[PATCH] Driver Core: driver model doc update

This updates some driver data documentation:

 - removes references to some fields that haven't been there for a
   long time now, e.g. pre-kobject or even older;

 - giving more information about the probe() method;

 - adding an example of how platform_data is used

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 0 deletions

diff --git a/Documentation/driver-model/device.txt b/Documentation/driver-model/device.txt
index 58cc5dc8fd3e..a05ec50f8004 100644
--- a/Documentation/driver-model/device.txt
+++ b/Documentation/driver-model/device.txt
@@ -76,6 +76,14 @@ driver_data:   Driver-specific data.
 
 platform_data: Platform data specific to the device.
 
+               Example:  for devices on custom boards, as typical of embedded
+               and SOC based hardware, Linux often uses platform_data to point
+               to board-specific structures describing devices and how they
+               are wired.  That can include what ports are available, chip
+               variants, which GPIO pins act in what additional roles, and so
+               on.  This shrinks the "Board Support Packages" (BSPs) and
+               minimizes board-specific #ifdefs in drivers.
+
 current_state: Current power state of the device.
 
 saved_state:   Pointer to saved state of the device. This is usable by