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Commit c81406d6 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging 

* 'i2c-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
  i2c-core: Use per-adapter userspace device lists
  i2c: Fix probing of FSC hardware monitoring chips
  i2c-core: Erase pointer to clientdata on removal
parents f5fa05d9 6629dcff

Documentation/i2c/writing-clients

+5 −0
Original line number Diff line number Diff line
@@ -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

====================

drivers/i2c/i2c-core.c

+40 −23
Original line number Diff line number Diff line
@@ -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);

	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)

	if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) {

		/* Special probe for FSC hwmon chips */

		union i2c_smbus_data dummy;



		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, 0, 0, I2C_SMBUS_QUICK, NULL);

			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));

include/linux/i2c.h

+2 −0
Original line number Diff line number Diff line
@@ -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)