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* 'for-linus/2635-updates' of git://git.fluff.org/bjdooks/linux:
  ARM: S5PV210: serial: Fix section mismatch warning
  ARM: s3c2410_defconfig: Add new machines
  ARM: s3c6400_defconfig: Add framebuffer and basic LCD
  ARM: s3c6400_defconfig: Add RTC driver support
  ARM: s3c6400_defconfig: Enable USB host side
  ARM: s3c6400_defconfig: Add SPI driver
  ARM: s3c6400_defconfig: Update compiled machines
  ARM: S5P: Regoster clk_xusbxti clock for hsotg driver
  ARM: S3C64XX: Add USB OTG HCLK to the list of clocks
  ARM: SAMSUNG: gpio-cfg.h: update documentation
  ARM: SAMSUNG: Documentation: add documentation on GPIO code
  ARM: SAMSUNG: Fix documentation for s3c_gpio_cfgpin()
  ARM: S3C24XX: Documentation: add section on gpiolib changes
  ARM: S3C24XX: Documentation: update GPIO documentation
  ARM: S3C24XX: Documentation: update documentation overview
  ARM: SAMSUNG: Documentation: update directory layout
  ARM: SAMSUNG: Documentation: update the list of SoCs supported
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Linus Torvalds committed May 28, 2010
2 parents 72da3bc + 5d66cee commit 043f275
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81 changes: 79 additions & 2 deletions Documentation/arm/Samsung-S3C24XX/GPIO.txt
Original file line number Diff line number Diff line change
Expand Up @@ -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.

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


GPIOLIB
-------
Expand All @@ -24,8 +26,60 @@ 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
Expand Down Expand Up @@ -54,6 +108,11 @@ 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
-----------------
Expand All @@ -71,6 +130,8 @@ 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
---------------------------------
Expand All @@ -82,6 +143,9 @@ 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
------------------------------
Expand All @@ -95,6 +159,10 @@ 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
--------------------------
Expand All @@ -106,6 +174,9 @@ 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
--------------------------
Expand All @@ -117,6 +188,9 @@ 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
--------------------------------------------
Expand All @@ -128,6 +202,9 @@ 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
-------
Expand Down
15 changes: 14 additions & 1 deletion Documentation/arm/Samsung-S3C24XX/Overview.txt
Original file line number Diff line number Diff line change
Expand Up @@ -8,10 +8,16 @@ Introduction

The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported
by the 's3c2410' architecture of ARM Linux. Currently the S3C2410,
S3C2412, S3C2413, S3C2440, S3C2442 and S3C2443 devices are supported.
S3C2412, S3C2413, S3C2416 S3C2440, S3C2442, S3C2443 and S3C2450 devices
are supported.

Support for the S3C2400 and S3C24A0 series are in progress.

The S3C2416 and S3C2450 devices are very similar and S3C2450 support is
included under the arch/arm/mach-s3c2416 directory. Note, whilst core
support for these SoCs is in, work on some of the extra peripherals
and extra interrupts is still ongoing.


Configuration
-------------
Expand Down Expand Up @@ -209,6 +215,13 @@ GPIO
Newer kernels carry GPIOLIB, and support is being moved towards
this with some of the older support in line to be removed.

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
----------------
Expand Down
42 changes: 42 additions & 0 deletions Documentation/arm/Samsung/GPIO.txt
Original file line number Diff line number Diff line change
@@ -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.


33 changes: 23 additions & 10 deletions Documentation/arm/Samsung/Overview.txt
Original file line number Diff line number Diff line change
Expand Up @@ -13,9 +13,10 @@ Introduction

- S3C24XX: See Documentation/arm/Samsung-S3C24XX/Overview.txt for full list
- S3C64XX: S3C6400 and S3C6410
- S5PC6440

S5PC100 and S5PC110 support is currently being merged
- S5P6440
- S5P6442
- S5PC100
- S5PC110 / S5PV210


S3C24XX Systems
Expand All @@ -35,7 +36,10 @@ Configuration
unifying all the SoCs into one kernel.

s5p6440_defconfig - S5P6440 specific default configuration
s5p6442_defconfig - S5P6442 specific default configuration
s5pc100_defconfig - S5PC100 specific default configuration
s5pc110_defconfig - S5PC110 specific default configuration
s5pv210_defconfig - S5PV210 specific default configuration


Layout
Expand All @@ -50,18 +54,27 @@ Layout
specific information. It contains the base clock, GPIO and device definitions
to get the system running.

plat-s3c is the s3c24xx/s3c64xx platform directory, although it is currently
involved in other builds this will be phased out once the relevant code is
moved elsewhere.

plat-s3c24xx is for s3c24xx specific builds, see the S3C24XX docs.

plat-s3c64xx is for the s3c64xx specific bits, see the S3C24XX docs.
plat-s5p is for s5p specific builds, and contains common support for the
S5P specific systems. Not all S5Ps use all the features in this directory
due to differences in the hardware.


Layout changes
--------------

The old plat-s3c and plat-s5pc1xx directories have been removed, with
support moved to either plat-samsung or plat-s5p as necessary. These moves
where to simplify the include and dependency issues involved with having
so many different platform directories.

plat-s5p is for s5p specific builds, more to be added.
It was decided to remove plat-s5pc1xx as some of the support was already
in plat-s5p or plat-samsung, with the S5PC110 support added with S5PV210
the only user was the S5PC100. The S5PC100 specific items where moved to
arch/arm/mach-s5pc100.


[ to finish ]


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