Commit Graph

71 Commits

Author SHA1 Message Date
Linus Walleij
e3863fa123 gpio: Get rid of gpio_to_chip()
The gpio_to_chip() function refers to the global GPIO numberspace
which is a problem we want to get rid of. Get this function out
of the header and open code it into gpiolib with appropriate FIXME
notices so no new users appear in the kernel.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-01-30 15:55:30 +01:00
Andy Shevchenko
f2527d8f56 gpio: Remove unused and obsoleted gpio_export_link()
gpio_export_link() is legacy and unused API, remove it for good.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Yanteng Si <siyanteng@loongson.cn>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-01-30 15:55:29 +01:00
Christophe Leroy
7b61212f2a gpiolib: Get rid of ARCH_NR_GPIOS
Since commit 14e85c0e69 ("gpio: remove gpio_descs global array")
there is no limitation on the number of GPIOs that can be allocated
in the system since the allocation is fully dynamic.

ARCH_NR_GPIOS is today only used in order to provide downwards
gpiobase allocation from that value, while static allocation is
performed upwards from 0. However that has the disadvantage of
limiting the number of GPIOs that can be registered in the system.

To overcome this limitation without requiring each and every
platform to provide its 'best-guess' maximum number, rework the
allocation to allocate upwards, allowing approx 2 millions of
GPIOs.

In order to still allow static allocation for legacy drivers, define
GPIO_DYNAMIC_BASE with the value 512 as the start for dynamic
allocation. The 512 value is chosen because it is the end of
the current default range so all current static allocations are
expected to be below that value. Of course that's just a rough
estimate based on the default value, but assuming static
allocations come first, even if there are more static allocations
it should fit under the 512 value.

In the future, it is expected that all static allocations go away
and then dynamic allocation will be patched to start at 0.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2022-10-17 11:03:09 +02:00
Andy Shevchenko
046e14afb3 gpio: Avoid kernel.h inclusion where it's possible
Inclusion of kernel.h increases the mess with the header dependencies.
Avoid kernel.h inclusion where it's possible.

Besides that, clean up a bit other inclusions inside GPIO subsystem headers.
It includes:
 - removal pin control bits (forward declaration and header) from linux/gpio.h
 - removal of.h from asm-generic/gpio.h
 - use of explicit headers in gpio/consumer.h
 - add FIXME note with regard to gpio.h inclusion in of_gpio,h

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20200205134336.20197-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-02-10 12:58:36 +01:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Arnd Bergmann
aa6aedb547 gpio: allow setting ARCH_NR_GPIOS from Kconfig
The ARM version of asm/gpio.h basically just contains the same definitions
as the gpiolib version, with the exception of ARCH_NR_GPIOS.

This adds the option for overriding the constant through Kconfig to
the architecture-independent header, so we can remove the ARM specific
file later.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-19 00:22:54 +01:00
Johan Hovold
166a85e442 gpio: remove gpiod_sysfs_set_active_low
Remove gpiod_sysfs_set_active_low (and gpio_sysfs_set_active_low) which
allowed code to change the polarity of a gpio line even after it had
been exported through sysfs.

Drivers should not care, and generally does not know, about gpio-line
polarity which is a hardware feature that needs to be described by
firmware.

It is currently possible to define gpio-line polarity in device-tree and
acpi firmware or using platform data. Userspace can also change the
polarity through sysfs.

Note that drivers using the legacy gpio interface could still use
GPIOF_ACTIVE_LOW to change the polarity before exporting the gpio.

There are no in-kernel users of this interface.

Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@zh-kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-12 10:46:53 +02:00
Linus Walleij
964cb34188 gpio: move pincontrol calls to <linux/gpio/driver.h>
These functions do not belong in <asm-generic/gpio.h> since the
split into separate GPIO headers under <linux/gpio/*>. Move them
to <linux/gpio/driver.h> as is apropriate.

Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-03-19 09:45:54 +01:00
Mika Westerberg
7ca267faba gpio: Increase ARCH_NR_GPIOs to 512
Some newer Intel SoCs, like Braswell already have more than 256 GPIOs
available so the default limit is exceeded. Instead of adding more
architecture specific gpio.h files with custom ARCH_NR_GPIOs we increase
the gpiolib default limit to be twice the current.

Current generic ARCH_NR_GPIOS limit is 256 which starts to be too small
for newer Intel SoCs like Braswell. In order to support GPIO controllers
on these SoCs we increase ARCH_NR_GPIOS to be 512 which should be
sufficient for now.

The kernel size increases a bit with this change. Below is an example of
x86_64 kernel image.

ARCH_NR_GPIOS=256
 text     data    bss     dec      hex    filename
 11476173 1971328 1265664 14713165 e0814d vmlinux

ARCH_NR_GPIOS=512
 text     data    bss     dec      hex    filename
 11476173 1971328 1269760 14717261 e0914d vmlinux

So the BSS size and this the kernel image size increases by 4k.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-09-23 17:51:39 +02:00
Alexandre Courbot
c7caf86823 gpio: remove gpio_ensure_requested()
gpio_ensure_requested() has been introduced in Feb. 2008 by commit
d2876d08d8 to force users of the GPIO API to explicitly request GPIOs
before using them.

Hopefully by now all GPIOs are correctly requested and this extra check
can be omitted ; in any case the GPIO maintainers won't feel bad if
machines start failing after 6 years of warnings.

This patch removes that function from the dark ages.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-24 18:18:47 +02:00
Alexandre Courbot
d82da79722 gpio: move gpio_ensure_requested() into legacy C file
gpio_ensure_requested() only makes sense when using the integer-based
GPIO API, so make sure it is called from there instead of the gpiod
API which we know cannot be called with a non-requested GPIO anyway.

The uses of gpio_ensure_requested() in the gpiod API were kind of
out-of-place anyway, so putting them in gpio-legacy.c helps clearing the
code.

Actually, considering the time this ensure_requested mechanism has been
around, maybe we should just turn this patch into "remove
gpio_ensure_requested()" if we know for sure that no user depend on it
anymore?

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23 17:46:00 +02:00
Alexandre Courbot
d74be6dfea gpio: remove gpiod_lock/unlock_as_irq()
gpio_lock/unlock_as_irq() are working with (chip, offset) arguments and
are thus not using the old integer namespace. Therefore, there is no
reason to have gpiod variants of these functions working with
descriptors, especially since the (chip, offset) tuple is more suitable
to the users of these functions (GPIO drivers, whereas GPIO descriptors
are targeted at GPIO consumers).

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-23 17:43:24 +02:00
Philipp Zabel
ef70bbe1aa gpio: make gpiod_direction_output take a logical value
The documentation was not clear about whether
gpio_direction_output should take a logical value or the physical
level on the output line, i.e. whether the ACTIVE_LOW status
would be taken into account.

This converts gpiod_direction_output to use the logical level
and adds a new gpiod_direction_output_raw for the raw value.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-07 09:47:02 +01:00
Linus Torvalds
c2d3306991 GPIO bulk changes for the v3.13 development cycle
- Merged the GPIO descriptor API from Alexandre Courbot.
   This is a first step toward trying to get rid of the
   global GPIO numberspace for the future.
 
 - Add an API so that driver can flag that a certain GPIO
   line is being used by a irqchip backend for generating
   IRQs, so that we can enforce checks, like not allowing
   users to switch that line to an output at runtime, since
   this makes no sense. Implemented corresponding calls
   in a few select drivers.
 
 - ACPI GPIO cleanups, refactorings and switch to using the
   descriptor-based interface.
 
 - Support for the TPS80036 Palmas GPIO variant.
 
 - A new driver for the Broadcom Kona GPIO SoC IP block.
 
 - Device tree support for the PCF857x driver.
 
 - A set of ARM GPIO refactorings with the goal of getting
   rid of a bunch of custom GPIO implementations from the
   arch/arm/* tree:
 
   - Move the IOP GPIO driver to the GPIO subsystem and
     fix all users to use the gpiolib API for accessing
     GPIOs. Delete the old custom GPIO implementation.
 
   - Delete the unused custom PXA GPIO implemention.
 
   - Convert all users of the IXP4 custom GPIO
     implementation to use gpiolib and delete the custom
     implementation.
 
   - Delete the custom Gemini GPIO implementation, also
     completely unused.
 
 - Various cleanups and renamings.
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Merge tag 'gpio-v3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO changes from Linus Walleij:
 "Here is the bulk of GPIO changes for the v3.13 development cycle.

  I've got ACKs for the things that affect other subsystems (or it's my
  own subsystem, like pinctrl).  Most of that pertain to an attempt from
  my side to consolidate and get rid of custom GPIO implementations in
  the ARM tree.  I will continue doing this.

  The main change this time is the new GPIO descriptor API, background
  for this can be found in Corbet's summary from this january in LWN:

    http://lwn.net/Articles/533632/

  Summary:

   - Merged the GPIO descriptor API from Alexandre Courbot.  This is a
     first step toward trying to get rid of the global GPIO numberspace
     for the future.

   - Add an API so that driver can flag that a certain GPIO line is
     being used by a irqchip backend for generating IRQs, so that we can
     enforce checks, like not allowing users to switch that line to an
     output at runtime, since this makes no sense.  Implemented
     corresponding calls in a few select drivers.

   - ACPI GPIO cleanups, refactorings and switch to using the
     descriptor-based interface.

   - Support for the TPS80036 Palmas GPIO variant.

   - A new driver for the Broadcom Kona GPIO SoC IP block.

   - Device tree support for the PCF857x driver.

   - A set of ARM GPIO refactorings with the goal of getting rid of a
     bunch of custom GPIO implementations from the arch/arm/* tree:

     * Move the IOP GPIO driver to the GPIO subsystem and fix all users
       to use the gpiolib API for accessing GPIOs.  Delete the old
       custom GPIO implementation.

     * Delete the unused custom PXA GPIO implemention.

     * Convert all users of the IXP4 custom GPIO implementation to use
       gpiolib and delete the custom implementation.

     * Delete the custom Gemini GPIO implementation, also completely
       unused.

   - Various cleanups and renamings"

* tag 'gpio-v3.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (85 commits)
  gpio: gpio-mxs: Remove unneeded dt checks
  gpio: pl061: don't depend on CONFIG_ARM
  gpio: bcm-kona: add missing .owner to struct gpio_chip
  gpiolib: provide a declaration of seq_file in gpio/driver.h
  gpiolib: include gpio/consumer.h in of_gpio.h for desc_to_gpio()
  gpio: provide stubs for devres gpio functions
  gpiolib: devres: add missing headers
  gpiolib: make GPIO_DEVRES depend on GPIOLIB
  gpiolib: devres: fix devm_gpiod_get_index()
  gpiolib / ACPI: document the GPIO descriptor based interface
  gpiolib / ACPI: allow passing GPIOF_ACTIVE_LOW for GpioInt resources
  gpiolib / ACPI: add ACPI support for gpiod_get_index()
  gpiolib / ACPI: convert to gpiod interfaces
  gpiolib: add gpiod_get() and gpiod_put() functions
  gpiolib: port of_ functions to use gpiod
  gpiolib: export descriptor-based GPIO interface
  Fixup "MAINTAINERS: GPIO-INTEL-MID: add maintainer"
  gpio: bcm281xx: Don't print addresses of GPIO area in probe()
  gpio: tegra: use new gpio_lock_as_irq() API
  gpio: rcar: Include linux/of.h header
  ...
2013-11-12 15:50:46 +09:00
Alexandre Courbot
79a9becda8 gpiolib: export descriptor-based GPIO interface
This patch exports the gpiod_* family of API functions, a safer
alternative to the legacy GPIO interface. Differences between the gpiod
and legacy gpio APIs are:

- gpio works with integers, whereas gpiod operates on opaque handlers
  which cannot be forged or used before proper acquisition
- gpiod get/set functions are aware of the active low state of a GPIO
- gpio consumers should now include <linux/gpio/consumer.h> to access
  the new interface, whereas chips drivers will use
  <linux/gpio/driver.h>

The legacy gpio API is now built as inline functions on top of gpiod.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-19 23:24:45 +02:00
Christian Ruppert
586a87e6ed pinctrl/gpio: non-linear GPIO ranges accesible from gpiolib
This patch adds the infrastructure required to register non-linear gpio
ranges through gpiolib and the standard GPIO device tree bindings.

Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-16 15:33:50 +02:00
Linus Walleij
d468bf9eca gpio: add API to be strict about GPIO IRQ usage
It is currently often possible in many GPIO drivers to request
a GPIO line to be used as IRQ after calling gpio_to_irq() and,
as the gpiolib is not aware of this, set the same line to
output and start driving it, with undesired side effects.

As it is a bogus usage scenario to request a line flagged as
output to used as IRQ, we introduce APIs to let gpiolib track
the use of a line as IRQ, and also set this flag from the
userspace ABI.

The API is symmetric so that lines can also be flagged from
.irq_enable() and unflagged from IRQ by .irq_disable().
The debugfs file is altered so that we see if a line is
reserved for IRQ.

Cc: Enric Balletbo i Serra <eballetbo@gmail.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-10-16 09:59:54 +02:00
Alexandre Courbot
6c0b4e6c85 gpiolib: let gpio_chip reference its descriptors
Add a pointer to the gpio_chip structure that references the array of
GPIO descriptors belonging to the chip, and update gpiolib code to use
this pointer instead of the global gpio_desc[] array. This is another
step towards the removal of the gpio_desc[] global array.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.orh>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-11 22:21:28 +00:00
Alexandre Courbot
1a989d0f1d gpiolib: link all gpio_chips using a list
Add a list member to gpio_chip that allows all chips to be parsed
quickly. The current method requires parsing the entire GPIO integer
space, which is painfully slow. Using a list makes many chip operations
that involve lookup or parsing faster, and also simplifies the code. It
is also necessary to eventually get rid of the global gpio_desc[] array.

The list of gpio_chips is always ordered by base GPIO number to ensure
chips traversal is done in the right order.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2013-02-09 09:20:12 +00:00
Alexandre Courbot
710b40eac4 gpiolib: remove gpiochip_reserve()
gpiochip_reserve() has no user and stands in the way of the removal of
the static gpio_desc[] array. Remove this function as well as the now
unneeded RESERVED flag of struct gpio_desc.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-02-04 21:41:46 +01:00
Shawn Guo
6a89a314ab gpio: devm_gpio_* support should not depend on GPIOLIB
Some architectures (e.g. blackfin) provide gpio API without requiring
GPIOLIB support (ARCH_WANT_OPTIONAL_GPIOLIB).  devm_gpio_* functions
should also work for these architectures, since they do not really
depend on GPIOLIB.

Add a new option GPIO_DEVRES (enabled by default) to control the build
of devres.c.  It also removes the empty version of devm_gpio_*
functions for !GENERIC_GPIO build from linux/gpio.h, and moves the
function declarations from asm-generic/gpio.h into linux/gpio.h.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-22 10:23:35 +01:00
Shawn Guo
d59b4eaaf0 gpio: fix warning of 'struct gpio_chip' declaration
The struct gpio_chip is only defined inside #ifdef CONFIG_GPIOLIB,
but it's referenced by gpiochip_add_pin_range() and
gpiochip_remove_pin_ranges() which are outside #ifdef CONFIG_GPIOLIB.
Thus, we see the following warning when building blackfin image, where
GPIOLIB is not required.

  CC      arch/blackfin/kernel/bfin_gpio.o
  CC      init/version.o
In file included from arch/blackfin/include/asm/gpio.h:321,
                 from arch/blackfin/kernel/bfin_gpio.c:15:
include/asm-generic/gpio.h:298: warning: 'struct gpio_chip' declared inside parameter list
include/asm-generic/gpio.h:298: warning: its scope is only this definition or declaration, which is probably not what you want
include/asm-generic/gpio.h:304: warning: 'struct gpio_chip' declared inside parameter list

Move pinctrl trunk into #ifdef CONFIG_GPIOLIB to fix the warning,
since it appears that pinctrl gpio range support depends on GPIOLIB.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-22 10:23:34 +01:00
Linus Torvalds
b0885d01f9 GPIO follow up patch and type change for v3.5 merge window
Primarily device driver additions, features and bug fixes. Not much
 touching gpio common subsystem support. Should not be scary.
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Merge tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull GPIO updates from Grant Likely:
 "GPIO follow up patch and type change for v3.5 merge window

  Primarily device driver additions, features and bug fixes.  Not much
  touching gpio common subsystem support.  Should not be scary."

* tag 'gpio-for-linus' of git://git.secretlab.ca/git/linux-2.6: (34 commits)
  gpio: Provide the STMPE GPIO driver with its own IRQ Domain
  gpio: add TS-5500 DIO blocks support
  gpio: pcf857x: use client->irq for gpio_to_irq()
  gpio: stmpe: Add DT support for stmpe gpio
  gpio: pl061 depends on ARM
  gpio/pl061: remove old comment
  gpio: SPEAr: add spi chipselect control driver
  gpio: gpio-max710x: Support device tree probing
  gpio: twl4030: Use only TWL4030_MODULE_LED for LED configuration
  gpio: tegra: read output value when gpio is set in direction_out
  gpio: pca953x: Add compatible strings to gpio-pca953x driver
  gpio: pca953x: Register an IRQ domain
  gpio: mvebu: Set free callback for gpio_chip
  gpio: tegra: Drop exporting static functions
  gpio: tegra: Staticize non-exported symbols
  gpio: tegra: fix suspend/resume apis
  gpio-pch: Set parent dev for gpio chip
  gpio: em: Fix build errors
  GPIO: clps711x: use platform_device_unregister in gpio_clps711x_init()
  gpio/tc3589x: convert to use the simple irqdomain
  ...
2012-12-11 13:00:56 -08:00
Linus Walleij
316511c013 gpiolib: rename pin range arguments
To be crystal clear on what the arguments mean in this
funtion dealing with both GPIO and PIN ranges with confusing
naming, we now have gpio_offset and pin_offset and we are
on the clear that these are offsets into the specific GPIO
and pin controller respectively. The GPIO chip itself will
of course keep track of the base offset into the global
GPIO number space.

Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-21 10:07:48 +01:00
Linus Walleij
3f0f867060 gpiolib: let gpiochip_add_pin_range() specify offset
Like with commit 3c739ad0df
it is not always enough to specify all the pins of a gpio_chip
from offset zero to be added to a pin map range, since the
mapping from GPIO to pin controller may not be linear at all,
but need to be broken into a few consecutive sub-ranges or
1-pin entries for complicated cases. The ranges may also be
sparse.

This alters the signature of the function to accept offsets
into both the GPIO-chip local pinspace and the pin controller
local pinspace.

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-21 08:55:03 +01:00
Linus Walleij
50309a9c2e gpiolib: iron out include ladder mistakes
The <*/gpio.h> includes are updated again: now we need to account
for the problem introduced by commit:
595679a8038584df7b9398bf34f61db3c038bfea
"gpiolib: fix up function prototypes etc"

Actually we need static inlines in include/asm-generic/gpio.h
as well since we may have GPIOLIB but not PINCTRL.
Make sure to move all the CONFIG_PINCTRL business
to the end of the file so we are sure we have
declared struct gpio_chip.

And we need to keep the static inlines in <linux/gpio.h>
but here for the !CONFIG_GENERIC_GPIO case, and then we
may as well throw in a few warnings like the other
prototypes there, if someone would have the bad taste
of compiling without GENERIC_GPIO even.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:06:07 +01:00
Linus Walleij
1e63d7b936 gpiolib: separation of pin concerns
The fact that of_gpiochip_add_pin_range() and
gpiochip_add_pin_range() share too much code is fragile and
will invariably mean that bugs need to be fixed in two places
instead of one.

So separate the concerns of gpiolib.c and gpiolib-of.c and
have the latter call the former as back-end. This is necessary
also when going forward with other device descriptions such
as ACPI.

This is done by:

- Adding a return code to gpiochip_add_pin_range() so we can
  reliably check whether this succeeds.

- Get rid of the custom of_pinctrl_add_gpio_range() from
  pinctrl. Instead create of_pinctrl_get() to just retrive the
  pin controller per se from an OF node. This composite
  function was just begging to be deleted, it was way to
  purpose-specific.

- Use pinctrl_dev_get_name() to get the name of the retrieved
  pin controller and use that to call back into the generic
  gpiochip_add_pin_range().

Now the pin range is only allocated and tied to a pin
controller from the core implementation in gpiolib.c.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:06:07 +01:00
Linus Walleij
165adc9c17 gpiolib: fix up function prototypes etc
Commit 69e1601bca88809dc118abd1becb02c15a02ec71
"gpiolib: provide provision to register pin ranges"

Got most of it's function prototypes wrong, so fix this up by:

- Moving the void declarations into static inlines in
  <linux/gpio.h> (previously the actual prototypes were declared
  here...)

- Declare the gpiochip_add_pin_range() and
  gpiochip_remove_pin_ranges() functions in <asm-generic/gpio.h>
  together with the pin range struct declaration itself.

- Actually only implement these very functions in gpiolib.c
  if CONFIG_PINCTRL is set.

- Additionally export the symbols since modules will need to
  be able to do this.

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:06:04 +01:00
Shiraz Hashim
f23f1516b6 gpiolib: provide provision to register pin ranges
pinctrl subsystem needs gpio chip base to prepare set of gpio
pin ranges, which a given pinctrl driver can handle. This is
important to handle pinctrl gpio request calls in order to
program a given pin properly for gpio operation.

As gpio base is allocated dynamically during gpiochip
registration, presently there exists no clean way to pass this
information to the pinctrl subsystem.

After few discussions from [1], it was concluded that may be
gpio controller reporting the pin range it supports, is a
better way than pinctrl subsystem directly registering it.

[1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/184816

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
[Edited documentation a bit]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:06:00 +01:00
Mathias Nyman
80b0a60292 gpiolib: add gpio get direction callback support
Add .get_direction callback to gpio_chip. This allows gpiolib
to check the current direction of a gpio.
Used to show the correct gpio direction in sysfs and debug entries.

If callback is not set then gpiolib will work as previously;
e.g. guessing everything is input until a direction is set.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-10-26 09:18:55 +02:00
Roland Stigge
1ae963143e gpio: Document device_node's det_debounce
This patch adds documentation for set_debounce in struct device_node.

Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-09-30 10:27:01 +02:00
Grant Likely
07ce8ec730 gpiolib: Remove 'const' from data argument of gpiochip_find()
Commit 3d0f7cf0 "gpio: Adjust of_xlate API to support multiple GPIO
chips" changed the api of gpiochip_find to drop const from the data
parameter of the match hook, but didn't also drop const from data
causing a build warning.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 23:01:05 -06:00
Grant Likely
3d0f7cf0f3 gpio: Adjust of_xlate API to support multiple GPIO chips
This patch changes the of_xlate API to make it possible for multiple
gpio_chips to refer to the same device tree node.  This is useful for
banked GPIO controllers that use multiple gpio_chips for a single
device.  With this change the core code will try calling of_xlate on
each gpio_chip that references the device_node and will return the
gpio number for the first one to return 'true'.

Tested-by: Roland Stigge <stigge@antcom.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 16:48:36 -06:00
Mark Brown
09d71ff194 gpiolib: Implement devm_gpio_request_one()
Allow drivers to use the modern request and configure idiom together
with devres.

As with plain gpio_request() and gpio_request_one() we can't implement
the old school version in terms of _one() as this would force the
explicit selection of a direction in gpio_request() which could break
systems if we pick the wrong one.  Implementing devm_gpio_request_one()
in terms of devm_gpio_request() would needlessly complicate things or
lead to duplication from the unmanaged version depending on how it's
done.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-18 16:48:35 -06:00
Grant Likely
6e2cf65140 gpio: constify the data parameter to gpiochip_find()
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-03-02 15:56:03 -07:00
John Crispin
1a0703ede4 GPIO: add bindings for managed devices
This patch adds 2 functions that allow managed devices to request GPIOs.
These GPIOs will then be managed by drivers/base/devres.c.

Signed-off-by: John Crispin <blogic@openwrt.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-01-04 11:37:42 -07:00
Grant Likely
15c9a0acc3 of: create of_phandle_args to simplify return of phandle parsing data
of_parse_phandle_with_args() needs to return quite a bit of data.  Rather
than making each datum a separate **out_ argument, this patch creates
struct of_phandle_args to contain all the returned data and reworks the
user of the function.  This patch also enables of_parse_phandle_with_args()
to return the device node pointer for the phandle node.

This patch also ends up being fairly major surgery to
of_parse_handle_with_args().  The existing structure didn't work well
when extending to use of_phandle_args, and I discovered bugs during testing.
I also took the opportunity to rename the function to be like the
existing of_parse_phandle().

v2: - moved declaration of of_phandle_args to fix compile on non-DT builds
    - fixed incorrect index in example usage
    - fixed incorrect return code handling for empty entries

Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-12-12 13:40:16 -07:00
Grant Likely
1a2d397a6e gpio/powerpc: Eliminate duplication of of_get_named_gpio_flags()
A large chunk of qe_pin_request() is unnecessarily cut-and-paste
directly from of_get_named_gpio_flags().  This patch cuts out the
duplicate code and replaces it with a call to of_get_gpio().

v2: fixed compile error due to missing gpio_to_chip()

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
2011-12-12 13:40:16 -07:00
Hamo
eb9ae7f2a3 gpio: fix build error in include/asm-generic/gpio.h
Should call the platform-specific __gpio_{get,set}_value
instead of generic gpio_{get,set}_value

Signed-off-by: Yang Bai <hamo.by@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-10-26 23:15:28 +02:00
Mark Brown
feb8369924 gpiolib: Ensure struct gpio is always defined
Currently struct gpio is only defined when using gpiolib which makes the
stub gpio_request_array() much less useful in drivers than is ideal as
they can't work with struct gpio.  Since there are no other definitions
in kernel instead make the define always available no matter if gpiolib
is selectable or selected, ensuring that drivers can always use the
type.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-10-24 16:04:06 +02:00
Randy Dunlap
c001fb72a7 gpio: add GPIOF_ values regardless on kconfig settings
Make GPIOF_ defined values available even when GPIOLIB nor GENERIC_GPIO
is enabled by moving them to <linux/gpio.h>.

Fixes these build errors in linux-next:
sound/soc/codecs/ak4641.c:524: error: 'GPIOF_OUT_INIT_LOW' undeclared (first use in this function)
sound/soc/codecs/wm8915.c:2921: error: 'GPIOF_OUT_INIT_LOW' undeclared (first use in this function)

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-06-16 08:40:52 -06:00
Lars-Peter Clausen
7c295975a8 gpio: make gpio_{request,free}_array gpio array parameter const
gpio_{request,free}_array should not (and do not) modify the passed gpio
array, so make the parameter const.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Eric Miao <eric.y.miao@gmail.com>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-27 17:56:45 -06:00
Joe Perches
3474cb3cc0 gpio: Convert gpio_is_valid to return bool
Make the code a bit more readable.

Instead of casting an int to an unsigned then comparing to
MAX_NR_GPIOS, add a >= 0 test and let the compiler optimizer
do the conversion to unsigned.

The generated code should be the same.

Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-26 21:02:43 -06:00
Linus Torvalds
d8a3515e2a Revert "gpiolib: annotate gpio-intialization with __must_check"
This reverts commit 0fdae42d36, which
wasn't really supposed to go in, and causes lots of annoying warnings.

Quoth Andrew:
  "Complete brainfart - I meant to drop that patch ages ago."

Quoth Greg:
  "Ick, yeah, that patch isn't ok to go in as-is, all of the callers
   need to be fixed up first, which is what I thought we had agreed on..."

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 17:26:46 -08:00
Wolfram Sang
0fdae42d36 gpiolib: annotate gpio-intialization with __must_check
Because GPIOs can have crucial functions especially in embedded systems,
we are better safe than sorry regarding their configuration.  For
gpio_request, the documentation is simply enforced: <quote>"The return
value of gpio_request() must be checked."</quote> For gpio_direction_* and
gpio_request_*, we now act accordingly.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Greg KH <gregkh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13 08:03:14 -08:00
Anton Vorontsov
09cd9527d6 gpiolib: fix HAVE_GPIO_LIB leftovers in asm-generic/gpio.h
commit 7444a72eff ("gpiolib: allow user-selection")
removed HAVE_GPIO_LIB Kconfig symbol, but the header file still uses the
name [to confuse readers wrt #ifdef/#else/#endif location].

The real Kconfig symbol nowadays is CONFIG_GPIOLIB.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
David Brownell
c956126c13 gpio: doc updates
There's been some recent confusion about error checking GPIO numbers.
briefly, it should be handled mostly during setup, when gpio_request() is
called, and NEVER by expectig gpio_is_valid to report more than
never-usable GPIO numbers.

[akpm@linux-foundation.org: terminate unterminated comment]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Eric Miao" <eric.y.miao@gmail.com>
Cc: "Ryan Mallon" <ryan@bluewatersys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-09-09 18:57:24 -07:00
Grant Likely
594fa265e0 of/gpio: stop using device_node data pointer to find gpio_chip
Currently the kernel uses the struct device_node.data pointer to resolve
a struct gpio_chip pointer from a device tree node.  However, the .data
member doesn't provide any type checking and there aren't any rules
enforced on what it should be used for.  There's no guarantee that the
data stored in it actually points to an gpio_chip pointer.

Instead of relying on the .data pointer, this patch modifies the code
to add a lookup function which scans through the registered gpio_chips
and returns the gpio_chip that has a pointer to the specified
device_node.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Anton Vorontsov <avorontsov@ru.mvista.com>
CC: Grant Likely <grant.likely@secretlab.ca>
CC: David Brownell <dbrownell@users.sourceforge.net>
CC: Bill Gatliff <bgat@billgatliff.com>
CC: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Jean Delvare <khali@linux-fr.org>
CC: linux-kernel@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org
2010-07-05 16:14:30 -06:00
Anton Vorontsov
a19e3da5bc of/gpio: Kill of_gpio_chip and add members directly to gpio_chip
The OF gpio infrastructure is great for describing GPIO connections within
the device tree.  However, using a GPIO binding still requires changes to
the gpio controller just to add an of_gpio structure.  In most cases, the
gpio controller doesn't actually need any special support and the simple
OF gpio mapping function is more than sufficient.  Additional, the current
scheme of using of_gpio_chip requires a convoluted scheme to maintain
1:1 mappings between of_gpio_chip and gpio_chip instances.

If the struct of_gpio_chip data members were moved into struct gpio_chip,
then it would simplify the processing of OF gpio bindings, and it would
make it trivial to use device tree OF connections on existing gpiolib
controller drivers.

This patch eliminates the of_gpio_chip structure and moves the relevant
fields into struct gpio_chip (conditional on CONFIG_OF_GPIO).  This move
simplifies the existing code and prepares for adding automatic device tree
support to existing drivers.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jean Delvare <khali@linux-fr.org>
2010-07-05 16:14:30 -06:00
Felipe Balbi
c4b5be98fe gpiolib: introduce set_debounce method
A few architectures, like OMAP, allow you to set a debouncing time for the
gpio before generating the IRQ.  Teach gpiolib about that.

Mark said:
: This would be generally useful for embedded systems, especially where
: the interrupt concerned is a wake source.  It allows drivers to avoid
: spurious interrupts from noisy sources so if the hardware supports it
: the driver can avoid having to explicitly wait for the signal to become
: stable and software has to cope with fewer events.  We've lived without
: it for quite some time, though.

David said:
: I looked at adding debounce support to the generic GPIO calls (and thus
: gpiolib) some time back, but decided against it.  I forget why at this
: time (check list archives) but it wasn't because of lack of utility in
: certain contexts.
:
: One thing to watch out for is just how variable the hardware capabilities
: are.  Atmel GPIOs have something like a fixed number of 32K clock cycles
: for debounce, twl4030 had something odd, OMAPs were more like the Atmel
: chips but with a different clock.  In some cases debouncing had to be
: ganged, not per-GPIO.  And so forth.

Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: David Brownell <david-b@pacbell.net>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:42 -07:00