Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / Documentation / driver-model / device.txt

diff --git a/Documentation/driver-model/device.txt b/Documentation/driver-model/device.txt
index 58cc5dc..a05ec50 100644 (file)
--- 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