + "Can't create device at 0x%02x\n", devinfo->board_info.addr); } - mutex_unlock(&__i2c_board_lock); + 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; } -static int i2c_do_add_adapter(struct device_driver *d, void *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 i2c_driver *driver = to_i2c_driver(d); - struct i2c_adapter *adap = data; + 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) +{ + /* Detect supported devices on that bus, and instantiate them */ + i2c_detect(adap, 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); } return 0; } -static int i2c_register_adapter(struct i2c_adapter *adap) +static int __process_new_adapter(struct device_driver *d, void *data) { - int res = 0, dummy; + return i2c_do_add_adapter(to_i2c_driver(d), data); +} - mutex_init(&adap->bus_lock); - mutex_init(&adap->clist_lock); - INIT_LIST_HEAD(&adap->clients); +static int i2c_register_adapter(struct i2c_adapter *adap) +{ + int res = 0; - mutex_lock(&core_lock); + /* Can't register until after driver model init */ + if (unlikely(WARN_ON(!i2c_bus_type.p))) { + res = -EAGAIN; + goto out_list; + } - /* Add the adapter to the driver core. - * If the parent pointer is not set up, - * we add this adapter to the host bus. - */ - if (adap->dev.parent == NULL) { - adap->dev.parent = &platform_bus; - pr_debug("I2C adapter driver [%s] forgot to specify " - "physical device\n", adap->name); + /* Sanity checks */ + if (unlikely(adap->name[0] == '\0')) { + pr_err("i2c-core: Attempt to register an adapter with " + "no name!\n"); + return -EINVAL; } - sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); - adap->dev.release = &i2c_adapter_dev_release; - adap->dev.class = &i2c_adapter_class; + 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) + adap->timeout = HZ; + + 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) goto out_list; dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); - /* create pre-declared device nodes for new-style drivers */ +#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 + + /* 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); - /* let legacy drivers scan this bus for matching devices */ - dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, - i2c_do_add_adapter); - -out_unlock: + /* Notify drivers */ + mutex_lock(&core_lock); + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); mutex_unlock(&core_lock); - return res; + + return 0; out_list: + mutex_lock(&core_lock); idr_remove(&i2c_adapter_idr, adap->nr); - goto out_unlock; + 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 (id < 0) + return id == -ENOSPC ? -EBUSY : id; + + return i2c_register_adapter(adap); } /** @@ -451,8 +1338,9 @@ out_list: * 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. @@ -460,25 +1348,26 @@ out_list: */ int i2c_add_adapter(struct i2c_adapter *adapter) { - int id, res = 0; - -retry: - if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) - return -ENOMEM; + 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); - /* "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); @@ -493,6 +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. @@ -505,48 +1397,50 @@ EXPORT_SYMBOL(i2c_add_adapter); */ int i2c_add_numbered_adapter(struct i2c_adapter *adap) { - int id; - int status; + if (adap->nr == -1) /* -1 means dynamically assign bus id */ + return i2c_add_adapter(adap); - if (adap->nr & ~MAX_ID_MASK) - return -EINVAL; + return __i2c_add_numbered_adapter(adap); +} +EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); -retry: - if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) - return -ENOMEM; +static void i2c_do_del_adapter(struct i2c_driver *driver, + struct i2c_adapter *adapter) +{ + struct i2c_client *client, *_n; - 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); + /* 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); + } } - mutex_unlock(&core_lock); - if (status == -EAGAIN) - goto retry; +} - if (status == 0) - status = i2c_register_adapter(adap); - return status; +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; } -EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); -static int i2c_do_del_adapter(struct device_driver *d, void *data) +static int __unregister_dummy(struct device *dev, void *dummy) { - struct i2c_driver *driver = to_i2c_driver(d); - struct i2c_adapter *adapter = data; - int res; + struct i2c_client *client = i2c_verify_client(dev); + if (client) + i2c_unregister_device(client); + return 0; +} - 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 __process_removed_adapter(struct device_driver *d, void *data) +{ + i2c_do_del_adapter(to_i2c_driver(d), data); + return 0; } /** @@ -557,50 +1451,54 @@ static int i2c_do_del_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) { - struct list_head *item, *_n; - struct i2c_client *client; - int res = 0; - - mutex_lock(&core_lock); + struct i2c_adapter *found; + struct i2c_client *client, *next; /* First make sure that this adapter was ever added */ - if (idr_find(&i2c_adapter_idr, adap->nr) != adap) { + mutex_lock(&core_lock); + found = idr_find(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); + if (found != adap) { pr_debug("i2c-core: attempting to delete unregistered " "adapter [%s]\n", adap->name); - res = -EINVAL; - goto out_unlock; + return; } /* Tell drivers about this removal */ - res = bus_for_each_drv(&i2c_bus_type, NULL, adap, - i2c_do_del_adapter); - if (res) - goto out_unlock; - - /* detach any active clients. This must be done first, because - * it can fail; in which case we give up. */ - list_for_each_safe(item, _n, &adap->clients) { - struct i2c_driver *driver; - - client = list_entry(item, struct i2c_client, list); - driver = client->driver; - - /* new style, follow standard driver model */ - if (!driver || is_newstyle_driver(driver)) { - i2c_unregister_device(client); - continue; - } + mutex_lock(&core_lock); + bus_for_each_drv(&i2c_bus_type, NULL, adap, + __process_removed_adapter); + mutex_unlock(&core_lock); - /* legacy drivers create and remove clients themselves */ - if ((res = driver->detach_client(client))) { - dev_err(&adap->dev, "detach_client failed for client " - "[%s] at address 0x%02x\n", client->name, - client->addr); - goto out_unlock; - } + /* 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); /* clean up the sysfs representation */ init_completion(&adap->dev_released); @@ -610,75 +1508,86 @@ int i2c_del_adapter(struct i2c_adapter *adap) wait_for_completion(&adap->dev_released); /* free bus id */ + mutex_lock(&core_lock); 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)); +} +EXPORT_SYMBOL(i2c_del_adapter); + +/* ------------------------------------------------------------------------- */ - out_unlock: +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(i2c_del_adapter); - +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. There - * are two models for binding the driver to its device: "new style" drivers - * follow the standard Linux driver model and just respond to probe() calls - * issued if the driver core sees they match(); "legacy" drivers create device - * nodes themselves. + * 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; - /* new style driver methods can't mix with legacy ones */ - if (is_newstyle_driver(driver)) { - if (driver->attach_adapter || driver->detach_adapter - || driver->detach_client) { - printk(KERN_WARNING - "i2c-core: driver [%s] is confused\n", - driver->driver.name); - return -EINVAL; - } - } + /* Can't register until after driver model init */ + if (unlikely(WARN_ON(!i2c_bus_type.p))) + 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; - /* for new style drivers, when registration returns the driver core + /* 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; - mutex_lock(&core_lock); + /* 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); - /* legacy drivers scan i2c busses directly */ - if (driver->attach_adapter) { - struct i2c_adapter *adapter; - - down(&i2c_adapter_class.sem); - list_for_each_entry(adapter, &i2c_adapter_class.devices, - dev.node) { - driver->attach_adapter(adapter); - } - up(&i2c_adapter_class.sem); - } + INIT_LIST_HEAD(&driver->clients); + /* Walk the adapters that are already present */ + i2c_for_each_dev(driver, __process_new_driver); - mutex_unlock(&core_lock); 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 @@ -686,147 +1595,15 @@ EXPORT_SYMBOL(i2c_register_driver); */ void i2c_del_driver(struct i2c_driver *driver) { - struct list_head *item2, *_n; - struct i2c_client *client; - struct i2c_adapter *adap; - - mutex_lock(&core_lock); - - /* new-style driver? */ - if (is_newstyle_driver(driver)) - goto unregister; + i2c_for_each_dev(driver, __process_removed_driver); - /* Have a look at each adapter, if clients of this driver are still - * attached. If so, detach them to be able to kill the driver - * afterwards. - */ - down(&i2c_adapter_class.sem); - list_for_each_entry(adap, &i2c_adapter_class.devices, dev.node) { - if (driver->detach_adapter) { - if (driver->detach_adapter(adap)) { - dev_err(&adap->dev, "detach_adapter failed " - "for driver [%s]\n", - driver->driver.name); - } - } else { - list_for_each_safe(item2, _n, &adap->clients) { - client = list_entry(item2, struct i2c_client, list); - if (client->driver != driver) - continue; - dev_dbg(&adap->dev, "detaching client [%s] " - "at 0x%02x\n", client->name, - client->addr); - if (driver->detach_client(client)) { - dev_err(&adap->dev, "detach_client " - "failed for client [%s] at " - "0x%02x\n", client->name, - client->addr); - } - } - } - } - up(&i2c_adapter_class.sem); - - unregister: driver_unregister(&driver->driver); pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); - - mutex_unlock(&core_lock); } 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); -} - -int i2c_attach_client(struct i2c_client *client) -{ - struct i2c_adapter *adapter = client->adapter; - int res = 0; - - client->dev.parent = &client->adapter->dev; - client->dev.bus = &i2c_bus_type; - - if (client->driver) - client->dev.driver = &client->driver->driver; - - if (client->driver && !is_newstyle_driver(client->driver)) { - client->dev.release = i2c_client_release; - client->dev.uevent_suppress = 1; - } else - client->dev.release = i2c_client_dev_release; - - snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), - "%d-%04x", i2c_adapter_id(adapter), client->addr); - res = device_register(&client->dev); - if (res) - goto out_err; - - mutex_lock(&adapter->clist_lock); - list_add_tail(&client->list, &adapter->clients); - mutex_unlock(&adapter->clist_lock); - - dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", - client->name, client->dev.bus_id); - - if (adapter->client_register) { - if (adapter->client_register(client)) { - dev_dbg(&adapter->dev, "client_register " - "failed for client [%s] at 0x%02x\n", - client->name, client->addr); - } - } - - return 0; - -out_err: - dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x " - "(%d)\n", client->name, client->addr, res); - return res; -} -EXPORT_SYMBOL(i2c_attach_client); - -int i2c_detach_client(struct i2c_client *client) -{ - struct i2c_adapter *adapter = client->adapter; - int res = 0; - - if (adapter->client_unregister) { - res = adapter->client_unregister(client); - if (res) { - dev_err(&client->dev, - "client_unregister [%s] failed, " - "client not detached\n", client->name); - goto out; - } - } - - mutex_lock(&adapter->clist_lock); - list_del(&client->list); - mutex_unlock(&adapter->clist_lock); - - init_completion(&client->released); - device_unregister(&client->dev); - wait_for_completion(&client->released); - - out: - return res; -} -EXPORT_SYMBOL(i2c_detach_client); - /** * i2c_use_client - increments the reference count of the i2c client structure * @client: the client being referenced @@ -840,8 +1617,9 @@ EXPORT_SYMBOL(i2c_detach_client); */ struct i2c_client *i2c_use_client(struct i2c_client *client) { - get_device(&client->dev); - return client; + if (client && get_device(&client->dev)) + return client; + return NULL; } EXPORT_SYMBOL(i2c_use_client); @@ -853,7 +1631,8 @@ EXPORT_SYMBOL(i2c_use_client); */ void i2c_release_client(struct i2c_client *client) { - put_device(&client->dev); + if (client) + put_device(&client->dev); } EXPORT_SYMBOL(i2c_release_client); @@ -866,9 +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->dev.driver) + return 0; - if (client && client->driver && client->driver->command) - client->driver->command(client, arg->cmd, arg->arg); + driver = to_i2c_driver(client->dev.driver); + if (driver->command) + driver->command(client, arg->cmd, arg->arg); return 0; } @@ -889,17 +1673,23 @@ static int __init i2c_init(void) retval = bus_register(&i2c_bus_type); if (retval) return retval; - retval = class_register(&i2c_adapter_class); - if (retval) +#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; return 0; class_err: - class_unregister(&i2c_adapter_class); +#ifdef CONFIG_I2C_COMPAT + class_compat_unregister(i2c_adapter_compat_class); bus_err: +#endif bus_unregister(&i2c_bus_type); return retval; } @@ -907,11 +1697,17 @@ bus_err: static void __exit i2c_exit(void) { i2c_del_driver(&dummy_driver); - class_unregister(&i2c_adapter_class); +#ifdef CONFIG_I2C_COMPAT + class_compat_unregister(i2c_adapter_compat_class); +#endif bus_unregister(&i2c_bus_type); + tracepoint_synchronize_unregister(); } -subsys_initcall(i2c_init); +/* 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); /* ---------------------------------------------------- @@ -919,10 +1715,91 @@ module_exit(i2c_exit); * ---------------------------------------------------- */ -int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) +/** + * __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 + * 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; + /* 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). + */ + if (adap->algo->master_xfer) { #ifdef DEBUG for (ret = 0; ret < num; ret++) { @@ -934,29 +1811,37 @@ int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) #endif if (in_atomic() || irqs_disabled()) { - ret = mutex_trylock(&adap->bus_lock); + ret = i2c_trylock_adapter(adap); if (!ret) /* I2C activity is ongoing. */ return -EAGAIN; } else { - mutex_lock_nested(&adap->bus_lock, adap->level); + i2c_lock_adapter(adap); } - ret = adap->algo->master_xfer(adap,msgs,num); - mutex_unlock(&adap->bus_lock); + ret = __i2c_transfer(adap, msgs, num); + i2c_unlock_adapter(adap); return ret; } else { dev_dbg(&adap->dev, "I2C level transfers not supported\n"); - return -ENOSYS; + return -EOPNOTSUPP; } } EXPORT_SYMBOL(i2c_transfer); -int i2c_master_send(struct i2c_client *client,const char *buf ,int count) +/** + * 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, must be less than 64k since msg.len is u16 + * + * Returns negative errno, or else the number of bytes written. + */ +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; @@ -966,15 +1851,25 @@ 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); -int i2c_master_recv(struct i2c_client *client, char *buf ,int count) +/** + * 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, must be less than 64k since msg.len is u16 + * + * Returns negative errno, or else the number of bytes read. + */ +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; @@ -986,8 +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); @@ -997,192 +1894,179 @@ EXPORT_SYMBOL(i2c_master_recv); * Will not work for 10-bit addresses! * ---------------------------------------------------- */ -static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, - int (*found_proc) (struct i2c_adapter *, int, int)) + +/* + * 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 */ - 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, unless forced */ - if (kind < 0) { - if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, - I2C_SMBUS_QUICK, NULL) < 0) - return 0; + /* Make sure there is something at this address */ + 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; + 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; } - /* Finally call the custom detection function */ - err = found_proc(adapter, addr, kind); - /* -ENODEV can be returned if there is a chip at the given address - but it isn't supported by this chip driver. We catch it here as - this isn't an error. */ - if (err == -ENODEV) - err = 0; - - if (err) - dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n", - addr, err); - return 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' 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); + if (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; } -int i2c_probe(struct i2c_adapter *adapter, - const struct i2c_client_address_data *address_data, - int (*found_proc) (struct i2c_adapter *, int, int)) +static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) { - int i, err; + const unsigned short *address_list; + struct i2c_client *temp_client; + int i, err = 0; int adap_id = i2c_adapter_id(adapter); - /* Force entries are done first, and are not affected by ignore - entries */ - if (address_data->forces) { - const unsigned short * const *forces = address_data->forces; - int kind; - - for (kind = 0; forces[kind]; kind++) { - for (i = 0; forces[kind][i] != I2C_CLIENT_END; - i += 2) { - if (forces[kind][i] == adap_id - || forces[kind][i] == ANY_I2C_BUS) { - dev_dbg(&adapter->dev, "found force " - "parameter for adapter %d, " - "addr 0x%02x, kind %d\n", - adap_id, forces[kind][i + 1], - kind); - err = i2c_probe_address(adapter, - forces[kind][i + 1], - kind, found_proc); - if (err) - return err; - } - } - } - } - - /* Stop here if we can't use SMBUS_QUICK */ - if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { - if (address_data->probe[0] == I2C_CLIENT_END - && address_data->normal_i2c[0] == I2C_CLIENT_END) - return 0; - - dev_warn(&adapter->dev, "SMBus Quick command not supported, " - "can't probe for chips\n"); - return -1; - } + address_list = driver->address_list; + if (!driver->detect || !address_list) + return 0; - /* Probe entries are done second, and are not affected by ignore - entries either */ - for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { - if (address_data->probe[i] == adap_id - || address_data->probe[i] == ANY_I2C_BUS) { - dev_dbg(&adapter->dev, "found probe parameter for " - "adapter %d, addr 0x%02x\n", adap_id, - address_data->probe[i + 1]); - err = i2c_probe_address(adapter, - address_data->probe[i + 1], - -1, found_proc); - if (err) - return err; - } - } + /* Stop here if the classes do not match */ + if (!(adapter->class & driver->class)) + return 0; - /* Normal entries are done last, unless shadowed by an ignore entry */ - for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { - int j, ignore; - - ignore = 0; - for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; - j += 2) { - if ((address_data->ignore[j] == adap_id || - address_data->ignore[j] == ANY_I2C_BUS) - && address_data->ignore[j + 1] - == address_data->normal_i2c[i]) { - dev_dbg(&adapter->dev, "found ignore " - "parameter for adapter %d, " - "addr 0x%02x\n", adap_id, - address_data->ignore[j + 1]); - ignore = 1; - break; - } - } - if (ignore) - continue; + /* 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_data->normal_i2c[i]); - err = i2c_probe_address(adapter, address_data->normal_i2c[i], - -1, found_proc); - if (err) - return err; + "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; } - return 0; + kfree(temp_client); + return err; } -EXPORT_SYMBOL(i2c_probe); + +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)) { - if (i2c_smbus_xfer(adap, addr_list[i], 0, - I2C_SMBUS_READ, 0, - I2C_SMBUS_BYTE, NULL) >= 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) { @@ -1195,12 +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 = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id); + adapter = idr_find(&i2c_adapter_idr, nr); if (adapter && !try_module_get(adapter->owner)) adapter = NULL; @@ -1211,19 +2095,19 @@ 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); /* The SMBus parts */ #define POLY (0x1070U << 3) -static u8 -crc8(u16 data) +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; @@ -1236,7 +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; } @@ -1272,110 +2156,168 @@ static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) if (rpec != cpec) { pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", rpec, cpec); - return -1; + return -EBADMSG; } return 0; } -s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value) -{ - return i2c_smbus_xfer(client->adapter,client->addr,client->flags, - value,0,I2C_SMBUS_QUICK,NULL); -} -EXPORT_SYMBOL(i2c_smbus_write_quick); - -s32 i2c_smbus_read_byte(struct i2c_client *client) +/** + * i2c_smbus_read_byte - SMBus "receive byte" protocol + * @client: Handle to slave device + * + * This executes the SMBus "receive byte" protocol, returning negative errno + * else the byte received from the device. + */ +s32 i2c_smbus_read_byte(const struct i2c_client *client) { union i2c_smbus_data data; - if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_READ,0,I2C_SMBUS_BYTE, &data)) - return -1; - else - return data.byte; + int status; + + status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, 0, + I2C_SMBUS_BYTE, &data); + return (status < 0) ? status : data.byte; } EXPORT_SYMBOL(i2c_smbus_read_byte); -s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) +/** + * i2c_smbus_write_byte - SMBus "send byte" protocol + * @client: Handle to slave device + * @value: Byte to be sent + * + * This executes the SMBus "send byte" protocol, returning negative errno + * else zero on success. + */ +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); -s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) +/** + * i2c_smbus_read_byte_data - SMBus "read byte" protocol + * @client: Handle to slave device + * @command: Byte interpreted by slave + * + * This executes the SMBus "read byte" protocol, returning negative errno + * else a data byte received from the device. + */ +s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) { union i2c_smbus_data data; - if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_READ,command, I2C_SMBUS_BYTE_DATA,&data)) - return -1; - else - return data.byte; + int status; + + status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, command, + I2C_SMBUS_BYTE_DATA, &data); + return (status < 0) ? status : data.byte; } EXPORT_SYMBOL(i2c_smbus_read_byte_data); -s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) +/** + * i2c_smbus_write_byte_data - SMBus "write byte" protocol + * @client: Handle to slave device + * @command: Byte interpreted by slave + * @value: Byte being written + * + * This executes the SMBus "write byte" protocol, returning negative errno + * else zero on success. + */ +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); -s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) +/** + * i2c_smbus_read_word_data - SMBus "read word" protocol + * @client: Handle to slave device + * @command: Byte interpreted by slave + * + * 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(const struct i2c_client *client, u8 command) { union i2c_smbus_data data; - if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_READ,command, I2C_SMBUS_WORD_DATA, &data)) - return -1; - else - return data.word; + int status; + + status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, command, + I2C_SMBUS_WORD_DATA, &data); + return (status < 0) ? status : data.word; } EXPORT_SYMBOL(i2c_smbus_read_word_data); -s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) +/** + * i2c_smbus_write_word_data - SMBus "write word" protocol + * @client: Handle to slave device + * @command: Byte interpreted by slave + * @value: 16-bit "word" being written + * + * This executes the SMBus "write word" protocol, returning negative errno + * else zero on success. + */ +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_read_block_data - SMBus block read request + * i2c_smbus_read_block_data - SMBus "block read" protocol * @client: Handle to slave device - * @command: Command byte issued to let the slave know what data should - * be returned + * @command: Byte interpreted by slave * @values: Byte array into which data will be read; big enough to hold * the data returned by the slave. SMBus allows at most 32 bytes. * - * Returns the number of bytes read in the slave's response, else a - * negative number to indicate some kind of error. + * This executes the SMBus "block read" protocol, returning negative errno + * else the number of data bytes in the slave's response. * * Note that using this function requires that the client's adapter support * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers * 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; + int status; - if (i2c_smbus_xfer(client->adapter, client->addr, client->flags, - I2C_SMBUS_READ, command, - I2C_SMBUS_BLOCK_DATA, &data)) - return -1; + status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, command, + I2C_SMBUS_BLOCK_DATA, &data); + if (status) + return status; memcpy(values, &data.block[1], data.block[0]); return data.block[0]; } EXPORT_SYMBOL(i2c_smbus_read_block_data); -s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, +/** + * i2c_smbus_write_block_data - SMBus "block write" protocol + * @client: Handle to slave device + * @command: Byte interpreted by slave + * @length: Size of data block; SMBus allows at most 32 bytes + * @values: Byte array which will be written. + * + * This executes the SMBus "block write" protocol, returning negative errno + * else zero on success. + */ +s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values) { union i2c_smbus_data data; @@ -1384,32 +2326,34 @@ 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; + int status; if (length > I2C_SMBUS_BLOCK_MAX) length = I2C_SMBUS_BLOCK_MAX; data.block[0] = length; - if (i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_READ,command, - I2C_SMBUS_I2C_BLOCK_DATA,&data)) - return -1; + status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, command, + I2C_SMBUS_I2C_BLOCK_DATA, &data); + if (status < 0) + return status; memcpy(values, &data.block[1], data.block[0]); return data.block[0]; } 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; @@ -1426,10 +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 @@ -1437,19 +2381,31 @@ 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 */ - msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0; + msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? + I2C_M_RD : 0); num = 1; break; case I2C_SMBUS_BYTE: @@ -1471,7 +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; } @@ -1492,10 +2448,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, } else { msg[0].len = data->block[0] + 2; if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { - dev_err(&adapter->dev, "smbus_access called with " - "invalid block write size (%d)\n", - data->block[0]); - return -1; + dev_err(&adapter->dev, + "Invalid block write size %d\n", + data->block[0]); + return -EINVAL; } for (i = 1; i < msg[0].len; i++) msgbuf0[i] = data->block[i-1]; @@ -1505,10 +2461,10 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, num = 2; /* Another special case */ read_write = I2C_SMBUS_READ; if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { - dev_err(&adapter->dev, "%s called with invalid " - "block proc call size (%d)\n", __FUNCTION__, + dev_err(&adapter->dev, + "Invalid block write size %d\n", data->block[0]); - return -1; + return -EINVAL; } msg[0].len = data->block[0] + 2; for (i = 1; i < msg[0].len; i++) @@ -1523,19 +2479,18 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, } else { msg[0].len = data->block[0] + 1; if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { - dev_err(&adapter->dev, "i2c_smbus_xfer_emulated called with " - "invalid block write size (%d)\n", - data->block[0]); - return -1; + dev_err(&adapter->dev, + "Invalid block write size %d\n", + data->block[0]); + return -EINVAL; } for (i = 1; i <= data->block[0]; i++) msgbuf0[i] = data->block[i]; } break; default: - dev_err(&adapter->dev, "smbus_access called with invalid size (%d)\n", - size); - return -1; + dev_err(&adapter->dev, "Unsupported transaction %d\n", size); + return -EOPNOTSUPP; } i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK @@ -1553,57 +2508,107 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, msg[num-1].len++; } - if (i2c_transfer(adapter, msg, num) < 0) - return -1; + status = i2c_transfer(adapter, msg, num); + if (status < 0) + return status; /* Check PEC if last message is a read */ if (i && (msg[num-1].flags & I2C_M_RD)) { - if (i2c_smbus_check_pec(partial_pec, &msg[num-1]) < 0) - return -1; + status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); + if (status < 0) + return status; } 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; } - -s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, - char read_write, u8 command, int size, - union i2c_smbus_data * data) +/** + * i2c_smbus_xfer - execute SMBus protocol operations + * @adapter: Handle to I2C bus + * @addr: Address of SMBus slave on that bus + * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) + * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE + * @command: Byte interpreted by slave, for protocols which use such bytes + * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL + * @data: Data to be read or written + * + * This executes an SMBus protocol operation, and returns a negative + * errno code else zero on success. + */ +s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, + char read_write, u8 command, int protocol, + union i2c_smbus_data *data) { + unsigned long orig_jiffies; + 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) { - mutex_lock(&adapter->bus_lock); - res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, - command,size,data); - mutex_unlock(&adapter->bus_lock); - } else - res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, - command,size,data); + i2c_lock_adapter(adapter); + + /* Retry automatically on arbitration loss */ + orig_jiffies = jiffies; + for (res = 0, try = 0; try <= adapter->retries; try++) { + res = adapter->algo->smbus_xfer(adapter, addr, flags, + read_write, command, + protocol, data); + if (res != -EAGAIN) + break; + if (time_after(jiffies, + orig_jiffies + adapter->timeout)) + break; + } + 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; } |