diff options
| -rw-r--r-- | Documentation/i2c/writing-clients | 5 | ||||
| -rw-r--r-- | drivers/i2c/i2c-core.c | 63 | ||||
| -rw-r--r-- | include/linux/i2c.h | 2 |
3 files changed, 47 insertions, 23 deletions
diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 3219ee0dbfe..5ebf5af1d71 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -74,6 +74,11 @@ structure at all. You should use this to keep device-specific data. /* retrieve the value */ void *i2c_get_clientdata(const struct i2c_client *client); +Note that starting with kernel 2.6.34, you don't have to set the `data' field +to NULL in remove() or if probe() failed anymore. The i2c-core does this +automatically on these occasions. Those are also the only times the core will +touch this field. + Accessing the client ==================== diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index 3202a86f420..c2258a51fe0 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -40,12 +40,11 @@ #include "i2c-core.h" -/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees +/* core_lock protects i2c_adapter_idr, and guarantees that device detection, deletion of detected devices, and attach_adapter and detach_adapter calls are serialized */ static DEFINE_MUTEX(core_lock); static DEFINE_IDR(i2c_adapter_idr); -static LIST_HEAD(userspace_devices); static struct device_type i2c_client_type; static int i2c_check_addr(struct i2c_adapter *adapter, int addr); @@ -117,8 +116,10 @@ static int i2c_device_probe(struct device *dev) dev_dbg(dev, "probe\n"); status = driver->probe(client, i2c_match_id(driver->id_table, client)); - if (status) + if (status) { client->driver = NULL; + i2c_set_clientdata(client, NULL); + } return status; } @@ -139,8 +140,10 @@ static int i2c_device_remove(struct device *dev) dev->driver = NULL; status = 0; } - if (status == 0) + if (status == 0) { client->driver = NULL; + i2c_set_clientdata(client, NULL); + } return status; } @@ -538,9 +541,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, return -EEXIST; /* Keep track of the added device */ - mutex_lock(&core_lock); - list_add_tail(&client->detected, &userspace_devices); - mutex_unlock(&core_lock); + i2c_lock_adapter(adap); + list_add_tail(&client->detected, &adap->userspace_clients); + i2c_unlock_adapter(adap); dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", info.type, info.addr); @@ -579,9 +582,10 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, /* Make sure the device was added through sysfs */ res = -ENOENT; - mutex_lock(&core_lock); - list_for_each_entry_safe(client, next, &userspace_devices, detected) { - if (client->addr == addr && client->adapter == adap) { + i2c_lock_adapter(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); @@ -591,7 +595,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, break; } } - mutex_unlock(&core_lock); + i2c_unlock_adapter(adap); if (res < 0) dev_err(dev, "%s: Can't find device in list\n", @@ -673,6 +677,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap) } rt_mutex_init(&adap->bus_lock); + INIT_LIST_HEAD(&adap->userspace_clients); /* Set default timeout to 1 second if not already set */ if (adap->timeout == 0) @@ -875,14 +880,15 @@ int i2c_del_adapter(struct i2c_adapter *adap) return res; /* Remove devices instantiated from sysfs */ - list_for_each_entry_safe(client, next, &userspace_devices, detected) { - if (client->adapter == adap) { - dev_dbg(&adap->dev, "Removing %s at 0x%x\n", - client->name, client->addr); - list_del(&client->detected); - i2c_unregister_device(client); - } + i2c_lock_adapter(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); } + i2c_unlock_adapter(adap); /* Detach any active clients. This can't fail, thus we do not checking the returned value. */ @@ -1260,12 +1266,23 @@ static int i2c_detect_address(struct i2c_client *temp_client, return 0; /* Make sure there is something at this address */ - if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0) - return 0; + if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) { + /* Special probe for FSC hwmon chips */ + union i2c_smbus_data dummy; - /* Prevent 24RF08 corruption */ - if ((addr & ~0x0f) == 0x50) - i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL); + if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_READ, 0, + I2C_SMBUS_BYTE_DATA, &dummy) < 0) + return 0; + } else { + if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0, + I2C_SMBUS_QUICK, NULL) < 0) + return 0; + + /* Prevent 24RF08 corruption */ + if ((addr & ~0x0f) == 0x50) + i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0, + I2C_SMBUS_QUICK, NULL); + } /* Finally call the custom detection function */ memset(&info, 0, sizeof(struct i2c_board_info)); diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 0a5da639b32..6ed1d59bfb1 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -355,6 +355,8 @@ struct i2c_adapter { int nr; char name[48]; struct completion dev_released; + + struct list_head userspace_clients; }; #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) |