X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=Documentation%2Fdriver-model%2Fdevice.txt;fp=Documentation%2Fdriver-model%2Fdevice.txt;h=a05ec50f8004dd65f29c87579612389f93660187;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=58cc5dc8fd3eac2f8851674db7909d0f56c32f79;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/Documentation/driver-model/device.txt b/Documentation/driver-model/device.txt
index 58cc5dc8f..a05ec50f8 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