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2020-09-12pinctrl: devicetree: Keep deferring even on timeoutThierry Reding1-3/+2
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: bec6c0ecb243 ("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>
2020-07-16pinctrl: devicetree: Add one new attribute description and rename another twoLee Jones1-2/+3
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>
2020-04-04Merge tag 'gpio-v5.7-1' of ↵Linus Torvalds1-0/+1
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 ...
2020-04-01gpio: export of_pinctrl_get to modulesStephen Rothwell1-0/+1
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>
2020-03-04pinctrl: Remove use of driver_deferred_probe_check_state_continue()John Stultz1-4/+5
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>
2019-12-30pinctrl: Allow modules to use pinctrl_[un]register_mappingsHans de Goede1-2/+2
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>
2019-11-05pinctrl: just return if no valid mapslijiazi1-0/+10
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>
2019-10-04pinctrl: devicetree.c: remove orphan pinctrl_dt_has_hogs()Rasmus Villemoes1-15/+0
The helper pinctrl_dt_has_hogs() was introduced in 99e4f67508e1 (pinctrl: core: Use delayed work for hogs), but the sole use then got removed shortly after in 950b0d91dc10 (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>
2019-10-03pinctrl: devicetree: Avoid taking direct reference to device name stringWill Deacon1-5/+20
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>
2019-08-05pinctrl: devicetree: Use strlen() instead of hardcoded numberGeert Uytterhoeven1-4/+2
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>
2019-07-03driver: core: Allow subsystems to continue deferring probeThierry Reding1-4/+3
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>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 201Thomas Gleixner1-12/+1
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>
2018-07-10pinctrl: Support stopping deferred probe after initcallsRob Herring1-4/+11
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>
2018-06-18pinctrl: devicetree: Fix pctldev pointer overwriteFabio Estevam1-2/+5
Commit b89405b6102f ("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: b89405b6102f ("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>
2018-03-02pinctrl: devicetree: Fix dt_to_map_one_config handling of hogsRichard Fitzgerald1-2/+4
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>
2017-08-31pinctrl: Delete an error messageMarkus Elfring1-4/+1
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>
2017-08-14pinctrl: Convert to using %pOF instead of full_nameRob Herring1-2/+2
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>
2017-01-09pinctrl: core: Make dt_free_map optionalTony Lindgren1-1/+2
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>
2017-01-03pinctrl: core: Use delayed work for hogsTony Lindgren1-5/+23
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>
2016-11-04pinctrl: Introduce generic #pinctrl-cells and pinctrl_parse_index_with_argsTony Lindgren1-0/+144
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>
2016-06-18pinctrl: OF: Don't create a pinctrl handle if no pinctrl entries existJon Hunter1-1/+6
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>
2015-07-16pinctrl: simplify of_pinctrl_get()Masahiro Yamada1-7/+1
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>
2015-05-06pinctrl: Don't just pretend to protect pinctrl_maps, do it for realDoug Anderson1-1/+1
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: 42fed7ba44e4 ("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>
2014-02-24pinctrl: Quiet logging about missing DT nodes when not using DTMark Brown1-1/+3
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>
2013-04-26pinctrl: move subsystem mutex to pinctrl_dev structPatrice Chotard1-13/+2
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>
2013-03-07pinctrl: Declare operation structures as constLaurent Pinchart1-2/+2
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>
2013-01-11pinctrl: do not defer device tree hogsLinus Walleij1-0/+5
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>
2012-11-11gpiolib: separation of pin concernsLinus Walleij1-3/+1
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>
2012-11-11gpiolib: provide provision to register pin rangesShiraz Hashim1-0/+13
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>
2012-04-18pinctrl: implement pinctrl deferred probingLinus Walleij1-3/+3
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>
2012-04-18pinctrl: core device tree mapping table parsing supportStephen Warren1-0/+249
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>