kernel/linux.git/drivers/pinctrl/core.c, branch v4.4.235

pinctrl: Really force states during suspend/resume

2018-03-24T09:58:48+00:00

[ Upstream commit 981ed1bfbc6c4660b2ddaa8392893e20a6255048 ] In case a platform only defaults a "default" set of pins, but not a "sleep" set of pins, and this particular platform suspends and resumes in a way that the pin states are not preserved by the hardware, when we resume, we would call pinctrl_single_resume() -> pinctrl_force_default() -> pinctrl_select_state() and the first thing we do is check that the pins state is the same as before, and do nothing. In order to fix this, decouple the actual state change from pinctrl_select_state() and move it pinctrl_commit_state(), while keeping the p->state == state check in pinctrl_select_state() not to change the caller assumptions. pinctrl_force_sleep() and pinctrl_force_default() are updated to bypass the state check by calling pinctrl_commit_state(). [Linus Walleij] The forced pin control states are currently only used in some pin controller drivers that grab their own reference to their own pins. This is equal to the pin control hogs: pins taken by pin control devices since there are no corresponding device in the Linux device hierarchy, such as memory controller lines or unused GPIO lines, or GPIO lines that are used orthogonally from the GPIO subsystem but pincontrol-wise managed as hogs (non-strict mode, allowing simultaneous use by GPIO and pin control). For this case forcing the state from the drivers' suspend()/resume() callbacks makes sense and should semantically match the name of the function. Fixes: 6e5e959dde0d ("pinctrl: API changes to support multiple states per device") Signed-off-by: Florian Fainelli Reviewed-by: Andy Shevchenko Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

drivers/pinctrl: Add the concept of an "init" state

2015-10-27T10:24:23+00:00

For pinctrl the "default" state is applied to pins before the driver's probe function is called. This is normally a sensible thing to do, but in some cases can cause problems. That's because the pins will change state before the driver is given a chance to program how those pins should behave. As an example you might have a regulator that is controlled by a PWM (output high = high voltage, output low = low voltage). The firmware might leave this pin as driven high. If we allow the driver core to reconfigure this pin as a PWM pin before the PWM's probe function runs then you might end up running at too low of a voltage while we probe. Let's introudce a new "init" state. If this is defined we'll set pinctrl to this state before probe and then "default" after probe (unless the driver explicitly changed states already). An alternative idea that was thought of was to use the pre-existing "sleep" or "idle" states and add a boolean property that we should start in that mode. This was not done because the "init" state is needed for correctness and those other states are only present (and only transitioned in to and out of) when (optional) power management is enabled. Changes in v3: - Moved declarations to pinctrl/devinfo.h - Fixed author/SoB Changes in v2: - Added comment to pinctrl_init_done() as per Linus W. Signed-off-by: Douglas Anderson Acked-by: Greg Kroah-Hartman Tested-by: Caesar Wang Signed-off-by: Linus Walleij

pinctrl: core: Warn about NULL gpio_chip in pinctrl_ready_for_gpio_range()

2015-09-14T07:13:43+00:00

If the gpio driver is confused about the numbers for gpio-ranges, pinctrl_ready_for_gpio_range() may get called with invalid GPIO causing a NULL pointer exception. Let's instead provide a warning that allows fixing the problem and return with error. Signed-off-by: Tony Lindgren Signed-off-by: Linus Walleij

pinctrl: use dev_err() to show message in pinctrl_register_one_pin()

2015-07-27T12:43:43+00:00

Use dev_err() rather than pr_err() to display the error message. (Besides, dev_err() is already used 7 lines below in this function.) Also, drop the redundant information "on %s" because dev_err() shows which device the message is related to. Signed-off-by: Masahiro Yamada Signed-off-by: Linus Walleij

Merge tag 'pinctrl-v4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

2015-06-25T02:21:02+00:00

Pull pin control updates from Linus Walleij: "Here is the bulk of pin control changes for the v4.2 series: Quite a lot of new SoC subdrivers and two new main drivers this time, apart from that business as usual. Details: Core functionality: - Enable exclusive pin ownership: it is possible to flag a pin controller so that GPIO and other functions cannot use a single pin simultaneously. New drivers: - NXP LPC18xx System Control Unit pin controller - Imagination Pistachio SoC pin controller New subdrivers: - Freescale i.MX7d SoC - Intel Sunrisepoint-H PCH - Renesas PFC R8A7793 - Renesas PFC R8A7794 - Mediatek MT6397, MT8127 - SiRF Atlas 7 - Allwinner A33 - Qualcomm MSM8660 - Marvell Armada 395 - Rockchip RK3368 Cleanups: - A big cleanup of the Marvell MVEBU driver rectifying it to correspond to reality - Drop platform device probing from the SH PFC driver, we are now a DT only shop for SuperH - Drop obsolte multi-platform check for SH PFC - Various janitorial: constification, grammar etc Improvements: - The AT91 GPIO portions now supports the set_multiple() feature - Split out SPI pins on the Xilinx Zynq - Support DTs without specific function nodes in the i.MX driver" * tag 'pinctrl-v4.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (99 commits) pinctrl: rockchip: add support for the rk3368 pinctrl: rockchip: generalize perpin driver-strength setting pinctrl: sh-pfc: r8a7794: add SDHI pin groups pinctrl: sh-pfc: r8a7794: add MMCIF pin groups pinctrl: sh-pfc: add R8A7794 PFC support pinctrl: make pinctrl_register() return proper error code pinctrl: mvebu: armada-39x: add support for Armada 395 variant pinctrl: mvebu: armada-39x: add missing SATA functions pinctrl: mvebu: armada-39x: add missing PCIe functions pinctrl: mvebu: armada-38x: add ptp functions pinctrl: mvebu: armada-38x: add ua1 functions pinctrl: mvebu: armada-38x: add nand functions pinctrl: mvebu: armada-38x: add sata functions pinctrl: mvebu: armada-xp: add dram functions pinctrl: mvebu: armada-xp: add nand rb function pinctrl: mvebu: armada-xp: add spi1 function pinctrl: mvebu: armada-39x: normalize ref clock naming pinctrl: mvebu: armada-xp: rename spi to spi0 pinctrl: mvebu: armada-370: align spi1 clock pin naming pinctrl: mvebu: armada-370: align VDD cpu-pd pin naming with datasheet ...

pinctrl: make pinctrl_register() return proper error code

2015-06-10T12:49:52+00:00

Currently, pinctrl_register() just returns NULL on error, so the callers can not know the exact reason of the failure. Some of the pinctrl drivers return -EINVAL, some -ENODEV, and some -ENOMEM on error of pinctrl_register(), although the error code might be different from the real cause of the error. This commit reworks pinctrl_register() to return the appropriate error code and modifies all of the pinctrl drivers to use IS_ERR() for the error checking and PTR_ERR() for getting the error code. Signed-off-by: Masahiro Yamada Acked-by: Patrice Chotard Acked-by: Thierry Reding Acked-by: Heiko Stuebner Tested-by: Mika Westerberg Acked-by: Mika Westerberg Acked-by: Lee Jones Acked-by: Sören Brinkmann Acked-by: Laurent Pinchart Acked-by: Ray Jui Acked-by: Antoine Tenart Acked-by: Hongzhou Yang Acked-by: Wei Chen Signed-off-by: Linus Walleij

pinctrl: fix confusing debug message in pinctrl_register_map()

2015-06-02T11:32:20+00:00

There are two types for pinctrl maps: pinmux and pinconfig This debug message shows the number of maps of both types. The string "pinmux map" is not precise. Let's say "pinctrl map" instead. Signed-off-by: Masahiro Yamada [also fixed %d -> %u] Signed-off-by: Linus Walleij

pinctrl: Grammar s/used in as/used as/

2015-05-12T11:17:41+00:00

Signed-off-by: Geert Uytterhoeven Signed-off-by: Linus Walleij

pinctrl: Don't just pretend to protect pinctrl_maps, do it for real

2015-05-06T14:24:28+00:00

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 Signed-off-by: Linus Walleij

pinctrl: Fix two deadlocks

2015-01-14T13:20:33+00:00

This patch is to fix two deadlock cases. Deadlock 1: CPU #1 pinctrl_register-> pinctrl_get -> create_pinctrl (Holding lock pinctrl_maps_mutex) -> get_pinctrl_dev_from_devname (Trying to acquire lock pinctrldev_list_mutex) CPU #0 pinctrl_unregister (Holding lock pinctrldev_list_mutex) -> pinctrl_put ->> pinctrl_free -> pinctrl_dt_free_maps -> pinctrl_unregister_map (Trying to acquire lock pinctrl_maps_mutex) Simply to say CPU#1 is holding lock A and trying to acquire lock B, CPU#0 is holding lock B and trying to acquire lock A. Deadlock 2: CPU #3 pinctrl_register-> pinctrl_get -> create_pinctrl (Holding lock pinctrl_maps_mutex) -> get_pinctrl_dev_from_devname (Trying to acquire lock pinctrldev_list_mutex) CPU #2 pinctrl_unregister (Holding lock pctldev->mutex) -> pinctrl_put ->> pinctrl_free -> pinctrl_dt_free_maps -> pinctrl_unregister_map (Trying to acquire lock pinctrl_maps_mutex) CPU #0 tegra_gpio_request (Holding lock pinctrldev_list_mutex) -> pinctrl_get_device_gpio_range (Trying to acquire lock pctldev->mutex) Simply to say CPU#3 is holding lock A and trying to acquire lock D, CPU#2 is holding lock B and trying to acquire lock A, CPU#0 is holding lock D and trying to acquire lock B. Cc: Stable Signed-off-by: Jim Lin Signed-off-by: Linus Walleij