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Mika Westerberg 03c4749dd6 gpio / ACPI: Drop unnecessary ACPI GPIO to Linux GPIO translation
We added acpi_gpiochip_pin_to_gpio_offset() because there was a need to
translate from ACPI GpioIo/GpioInt number to Linux GPIO number in the
Cherryview pinctrl driver. This translation is necessary because
Cherryview has gaps in the pin list and the driver used continuous GPIO
number space in Linux side as follows:

  created GPIO range 0->7 ==> INT33FF:03 PIN 0->7
  created GPIO range 8->19 ==> INT33FF:03 PIN 15->26
  created GPIO range 20->25 ==> INT33FF:03 PIN 30->35
  created GPIO range 26->33 ==> INT33FF:03 PIN 45->52
  created GPIO range 34->43 ==> INT33FF:03 PIN 60->69
  created GPIO range 44->54 ==> INT33FF:03 PIN 75->85

For example when ACPI GpioInt resource refers to GPIO 81 (SDMMC3_CD_B)
we translate from pin 81 to the corresponding Linux GPIO number, which
is 50. This number is then used when the GPIO is accessed through gpiolib.

It turns out, this is not necessary at all. We can just pass 1:1 mapping
between Linux GPIO numbers and pin numbers (including gaps) and the
pinctrl core handles all the details automatically:

  created GPIO range 0->7 ==> INT33FF:03 PIN 0->7
  created GPIO range 15->26 ==> INT33FF:03 PIN 15->26
  created GPIO range 30->35 ==> INT33FF:03 PIN 30->35
  created GPIO range 45->52 ==> INT33FF:03 PIN 45->52
  created GPIO range 60->69 ==> INT33FF:03 PIN 60->69
  created GPIO range 75->85 ==> INT33FF:03 PIN 75->85

Here GPIO 81 is exactly same than the hardware pin 81 (SDMMC3_CD_B).

As an added bonus this simplifies both the ACPI GPIO core code and the
Cherryview pinctrl driver.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-11-29 13:41:46 +01:00
Documentation Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:11:54 -08:00
arch Merge branch 'fixes' of git://git.armlinux.org.uk/~rmk/linux-arm 2017-11-26 15:03:49 -08:00
block treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto Keys devel 2017-11-24 11:54:11 +11:00
drivers gpio / ACPI: Drop unnecessary ACPI GPIO to Linux GPIO translation 2017-11-29 13:41:46 +01:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
include Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:39:20 -08:00
init EXPERT Kconfig menu: fix broken EXPERT menu 2017-11-17 16:10:05 -08:00
ipc Merge branch 'akpm' (patches from Andrew) 2017-11-17 16:56:17 -08:00
kernel Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:39:20 -08:00
lib Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
mm block/laptop_mode: Convert timers to use timer_setup() 2017-11-21 15:46:44 -08:00
net Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
samples kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
scripts Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
security Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
sound Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-25 08:37:16 -10:00
tools Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-26 14:11:54 -08:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt Trimmed second batch of KVM changes for Linux 4.15 2017-11-24 19:44:25 -10:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild misc updates for v4.15 2017-11-17 17:51:33 -08:00
.mailmap Add Jason Gunthorpe as co-maintainer of the RDMA stack 2017-11-17 09:36:18 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS RTC for 4.15 2017-11-22 20:58:23 -10:00
Makefile Linux 4.15-rc1 2017-11-26 16:01:47 -08:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

README

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.