From 9ea3e941d161f41f920462c50e9b651cc00eccc7 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Sun, 20 Mar 2011 14:50:52 +0100 Subject: i2c-dev: Use standard bus notification mechanism Use the standard driver core mechanism to keep track of i2c adapters present on the system: i2c_for_each_dev and a notifier. This will let us deprecate and ultimately remove the legacy attach_adapter and detach_adapter callbacks in i2c_driver. Signed-off-by: Jean Delvare --- drivers/i2c/i2c-dev.c | 60 +++++++++++++++++++++++++++++++++------------------ 1 file changed, 39 insertions(+), 21 deletions(-) diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index cec0f3ba97f8..c90ce50b619f 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -28,6 +28,8 @@ #include #include +#include +#include #include #include #include @@ -37,16 +39,13 @@ #include #include -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"); } -- cgit v1.2.1