diff options
Diffstat (limited to 'drivers/i2c/i2c-core.c')
| -rw-r--r-- | drivers/i2c/i2c-core.c | 2739 |
1 files changed, 2095 insertions, 644 deletions
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 9cb277d6aa4..7c7f4b856ba 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -14,519 +14,1657 @@ 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>. +/* 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 "i2c-core.h" + +#define CREATE_TRACE_POINTS +#include <trace/events/i2c.h> -static LIST_HEAD(adapters); -static LIST_HEAD(drivers); -static DEFINE_MUTEX(core_lists); +/* 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); -/* match always succeeds, as we want the probe() to tell if we really accept this match */ +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) { - return 1; + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; + + 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) + return i2c_match_id(driver->id_table, client) != NULL; + + return 0; +} + + +/* 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)) + return -ENOMEM; + dev_dbg(dev, "uevent\n"); + return 0; +} + +/* 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 int i2c_bus_suspend(struct device * dev, pm_message_t state) +static void set_scl_gpio_value(struct i2c_adapter *adap, int val) { - int rc = 0; + gpio_set_value(adap->bus_recovery_info->scl_gpio, val); +} - if (dev->driver && dev->driver->suspend) - rc = dev->driver->suspend(dev, state); - return rc; +static int get_sda_gpio_value(struct i2c_adapter *adap) +{ + return gpio_get_value(adap->bus_recovery_info->sda_gpio); } -static int i2c_bus_resume(struct device * dev) +static int i2c_get_gpios_for_recovery(struct i2c_adapter *adap) { - int rc = 0; - - if (dev->driver && dev->driver->resume) - rc = dev->driver->resume(dev); - return rc; + 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) { - return -ENODEV; + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; + int status; + + if (!client) + return 0; + + driver = to_i2c_driver(dev->driver); + if (!driver->probe || !driver->id_table) + return -ENODEV; + + 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) + acpi_dev_pm_detach(&client->dev, true); + + return status; } static int i2c_device_remove(struct device *dev) { - return 0; + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; + int status = 0; + + if (!client || !dev->driver) + return 0; + + driver = to_i2c_driver(dev->driver); + if (driver->remove) { + dev_dbg(dev, "remove\n"); + status = driver->remove(client); + } + + 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 (!client || !dev->driver) + return; + driver = to_i2c_driver(dev->driver); + if (driver->shutdown) + driver->shutdown(client); } +#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 (!client || !dev->driver) + return 0; + driver = to_i2c_driver(dev->driver); + if (!driver->suspend) + return 0; + return driver->suspend(client, mesg); +} + +static int i2c_legacy_resume(struct device *dev) +{ + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_driver *driver; + + if (!client || !dev->driver) + return 0; + driver = to_i2c_driver(dev->driver); + if (!driver->resume) + return 0; + 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)); +} + +static ssize_t +show_name(struct device *dev, struct device_attribute *attr, char *buf) +{ + return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? + to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); +} + +static 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); +} + +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) */ + &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 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", - .match = i2c_device_match, - .probe = i2c_device_probe, - .remove = i2c_device_remove, - .suspend = i2c_bus_suspend, - .resume = i2c_bus_resume, + .name = "i2c", + .match = i2c_device_match, + .probe = i2c_device_probe, + .remove = i2c_device_remove, + .shutdown = i2c_device_shutdown, + .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, }; -void i2c_adapter_dev_release(struct device *dev) + +/** + * i2c_verify_client - return parameter as i2c_client, or NULL + * @dev: device, probably from some driver model iterator + * + * When traversing the driver model tree, perhaps using driver model + * iterators like @device_for_each_child(), you can't assume very much + * about the nodes you find. Use this function to avoid oopses caused + * by wrongly treating some non-I2C device as an i2c_client. + */ +struct i2c_client *i2c_verify_client(struct device *dev) { - struct i2c_adapter *adap = dev_to_i2c_adapter(dev); - complete(&adap->dev_released); + return (dev->type == &i2c_client_type) + ? to_i2c_client(dev) + : NULL; } +EXPORT_SYMBOL(i2c_verify_client); -struct device_driver i2c_adapter_driver = { - .owner = THIS_MODULE, - .name = "i2c_adapter", - .bus = &i2c_bus_type, -}; -static void i2c_adapter_class_dev_release(struct class_device *dev) +/* 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) { - struct i2c_adapter *adap = class_dev_to_i2c_adapter(dev); - complete(&adap->class_dev_released); + 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; } -struct class i2c_adapter_class = { - .owner = THIS_MODULE, - .name = "i2c-adapter", - .release = &i2c_adapter_class_dev_release, -}; +/* 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 ssize_t show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) +static int __i2c_check_addr_busy(struct device *dev, void *addrp) { - struct i2c_adapter *adap = dev_to_i2c_adapter(dev); - return sprintf(buf, "%s\n", adap->name); + struct i2c_client *client = i2c_verify_client(dev); + int addr = *(int *)addrp; + + if (client && client->addr == addr) + return -EBUSY; + return 0; } -static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); +/* 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); -static void i2c_client_release(struct device *dev) + return result; +} + +/* recurse down mux tree */ +static int i2c_check_mux_children(struct device *dev, void *addrp) { - struct i2c_client *client = to_i2c_client(dev); - complete(&client->released); + 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 ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf) +static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) { - struct i2c_client *client = to_i2c_client(dev); - return sprintf(buf, "%s\n", client->name); + 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; } -/* - * We can't use the DEVICE_ATTR() macro here as we want the same filename for a - * different type of a device. So beware if the DEVICE_ATTR() macro ever - * changes, this definition will also have to change. +/** + * i2c_lock_adapter - Get exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment */ -static struct device_attribute dev_attr_client_name = { - .attr = {.name = "name", .mode = S_IRUGO, .owner = THIS_MODULE }, - .show = &show_client_name, -}; +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); -/* --------------------------------------------------- - * registering functions - * --------------------------------------------------- +/** + * 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_add_adapter is called from within the algorithm layer, - * when a new hw adapter registers. A new device is register to be - * available for clients. +/** + * i2c_unlock_adapter - Release exclusive access to an I2C bus segment + * @adapter: Target I2C bus segment */ -int i2c_add_adapter(struct i2c_adapter *adap) +void i2c_unlock_adapter(struct i2c_adapter *adapter) { - int id, res = 0; - struct list_head *item; - struct i2c_driver *driver; + struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); - mutex_lock(&core_lists); + if (parent) + i2c_unlock_adapter(parent); + else + rt_mutex_unlock(&adapter->bus_lock); +} +EXPORT_SYMBOL_GPL(i2c_unlock_adapter); - if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) { - res = -ENOMEM; - goto out_unlock; - } +static void i2c_dev_set_name(struct i2c_adapter *adap, + struct i2c_client *client) +{ + struct acpi_device *adev = ACPI_COMPANION(&client->dev); - res = idr_get_new(&i2c_adapter_idr, adap, &id); - if (res < 0) { - if (res == -EAGAIN) - res = -ENOMEM; - goto out_unlock; + if (adev) { + dev_set_name(&client->dev, "i2c-%s", acpi_dev_name(adev)); + return; } - adap->nr = id & MAX_ID_MASK; - mutex_init(&adap->bus_lock); - mutex_init(&adap->clist_lock); - list_add_tail(&adap->list,&adapters); - INIT_LIST_HEAD(&adap->clients); + /* 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)); +} - /* 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; - sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); - adap->dev.driver = &i2c_adapter_driver; - adap->dev.release = &i2c_adapter_dev_release; - device_register(&adap->dev); - device_create_file(&adap->dev, &dev_attr_name); - - /* Add this adapter to the i2c_adapter class */ - memset(&adap->class_dev, 0x00, sizeof(struct class_device)); - adap->class_dev.dev = &adap->dev; - adap->class_dev.class = &i2c_adapter_class; - strlcpy(adap->class_dev.class_id, adap->dev.bus_id, BUS_ID_SIZE); - class_device_register(&adap->class_dev); +/** + * 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 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. + */ +struct i2c_client * +i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) +{ + struct i2c_client *client; + int status; - dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); + client = kzalloc(sizeof *client, GFP_KERNEL); + if (!client) + return NULL; + + client->adapter = adap; + + client->dev.platform_data = info->platform_data; + + if (info->archdata) + client->dev.archdata = *info->archdata; + + client->flags = info->flags; + client->addr = info->addr; + client->irq = info->irq; - /* inform drivers of new adapters */ - list_for_each(item,&drivers) { - driver = list_entry(item, struct i2c_driver, list); - if (driver->attach_adapter) - /* We ignore the return code; if it fails, too bad */ - driver->attach_adapter(adap); + 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; } -out_unlock: - mutex_unlock(&core_lists); - return res; + /* 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); -int i2c_del_adapter(struct i2c_adapter *adap) +/** + * i2c_unregister_device - reverse effect of i2c_new_device() + * @client: value returned from i2c_new_device() + * Context: can sleep + */ +void i2c_unregister_device(struct i2c_client *client) { - struct list_head *item, *_n; - struct i2c_adapter *adap_from_list; - struct i2c_driver *driver; + device_unregister(&client->dev); +} +EXPORT_SYMBOL_GPL(i2c_unregister_device); + + +static const struct i2c_device_id dummy_id[] = { + { "dummy", 0 }, + { }, +}; + +static int dummy_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + return 0; +} + +static int dummy_remove(struct i2c_client *client) +{ + return 0; +} + +static struct i2c_driver dummy_driver = { + .driver.name = "dummy", + .probe = dummy_probe, + .remove = dummy_remove, + .id_table = dummy_id, +}; + +/** + * i2c_new_dummy - return a new i2c device bound to a dummy driver + * @adapter: the adapter managing the device + * @address: seven bit address to be used + * Context: can sleep + * + * This returns an I2C client bound to the "dummy" driver, intended for use + * with devices that consume multiple addresses. Examples of such chips + * include various EEPROMS (like 24c04 and 24c08 models). + * + * These dummy devices have two main uses. First, most I2C and SMBus calls + * except i2c_transfer() need a client handle; the dummy will be that handle. + * And second, this prevents the specified address from being bound to a + * different driver. + * + * This returns the new i2c client, which should be saved for later use with + * i2c_unregister_device(); or NULL to indicate an error. + */ +struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) +{ + struct i2c_board_info info = { + I2C_BOARD_INFO("dummy", address), + }; + + return i2c_new_device(adapter, &info); +} +EXPORT_SYMBOL_GPL(i2c_new_dummy); + +/* ------------------------------------------------------------------------- */ + +/* I2C bus adapters -- one roots each I2C or SMBUS segment */ + +static void i2c_adapter_dev_release(struct device *dev) +{ + struct i2c_adapter *adap = to_i2c_adapter(dev); + complete(&adap->dev_released); +} + +/* + * 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 +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); + struct i2c_board_info info; struct i2c_client *client; - int res = 0; + char *blank, end; + int res; - mutex_lock(&core_lists); + memset(&info, 0, sizeof(struct i2c_board_info)); - /* First make sure that this adapter was ever added */ - list_for_each_entry(adap_from_list, &adapters, list) { - if (adap_from_list == adap) - break; + blank = strchr(buf, ' '); + if (!blank) { + dev_err(dev, "%s: Missing parameters\n", "new_device"); + return -EINVAL; } - if (adap_from_list != adap) { - pr_debug("i2c-core: attempting to delete unregistered " - "adapter [%s]\n", adap->name); - res = -EINVAL; - goto out_unlock; + 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); - list_for_each(item,&drivers) { - driver = list_entry(item, struct i2c_driver, list); - if (driver->detach_adapter) - if ((res = driver->detach_adapter(adap))) { - dev_err(&adap->dev, "detach_adapter failed " - "for driver [%s]\n", - driver->driver.name); - goto out_unlock; - } + /* 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; } - /* 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) { - client = list_entry(item, struct i2c_client, list); + client = i2c_new_device(adap, &info); + if (!client) + return -EINVAL; - if ((res=client->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; - } - } + /* 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); - /* clean up the sysfs representation */ - init_completion(&adap->dev_released); - init_completion(&adap->class_dev_released); - class_device_unregister(&adap->class_dev); - device_remove_file(&adap->dev, &dev_attr_name); - device_unregister(&adap->dev); - list_del(&adap->list); + return count; +} - /* wait for sysfs to drop all references */ - wait_for_completion(&adap->dev_released); - wait_for_completion(&adap->class_dev_released); +/* + * 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; - /* free dynamically allocated bus id */ - idr_remove(&i2c_adapter_idr, adap->nr); + /* 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; + } - dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); + /* 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); - out_unlock: - mutex_unlock(&core_lists); + 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 +}; -/* ----- - * What follows is the "upwards" interface: commands for talking to clients, - * which implement the functions to access the physical information of the - * chips. +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); -int i2c_register_driver(struct module *owner, struct i2c_driver *driver) +#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 list_head *item; - struct i2c_adapter *adapter; - int res; + struct i2c_devinfo *devinfo; + + 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)) + dev_err(&adapter->dev, + "Can't create device at 0x%02x\n", + devinfo->board_info.addr); + } + up_read(&__i2c_board_lock); +} - /* add the driver to the list of i2c drivers in the driver core */ - driver->driver.owner = owner; - driver->driver.bus = &i2c_bus_type; +/* OF support code */ - res = driver_register(&driver->driver); - if (res) - return res; - - mutex_lock(&core_lists); +#if IS_ENABLED(CONFIG_OF) +static void of_i2c_register_devices(struct i2c_adapter *adap) +{ + void *result; + struct device_node *node; - list_add_tail(&driver->list,&drivers); - pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); + /* Only register child devices if the adapter has a node pointer set */ + if (!adap->dev.of_node) + return; - /* now look for instances of driver on our adapters */ - if (driver->attach_adapter) { - list_for_each(item,&adapters) { - adapter = list_entry(item, struct i2c_adapter, list); - driver->attach_adapter(adapter); + 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)); } - mutex_unlock(&core_lists); + 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; } -EXPORT_SYMBOL(i2c_register_driver); -int i2c_del_driver(struct i2c_driver *driver) +static int __process_new_adapter(struct device_driver *d, void *data) +{ + return i2c_do_add_adapter(to_i2c_driver(d), data); +} + +static int i2c_register_adapter(struct i2c_adapter *adap) { - struct list_head *item1, *item2, *_n; - struct i2c_client *client; - struct i2c_adapter *adap; - int res = 0; - mutex_lock(&core_lists); + /* Can't register until after driver model init */ + if (unlikely(WARN_ON(!i2c_bus_type.p))) { + res = -EAGAIN; + goto out_list; + } - /* 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. - */ - list_for_each(item1,&adapters) { - adap = list_entry(item1, struct i2c_adapter, list); - if (driver->detach_adapter) { - if ((res = driver->detach_adapter(adap))) { - dev_err(&adap->dev, "detach_adapter failed " - "for driver [%s]\n", - driver->driver.name); - goto out_unlock; - } - } 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 ((res = driver->detach_client(client))) { - dev_err(&adap->dev, "detach_client " - "failed for client [%s] at " - "0x%02x\n", client->name, - client->addr); - goto out_unlock; - } + /* 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) + 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); + +#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; } } - driver_unregister(&driver->driver); - list_del(&driver->list); - pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); +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); + bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); + mutex_unlock(&core_lock); - out_unlock: - mutex_unlock(&core_lists); return 0; + +out_list: + mutex_lock(&core_lock); + idr_remove(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); + return res; } -static int __i2c_check_addr(struct i2c_adapter *adapter, unsigned int addr) +/** + * __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) { - struct list_head *item; - struct i2c_client *client; + int id; - list_for_each(item,&adapter->clients) { - client = list_entry(item, struct i2c_client, list); - if (client->addr == addr) - return -EBUSY; - } - return 0; + 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); } -int i2c_check_addr(struct i2c_adapter *adapter, int addr) +/** + * i2c_add_adapter - declare i2c adapter, use dynamic bus number + * @adapter: the adapter to add + * Context: can sleep + * + * This routine is used to declare an I2C adapter when its bus number + * doesn't matter or when its bus number is specified by an dt alias. + * Examples of bases when the bus number doesn't matter: I2C adapters + * dynamically added by USB links or PCI plugin cards. + * + * When this returns zero, a new bus number was allocated and stored + * in adap->nr, and the specified adapter became available for clients. + * Otherwise, a negative errno value is returned. + */ +int i2c_add_adapter(struct i2c_adapter *adapter) { - int rval; + 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(&adapter->clist_lock); - rval = __i2c_check_addr(adapter, addr); - mutex_unlock(&adapter->clist_lock); + mutex_lock(&core_lock); + id = idr_alloc(&i2c_adapter_idr, adapter, + __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); + mutex_unlock(&core_lock); + if (id < 0) + return id; - return rval; + adapter->nr = id; + + return i2c_register_adapter(adapter); } +EXPORT_SYMBOL(i2c_add_adapter); -int i2c_attach_client(struct i2c_client *client) +/** + * i2c_add_numbered_adapter - declare i2c adapter, use static bus number + * @adap: the adapter to register (with adap->nr initialized) + * Context: can sleep + * + * This routine is used to declare an I2C adapter when its bus number + * matters. For example, use it for I2C adapters from system-on-chip CPUs, + * or otherwise built in to the system's mainboard, and where i2c_board_info + * is used to properly configure I2C devices. + * + * If the requested bus number is set to -1, then this function will behave + * identically to i2c_add_adapter, and will dynamically assign a bus number. + * + * If no devices have pre-been declared for this bus, then be sure to + * register the adapter before any dynamically allocated ones. Otherwise + * the required bus ID may not be available. + * + * When this returns zero, the specified adapter became available for + * clients using the bus number provided in adap->nr. Also, the table + * of I2C devices pre-declared using i2c_register_board_info() is scanned, + * and the appropriate driver model device nodes are created. Otherwise, a + * negative errno value is returned. + */ +int i2c_add_numbered_adapter(struct i2c_adapter *adap) { - struct i2c_adapter *adapter = client->adapter; + if (adap->nr == -1) /* -1 means dynamically assign bus id */ + return i2c_add_adapter(adap); - mutex_lock(&adapter->clist_lock); - if (__i2c_check_addr(client->adapter, client->addr)) { - mutex_unlock(&adapter->clist_lock); - return -EBUSY; - } - list_add_tail(&client->list,&adapter->clients); - mutex_unlock(&adapter->clist_lock); - - if (adapter->client_register) { - if (adapter->client_register(client)) { - dev_dbg(&adapter->dev, "client_register " - "failed for client [%s] at 0x%02x\n", + return __i2c_add_numbered_adapter(adap); +} +EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); + +static void i2c_do_del_adapter(struct i2c_driver *driver, + struct i2c_adapter *adapter) +{ + struct i2c_client *client, *_n; + + /* Remove the devices we created ourselves as the result of hardware + * probing (using a driver's detect method) */ + list_for_each_entry_safe(client, _n, &driver->clients, detected) { + if (client->adapter == adapter) { + dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", client->name, client->addr); + list_del(&client->detected); + i2c_unregister_device(client); } } +} - client->usage_count = 0; +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; +} - client->dev.parent = &client->adapter->dev; - client->dev.driver = &client->driver->driver; - client->dev.bus = &i2c_bus_type; - client->dev.release = &i2c_client_release; - - snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), - "%d-%04x", i2c_adapter_id(adapter), client->addr); - dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", - client->name, client->dev.bus_id); - device_register(&client->dev); - device_create_file(&client->dev, &dev_attr_client_name); - +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; } +static int __process_removed_adapter(struct device_driver *d, void *data) +{ + i2c_do_del_adapter(to_i2c_driver(d), data); + return 0; +} -int i2c_detach_client(struct i2c_client *client) +/** + * i2c_del_adapter - unregister I2C adapter + * @adap: the adapter being unregistered + * Context: can sleep + * + * This unregisters an I2C adapter which was previously registered + * by @i2c_add_adapter or @i2c_add_numbered_adapter. + */ +void i2c_del_adapter(struct i2c_adapter *adap) { - struct i2c_adapter *adapter = client->adapter; - int res = 0; - - if (client->usage_count > 0) { - dev_warn(&client->dev, "Client [%s] still busy, " - "can't detach\n", client->name); - return -EBUSY; + struct i2c_adapter *found; + struct i2c_client *client, *next; + + /* First make sure that this adapter was ever added */ + mutex_lock(&core_lock); + found = idr_find(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); + if (found != adap) { + pr_debug("i2c-core: attempting to delete unregistered " + "adapter [%s]\n", adap->name); + return; } - 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; - } + /* Tell drivers about this removal */ + mutex_lock(&core_lock); + bus_for_each_drv(&i2c_bus_type, NULL, adap, + __process_removed_adapter); + mutex_unlock(&core_lock); + + /* Remove devices instantiated from sysfs */ + mutex_lock_nested(&adap->userspace_clients_lock, + i2c_adapter_depth(adap)); + list_for_each_entry_safe(client, next, &adap->userspace_clients, + detected) { + dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, + client->addr); + list_del(&client->detected); + i2c_unregister_device(client); } + mutex_unlock(&adap->userspace_clients_lock); + + /* Detach any active clients. This can't fail, thus we do not + * check the returned value. This is a two-pass process, because + * we can't remove the dummy devices during the first pass: they + * could have been instantiated by real devices wishing to clean + * them up properly, so we give them a chance to do that first. */ + device_for_each_child(&adap->dev, NULL, __unregister_client); + device_for_each_child(&adap->dev, NULL, __unregister_dummy); + +#ifdef CONFIG_I2C_COMPAT + class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, + adap->dev.parent); +#endif - mutex_lock(&adapter->clist_lock); - list_del(&client->list); - init_completion(&client->released); - device_remove_file(&client->dev, &dev_attr_client_name); - device_unregister(&client->dev); - mutex_unlock(&adapter->clist_lock); - wait_for_completion(&client->released); + /* 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); + + /* wait for sysfs to drop all references */ + wait_for_completion(&adap->dev_released); + + /* free bus id */ + mutex_lock(&core_lock); + idr_remove(&i2c_adapter_idr, adap->nr); + mutex_unlock(&core_lock); + + /* Clear the device structure in case this adapter is ever going to be + added again */ + memset(&adap->dev, 0, sizeof(adap->dev)); +} +EXPORT_SYMBOL(i2c_del_adapter); + +/* ------------------------------------------------------------------------- */ + +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); - out: return res; } +EXPORT_SYMBOL_GPL(i2c_for_each_dev); -static int i2c_inc_use_client(struct i2c_client *client) +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)); +} - if (!try_module_get(client->driver->driver.owner)) - return -ENODEV; - if (!try_module_get(client->adapter->owner)) { - module_put(client->driver->driver.owner); - return -ENODEV; - } +/* + * An i2c_driver is used with one or more i2c_client (device) nodes to access + * i2c slave chips, on a bus instance associated with some i2c_adapter. + */ + +int i2c_register_driver(struct module *owner, struct i2c_driver *driver) +{ + int res; + + /* Can't register until after driver model init */ + if (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; + + /* 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; + + /* 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 */ + i2c_for_each_dev(driver, __process_new_driver); return 0; } +EXPORT_SYMBOL(i2c_register_driver); -static void i2c_dec_use_client(struct i2c_client *client) +static int __process_removed_driver(struct device *dev, void *data) { - module_put(client->driver->driver.owner); - module_put(client->adapter->owner); + if (dev->type == &i2c_adapter_type) + i2c_do_del_adapter(data, to_i2c_adapter(dev)); + return 0; } -int i2c_use_client(struct i2c_client *client) +/** + * i2c_del_driver - unregister I2C driver + * @driver: the driver being unregistered + * Context: can sleep + */ +void i2c_del_driver(struct i2c_driver *driver) { - int ret; + i2c_for_each_dev(driver, __process_removed_driver); - ret = i2c_inc_use_client(client); - if (ret) - return ret; + driver_unregister(&driver->driver); + pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); +} +EXPORT_SYMBOL(i2c_del_driver); - client->usage_count++; +/* ------------------------------------------------------------------------- */ - return 0; +/** + * i2c_use_client - increments the reference count of the i2c client structure + * @client: the client being referenced + * + * Each live reference to a client should be refcounted. The driver model does + * that automatically as part of driver binding, so that most drivers don't + * need to do this explicitly: they hold a reference until they're unbound + * from the device. + * + * A pointer to the client with the incremented reference counter is returned. + */ +struct i2c_client *i2c_use_client(struct i2c_client *client) +{ + if (client && get_device(&client->dev)) + return client; + return NULL; } +EXPORT_SYMBOL(i2c_use_client); -int i2c_release_client(struct i2c_client *client) +/** + * i2c_release_client - release a use of the i2c client structure + * @client: the client being no longer referenced + * + * Must be called when a user of a client is finished with it. + */ +void i2c_release_client(struct i2c_client *client) { - if (!client->usage_count) { - pr_debug("i2c-core: %s used one too many times\n", - __FUNCTION__); - return -EPERM; - } - - client->usage_count--; - i2c_dec_use_client(client); - + if (client) + put_device(&client->dev); +} +EXPORT_SYMBOL(i2c_release_client); + +struct i2c_cmd_arg { + unsigned cmd; + void *arg; +}; + +static int i2c_cmd(struct device *dev, void *_arg) +{ + struct i2c_client *client = i2c_verify_client(dev); + struct i2c_cmd_arg *arg = _arg; + struct i2c_driver *driver; + + if (!client || !client->dev.driver) + return 0; + + driver = to_i2c_driver(client->dev.driver); + if (driver->command) + driver->command(client, arg->cmd, arg->arg); return 0; } void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) { - struct list_head *item; - struct i2c_client *client; + struct i2c_cmd_arg cmd_arg; - mutex_lock(&adap->clist_lock); - list_for_each(item,&adap->clients) { - client = list_entry(item, struct i2c_client, list); - if (!try_module_get(client->driver->driver.owner)) - continue; - if (NULL != client->driver->command) { - mutex_unlock(&adap->clist_lock); - client->driver->command(client,cmd,arg); - mutex_lock(&adap->clist_lock); - } - module_put(client->driver->driver.owner); - } - mutex_unlock(&adap->clist_lock); + cmd_arg.cmd = cmd; + cmd_arg.arg = arg; + device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); } +EXPORT_SYMBOL(i2c_clients_command); static int __init i2c_init(void) { @@ -535,20 +1673,41 @@ static int __init i2c_init(void) retval = bus_register(&i2c_bus_type); if (retval) return retval; - retval = driver_register(&i2c_adapter_driver); +#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) - return retval; - return class_register(&i2c_adapter_class); + goto class_err; + return 0; + +class_err: +#ifdef CONFIG_I2C_COMPAT + class_compat_unregister(i2c_adapter_compat_class); +bus_err: +#endif + bus_unregister(&i2c_bus_type); + return retval; } static void __exit i2c_exit(void) { - class_unregister(&i2c_adapter_class); - driver_unregister(&i2c_adapter_driver); + i2c_del_driver(&dummy_driver); +#ifdef CONFIG_I2C_COMPAT + class_compat_unregister(i2c_adapter_compat_class); +#endif bus_unregister(&i2c_bus_type); + tracepoint_synchronize_unregister(); } -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); /* ---------------------------------------------------- @@ -556,51 +1715,161 @@ 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++) { dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " - "len=%d\n", ret, msgs[ret].flags & I2C_M_RD ? - 'R' : 'W', msgs[ret].addr, msgs[ret].len); + "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) + ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, + (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); } #endif - mutex_lock(&adap->bus_lock); - ret = adap->algo->master_xfer(adap,msgs,num); - mutex_unlock(&adap->bus_lock); + if (in_atomic() || irqs_disabled()) { + ret = i2c_trylock_adapter(adap); + if (!ret) + /* I2C activity is ongoing. */ + return -EAGAIN; + } else { + i2c_lock_adapter(adap); + } + + 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; msg.flags = client->flags & I2C_M_TEN; msg.len = count; msg.buf = (char *)buf; - + 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; @@ -612,197 +1881,234 @@ 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); +/* ---------------------------------------------------- + * the i2c address scanning function + * Will not work for 10-bit addresses! + * ---------------------------------------------------- + */ -int i2c_control(struct i2c_client *client, - unsigned int cmd, unsigned long arg) +/* + * 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 ret = 0; - struct i2c_adapter *adap = client->adapter; + int err; + union i2c_smbus_data dummy; - dev_dbg(&client->adapter->dev, "i2c ioctl, cmd: 0x%x, arg: %#lx\n", cmd, arg); - switch (cmd) { - case I2C_RETRIES: - adap->retries = arg; - break; - case I2C_TIMEOUT: - adap->timeout = arg; - break; - default: - if (adap->algo->algo_control!=NULL) - ret = adap->algo->algo_control(adap,cmd,arg); +#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 ret; + + return err >= 0; } -/* ---------------------------------------------------- - * the i2c address scanning function - * 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)) +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; - - /* prevent 24RF08 corruption */ - if ((addr & ~0x0f) == 0x50) - i2c_smbus_xfer(adapter, addr, 0, 0, 0, - I2C_SMBUS_QUICK, NULL); - } + /* Make sure there is something at this address */ + if (!i2c_default_probe(adapter, addr)) + return 0; /* Finally call the custom detection function */ - err = found_proc(adapter, addr, kind); + 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; + } - /* -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. */ - return (err == -ENODEV) ? 0 : err; + /* Consistency check */ + if (info.type[0] == '\0') { + dev_err(&adapter->dev, "%s detection function provided " + "no name for 0x%x\n", driver->driver.name, + addr); + } else { + struct i2c_client *client; + + /* Detection succeeded, instantiate the device */ + if (adapter->class & I2C_CLASS_DEPRECATED) + dev_warn(&adapter->dev, + "This adapter will soon drop class based instantiation of devices. " + "Please make sure client 0x%02x gets instantiated by other means. " + "Check 'Documentation/i2c/instantiating-devices' 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, - 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) { - unsigned short **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; - } - } - } - } + address_list = driver->address_list; + if (!driver->detect || !address_list) + return 0; - /* 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; + /* Stop here if the classes do not match */ + if (!(adapter->class & driver->class)) + return 0; - dev_warn(&adapter->dev, "SMBus Quick command not supported, " - "can't probe for chips\n"); - return -1; - } + /* 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; - /* 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; - } + for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { + dev_dbg(&adapter->dev, "found normal entry for adapter %d, " + "addr 0x%02x\n", adap_id, address_list[i]); + temp_client->addr = address_list[i]; + err = i2c_detect_address(temp_client, driver); + if (unlikely(err)) + break; } - /* 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; - } + 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, + int (*probe)(struct i2c_adapter *, unsigned short addr)) +{ + int i; + + if (!probe) + probe = i2c_default_probe; + + for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { + /* Check address validity */ + if (i2c_check_addr_validity(addr_list[i]) < 0) { + dev_warn(&adap->dev, "Invalid 7-bit address " + "0x%02x\n", addr_list[i]); + continue; } - if (ignore) + + /* Check address availability */ + 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; + } - 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; + /* Test address responsiveness */ + if (probe(adap, addr_list[i])) + break; } - return 0; + if (addr_list[i] == I2C_CLIENT_END) { + dev_dbg(&adap->dev, "Probing failed, no device found\n"); + return NULL; + } + + info->addr = addr_list[i]; + return i2c_new_device(adap, info); } +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_lists); - adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id); + + mutex_lock(&core_lock); + adapter = idr_find(&i2c_adapter_idr, nr); if (adapter && !try_module_get(adapter->owner)) adapter = NULL; - mutex_unlock(&core_lists); + mutex_unlock(&core_lock); return adapter; } +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) +#define POLY (0x1070U << 3) +static u8 crc8(u16 data) { int i; - - for(i = 0; i < 8; i++) { - if (data & 0x8000) + + for (i = 0; i < 8; i++) { + if (data & 0x8000) data = data ^ POLY; data = data << 1; } @@ -814,7 +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; } @@ -850,72 +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); + return 0; } -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 0x0FF & 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 0x0FF & 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 0x0FFFF & 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" protocol + * @client: Handle to slave device + * @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. + * + * 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(const struct i2c_client *client, u8 command, + u8 *values) +{ + union i2c_smbus_data data; + int status; + + status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, + I2C_SMBUS_READ, command, + I2C_SMBUS_BLOCK_DATA, &data); + if (status) + return status; -s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, + memcpy(values, &data.block[1], data.block[0]); + return data.block[0]; +} +EXPORT_SYMBOL(i2c_smbus_read_block_data); + +/** + * 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; @@ -924,26 +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, u8 *values) +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 (i2c_smbus_xfer(client->adapter,client->addr,client->flags, - I2C_SMBUS_READ,command, - I2C_SMBUS_I2C_BLOCK_DATA,&data)) - return -1; + if (length > I2C_SMBUS_BLOCK_MAX) + length = I2C_SMBUS_BLOCK_MAX; + data.block[0] = length; + 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; @@ -956,13 +2366,14 @@ s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, I2C_SMBUS_WRITE, command, I2C_SMBUS_I2C_BLOCK_DATA, &data); } +EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); -/* Simulate a SMBus command using the i2c protocol +/* 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 @@ -970,19 +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: @@ -1004,9 +2427,9 @@ 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) & 0xff; + msgbuf0[2] = data->word >> 8; } break; case I2C_SMBUS_PROC_CALL: @@ -1015,48 +2438,59 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, msg[0].len = 3; msg[1].len = 2; msgbuf0[1] = data->word & 0xff; - msgbuf0[2] = (data->word >> 8) & 0xff; + msgbuf0[2] = data->word >> 8; break; case I2C_SMBUS_BLOCK_DATA: if (read_write == I2C_SMBUS_READ) { - dev_err(&adapter->dev, "Block read not supported " - "under I2C emulation!\n"); - return -1; + msg[1].flags |= I2C_M_RECV_LEN; + msg[1].len = 1; /* block length will be added by + the underlying bus driver */ } 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]; } break; case I2C_SMBUS_BLOCK_PROC_CALL: - dev_dbg(&adapter->dev, "Block process call not supported " - "under I2C emulation!\n"); - return -1; + num = 2; /* Another special case */ + read_write = I2C_SMBUS_READ; + if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { + dev_err(&adapter->dev, + "Invalid block write size %d\n", + data->block[0]); + return -EINVAL; + } + msg[0].len = data->block[0] + 2; + for (i = 1; i < msg[0].len; i++) + msgbuf0[i] = data->block[i-1]; + msg[1].flags |= I2C_M_RECV_LEN; + msg[1].len = 1; /* block length will be added by + the underlying bus driver */ + break; case I2C_SMBUS_I2C_BLOCK_DATA: if (read_write == I2C_SMBUS_READ) { - msg[1].len = I2C_SMBUS_BLOCK_MAX; + msg[1].len = data->block[0]; } 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 @@ -1064,104 +2498,121 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, if (i) { /* Compute PEC if first message is a write */ if (!(msg[0].flags & I2C_M_RD)) { - if (num == 1) /* Write only */ + if (num == 1) /* Write only */ i2c_smbus_add_pec(&msg[0]); else /* Write followed by read */ partial_pec = i2c_smbus_msg_pec(0, &msg[0]); } /* Ask for PEC if last message is a read */ if (msg[num-1].flags & I2C_M_RD) - msg[num-1].len++; + 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: - /* fixed at 32 for now */ - data->block[0] = I2C_SMBUS_BLOCK_MAX; - for (i = 0; i < I2C_SMBUS_BLOCK_MAX; i++) - data->block[i+1] = 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 (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); - - return res; -} + /* 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; -/* Next four are needed by i2c-isa */ -EXPORT_SYMBOL_GPL(i2c_adapter_dev_release); -EXPORT_SYMBOL_GPL(i2c_adapter_driver); -EXPORT_SYMBOL_GPL(i2c_adapter_class); -EXPORT_SYMBOL_GPL(i2c_bus_type); + if (adapter->algo->smbus_xfer) { + 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. + */ + } -EXPORT_SYMBOL(i2c_add_adapter); -EXPORT_SYMBOL(i2c_del_adapter); -EXPORT_SYMBOL(i2c_del_driver); -EXPORT_SYMBOL(i2c_attach_client); -EXPORT_SYMBOL(i2c_detach_client); -EXPORT_SYMBOL(i2c_use_client); -EXPORT_SYMBOL(i2c_release_client); -EXPORT_SYMBOL(i2c_clients_command); -EXPORT_SYMBOL(i2c_check_addr); + res = i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, + command, protocol, data); -EXPORT_SYMBOL(i2c_master_send); -EXPORT_SYMBOL(i2c_master_recv); -EXPORT_SYMBOL(i2c_control); -EXPORT_SYMBOL(i2c_transfer); -EXPORT_SYMBOL(i2c_get_adapter); -EXPORT_SYMBOL(i2c_put_adapter); -EXPORT_SYMBOL(i2c_probe); +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; +} EXPORT_SYMBOL(i2c_smbus_xfer); -EXPORT_SYMBOL(i2c_smbus_write_quick); -EXPORT_SYMBOL(i2c_smbus_read_byte); -EXPORT_SYMBOL(i2c_smbus_write_byte); -EXPORT_SYMBOL(i2c_smbus_read_byte_data); -EXPORT_SYMBOL(i2c_smbus_write_byte_data); -EXPORT_SYMBOL(i2c_smbus_read_word_data); -EXPORT_SYMBOL(i2c_smbus_write_word_data); -EXPORT_SYMBOL(i2c_smbus_write_block_data); -EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); -EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); MODULE_DESCRIPTION("I2C-Bus main module"); |