Commit Graph

31 Commits

Author SHA1 Message Date
Thierry Reding 84f28fc38d pinctrl: devicetree: Keep deferring even on timeout
driver_deferred_probe_check_state() may return -ETIMEDOUT instead of
-EPROBE_DEFER after all built-in drivers have been probed. This can
cause issues for built-in drivers that depend on resources provided by
loadable modules.

One such case happens on Tegra where I2C controllers are used during
early boot to set up the system PMIC, so the I2C driver needs to be a
built-in driver. At the same time, some instances of the I2C controller
depend on the DPAUX hardware for pinmuxing. Since the DPAUX is handled
by the display driver, which is usually not built-in, the pin control
states will not become available until after the root filesystem has
been mounted and the display driver loaded from it.

Fixes: bec6c0ecb2 ("pinctrl: Remove use of driver_deferred_probe_check_state_continue()")
Suggested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20200825143348.1358679-1-thierry.reding@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-09-12 18:19:53 +02:00
Lee Jones 0b93a57a6a pinctrl: devicetree: Add one new attribute description and rename another two
Fixes the following W=1 kernel build warning(s):

 drivers/pinctrl/devicetree.c:27: warning: Function parameter or member 'map' not described in 'pinctrl_dt_map'
 drivers/pinctrl/devicetree.c:27: warning: Function parameter or member 'num_maps' not described in 'pinctrl_dt_map'
 drivers/pinctrl/devicetree.c:409: warning: Function parameter or member 'out_args' not described in 'pinctrl_parse_index_with_args'
 drivers/pinctrl/devicetree.c:409: warning: Excess function parameter 'out_arts' description in 'pinctrl_parse_index_with_args'

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20200713144930.1034632-14-lee.jones@linaro.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-07-16 15:12:39 +02:00
Linus Torvalds 828907ef25 This is the bulk of GPIO development for the v5.7 kernel cycle.
Core and userspace API:
 
 - The userspace API KFIFOs have been imoproved with locks that
   do not block interrupts. This makes us better at getting
   events to userspace without blocking or disturbing new events
   arriving in the same time. This was reviewed by the KFIFO
   maintainer Stefani. This is a generic improvement which
   paves the road for similar improvements in other subsystems.
 
 - We provide a new ioctl() for monitoring changes in the line
   information, such as when multiple clients are taking lines
   and giving them back, possibly reconfiguring them in the
   process: we can now monitor that and not get stuck with stale
   static information.
 
 - An example tool 'gpio-watch' is provided to showcase this
   functionality.
 
 - Timestamps for events are switched to ktime_get_ns() which is
   monotonic. We previously had a 'realtime' stamp which could
   move forward and *backward* in time, which probably would just
   cause silent bugs and weird behaviour. In the long run we
   see two relevant timestamps: ktime_get_ns() or the timestamp
   sometimes provided by the GPIO hardware itself, if that
   exists.
 
 - Device Tree overlay support for GPIO hogs. On systems that
   load overlays, these overlays can now contain hogs, and will
   then be respected.
 
 - Handle pin control interaction with nonexisting pin ranges
   in the GPIO library core instead of in the individual
   drivers.
 
 New drivers:
 
 - New driver for the Mellanox BlueField 2 GPIO controller.
 
 Driver improvements:
 
 - Introduce the BGPIOF_NO_SET_ON_INPUT flag to the generic
   MMIO GPIO library and use this flag in the MT7621 driver.
 
 - Texas Instruments OMAP CPU power management improvements,
   such as blocking of idle on pending GPIO interrupts.
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Merge tag 'gpio-v5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO updates from Linus Walleij:
 "This is the bulk of GPIO development for the v5.7 kernel cycle.

  Core and userspace API:

   - The userspace API KFIFOs have been imoproved with locks that do not
     block interrupts. This makes us better at getting events to
     userspace without blocking or disturbing new events arriving in the
     same time. This was reviewed by the KFIFO maintainer Stefani. This
     is a generic improvement which paves the road for similar
     improvements in other subsystems.

   - We provide a new ioctl() for monitoring changes in the line
     information, such as when multiple clients are taking lines and
     giving them back, possibly reconfiguring them in the process: we
     can now monitor that and not get stuck with stale static
     information.

   - An example tool 'gpio-watch' is provided to showcase this
     functionality.

   - Timestamps for events are switched to ktime_get_ns() which is
     monotonic. We previously had a 'realtime' stamp which could move
     forward and *backward* in time, which probably would just cause
     silent bugs and weird behaviour. In the long run we see two
     relevant timestamps: ktime_get_ns() or the timestamp sometimes
     provided by the GPIO hardware itself, if that exists.

   - Device Tree overlay support for GPIO hogs. On systems that load
     overlays, these overlays can now contain hogs, and will then be
     respected.

   - Handle pin control interaction with nonexisting pin ranges in the
     GPIO library core instead of in the individual drivers.

  New drivers:

   - New driver for the Mellanox BlueField 2 GPIO controller.

  Driver improvements:

   - Introduce the BGPIOF_NO_SET_ON_INPUT flag to the generic MMIO GPIO
     library and use this flag in the MT7621 driver.

   - Texas Instruments OMAP CPU power management improvements, such as
     blocking of idle on pending GPIO interrupts"

* tag 'gpio-v5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (59 commits)
  Revert "gpio: eic-sprd: Use devm_platform_ioremap_resource()"
  pinctrl: Unconditionally assign .request()/.free()
  gpio: Unconditionally assign .request()/.free()
  gpio: export of_pinctrl_get to modules
  pinctrl: Define of_pinctrl_get() dummy for !PINCTRL
  gpio: Rename variable in core APIs
  gpio: Avoid using pin ranges with !PINCTRL
  gpiolib: Remove unused gpio_chip parameter from gpio_set_bias()
  gpiolib: Pass gpio_desc to gpio_set_config()
  gpiolib: Introduce gpiod_set_config()
  tools: gpio: Fix out-of-tree build regression
  gpio: gpiolib: fix a doc warning
  gpio: tegra186: Add Tegra194 pin ranges for GG.0 and GG.1
  gpio: tegra186: Add support for pin ranges
  gpio: Support GPIO controllers without pin-ranges
  ARM: integrator: impd1: Use GPIO_LOOKUP() helper macro
  gpio: brcmstb: support gpio-line-names property
  tools: gpio: Fix typo in gpio-utils
  tools: gpio-hammer: Apply scripts/Lindent and retain good changes
  gpiolib: gpio_name_to_desc: factor out !name check
  ...
2020-04-04 10:27:00 -07:00
Stephen Rothwell 33dd888263 gpio: export of_pinctrl_get to modules
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Link: https://lore.kernel.org/r/20200401151904.6948af20@canb.auug.org.au
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2020-04-01 08:01:39 +02:00
John Stultz bec6c0ecb2 pinctrl: Remove use of driver_deferred_probe_check_state_continue()
With the earlier sanity fixes to
driver_deferred_probe_check_state() it should be usable for the
pinctrl logic here.

So tweak the logic to use driver_deferred_probe_check_state()
instead of driver_deferred_probe_check_state_continue()

Cc: linux-pm@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Todd Kjos <tkjos@google.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Kevin Hilman <khilman@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Rob Herring <robh@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Link: https://lore.kernel.org/r/20200225050828.56458-4-john.stultz@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-04 18:11:44 +01:00
Hans de Goede c72bed23b9 pinctrl: Allow modules to use pinctrl_[un]register_mappings
Currently only the drivers/pinctrl/devicetree.c code allows registering
pinctrl-mappings which may later be unregistered, all other mappings
are assumed to be permanent.

Non-dt platforms may also want to register pinctrl mappings from code which
is build as a module, which requires being able to unregister the mapping
when the module is unloaded to avoid dangling pointers.

To allow unregistering the mappings the devicetree code uses 2 internal
functions: pinctrl_register_map and pinctrl_unregister_map.

pinctrl_register_map allows the devicetree code to tell the core to
not memdup the mappings as it retains ownership of them and
pinctrl_unregister_map does the unregistering, note this only works
when the mappings where not memdupped.

The only code relying on the memdup/shallow-copy done by
pinctrl_register_mappings is arch/arm/mach-u300/core.c this commit
replaces the __initdata with const, so that the shallow-copy is no
longer necessary.

After that we can get rid of the internal pinctrl_unregister_map function
and just use pinctrl_register_mappings directly everywhere.

This commit also renames pinctrl_unregister_map to
pinctrl_unregister_mappings so that its naming matches its
pinctrl_register_mappings counter-part and exports it.

Together these 2 changes will allow non-dt platform code to
register pinctrl-mappings from modules without breaking things on
module unload (as they can now unregister the mapping on unload).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20191216205122.1850923-2-hdegoede@redhat.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-12-30 14:27:17 +01:00
lijiazi 6e4f3db8df pinctrl: just return if no valid maps
If there is a problem with a pinctrl node of a device,
for example, config child node do not have prop specified in
dt_params, num_maps maybe 0. On this condition, no need remember
this map.

Signed-off-by: lijiazi <lijiazi@xiaomi.com>
Link: https://lore.kernel.org/r/29421e7720443a2454830963186f00583c76ce1e.1572588550.git.lijiazi@xiaomi.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-11-05 11:25:39 +01:00
Rasmus Villemoes 037699139e pinctrl: devicetree.c: remove orphan pinctrl_dt_has_hogs()
The helper pinctrl_dt_has_hogs() was introduced in
99e4f67508 (pinctrl: core: Use delayed work for hogs), but the sole
use then got removed shortly after in 950b0d91dc (pinctrl: core: Fix
regression caused by delayed work for hogs).

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Link: https://lore.kernel.org/r/20190923142005.5632-1-linux@rasmusvillemoes.dk
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-10-04 23:26:23 +02:00
Will Deacon be4c60b563 pinctrl: devicetree: Avoid taking direct reference to device name string
When populating the pinctrl mapping table entries for a device, the
'dev_name' field for each entry is initialised to point directly at the
string returned by 'dev_name()' for the device and subsequently used by
'create_pinctrl()' when looking up the mappings for the device being
probed.

This is unreliable in the presence of calls to 'dev_set_name()', which may
reallocate the device name string leaving the pinctrl mappings with a
dangling reference. This then leads to a use-after-free every time the
name is dereferenced by a device probe:

  | BUG: KASAN: invalid-access in strcmp+0x20/0x64
  | Read of size 1 at addr 13ffffc153494b00 by task modprobe/590
  | Pointer tag: [13], memory tag: [fe]
  |
  | Call trace:
  |  __kasan_report+0x16c/0x1dc
  |  kasan_report+0x10/0x18
  |  check_memory_region
  |  __hwasan_load1_noabort+0x4c/0x54
  |  strcmp+0x20/0x64
  |  create_pinctrl+0x18c/0x7f4
  |  pinctrl_get+0x90/0x114
  |  devm_pinctrl_get+0x44/0x98
  |  pinctrl_bind_pins+0x5c/0x450
  |  really_probe+0x1c8/0x9a4
  |  driver_probe_device+0x120/0x1d8

Follow the example of sysfs, and duplicate the device name string before
stashing it away in the pinctrl mapping entries.

Cc: Linus Walleij <linus.walleij@linaro.org>
Reported-by: Elena Petrova <lenaptr@google.com>
Tested-by: Elena Petrova <lenaptr@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20191002124206.22928-1-will@kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-10-03 14:50:16 +02:00
Geert Uytterhoeven f0b0e923e0 pinctrl: devicetree: Use strlen() instead of hardcoded number
Improve readability by replacing a hardcoded number requiring a comment
by strlen().

Gcc is smart enough to evaluate the length of a constant string at
compile-time.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20190731132917.17607-2-geert+renesas@glider.be
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2019-08-05 13:29:29 +02:00
Thierry Reding 62a6bc3a1e driver: core: Allow subsystems to continue deferring probe
Some subsystems, such as pinctrl, allow continuing to defer probe
indefinitely. This is useful for devices that depend on resources
provided by devices that are only probed after the init stage.

One example of this can be seen on Tegra, where the DPAUX hardware
contains pinmuxing controls for pins that it shares with an I2C
controller. The I2C controller is typically used for communication
with a monitor over HDMI (DDC). However, other instances of the I2C
controller are used to access system critical components, such as a
PMIC. The I2C controller driver will therefore usually be a builtin
driver, whereas the DPAUX driver is part of the display driver that
is loaded from a module to avoid bloating the kernel image with all
of the DRM/KMS subsystem.

In this particular case the pins used by this I2C/DDC controller
become accessible very late in the boot process. However, since the
controller is only used in conjunction with display, that's not an
issue.

Unfortunately the driver core currently outputs a warning message
when a device fails to get the pinctrl before the end of the init
stage. That can be confusing for the user because it may sound like
an unwanted error occurred, whereas it's really an expected and
harmless situation.

In order to eliminate this warning, this patch allows callers of the
driver_deferred_probe_check_state() helper to specify that they want
to continue deferring probe, regardless of whether we're past the
init stage or not. All of the callers of that function are updated
for the new signature, but only the pinctrl subsystem passes a true
value in the new persist parameter if appropriate.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20190621151725.20414-1-thierry.reding@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03 21:28:20 +02:00
Thomas Gleixner 9952f6918d treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms and conditions of the gnu general public license
  version 2 as published by the free software foundation this program
  is distributed in the hope it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 228 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.107155473@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:52 -07:00
Rob Herring d19c5e79d4 pinctrl: Support stopping deferred probe after initcalls
Pinctrl drivers are a common dependency which can prevent a system
booting even if the default or bootloader configured settings can work.
If a pinctrl node in DT indicates that the default pin setup can be used
with the 'pinctrl-use-default' property, then only defer probe until
initcalls are done. If the deferred probe timeout is enabled or loadable
modules are disabled, then we'll stop deferring probe regardless of the
DT property. This gives platforms the option to work without their
pinctrl driver being enabled.

Dropped the pinctrl specific deferring probe message as the driver core
can print deferred probe related messages if needed.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-10 17:22:35 +02:00
Fabio Estevam bc3322bc16 pinctrl: devicetree: Fix pctldev pointer overwrite
Commit b89405b610 ("pinctrl: devicetree: Fix dt_to_map_one_config
handling of hogs") causes the pinctrl hog pins to not get initialized
on i.MX platforms leaving them with the IOMUX settings untouched.

This causes several regressions on i.MX such as:

- OV5640 camera driver can not be probed anymore on imx6qdl-sabresd
because the camera clock pin is in a pinctrl_hog group and since
its pinctrl initialization is skipped, the camera clock is kept
in GPIO functionality instead of CLK_CKO function.

- Audio stopped working on imx6qdl-wandboard and imx53-qsb for
the same reason.

Richard Fitzgerald explains the problem:

"I see the bug. If the hog node isn't a 1st level child of the pinctrl
parent node it will go around the for(;;) loop again but on the first
pass I overwrite pctldev with the result of
get_pinctrl_dev_from_of_node() so it doesn't point to the pinctrl driver
any more."

Fix the issue by stashing the original pctldev so it doesn't
get overwritten.

Fixes:  b89405b610 ("pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs")
Cc: <stable@vger.kernel.org>
Reported-by: Mika Penttilä <mika.penttila@nextfour.com>
Reported-by: Steve Longerbeam <slongerbeam@gmail.com>
Suggested-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-06-18 07:55:56 +02:00
Richard Fitzgerald b89405b610 pinctrl: devicetree: Fix dt_to_map_one_config handling of hogs
When dt_to_map_one_config() is called with a pinctrl_dev passed
in, it should only be using this if the node being looked up
is a hog. The code was always using the passed pinctrl_dev
without checking whether the dt node referred to it.

A pin controller can have pinctrl-n dependencies on other pin
controllers in these cases:

- the pin controller hardware is external, for example I2C, so
  needs other pin controller(s) to be setup to communicate with
  the hardware device.

- it is a child of a composite MFD so its of_node is shared with
  the parent MFD and other children of that MFD. Any part of that
  MFD could have dependencies on other pin controllers.

Because of this, dt_to_map_one_config() can't assume that if it
has a pinctrl_dev passed in then the node it looks up must be
a hog. It could be a reference to some other pin controller.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-03-02 09:41:21 +01:00
Markus Elfring 9b21e72e8c pinctrl: Delete an error message
Omit an extra message for a memory allocation failure in these functions.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-08-31 15:45:29 +02:00
Rob Herring f5292d06c4 pinctrl: Convert to using %pOF instead of full_name
Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Lee Jones <lee@kernel.org>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Barry Song <baohua@kernel.org>
Cc: linux-gpio@vger.kernel.org
Cc: linux-rpi-kernel@lists.infradead.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: kernel@stlinux.com
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-08-14 15:01:02 +02:00
Tony Lindgren 92c2b67184 pinctrl: core: Make dt_free_map optional
If the pin controller driver is using devm_kzalloc, there may not be
anything to do for dt_free_map. Let's make it optional to avoid
unncessary boilerplate code.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-09 19:41:07 +01:00
Tony Lindgren 99e4f67508 pinctrl: core: Use delayed work for hogs
Having the pin control framework call pin controller functions
before it's probe has finished is not nice as the pin controller
device driver does not yet have struct pinctrl_dev handle.

Let's fix this issue by adding deferred work for late init. This is
needed to be able to add pinctrl generic helper functions that expect
to know struct pinctrl_dev handle. Note that we now need to call
create_pinctrl() directly as we don't want to add the pin controller
to the list of controllers until the hogs are claimed. We also need
to pass the pinctrl_dev to the device tree parser functions as they
otherwise won't find the right controller at this point.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-03 09:26:16 +01:00
Tony Lindgren 42124bc598 pinctrl: Introduce generic #pinctrl-cells and pinctrl_parse_index_with_args
Introduce #pinctrl-cells helper binding and generic helper functions
pinctrl_count_index_with_args() and pinctrl_parse_index_with_args().

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
[Forward-declare of_phandle_args]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-11-04 22:50:55 +01:00
Jon Hunter 98849fa016 pinctrl: OF: Don't create a pinctrl handle if no pinctrl entries exist
When pinctrl_get() is called for a device, it will return a valid handle
even if the device itself has no pinctrl state entries defined in
device-tree. This is caused by the function pinctrl_dt_to_map() which
will return success even if the first pinctrl state, 'pinctrl-0', is not
found in the device-tree node for a device.

According to the pinctrl device-tree binding documentation, pinctrl
states must be numbered starting from 0 and so 'pinctrl-0' should always
be present if a device uses pinctrl and therefore, if 'pinctrl-0' is not
present it seems valid that we should not return a valid pinctrl handle.

Fix this by returning an error code if the property 'pinctrl-0' is not
present for a device.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-18 10:40:15 +02:00
Masahiro Yamada fb00de771b pinctrl: simplify of_pinctrl_get()
This commit does not change the logic at all.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-16 09:39:03 +02:00
Doug Anderson c5272a2856 pinctrl: Don't just pretend to protect pinctrl_maps, do it for real
Way back, when the world was a simpler place and there was no war, no
evil, and no kernel bugs, there was just a single pinctrl lock.  That
was how the world was when (57291ce pinctrl: core device tree mapping
table parsing support) was written.  In that case, there were
instances where the pinctrl mutex was already held when
pinctrl_register_map() was called, hence a "locked" parameter was
passed to the function to indicate that the mutex was already locked
(so we shouldn't lock it again).

A few years ago in (42fed7b pinctrl: move subsystem mutex to
pinctrl_dev struct), we switched to a separate pinctrl_maps_mutex.
...but (oops) we forgot to re-think about the whole "locked" parameter
for pinctrl_register_map().  Basically the "locked" parameter appears
to still refer to whether the bigger pinctrl_dev mutex is locked, but
we're using it to skip locks of our (now separate) pinctrl_maps_mutex.

That's kind of a bad thing(TM).  Probably nobody noticed because most
of the calls to pinctrl_register_map happen at boot time and we've got
synchronous device probing.  ...and even cases where we're
asynchronous don't end up actually hitting the race too often.  ...but
after banging my head against the wall for a bug that reproduced 1 out
of 1000 reboots and lots of looking through kgdb, I finally noticed
this.

Anyway, we can now safely remove the "locked" parameter and go back to
a war-free, evil-free, and kernel-bug-free world.

Fixes: 42fed7ba44 ("pinctrl: move subsystem mutex to pinctrl_dev struct")
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-06 16:24:28 +02:00
Mark Brown 5d88dceac7 pinctrl: Quiet logging about missing DT nodes when not using DT
On systems which were not booted using DT it is entirely unsurprising that
device nodes don't have any DT information and this is going to happen for
every single device in the system. Make pinctrl be less chatty about this
situation by only logging in the case where we have DT.

Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-02-24 10:44:54 +01:00
Patrice Chotard 42fed7ba44 pinctrl: move subsystem mutex to pinctrl_dev struct
This mutex avoids deadlock in case of use of multiple pin
controllers. Before this modification, by using a global
mutex, deadlock appeared when, for example, a call to
pinctrl_pins_show() locked the pinctrl_mutex, called the
ops->pin_dbg_show of a particular pin controller. If this
pin controller needs I2C access to retrieve configuration
information and I2C driver is using pinctrl to drive its
pins, a call to pinctrl_select_state() try to lock again
pinctrl_mutex which leads to a deadlock.

Notice that the mutex grab from the two direction functions
was moved into pinctrl_gpio_direction().

For several cases, we can't replace pinctrl_mutex by
pctldev->mutex, because at this stage, pctldev is
not accessible :
	- pinctrl_get()/pinctrl_put()
	- pinctrl_register_maps()

So add respectively pinctrl_list_mutex and
pinctrl_maps_mutex in order to protect
pinctrl_list and pinctrl_maps list instead.

Reintroduce pinctrldev_list_mutex in
find_pinctrl_by_of_node(),
pinctrl_find_and_add_gpio_range()
pinctrl_request_gpio(), pinctrl_free_gpio(),
pinctrl_gpio_direction(), pinctrl_devices_show(),
pinctrl_register() and pinctrl_unregister() to
protect pinctrldev_list.

Changes v2->v3:
- Fix a missing EXPORT_SYMBOL_GPL() for pinctrl_select_state().

Changes v1->v2:
- pinctrl_select_state_locked() is removed, all lock mechanism
  is located inside pinctrl_select_state(). When parsing
  the state->setting list, take the per-pin-controller driver
  lock. (Patrice).
- Introduce pinctrldev_list_mutex to protect pinctrldev_list
  in all functions which parse or modify pictrldev_list.
  (Patrice).
- move find_pinctrl_by_of_node() from pinctrl/devicetree.c to
  pinctrl/core.c in order to protect pinctrldev_list.
  (Patrice).
- Sink mutex:es into some functions and remove some _locked
  variants down to where the lists are actually accessed to
  make things simpler. (Linus)
- Drop *all* mutexes completely from pinctrl_lookup_state()
  and pinctrl_select_state() - no relevant mutex was taken
  and it was unclear what this was protecting against. (Linus)

Reported by : Seraphin Bonnaffe <seraphin.bonnaffe@stericsson.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-04-26 17:01:35 +02:00
Laurent Pinchart 022ab148d2 pinctrl: Declare operation structures as const
The pinconf, pinctrl and pinmux operation structures hold function
pointers that are never modified. Declare them as const.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-03-07 05:27:29 +01:00
Linus Walleij b2083062a3 pinctrl: do not defer device tree hogs
commit af1024e0f7cde9023ddd0f3116db03911d5914c0
"pinctrl: skip deferral of hogs"

Attempts to avoid probe deferral on hogged pins, but we
forgot the device tree case. This patch fixes this.

Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-11 21:49:21 +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
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
Linus Walleij c05127c4e2 pinctrl: implement pinctrl deferred probing
If drivers try to obtain pinctrl handles for a pin controller that
has not yet registered to the subsystem, we need to be able to
back out and retry with deferred probing. So let's return
-EPROBE_DEFER whenever this location fails. Also downgrade the
errors to info, maybe we will even set them to debug once the
deferred probing is commonplace.

Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:11 +02:00
Stephen Warren 57291ce295 pinctrl: core device tree mapping table parsing support
During pinctrl_get(), if the client device has a device tree node, look
for the common pinctrl properties there. If found, parse the referenced
device tree nodes, with the help of the pinctrl drivers, and generate
mapping table entries from them.

During pinctrl_put(), free any results of device tree parsing.

Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:10 +02:00