i2c: Add kernel documentation

Generate I2C kerneldoc; fix various glitches and add "context" sections to
that documentation.  Most I2C and SMBus functions still have no kerneldoc.

Let me suggest providing kerneldoc for all the i2c_smbus_*() functions as
a small and mostly self-contained project for anyone so inclined.  :)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index cae7d61..a24e267 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -150,15 +150,20 @@
 
 /**
  * struct i2c_client - represent an I2C slave device
+ * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
+ *	I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
  * @addr: Address used on the I2C bus connected to the parent adapter.
  * @name: Indicates the type of the device, usually a chip name that's
  *	generic enough to hide second-sourcing and compatible revisions.
+ * @adapter: manages the bus segment hosting this I2C device
  * @dev: Driver model device node for the slave.
+ * @irq: indicates the IRQ generated by this device (if any)
  * @driver_name: Identifies new-style driver used with this device; also
  *	used as the module name for hotplug/coldplug modprobe support.
  *
  * An i2c_client identifies a single device (i.e. chip) connected to an
- * i2c bus. The behaviour is defined by the routines of the driver.
+ * i2c bus. The behaviour exposed to Linux is defined by the driver
+ * managing the device.
  */
 struct i2c_client {
 	unsigned short flags;		/* div., see below		*/
@@ -201,7 +206,7 @@
  * @addr: stored in i2c_client.addr
  * @platform_data: stored in i2c_client.dev.platform_data
  * @irq: stored in i2c_client.irq
-
+ *
  * I2C doesn't actually support hardware probing, although controllers and
  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
  * a device at a given address.  Drivers commonly need more information than
@@ -210,7 +215,7 @@
  * i2c_board_info is used to build tables of information listing I2C devices
  * that are present.  This information is used to grow the driver model tree
  * for "new style" I2C drivers.  For mainboards this is done statically using
- * i2c_register_board_info(), where @bus_num represents an adapter that isn't
+ * i2c_register_board_info(); bus numbers identify adapters that aren't
  * yet available.  For add-on boards, i2c_new_device() does this dynamically
  * with the adapter already known.
  */