[i2c] [PATCH 6/6] i2c: Remove the duplicated i2c drivers list

[Jean Delvare]

Get rid of the I2C-private list of drivers; instead, use the list
already maintained by the driver model core.

This is largely inspired from a patch posted by David Brownell back
in November 2006.

Signed-off-by: Jean Delvare <khali at linux-fr.org>
---
 Documentation/feature-removal-schedule.txt |    9 ----
 drivers/i2c/i2c-core.c                     |   60 +++++++++++++++++-----------
 include/linux/i2c.h                        |    1 -
 3 files changed, 37 insertions(+), 33 deletions(-)

--- linux-2.6.21-pre.orig/Documentation/feature-removal-schedule.txt	2007-02-10 13:55:35.000000000 +0100
+++ linux-2.6.21-pre/Documentation/feature-removal-schedule.txt	2007-02-10 13:56:14.000000000 +0100
@@ -198,15 +198,6 @@ Who:	Jean Delvare <khali at linux-fr.org>
 
 ---------------------------
 
-What:	i2c_adapter.list
-When:	July 2007
-Why:	Superfluous, this list duplicates the one maintained by the driver
-	core.
-Who:	Jean Delvare <khali at linux-fr.org>,
-	David Brownell <dbrownell at users.sourceforge.net>
-
----------------------------
-
 What:	IPv4 only connection tracking/NAT/helpers
 When:	2.6.22
 Why:	The new layer 3 independant connection tracking replaces the old
--- linux-2.6.21-pre.orig/drivers/i2c/i2c-core.c	2007-02-10 13:40:24.000000000 +0100
+++ linux-2.6.21-pre/drivers/i2c/i2c-core.c	2007-02-10 14:24:34.000000000 +0100
@@ -37,7 +37,6 @@
 
 
 static LIST_HEAD(adapters);
-static LIST_HEAD(drivers);
 static DEFINE_MUTEX(core_lists);
 static DEFINE_IDR(i2c_adapter_idr);
 
@@ -155,6 +154,21 @@ static struct device_attribute dev_attr_
  * ---------------------------------------------------
  */
 
+static int i2c_do_add_adapter(struct device_driver *d, void *data)
+{
+	struct i2c_driver *driver = to_i2c_driver(d);
+	struct i2c_adapter *adapter = data;
+	int res;
+
+	if (!driver->attach_adapter)
+		return 0;
+	res = driver->attach_adapter(adapter);
+	if (res)
+		dev_err(&adapter->dev, "attach_adapter failed (%d) "
+			"for driver [%s]\n", res, driver->driver.name);
+	return res;
+}
+
 /* -----
  * i2c_add_adapter is called from within the algorithm layer,
  * when a new hw adapter registers. A new device is register to be
@@ -163,8 +177,6 @@ static struct device_attribute dev_attr_
 int i2c_add_adapter(struct i2c_adapter *adap)
 {
 	int id, res = 0;
-	struct list_head   *item;
-	struct i2c_driver  *driver;
 
 	mutex_lock(&core_lists);
 
@@ -208,13 +220,9 @@ int i2c_add_adapter(struct i2c_adapter *
 
 	dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
 
-	/* inform drivers of new adapters */
-	list_for_each(item,&drivers) {
-		driver = list_entry(item, struct i2c_driver, list);
-		if (driver->attach_adapter)
-			/* We ignore the return code; if it fails, too bad */
-			driver->attach_adapter(adap);
-	}
+	/* let drivers scan this bus for matching devices */
+	res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
+			       i2c_do_add_adapter);
 
 out_unlock:
 	mutex_unlock(&core_lists);
@@ -230,12 +238,25 @@ out_list:
 	goto out_unlock;
 }
 
+static int i2c_do_del_adapter(struct device_driver *d, void *data)
+{
+	struct i2c_driver *driver = to_i2c_driver(d);
+	struct i2c_adapter *adapter = data;
+	int res;
+
+	if (!driver->detach_adapter)
+		return 0;
+	res = driver->detach_adapter(adapter);
+	if (res)
+		dev_err(&adapter->dev, "detach_adapter failed (%d) "
+			"for driver [%s]\n", res, driver->driver.name);
+	return res;
+}
 
 int i2c_del_adapter(struct i2c_adapter *adap)
 {
 	struct list_head  *item, *_n;
 	struct i2c_adapter *adap_from_list;
-	struct i2c_driver *driver;
 	struct i2c_client *client;
 	int res = 0;
 
@@ -253,16 +274,11 @@ int i2c_del_adapter(struct i2c_adapter *
 		goto out_unlock;
 	}
 
-	list_for_each(item,&drivers) {
-		driver = list_entry(item, struct i2c_driver, list);
-		if (driver->detach_adapter)
-			if ((res = driver->detach_adapter(adap))) {
-				dev_err(&adap->dev, "detach_adapter failed "
-					"for driver [%s]\n",
-					driver->driver.name);
-				goto out_unlock;
-			}
-	}
+	/* Tell drivers about this removal */
+	res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
+			       i2c_do_del_adapter);
+	if (res)
+		goto out_unlock;
 
 	/* detach any active clients. This must be done first, because
 	 * it can fail; in which case we give up. */
@@ -319,7 +335,6 @@ int i2c_register_driver(struct module *o
 
 	mutex_lock(&core_lists);
 
-	list_add_tail(&driver->list,&drivers);
 	pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
 
 	/* now look for instances of driver on our adapters */
@@ -378,7 +393,6 @@ int i2c_del_driver(struct i2c_driver *dr
 	}
 
 	driver_unregister(&driver->driver);
-	list_del(&driver->list);
 	pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
 
  out_unlock:
--- linux-2.6.21-pre.orig/include/linux/i2c.h	2007-02-10 14:25:21.000000000 +0100
+++ linux-2.6.21-pre/include/linux/i2c.h	2007-02-10 14:25:28.000000000 +0100
@@ -136,7 +136,6 @@ struct i2c_driver {
 	int (*command)(struct i2c_client *client,unsigned int cmd, void *arg);
 
 	struct device_driver driver;
-	struct list_head list;
 };
 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
 

-- 
Jean Delvare