Commit c4d3dfd8 authored by Wolfram Sang's avatar Wolfram Sang
Browse files

Revert "i2c: Replace list-based mechanism for handling userspace-created clients" 



This reverts commit 3cfe39b3. Mux
handling is not sufficiently implemented. It needs more time.

Signed-off-by: default avatarWolfram Sang <wsa+renesas@sang-engineering.com>
parent 2014c95a

drivers/i2c/i2c-core-base.c

+39 −22
Original line number Diff line number Diff line
@@ -1300,12 +1300,14 @@ new_device_store(struct device *dev, struct device_attribute *attr, 
		info.flags |= I2C_CLIENT_SLAVE;

	}



	info.flags |= I2C_CLIENT_USER;



	client = i2c_new_client_device(adap, &info);

	if (IS_ERR(client))

		return PTR_ERR(client);



	/* 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);
@@ -1313,15 +1315,6 @@ new_device_store(struct device *dev, struct device_attribute *attr, 
}

static DEVICE_ATTR_WO(new_device);



static int __i2c_find_user_addr(struct device *dev, const void *addrp)

{

	struct i2c_client *client = i2c_verify_client(dev);

	unsigned short addr = *(unsigned short *)addrp;



	return client && client->flags & I2C_CLIENT_USER &&

	       i2c_encode_flags_to_addr(client) == addr;

}



/*

 * 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
@@ -1336,7 +1329,7 @@ delete_device_store(struct device *dev, struct device_attribute *attr, 
		    const char *buf, size_t count)

{

	struct i2c_adapter *adap = to_i2c_adapter(dev);

	struct device *child_dev;

	struct i2c_client *client, *next;

	unsigned short addr;

	char end;

	int res;
@@ -1352,19 +1345,28 @@ delete_device_store(struct device *dev, struct device_attribute *attr, 
		return -EINVAL;

	}



	mutex_lock(&core_lock);

	/* Make sure the device was added through sysfs */

	child_dev = device_find_child(&adap->dev, &addr, __i2c_find_user_addr);

	if (child_dev) {

		i2c_unregister_device(i2c_verify_client(child_dev));

		put_device(child_dev);

	} else {

		dev_err(dev, "Can't find userspace-created device at %#x\n", addr);

		count = -ENOENT;

	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 (i2c_encode_flags_to_addr(client) == 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(&core_lock);

	}

	mutex_unlock(&adap->userspace_clients_lock);



	return count;

	if (res < 0)

		dev_err(dev, "%s: Can't find device in list\n",

			"delete_device");

	return res;

}

static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL,

				  delete_device_store);
@@ -1535,6 +1537,8 @@ static int i2c_register_adapter(struct i2c_adapter *adap) 
	adap->locked_flags = 0;

	rt_mutex_init(&adap->bus_lock);

	rt_mutex_init(&adap->mux_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)
@@ -1726,6 +1730,7 @@ static int __unregister_dummy(struct device *dev, void *dummy) 
void i2c_del_adapter(struct i2c_adapter *adap)

{

	struct i2c_adapter *found;

	struct i2c_client *client, *next;



	/* First make sure that this adapter was ever added */

	mutex_lock(&core_lock);
@@ -1738,6 +1743,18 @@ void i2c_del_adapter(struct i2c_adapter *adap) 


	i2c_acpi_remove_space_handler(adap);



	/* 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

include/linux/i2c.h

+6 −1
Original line number Diff line number Diff line
@@ -313,6 +313,8 @@ struct i2c_driver { 
 * @dev: Driver model device node for the slave.

 * @init_irq: IRQ that was set at initialization

 * @irq: indicates the IRQ generated by this device (if any)

 * @detected: member of an i2c_driver.clients list or i2c-core's

 *	userspace_devices list

 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter

 *	calls it to pass on slave events to the slave driver.

 * @devres_group_id: id of the devres group that will be created for resources
@@ -333,7 +335,6 @@ struct i2c_client { 
#define I2C_CLIENT_HOST_NOTIFY	0x40	/* We want to use I2C host notify */

#define I2C_CLIENT_WAKE		0x80	/* for board_info; true iff can wake */

#define I2C_CLIENT_AUTO		0x100	/* client was auto-detected */

#define I2C_CLIENT_USER		0x200	/* client was userspace-created */

#define I2C_CLIENT_SCCB		0x9000	/* Use Omnivision SCCB protocol */

					/* Must match I2C_M_STOP|IGNORE_NAK */
@@ -345,6 +346,7 @@ struct i2c_client { 
	struct device dev;		/* the device structure		*/

	int init_irq;			/* irq set at initialization	*/

	int irq;			/* irq issued by device		*/

	struct list_head detected;

#if IS_ENABLED(CONFIG_I2C_SLAVE)

	i2c_slave_cb_t slave_cb;	/* callback for slave mode	*/

#endif
@@ -751,6 +753,9 @@ struct i2c_adapter { 
	char name[48];

	struct completion dev_released;



	struct mutex userspace_clients_lock;

	struct list_head userspace_clients;



	struct i2c_bus_recovery_info *bus_recovery_info;

	const struct i2c_adapter_quirks *quirks;