gpio: samsung: Update documentation
Update Samsung GPIO API documentation to reflect removal of the s3c24xx specific gpio API. While at it, fix some typos. The notes on conversion from s3c2410_* functions to the gpiolib API are left here just in case there is any out of tree code that still needs to be converted. Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
This commit is contained in:
Sylwester Nawrocki
Kukjin Kim
parent
ef97fa65ef
commit
98025c8c75
|
|
@ -1,4 +1,4 @@
|
|||
S3C2410 GPIO Control
|
||||
S3C24XX GPIO Control
|
||||
====================
|
||||
|
||||
Introduction
|
||||
|
|
@ -12,7 +12,7 @@ Introduction
|
|||
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.
|
||||
See Documentation/arm/Samsung/GPIO.txt for the core implementation.
|
||||
|
||||
|
||||
GPIOLIB
|
||||
|
|
@ -41,8 +41,8 @@ GPIOLIB
|
|||
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.
|
||||
If you need to convert your board or driver to use gpiolib from the phased
|
||||
out 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
|
||||
|
|
@ -55,7 +55,7 @@ s3c2410 api, then here are some notes on the process.
|
|||
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
|
||||
3) s3c2410_gpio_pullup() changes 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.
|
||||
|
|
@ -74,7 +74,7 @@ s3c2410 api, then here are some notes on the process.
|
|||
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
|
||||
6) s3c2410_gpio_getirq() should be directly replaceable with the
|
||||
gpio_to_irq() call.
|
||||
|
||||
The s3c2410_gpio and gpio_ calls have always operated on the same gpio
|
||||
|
|
@ -105,7 +105,7 @@ PIN Numbers
|
|||
-----------
|
||||
|
||||
Each pin has an unique number associated with it in regs-gpio.h,
|
||||
eg S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell
|
||||
e.g. 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
|
||||
|
|
@ -120,31 +120,27 @@ Configuring a pin
|
|||
The following function allows the configuration of a given pin to
|
||||
be changed.
|
||||
|
||||
void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int function);
|
||||
void s3c_gpio_cfgpin(unsigned int pin, unsigned int function);
|
||||
|
||||
Eg:
|
||||
e.g.:
|
||||
|
||||
s3c2410_gpio_cfgpin(S3C2410_GPA(0), S3C2410_GPA0_ADDR0);
|
||||
s3c2410_gpio_cfgpin(S3C2410_GPE(8), S3C2410_GPE8_SDDAT1);
|
||||
s3c_gpio_cfgpin(S3C2410_GPA(0), S3C_GPIO_SFN(1));
|
||||
s3c_gpio_cfgpin(S3C2410_GPE(8), S3C_GPIO_SFN(2));
|
||||
|
||||
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 current configuration of a pin can be read by using:
|
||||
The current configuration of a pin can be read by using standard
|
||||
gpiolib function:
|
||||
|
||||
s3c2410_gpio_getcfg(unsigned int pin);
|
||||
s3c_gpio_getcfg(unsigned int pin);
|
||||
|
||||
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.
|
||||
passed to s3c_gpio_cfgpin().
|
||||
|
||||
|
||||
Configuring a pull-up resistor
|
||||
|
|
@ -154,61 +150,33 @@ Configuring a pull-up resistor
|
|||
pull-up resistors enabled. This can be configured by the following
|
||||
function:
|
||||
|
||||
void s3c2410_gpio_pullup(unsigned int pin, unsigned int to);
|
||||
void s3c_gpio_setpull(unsigned int pin, unsigned int to);
|
||||
|
||||
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.
|
||||
Where the to value is S3C_GPIO_PULL_NONE to set the pull-up off,
|
||||
and S3C_GPIO_PULL_UP to enable the specified pull-up. Any other
|
||||
values are currently undefined.
|
||||
|
||||
|
||||
Getting the state of a PIN
|
||||
--------------------------
|
||||
Getting and setting the state of a PIN
|
||||
--------------------------------------
|
||||
|
||||
The state of a pin can be read by using the function:
|
||||
|
||||
unsigned int s3c2410_gpio_getpin(unsigned int 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
|
||||
--------------------------
|
||||
|
||||
The value an pin is outputing can be modified by using the following:
|
||||
|
||||
void s3c2410_gpio_setpin(unsigned int pin, unsigned int to);
|
||||
|
||||
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
|
||||
These calls are now implemented by the relevant gpiolib calls, convert
|
||||
your board or driver to use gpiolib.
|
||||
|
||||
|
||||
Getting the IRQ number associated with a PIN
|
||||
--------------------------------------------
|
||||
|
||||
The following function can map the given pin number to an IRQ
|
||||
A standard gpiolib function can map the given pin number to an IRQ
|
||||
number to pass to the IRQ system.
|
||||
|
||||
int s3c2410_gpio_getirq(unsigned int pin);
|
||||
int gpio_to_irq(unsigned int 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
|
||||
Author
|
||||
-------
|
||||
|
||||
|
||||
Ben Dooks, 03 October 2004
|
||||
Copyright 2004 Ben Dooks, Simtec Electronics
|
||||
|
|
|
|||
|
|
@ -5,14 +5,14 @@ Introduction
|
|||
------------
|
||||
|
||||
This outlines the Samsung GPIO implementation and the architecture
|
||||
specific calls provided alongisde the drivers/gpio core.
|
||||
specific calls provided alongside 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
|
||||
about these devices. Their implementation has been brought into line
|
||||
with the core samsung implementation described in this document.
|
||||
|
||||
|
||||
|
|
@ -29,7 +29,7 @@ GPIO numbering is synchronised between the Samsung and gpiolib system.
|
|||
PIN configuration
|
||||
-----------------
|
||||
|
||||
Pin configuration is specific to the Samsung architecutre, with each SoC
|
||||
Pin configuration is specific to the Samsung architecture, with each SoC
|
||||
registering the necessary information for the core gpio configuration
|
||||
implementation to configure pins as necessary.
|
||||
|
||||
|
|
@ -38,5 +38,3 @@ driver or machine to change gpio configuration.
|
|||
|
||||
See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information
|
||||
on these functions.
|
||||
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue
Block a user