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authorBen Dooks <ben-linux@fluff.org>2010-05-24 06:11:50 +0400
committerBen Dooks <ben-linux@fluff.org>2010-05-28 14:31:30 +0400
commit70f5c9a4ddcbce3e6d7d54ec890a4bca19b4fc7a (patch)
tree614b4e8c7498cb813f1e0b355ec67e94d00aff2f /Documentation/arm
parentb9f141acf2a6b456e262bc54fd69c19d76c319d3 (diff)
downloadlinux-70f5c9a4ddcbce3e6d7d54ec890a4bca19b4fc7a.tar.xz
ARM: S3C24XX: Documentation: update GPIO documentation
Upate the S3C24XX GPIO documentation after the changes for gpiolib and show which calls are being replaced by gpiolib or the new s3c generic calls. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'Documentation/arm')
-rw-r--r--Documentation/arm/Samsung-S3C24XX/GPIO.txt35
1 files changed, 33 insertions, 2 deletions
diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
index 2af2cf39915f..9fe5feac212d 100644
--- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt
+++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt
@@ -24,8 +24,16 @@ GPIOLIB
listed below will be removed (they may be marked as __deprecated
in the near future).
- - s3c2410_gpio_getpin
- - s3c2410_gpio_setpin
+ The following functions now either have a s3c_ specific variant
+ or are merged into gpiolib. See the definitions in
+ arch/arm/plat-samsung/include/plat/gpio-cfg.h:
+
+ s3c2410_gpio_setpin() gpio_set_value() or gpio_direction_output()
+ s3c2410_gpio_getpin() gpio_get_value() or gpio_direction_input()
+ s3c2410_gpio_getirq() gpio_to_irq()
+ s3c2410_gpio_cfgpin() s3c_gpio_cfgpin()
+ s3c2410_gpio_getcfg() s3c_gpio_getcfg()
+ s3c2410_gpio_pullup() s3c_gpio_setpull()
Headers
@@ -54,6 +62,11 @@ PIN Numbers
eg S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell
the GPIO functions which pin is to be used.
+ With the conversion to gpiolib, there is no longer a direct conversion
+ from gpio pin number to register base address as in earlier kernels. This
+ is due to the number space required for newer SoCs where the later
+ GPIOs are not contiguous.
+
Configuring a pin
-----------------
@@ -71,6 +84,8 @@ Configuring a pin
which would turn GPA(0) into the lowest Address line A0, and set
GPE(8) to be connected to the SDIO/MMC controller's SDDAT1 line.
+ The s3c_gpio_cfgpin() call is a functional replacement for this call.
+
Reading the current configuration
---------------------------------
@@ -82,6 +97,9 @@ Reading the current configuration
The return value will be from the same set of values which can be
passed to s3c2410_gpio_cfgpin().
+ The s3c_gpio_getcfg() call should be a functional replacement for
+ this call.
+
Configuring a pull-up resistor
------------------------------
@@ -95,6 +113,10 @@ Configuring a pull-up resistor
Where the to value is zero to set the pull-up off, and 1 to enable
the specified pull-up. Any other values are currently undefined.
+ The s3c_gpio_setpull() offers similar functionality, but with the
+ ability to encode whether the pull is up or down. Currently there
+ is no 'just on' state, so up or down must be selected.
+
Getting the state of a PIN
--------------------------
@@ -106,6 +128,9 @@ Getting the state of a PIN
This will return either zero or non-zero. Do not count on this
function returning 1 if the pin is set.
+ This call is now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
Setting the state of a PIN
--------------------------
@@ -117,6 +142,9 @@ Setting the state of a PIN
Which sets the given pin to the value. Use 0 to write 0, and 1 to
set the output to 1.
+ This call is now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
Getting the IRQ number associated with a PIN
--------------------------------------------
@@ -128,6 +156,9 @@ Getting the IRQ number associated with a PIN
Note, not all pins have an IRQ.
+ This call is now implemented by the relevant gpiolib calls, convert
+ your board or driver to use gpiolib.
+
Authour
-------