i2c: Add i2c_add_numbered_adapter() (6e13e641) · Commits · 戴 / test

drivers/i2c/i2c-core.c

+100 −26

Original line number	Diff line number	Diff line
		@@ -320,38 +320,19 @@ static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
		mutex_unlock(&__i2c_board_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.
		*/
		int i2c_add_adapter(struct i2c_adapter *adap)
		static int i2c_register_adapter(struct i2c_adapter *adap)
		{
		int id, res = 0;
		int res = 0;
		struct list_head *item;
		struct i2c_driver *driver;

		mutex_lock(&core_lists);

		if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) {
		res = -ENOMEM;
		goto out_unlock;
		}

		res = idr_get_new(&i2c_adapter_idr, adap, &id);
		if (res < 0) {
		if (res == -EAGAIN)
		res = -ENOMEM;
		goto out_unlock;
		}

		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);

		mutex_lock(&core_lists);
		list_add_tail(&adap->list, &adapters);

		/* Add the adapter to the driver core.
		* If the parent pointer is not set up,
		* we add this adapter to the host bus.
		@@ -370,6 +351,10 @@ int i2c_add_adapter(struct i2c_adapter *adap)

		dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);

		/* create pre-declared device nodes for new-style drivers */
		if (adap->nr < __i2c_first_dynamic_bus_num)
		i2c_scan_static_board_info(adap);

		/* let legacy drivers scan this bus for matching devices */
		list_for_each(item,&drivers) {
		driver = list_entry(item, struct i2c_driver, list);
		@@ -388,6 +373,93 @@ out_list:
		goto out_unlock;
		}

		/**
		* i2c_add_adapter - declare i2c adapter, use dynamic bus number
		* @adapter: the adapter to add
		*
		* This routine is used to declare an I2C adapter when its bus number
		* doesn't matter. Examples: for I2C adapters dynamically added by
		* USB links or PCI plugin cards.
		*
		* 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 id, res = 0;

		retry:
		if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
		return -ENOMEM;

		mutex_lock(&core_lists);
		/* "above" here means "above or equal to", sigh */
		res = idr_get_new_above(&i2c_adapter_idr, adapter,
		__i2c_first_dynamic_bus_num, &id);
		mutex_unlock(&core_lists);

		if (res < 0) {
		if (res == -EAGAIN)
		goto retry;
		return res;
		}

		adapter->nr = id;
		return i2c_register_adapter(adapter);
		}
		EXPORT_SYMBOL(i2c_add_adapter);

		/**
		* i2c_add_numbered_adapter - declare i2c adapter, use static bus number
		* @adap: the adapter to register (with adap->nr initialized)
		*
		* This routine is used to declare an I2C adapter when its bus number
		* matters. Example: 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 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)
		{
		int id;
		int status;

		if (adap->nr & ~MAX_ID_MASK)
		return -EINVAL;

		retry:
		if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
		return -ENOMEM;

		mutex_lock(&core_lists);
		/* "above" here means "above or equal to", sigh;
		* we need the "equal to" result to force the result
		*/
		status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
		if (status == 0 && id != adap->nr) {
		status = -EBUSY;
		idr_remove(&i2c_adapter_idr, id);
		}
		mutex_unlock(&core_lists);
		if (status == -EAGAIN)
		goto retry;

		if (status == 0)
		status = i2c_register_adapter(adap);
		return status;
		}
		EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);

		int i2c_del_adapter(struct i2c_adapter *adap)
		{
		struct list_head item, _n;
		@@ -452,7 +524,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
		/* wait for sysfs to drop all references */
		wait_for_completion(&adap->dev_released);

		/* free dynamically allocated bus id */
		/* free bus id */
		idr_remove(&i2c_adapter_idr, adap->nr);

		dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
		@@ -493,6 +565,9 @@ int i2c_register_driver(struct module owner, struct i2c_driver driver)
		driver->driver.owner = owner;
		driver->driver.bus = &i2c_bus_type;

		/* for new style drivers, 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;
		@@ -1377,7 +1452,6 @@ EXPORT_SYMBOL_GPL(i2c_adapter_dev_release);
		EXPORT_SYMBOL_GPL(i2c_adapter_class);
		EXPORT_SYMBOL_GPL(i2c_bus_type);

		EXPORT_SYMBOL(i2c_add_adapter);
		EXPORT_SYMBOL(i2c_del_adapter);
		EXPORT_SYMBOL(i2c_del_driver);
		EXPORT_SYMBOL(i2c_attach_client);

include/linux/i2c.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -363,6 +363,7 @@ struct i2c_client_address_data {
		*/
		extern int i2c_add_adapter(struct i2c_adapter *);
		extern int i2c_del_adapter(struct i2c_adapter *);
		extern int i2c_add_numbered_adapter(struct i2c_adapter *);

		extern int i2c_register_driver(struct module , struct i2c_driver );
		extern int i2c_del_driver(struct i2c_driver *);

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