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ARM: S3C24XX: Documentation: update GPIO documentation

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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>
This commit is contained in:
Ben Dooks 2010-05-24 11:11:50 +09:00
parent b9f141acf2
commit 70f5c9a4dd
1 changed files with 33 additions and 2 deletions
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35
Documentation/arm/Samsung-S3C24XX/GPIO.txt
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@ -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
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