Pull documentation update from Jon Corbet:
"There is a nice new document from Neil on how pathname lookups work
and some new CAN driver documentation. Beyond that, we have
kernel-doc fixes, a bit more work to support reproducible builds, and
the usual collection of small fixes"
* tag 'docs-for-linus' of git://git.lwn.net/linux: (34 commits)
Documentation: add new description of path-name lookup.
Documentation/vm/slub.txt: document slabinfo-gnuplot.sh
Doc: ABI/stable: Fix typo in ABI/stable
doc: Clarify that nmi_watchdog param is for hardlockups
Typo correction for description in gpio document.
DocBook: Fix kernel-doc to be case-insensitive for private:
kernel-docs.txt: update kernelnewbies reference
Doc:kvm: Fix typo in Doc/virtual/kvm
Documentation/Changes: Add bc in "Current Minimal Requirements" section
Documentation/email-clients.txt: remove trailing whitespace
DocBook: Use a fixed encoding for output
MAINTAINERS: The docs tree has moved
Docs/kernel-parameters: Add earlycon devicetree usage
SubmittingPatches: make Subject examples match the de facto standard
Documentation: gpio: mention that <function>-gpio has been deprecated
Documentation: cgroups: just fix a few typos
Documentation: Update kselftest.txt
Documentation: DMA API: Be more explicit that nents is always the same
Documentation: Update the default value of crashkernel low
zram: update documentation
...
Add some information about real time compliance to the driver document.
Inspired by Grygorii Strashko's real time compliance patches.
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The gpiolib supports parsing DT properties of the form <function>-gpio
but it was only added for compatibility with older DT bindings that got
it wrong and should not be used in newer bindings.
The commit that added support for this was:
dd34c37aa3 ("gpio: of: Allow -gpio suffix for property names")
but didn't update the documentation to explain this so it's been a source
of confusion. So let's make clear this in the GPIO documentation.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The GPIO documentation mentions that GPIOs are mapped by defining a
<function>-gpios property in the consumer device's node but a -gpio
sufix is also supported after commit:
dd34c37aa3 ("gpio: of: Allow -gpio suffix for property names")
Update the documentation to match the implementation.
Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The con_id parameter has to match the GPIO description and is automatically
extended by the GPIO suffix if not NULL. I had to look into the code to
understand this and properly find the GPIO I've been looking for, so document
this.
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
With commit 39b2bbe3d7 ("gpio: add flags argument to gpiod_get*()
functions") the gpiod_get*() functions got a 'flags' parameter. Reflect
this in the documentation, too.
Signed-off-by: Dirk Behme <dirk.behme@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
I've been searching for any documentation of 'the active-low property of a GPIO'
already mentioned in this documenation. But couldn't find any. Add it.
Sigend-off-by: Dirk Behme <dirk.behme@gmail.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
[Spelling, grammar fixes]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Now I am very fed up with people reinventing kernel wheels in
userspace "just because they can" (read, sysfs). Put in a angry
blurb in sysfs doc and put in a new file with pointers to other
subsystem drivers utilizing GPIOs.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Pull documentation updates from Jonathan Corbet:
"The main thing here is Ingo's big subdirectory documenting feature
support for each architecture. Beyond that, it's the usual pile of
fixes, tweaks, and small additions"
* tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (79 commits)
doc:md: fix typo in md.txt.
Documentation/mic/mpssd: don't build x86 userspace when cross compiling
Documentation/prctl: don't build tsc tests when cross compiling
Documentation/vDSO: don't build tests when cross compiling
Doc:ABI/testing: Fix typo in sysfs-bus-fcoe
Doc: Docbook: Change wikipedia's URL from http to https in scsi.tmpl
Doc: Change wikipedia's URL from http to https
Documentation/kernel-parameters: add missing pciserial to the earlyprintk
Doc:pps: Fix typo in pps.txt
kbuild : Fix documentation of INSTALL_HDR_PATH
Documentation: filesystems: updated struct file_operations documentation in vfs.txt
kbuild: edit explanation of clean-files variable
Doc: ja_JP: Fix typo in HOWTO
Move freefall program from Documentation/ to tools/
Documentation: ARM: EXYNOS: Describe boot loaders interface
Doc:nfc: Fix typo in nfc-hci.txt
vfs: Minor documentation fix
Doc: networking: txtimestamp: fix printf format warning
Documentation, intel_pstate: Improve legacy mode internal governors description
Documentation: extend use case for EXPORT_SYMBOL_GPL()
...
Patch "gpiolib: rename gpiod_set_array to gpiod_set_array_value" omitted
to also change the function names in the documentation. Let's fix that.
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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>
Pull documentation updates from Jonathan Corbet:
"Numerous fixes, the overdue removal of the i2o docs, some new Chinese
translations, and, hopefully, the README fix that will end the flow of
identical patches to that file"
* tag 'docs-for-linus' of git://git.lwn.net/linux-2.6: (34 commits)
Documentation/memcg: update memcg/kmem status
Documentation: blackfin: Makefile: Typo building issue
Documentation/vm/pagemap.txt: correct location of page-types tool
Documentation/memory-barriers.txt: typo fix
doc: Add guest_nice column to example output of `cat /proc/stat'
Documentation/kernel-parameters: Move "eagerfpu" to its right place
Documentation: gpio: Update ACPI part of the document to mention _DSD
docs/completion.txt: Various tweaks and corrections
doc: completion: context, scope and language fixes
Documentation:Update Documentation/zh_CN/arm64/memory.txt
Documentation:Update Documentation/zh_CN/arm64/booting.txt
Documentation: Chinese translation of arm64/legacy_instructions.txt
DocBook media: fix broken EIA hyperlink
Documentation: tweak the maintainers entry
README: Change gzip/bzip2 to xz compression format
README: Update version number reference
doc:pci: Fix typo in Documentation/PCI
Documentation: drm: Use '->' when describing access through pointers.
Documentation: Remove mentioning of block barriers
Documentation/email-clients.txt: Fix one grammar mistake, add extra info about TB
...
With ACPI 5.1 _DSD (Device Specific Data) it is now possible to name
functions just like Device Tree is doing. Make sure that the documentation
mentions _DSD as the recommended way to describe GPIOs in ACPI systems.
Reported-by: Darren Hart <dvhart@linux.intel.com>
Reviewed-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Extend the documentation for the gpiod_set_array() functions and elaborate
a bit on possible use cases.
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Add device managed variants of gpiod_get_array() / gpiod_put_array()
functions for conveniently obtaining and disposing of an entire array
of GPIOs with one function call.
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Introduce new functions for conveniently obtaining and disposing of
an entire array of GPIOs with one function call.
ACPI parts tested by Mika Westerberg, DT parts tested by Rojhalat
Ibrahim.
Change log:
v5: move the ACPI functions to gpiolib-acpi.c
v4: - use shorter names for members of struct gpio_descs
- rename lut_gpio_count to platform_gpio_count for clarity
- add check for successful memory allocation
- use ERR_CAST()
v3: - rebase on current linux-gpio devel branch
- fix ACPI GPIO counting
- allow for zero-sized arrays
- make the flags argument mandatory for the new functions
- clarify documentation
v2: change interface
Suggested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As explained in this file:
"GPIOs mappings are defined in the consumer device's node, in a property named
<function>-gpios"
So fix the example to match the convention.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Pull take two of the GPIO updates:
"Same stuff as last time, now with a fixup patch for the previous
compile error plus I ran a few extra rounds of compile-testing.
This is the bulk of GPIO changes for the v3.19 series:
- A new API that allows setting more than one GPIO at the time. This
is implemented for the new descriptor-based API only and makes it
possible to e.g. toggle a clock and data line at the same time, if
the hardware can do this with a single register write. Both
consumers and drivers need new calls, and the core will fall back
to driving individual lines where needed. Implemented for the
MPC8xxx driver initially
- Patched the mdio-mux-gpio and the serial mctrl driver that drives
modems to use the new multiple-setting API to set several signals
simultaneously
- Get rid of the global GPIO descriptor array, and instead allocate
descriptors dynamically for each GPIO on a certain GPIO chip. This
moves us closer to getting rid of the limitation of using the
global, static GPIO numberspace
- New driver and device tree bindings for 74xx ICs
- New driver and device tree bindings for the VF610 Vybrid
- Support the RCAR r8a7793 and r8a7794
- Guidelines for GPIO device tree bindings trying to get things a bit
more strict with the advent of combined device properties
- Suspend/resume support for the MVEBU driver
- A slew of minor fixes and improvements"
* tag 'gpio-v3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (33 commits)
gpio: mcp23s08: fix up compilation error
gpio: pl061: document gpio-ranges property for bindings file
gpio: pl061: hook request if gpio-ranges avaiable
gpio: mcp23s08: Add option to configure IRQ output polarity as active high
gpio: fix deferred probe detection for legacy API
serial: mctrl_gpio: use gpiod_set_array function
mdio-mux-gpio: Use GPIO descriptor interface and new gpiod_set_array function
gpio: remove const modifier from gpiod_get_direction()
gpio: remove gpio_descs global array
gpio: mxs: implement get_direction callback
gpio: em: Use dynamic allocation of GPIOs
gpio: Check if base is positive before calling gpio_is_valid()
gpio: mcp23s08: Add simple IRQ support for SPI devices
gpio: mcp23s08: request a shared interrupt
gpio: mcp23s08: Do not free unrequested interrupt
gpio: rcar: Add r8a7793 and r8a7794 support
gpio-mpc8xxx: add mpc8xxx_gpio_set_multiple function
gpiolib: allow simultaneous setting of multiple GPIO outputs
gpio: mvebu: add suspend/resume support
gpio: gpio-davinci: remove duplicate check on resource
..
Introduce new functions gpiod_set_array & gpiod_set_raw_array to the consumer
interface which allow setting multiple outputs with just one function call.
Also add an optional set_multiple function to the driver interface. Without an
implementation of that function in the chip driver outputs are set
sequentially.
Implementing the set_multiple function in a chip driver allows for:
- Improved performance for certain use cases. The original motivation for this
was the task of configuring an FPGA. In that specific case, where 9 GPIO
lines have to be set many times, configuration time goes down from 48 s to
20 s when using the new function.
- Simultaneous glitch-free setting of multiple pins on any kind of parallel
bus attached to GPIOs provided they all reside on the same chip and bank.
Limitations:
Performance is only improved for normal high-low outputs. Open drain and
open source outputs are always set separately from each other. Those kinds
of outputs could probably be accelerated in a similar way if we could
forgo the error checking when setting GPIO directions.
Change log:
v6: - rebase on current linux-gpio devel branch
v5: - check can_sleep property per chip
- remove superfluous checks
- supplement documentation
v4: - add gpiod_set_array function for setting logical values
- change interface of the set_multiple driver function to use
unsigned long as type for the bit fields
- use generic bitops (which also use unsigned long for bit fields)
- do not use ARCH_NR_GPIOS any more
v3: - add documentation
- change commit message
v2: - use descriptor interface
- allow arbitrary groups of GPIOs spanning multiple chips
Signed-off-by: Rojhalat Ibrahim <imr@rtschenk.de>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Document the previously introduced method that can be used by device
drivers to provide the GPIO subsystem with mappings between GPIO names
(connection IDs) and GpioIo()/GpioInt() resources in _CRS.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
This function actually operates on a gpio_chip, so its prefix should
reflect that fact for consistency with other functions defined in
gpio/driver.h.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Linus Torvalds
Grygorii Strashko
Linus Walleij
Sachin Pandhare
Javier Martinez Canillas
Dirk Behme
Rojhalat Ibrahim
Geert Uytterhoeven
Johan Hovold
Mika Westerberg
Fabio Estevam
Rafael J. Wysocki
Alexandre Courbot