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
-------
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()
+
+
+GPIOLIB conversion
+------------------
+
+If you need to convert your board or driver to use gpiolib from the exiting
+s3c2410 api, then here are some notes on the process.
+
+1) If your board is exclusively using an GPIO, say to control peripheral
+ power, then it will require to claim the gpio with gpio_request() before
+ it can use it.
+
+ It is recommended to check the return value, with at least WARN_ON()
+ during initialisation.
+
+2) The s3c2410_gpio_cfgpin() can be directly replaced with s3c_gpio_cfgpin()
+ as they have the same arguments, and can either take the pin specific
+ values, or the more generic special-function-number arguments.
+
+3) s3c2410_gpio_pullup() changs have the problem that whilst the
+ s3c2410_gpio_pullup(x, 1) can be easily translated to the
+ s3c_gpio_setpull(x, S3C_GPIO_PULL_NONE), the s3c2410_gpio_pullup(x, 0)
+ are not so easy.
+
+ The s3c2410_gpio_pullup(x, 0) case enables the pull-up (or in the case
+ of some of the devices, a pull-down) and as such the new API distinguishes
+ between the UP and DOWN case. There is currently no 'just turn on' setting
+ which may be required if this becomes a problem.
+
+4) s3c2410_gpio_setpin() can be replaced by gpio_set_value(), the old call
+ does not implicitly configure the relevant gpio to output. The gpio
+ direction should be changed before using gpio_set_value().
+
+5) s3c2410_gpio_getpin() is replaceable by gpio_get_value() if the pin
+ has been set to input. It is currently unknown what the behaviour is
+ when using gpio_get_value() on an output pin (s3c2410_gpio_getpin
+ would return the value the pin is supposed to be outputting).
+
+6) s3c2410_gpio_getirq() should be directly replacable with the
+ gpio_to_irq() call.
+
+The s3c2410_gpio and gpio_ calls have always operated on the same gpio
+numberspace, so there is no problem with converting the gpio numbering
+between the calls.
Headers
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
-----------------
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
---------------------------------
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
------------------------------
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
--------------------------
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
--------------------------
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
--------------------------------------------
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
-------
git.openpandora.org / pandora-kernel.git / blobdiff