ARM: SAMSUNG: Documentation: add documentation on GPIO code

Add some documentation in Documentation/arm/Samsung for the GPIO code
and where to look for the necessary functions. Update the S3C24XX case
as well.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>

diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
index 228ecb61d2fd91c5a74d60140af2c06e2525542b..816d6071669e75380dc72da99fb9a27739e0a2d8 100644 (file)
--- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt
+++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
@@ -12,6 +12,8 @@ Introduction
   of the s3c2410 GPIO system, please read the Samsung provided
   data-sheet/users manual to find out the complete list.
 
   of the s3c2410 GPIO system, please read the Samsung provided
   data-sheet/users manual to find out the complete list.
 

+  See Documentation/arm/Samsung/GPIO.txt for the core implemetation.
+

 
 GPIOLIB
 -------
 
 GPIOLIB
 -------

diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt
index 0f11fcc1d51e54753b6d06dab1779319a1a91021..c12bfc1a00c9812ebfa8c95314f34228dc7a1a1f 100644 (file)
--- a/Documentation/arm/Samsung-S3C24XX/Overview.txt
+++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt
@@ -218,6 +218,10 @@ GPIO
   As of v2.6.34, the move towards using gpiolib support is almost
   complete, and very little of the old calls are left.
 
   As of v2.6.34, the move towards using gpiolib support is almost
   complete, and very little of the old calls are left.
 

+  See Documentation/arm/Samsung-S3C24XX/GPIO.txt for the S3C24XX specific
+  support and Documentation/arm/Samsung/GPIO.txt for the core Samsung
+  implementation.
+

 
 Clock Management
 ----------------
 
 Clock Management
 ----------------

diff --git a/Documentation/arm/Samsung/GPIO.txt b/Documentation/arm/Samsung/GPIO.txt
new file mode 100644 (file)
index 0000000..05850c6
--- /dev/null
+++ b/Documentation/arm/Samsung/GPIO.txt
@@ -0,0 +1,42 @@
+               Samsung GPIO implementation
+               ===========================
+
+Introduction
+------------
+
+This outlines the Samsung GPIO implementation and the architecture
+specfic calls provided alongisde the drivers/gpio core.
+
+
+S3C24XX (Legacy)
+----------------
+
+See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information
+about these devices. Their implementation is being brought into line
+with the core samsung implementation described in this document.
+
+
+GPIOLIB integration
+-------------------
+
+The gpio implementation uses gpiolib as much as possible, only providing
+specific calls for the items that require Samsung specific handling, such
+as pin special-function or pull resistor control.
+
+GPIO numbering is synchronised between the Samsung and gpiolib system.
+
+
+PIN configuration
+-----------------
+
+Pin configuration is specific to the Samsung architecutre, with each SoC
+registering the necessary information for the core gpio configuration
+implementation to configure pins as necessary.
+
+The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a
+driver or machine to change gpio configuration.
+
+See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information
+on these functions.
+
+