i2c-dev: Use standard bus notification mechanism (9ea3e941) · Commits · 戴 / test

drivers/i2c/i2c-dev.c

+39 −21

Original line number	Diff line number	Diff line
		@@ -28,6 +28,8 @@

		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/device.h>
		#include <linux/notifier.h>
		#include <linux/fs.h>
		#include <linux/slab.h>
		#include <linux/init.h>
		@@ -37,16 +39,13 @@
		#include <linux/jiffies.h>
		#include <linux/uaccess.h>

		static struct i2c_driver i2cdev_driver;

		/*
		* An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a
		* slave (i2c_client) with which messages will be exchanged. It's coupled
		* with a character special file which is accessed by user mode drivers.
		*
		* The list of i2c_dev structures is parallel to the i2c_adapter lists
		* maintained by the driver model, and is updated using notifications
		* delivered to the i2cdev_driver.
		* maintained by the driver model, and is updated using bus notifications.
		*/
		struct i2c_dev {
		struct list_head list;
		@@ -491,7 +490,6 @@ static int i2cdev_open(struct inode inode, struct file file)
		return -ENOMEM;
		}
		snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr);
		client->driver = &i2cdev_driver;

		client->adapter = adap;
		file->private_data = client;
		@@ -522,19 +520,18 @@ static const struct file_operations i2cdev_fops = {

		/* ------------------------------------------------------------------------- */

		/*
		* The legacy "i2cdev_driver" is used primarily to get notifications when
		* I2C adapters are added or removed, so that each one gets an i2c_dev
		* and is thus made available to userspace driver code.
		*/

		static struct class *i2c_dev_class;

		static int i2cdev_attach_adapter(struct i2c_adapter *adap)
		static int i2cdev_attach_adapter(struct device dev, void dummy)
		{
		struct i2c_adapter *adap;
		struct i2c_dev *i2c_dev;
		int res;

		if (dev->type != &i2c_adapter_type)
		return 0;
		adap = to_i2c_adapter(dev);

		i2c_dev = get_free_i2c_dev(adap);
		if (IS_ERR(i2c_dev))
		return PTR_ERR(i2c_dev);
		@@ -561,10 +558,15 @@ error:
		return res;
		}

		static int i2cdev_detach_adapter(struct i2c_adapter *adap)
		static int i2cdev_detach_adapter(struct device dev, void dummy)
		{
		struct i2c_adapter *adap;
		struct i2c_dev *i2c_dev;

		if (dev->type != &i2c_adapter_type)
		return 0;
		adap = to_i2c_adapter(dev);

		i2c_dev = i2c_dev_get_by_minor(adap->nr);
		if (!i2c_dev) /* attach_adapter must have failed */
		return 0;
		@@ -577,12 +579,23 @@ static int i2cdev_detach_adapter(struct i2c_adapter *adap)
		return 0;
		}

		static struct i2c_driver i2cdev_driver = {
		.driver = {
		.name = "dev_driver",
		},
		.attach_adapter = i2cdev_attach_adapter,
		.detach_adapter = i2cdev_detach_adapter,
		int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action,
		void *data)
		{
		struct device *dev = data;

		switch (action) {
		case BUS_NOTIFY_ADD_DEVICE:
		return i2cdev_attach_adapter(dev, NULL);
		case BUS_NOTIFY_DEL_DEVICE:
		return i2cdev_detach_adapter(dev, NULL);
		}

		return 0;
		}

		static struct notifier_block i2cdev_notifier = {
		.notifier_call = i2cdev_notifier_call,
		};

		/* ------------------------------------------------------------------------- */
		@@ -607,10 +620,14 @@ static int __init i2c_dev_init(void)
		goto out_unreg_chrdev;
		}

		res = i2c_add_driver(&i2cdev_driver);
		/* Keep track of adapters which will be added or removed later */
		res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier);
		if (res)
		goto out_unreg_class;

		/* Bind to already existing adapters right away */
		i2c_for_each_dev(NULL, i2cdev_attach_adapter);

		return 0;

		out_unreg_class:
		@@ -624,7 +641,8 @@ out:

		static void __exit i2c_dev_exit(void)
		{
		i2c_del_driver(&i2cdev_driver);
		bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
		i2c_for_each_dev(NULL, i2cdev_detach_adapter);
		class_destroy(i2c_dev_class);
		unregister_chrdev(I2C_MAJOR, "i2c");
		}

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