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 <khali@xxxxxxxxxxxx>
---
drivers/i2c/i2c-dev.c | 60 +++++++++++++++++++++++++++++++------------------
1 file changed, 39 insertions(+), 21 deletions(-)
--- linux-2.6.38-rc5.orig/drivers/i2c/i2c-dev.c 2011-02-19 18:54:23.000000000 +0100
+++ linux-2.6.38-rc5/drivers/i2c/i2c-dev.c 2011-02-19 21:30:17.000000000 +0100
@@ -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 *ino
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 i2cd
/* ------------------------------------------------------------------------- */
-/*
- * 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
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);
+ i2c_for_each_dev(NULL, i2cdev_detach_adapter);
+ bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier);
class_destroy(i2c_dev_class);
unregister_chrdev(I2C_MAJOR, "i2c");
}
--
Jean Delvare
--
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