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* pwm: Make pwmchip_[sg]et_drvdata() a wrapper around dev_set_drvdata()Uwe Kleine-König2024-04-301-12/+2
| | | | | | | | | | Now that a pwm_chip has a dedicated struct device, pwmchip_set_drvdata() and pwmchip_get_drvdata() can be made thin wrappers around dev_set_drvdata() and dev_get_drvdata() respectively and the previously needed pointer can be dropped from struct pwm_chip. Link: https://lore.kernel.org/r/a5e05bd2d83421a26fdef6a87d69253c0f98becf.1710670958.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Add a struct device to struct pwm_chipUwe Kleine-König2024-04-261-2/+3
| | | | | | | | | | This replaces the formerly dynamically allocated struct device. This allows to additionally use it to track the lifetime of the struct pwm_chip. Otherwise the new struct device provides the same sysfs API as was provided by the dynamic device before. Link: https://lore.kernel.org/r/35c65ea7f6de789a568ff39d7b6b4ce80de4b7dc.1710670958.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Ensure a struct pwm has the same lifetime as its pwm_chipUwe Kleine-König2024-04-261-1/+1
| | | | | | | | | | | | | | | It's required to not free the memory underlying a requested PWM while a consumer still has a reference to it. While currently a pwm_chip doesn't live long enough in all cases, linking the struct pwm to the pwm_chip results in the right lifetime as soon as the pwmchip is living long enough. This happens with the following commits. Note this is a breaking change for all pwm drivers that don't use pwmchip_alloc(). Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org> # for struct_size() and __counted_by() Link: https://lore.kernel.org/r/7e9e958841f049026c0023b309cc9deecf0ab61d.1710670958.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Move contents of sysfs.c into core.cUwe Kleine-König2024-04-261-13/+0
| | | | | | | | | | | | | | | | | | | | | With the upcoming restructuring having all in a single file simplifies things a bit. The relevant and somewhat visible changes are: - Some dropped prototypes from include/linux/pwm.h that were only necessary that core.c has a declaration of the symbols defined in sysfs.c. The respective functions are static now. - The pwm class now also exists if CONFIG_SYSFS isn't enabled. Having CONFIG_SYSFS is not very relevant today, but even without it the class and device stuff still provides lifetime tracking. - Both files had an initcall, these are merged into a single one now. Instead of a big #ifdef block for CONFIG_DEBUG_FS, a single if (IS_ENABLED(CONFIG_DEBUG_FS)) is used now. This increases compile coverage a bit and is a tad nicer on the eyes. Link: https://lore.kernel.org/r/9e2d39a5280d7dda5bfc6682a8aef510148635b2.1710670958.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Ensure that pwm_chips are allocated using pwmchip_alloc()Uwe Kleine-König2024-04-261-0/+2
| | | | | | | | | | | Memory holding a struct device must not be freed before the reference count drops to zero. So a struct pwm_chip must not live in memory freed by a driver on unbind. All in-tree drivers were fixed accordingly, but as out-of-tree drivers, that were not adapted, still compile fine, catch these in pwmchip_add(). Link: https://lore.kernel.org/r/35f5b229c98f78b2f6ce2397259a4a936be477c0.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Provide pwmchip_alloc() function and a devm variant of itUwe Kleine-König2024-02-151-0/+22
| | | | | | | | | | | | | | | | | | | | This function allocates a struct pwm_chip and driver data. Compared to the status quo the split into pwm_chip and driver data is new, otherwise it doesn't change anything relevant (yet). The intention is that after all drivers are switched to use this allocation function, its possible to add a struct device to struct pwm_chip to properly track the latter's lifetime without touching all drivers again. Proper lifetime tracking is a necessary precondition to introduce character device support for PWMs (that implements atomic setting and doesn't suffer from the sysfs overhead of the /sys/class/pwm userspace support). The new function pwmchip_priv() (obviously?) only works for chips allocated with pwmchip_alloc(). Link: https://lore.kernel.org/r/9577d6053a5a52536057dc8654ff567181c2da82.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Provide wrappers for storing and getting driver private dataUwe Kleine-König2024-02-151-0/+20
| | | | | | | | | | | | | These functions are useful to store and query driver private data depending on the pwm_chip. After struct pwm_chip got its own struct device, this can make use of dev_get_drvdata() and dev_set_drvdata() on that device. These functions are required already now to convert drivers to pwmchip_alloc() which must happen before changing pwm_chip::dev. Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Link: https://lore.kernel.org/r/67514cdf29d29bd8b4ad8d44fac87f6ae6dca1e5.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Provide an inline function to get the parent device of a given chipUwe Kleine-König2024-02-151-0/+5
| | | | | | | | | | | | | | | Currently a pwm_chip stores in its struct device *dev member a pointer to the parent device. Preparing a change that embeds a full struct device in struct pwm_chip, this accessor function should be used in all drivers directly accessing chip->dev now. This way struct pwm_chip and this new function can be changed without having to touch all drivers in the same change set. Make use of this function in the framework's core sources. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/cc30090d2f9762bed9854a55612144bccc910781.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: Drop useless member .of_pwm_n_cells of struct pwm_chipUwe Kleine-König2024-02-151-2/+0
| | | | | | | | | | | Apart from the two of_xlate implementations this member is write-only. In the of_xlate functions of_pwm_xlate_with_flags() and of_pwm_single_xlate() it's more sensible to check for args->args_count because this is what is actually used in the device tree. Acked-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/53d8c545aa8f79a920358be9e72e382b3981bdc4.1704835845.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: linux/pwm.h: fix Excess kernel-doc description warningRandy Dunlap2024-01-051-1/+0
| | | | | | | | | | | | | | Remove the @pwm: line to prevent the kernel-doc warning: include/linux/pwm.h:87: warning: Excess struct member 'pwm' description in 'pwm_device' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: <linux-pwm@vger.kernel.org> Fixes: f3e25e68ceb2 ("pwm: Drop unused member "pwm" from struct pwm_device") Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Add pwm_apply_state() compatibility stubThierry Reding2024-01-051-0/+7
| | | | | | | | | | | In order to make the transition to the new pwm_apply_might_sleep() a bit smoother, add a compatibility stub. This will prevent new calls to the old function introduced via other subsystems from breaking builds. Once the next merge window has closed we can take another stab at removing the stub. Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Drop two unused API functionsUwe Kleine-König2023-12-201-12/+0
| | | | | | | | These functions are unused. Also I think there is no valid use case where these are correct to be called. So drop them. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Make it possible to apply PWM changes in atomic contextSean Young2023-12-201-0/+25
| | | | | | | | | | | | | | | Some PWM devices require sleeping, for example if the pwm device is connected over I2C. However, many PWM devices could be used from atomic context, e.g. memory mapped PWM. This is useful for, for example, the pwm-ir-tx driver which requires precise timing. Sleeping causes havoc with the generated IR signal. Since not all PWM devices can support atomic context, we also add a pwm_might_sleep() function to check if is not supported. Signed-off-by: Sean Young <sean@mess.org> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Replace ENOTSUPP with EOPNOTSUPPSean Young2023-12-201-2/+2
| | | | | | | | | According to Documentation/dev-tools/checkpatch.rst ENOTSUPP is not recommended and EOPNOTSUPP should be used instead. Signed-off-by: Sean Young <sean@mess.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Rename pwm_apply_state() to pwm_apply_might_sleep()Sean Young2023-12-201-14/+14
| | | | | | | | | | | | | | | | | | | | | In order to introduce a pwm api which can be used from atomic context, we will need two functions for applying pwm changes: int pwm_apply_might_sleep(struct pwm *, struct pwm_state *); int pwm_apply_atomic(struct pwm *, struct pwm_state *); This commit just deals with renaming pwm_apply_state(), a following commit will introduce the pwm_apply_atomic() function. Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> # for input Acked-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Acked-by: Lee Jones <lee@kernel.org> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Update kernel doc for struct pwm_chipUwe Kleine-König2023-12-201-2/+1
| | | | | | | | | | | Commit c572f3b9c8b7 ("pwm: Replace PWM chip unique base by unique ID") changed the members of struct pwm_chip, but failed to update the documentation accordingly. Catch up and document the new member and drop description for the two removed ones. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Replace PWM chip unique base by unique IDUwe Kleine-König2023-12-201-2/+1
| | | | | | | | | | | | | | | | | | | | | | Traditionally each PWM device had a unique ID stored in the "pwm" member of struct pwm_device. However this number was hardly used and dropped in the previous commit. To identify a certain PWM you're supposed to use the chip's ID and the hwpwm of the PWM device now. With the PWM chip base gone PWM chips can get their IDs better and simpler using an idr. This is expected to change the numbering of PWM chips, but nothing should rely on the numbering anyhow. Other than that the side effects are: - The PWM chip IDs are smaller and in most cases consecutive. - The ordering in /sys/kernel/debug/pwm is ordered by ascending PWM chip ID. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Drop unused member "pwm" from struct pwm_deviceUwe Kleine-König2023-12-201-1/+0
| | | | | | | This member is only assigned to and never read. So drop it. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Fix double shift bugDan Carpenter2023-11-101-2/+2
| | | | | | | | | | | | | These enums are passed to set/test_bit(). The set/test_bit() functions take a bit number instead of a shifted value. Passing a shifted value is a double shift bug like doing BIT(BIT(1)). The double shift bug doesn't cause a problem here because we are only checking 0 and 1 but if the value was 5 or above then it can lead to a buffer overflow. Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Drop pwm_[sg]et_chip_data()Uwe Kleine-König2023-10-131-14/+0
| | | | | | | | | | | | | The semantic of chip_data is a bit surprising as it's cleared when pwm_put() is called. Also there is a big overlap with the standard driver data. All drivers were adapted to not make use of chip_data any more, so it can go away. Link: https://lore.kernel.org/r/20230705080650.2353391-9-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Manage owner assignment implicitly for driversUwe Kleine-König2023-10-131-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Instead of requiring each driver to care for assigning the owner member of struct pwm_ops, handle that implicitly using a macro. Note that the owner member has to be moved to struct pwm_chip, as the ops structure usually lives in read-only memory and so cannot be modified. The upside is that new low level drivers cannot forget the assignment and save one line each. The pwm-crc driver didn't assign .owner, that's not a problem in practice though as the driver cannot be compiled as a module. Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i Acked-by: Andi Shyti <andi.shyti@kernel.org> Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20230804142707.412137-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Use a consistent name for pwm_chip pointers in the coreUwe Kleine-König2023-07-201-3/+3
| | | | | | | | | Most variables of type struct pwm_chip * are named "chip", there are only three outliers called "pc". Change these three to "chip", too, for consistency. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Delete deprecated functions pwm_request() and pwm_free()Uwe Kleine-König2023-04-131-13/+0
| | | | | | | | | | | Since commit 5a7fbe452ad9 ("backlight: pwm_bl: Drop support for legacy PWM probing") the last user of pwm_request() and pwm_free() is gone. So remove these functions that were deprecated over 10 years ago in commit 8138d2ddbcca ("pwm: Add table-based lookup for static mappings"). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [thierry.reding@gmail.com: clean up a bit after removal] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Move pwm_capture() dummy to restore orderGeert Uytterhoeven2023-01-301-7/+7
| | | | | | | | | Move the dummy pwm_capture(), to make the declaration order of all dummies to match the declaration order of the real functions. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* Merge tag 'pwm/for-6.2-rc1' of ↵Linus Torvalds2022-12-211-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm Pull pwm updates from Thierry Reding: "Various changes across the board, mostly improvements and cleanups" * tag 'pwm/for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (42 commits) pwm: pca9685: Convert to i2c's .probe_new() pwm: sun4i: Propagate errors in .get_state() to the caller pwm: Handle .get_state() failures pwm: sprd: Propagate errors in .get_state() to the caller pwm: rockchip: Propagate errors in .get_state() to the caller pwm: mtk-disp: Propagate errors in .get_state() to the caller pwm: imx27: Propagate errors in .get_state() to the caller pwm: cros-ec: Propagate errors in .get_state() to the caller pwm: crc: Propagate errors in .get_state() to the caller leds: qcom-lpg: Propagate errors in .get_state() to the caller drm/bridge: ti-sn65dsi86: Propagate errors in .get_state() to the caller pwm/tracing: Also record trace events for failed API calls pwm: Make .get_state() callback return an error code pwm: pxa: Enable for MMP platform pwm: pxa: Add reference manual link and limitations pwm: pxa: Use abrupt shutdown mode pwm: pxa: Remove clk enable/disable from pxa_pwm_config pwm: pxa: Set duty cycle to 0 when disabling PWM pwm: pxa: Remove pxa_pwm_enable/disable pwm: mediatek: Add support for MT7986 ...
| * pwm: Make .get_state() callback return an error codeUwe Kleine-König2022-12-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | .get_state() might fail in some cases. To make it possible that a driver signals such a failure change the prototype of .get_state() to return an error code. This patch was created using coccinelle and the following semantic patch: @p1@ identifier getstatefunc; identifier driver; @@ struct pwm_ops driver = { ..., .get_state = getstatefunc ,... }; @p2@ identifier p1.getstatefunc; identifier chip, pwm, state; @@ -void +int getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { ... - return; + return 0; ... } plus the actual change of the prototype in include/linux/pwm.h (plus some manual fixing of indentions and empty lines). So for now all drivers return success unconditionally. They are adapted in the following patches to make the changes easier reviewable. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Acked-by: Douglas Anderson <dianders@chromium.org> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* | pwm: Add a stub for devm_pwmchip_add()Andy Shevchenko2022-11-221-0/+5
|/ | | | | | | | | | | The devm_pwmchip_add() can be called by a module that optionally instantiates PWM chip. In the case of CONFIG_PWM=n, the compilation can't be performed. Hence, add a necessary stub. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Thierry Reding <thierry.reding@gmail.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* pwm: core: Make of_pwm_get() staticAndy Shevchenko2022-09-191-10/+0
| | | | | | | | | | There are no users outside of PWM core of the of_pwm_get(). Make it static. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220826172642.16404-3-andriy.shevchenko@linux.intel.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
* pwm: core: Get rid of unused devm_of_pwm_get()Andy Shevchenko2022-09-191-10/+0
| | | | | | | | | | | | | The devm_of_pwm_get() has recently lost its single user, drop the dead API as well. Note, the new code should use either plain pwm_get() or managed devm_pwm_get() or devm_fwnode_pwm_get() APIs. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20220826172642.16404-2-andriy.shevchenko@linux.intel.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
* pwm: Drop unused forward declaration from pwm.hUwe Kleine-König2022-06-221-2/+0
| | | | | | | | The declaration was necessary until commit cc2d22477779 ("pwm: Drop per-chip dbg_show callback"). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Reorder header file to get rid of struct pwm_capture forward declarationUwe Kleine-König2022-06-221-11/+10
| | | | | | | | There is no cyclic dependency, so by reordering the forward declaration can be dropped. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Drop support for legacy driversUwe Kleine-König2022-06-221-12/+0
| | | | | | | | | | | | There are no drivers left providing the legacy callbacks. So drop support for these. If this commit breaks your out-of-tree pwm driver, look at e.g. commit ec00cd5e63f0 ("pwm: renesas-tpu: Implement .apply() callback") for an example of the needed conversion for your driver. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* Merge drm/drm-next into drm-misc-nextThomas Zimmermann2021-11-181-0/+13
|\ | | | | | | | | | | Backmerging from drm/drm-next for v5.16-rc1. Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
| * pwm: Make it explicit that pwm_apply_state() might sleepUwe Kleine-König2021-11-051-0/+4
| | | | | | | | | | | | | | | | | | | | | | At least some implementations sleep. So mark pwm_apply_state() with a might_sleep() to make callers aware. In the worst case this uncovers a valid atomic user, then we revert this patch and at least gained some more knowledge and then can work on a concept similar to gpio_get_value/gpio_get_value_cansleep. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
| * pwm: Add might_sleep() annotations for !CONFIG_PWM API functionsUwe Kleine-König2021-11-051-0/+9
| | | | | | | | | | | | | | | | | | The normal implementations of these functions make use of mutexes. To make it obvious that these functions might sleep also add annotations to the dummy implementations in the !CONFIG_PWM case. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* | pwm: Introduce single-PWM of_xlate functionBjorn Andersson2021-10-271-0/+2
|/ | | | | | | | | | | | | | | | | The existing pxa driver and the upcoming addition of PWM support in the TI sn565dsi86 DSI/eDP bridge driver both has a single PWM channel and thereby a need for a of_xlate function with the period as its single argument. Introduce a common helper function in the core that can be used as of_xlate by such drivers and migrate the pxa driver to use this. Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Tested-by: Steev Klimaszewski <steev@kali.org> Tested-By: Steev Klimaszewski <steev@kali.org> Signed-off-by: Robert Foss <robert.foss@linaro.org> Link: https://patchwork.freedesktop.org/patch/msgid/20211025170925.3096444-1-bjorn.andersson@linaro.org
* pwm: Make pwmchip_remove() return voidUwe Kleine-König2021-09-021-1/+1
| | | | | | | | | Since some time pwmchip_remove() always returns 0 so the return value isn't usefull. Now that all callers are converted to ignore its value the function can be changed to return void. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: core: Remove unused devm_pwm_put()Andy Shevchenko2021-06-301-5/+0
| | | | | | | | | | | There are no users and seems no will come of the devm_pwm_put(). Remove the function. While at it, slightly update documentation. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Add a device-managed function to add PWM chipsUwe Kleine-König2021-06-281-0/+3
| | | | | | | This potentially simplifies low-level PWM drivers. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: core: Support new usage_power setting in PWM stateClemens Gruber2021-06-041-0/+7
| | | | | | | | | | | If usage_power is set, the PWM driver is only required to maintain the power output but has more freedom regarding signal form. If supported, the signal can be optimized, for example to improve EMI by phase shifting individual channels. Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Clarify which state pwm_get_state() returnsUwe Kleine-König2021-04-091-0/+5
| | | | | | | | | | | | | Given that lowlevel drivers usually cannot implement exactly what a consumer requests with pwm_apply_state() there is some rounding involved. pwm_get_state() returns the setting that was requested most recently by the consumer (opposed to what was actually implemented in hardware in reply to the last request). Clarify this in the function kerneldoc. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Drop function pwmchip_add_with_polarity()Uwe Kleine-König2021-03-221-2/+0
| | | | | | | | | | | | pwmchip_add() only calls pwmchip_add_with_polarity() and nothing else. All other users of pwmchip_add_with_polarity() are gone. So drop pwmchip_add_with_polarity() and move the code instead to pwmchip_add(). The initial assignment to pwm->state.polarity is dropped. In every correct usage of the PWM API this value is overwritten later anyhow. Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Remove unused function pwmchip_add_inversed()Uwe Kleine-König2020-12-171-5/+0
| | | | | | | | | | | | | | | | This is only defined with CONFIG_PWM unset and was introduced together with pwmchip_add_with_polarity() (which is only defined with CONFIG_PWM enabled). I guess the series that introduced pwmchip_add_with_polarity() had a different concept in earlier revisions and the !CONFIG_PWM part was just not updated accordingly. Given that there is no implementation for pwmchip_add_with_polarity() without CONFIG_PWM, just drop pwmchip_add_inversed() instead of renaming it to pwmchip_add_with_polarity(). Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org> Acked-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Convert period and duty cycle to u64Guru Das Srinagesh2020-06-171-6/+6
| | | | | | | | | | | | | | | Because period and duty cycle are defined as ints with units of nanoseconds, the maximum time duration that can be set is limited to ~2.147 seconds. Change their definitions to u64 in the structs of the PWM framework so that higher durations may be set. Also use the right format specifiers in debug prints in both core.c, pwm-stm32-lp.c as well as video/fbdev/ssd1307fb.c. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Guru Das Srinagesh <gurus@codeaurora.org> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Implement some checks for lowlevel driversUwe Kleine-König2020-03-301-1/+3
| | | | | | | | | | There are some expectations which the callbacks provided by lowlevel drivers should fulfill. Implement checks that help driver authors to get these semantics right. As these have some overhead the checks can be disabled using a Kconfig setting. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Update comment on struct pwm_ops::applyRasmus Villemoes2019-10-211-4/+1
| | | | | | | | | | | Commit 71523d1812ac (pwm: Ensure pwm_apply_state() doesn't modify the state argument) updated the kernel-doc for pwm_apply_state(), but not for the ->apply callback in the pwm_ops struct. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Ensure pwm_apply_state() doesn't modify the state argumentUwe Kleine-König2019-09-211-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It is surprising for a PWM consumer when the variable holding the requested state is modified by pwm_apply_state(). Consider for example a driver doing: #define PERIOD 5000000 #define DUTY_LITTLE 10 ... struct pwm_state state = { .period = PERIOD, .duty_cycle = DUTY_LITTLE, .polarity = PWM_POLARITY_NORMAL, .enabled = true, }; pwm_apply_state(mypwm, &state); ... state.duty_cycle = PERIOD / 2; pwm_apply_state(mypwm, &state); For sure the second call to pwm_apply_state() should still have state.period = PERIOD and not something the hardware driver chose for a reason that doesn't necessarily apply to the second call. So declare the state argument as a pointer to a const type and adapt all drivers' .apply callbacks. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Add support referencing PWMs from ACPINikolaus Voss2019-06-261-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | In analogy to referencing a GPIO using the "gpios" property from ACPI, support referencing a PWM using the "pwms" property. ACPI entries must look like Package () {"pwms", Package () { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}} In contrast to the DT implementation, only _one_ PWM entry in the "pwms" property is supported. As a consequence "pwm-names"-property and con_id lookup aren't supported. Support for ACPI is added via the firmware-node framework which is an abstraction layer on top of ACPI/DT. To keep this patch clean, DT and ACPI paths are kept separate. The firmware-node framework could be used to unify both paths in a future patch. To support leds-pwm driver, an additional method devm_fwnode_pwm_get() which supports both ACPI and DT configuration is exported. Signed-off-by: Nikolaus Voss <nikolaus.voss@loewensteinmedical.de> [thierry.reding@gmail.com: fix build failures for !ACPI] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Add consumer device linkFabrice Gasnier2019-06-251-2/+4
| | | | | | | | | | | | | | | | | | | Add a device link between the PWM consumer and the PWM provider. This enforces the PWM user to get suspended before the PWM provider. It allows proper synchronization of suspend/resume sequences: the PWM user is responsible for properly stopping PWM, before the provider gets suspended: see [1]. Add the device link in: - of_pwm_get() - pwm_get() - devm_*pwm_get() variants as it requires a reference to the device for the PWM consumer. [1] https://lkml.org/lkml/2019/2/5/770 Suggested-by: Thierry Reding <thierry.reding@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Fix deadlock warning when removing PWM devicePhong Hoang2019-03-201-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes deadlock warning if removing PWM device when CONFIG_PROVE_LOCKING is enabled. This issue can be reproceduced by the following steps on the R-Car H3 Salvator-X board if the backlight is disabled: # cd /sys/class/pwm/pwmchip0 # echo 0 > export # ls device export npwm power pwm0 subsystem uevent unexport # cd device/driver # ls bind e6e31000.pwm uevent unbind # echo e6e31000.pwm > unbind [ 87.659974] ====================================================== [ 87.666149] WARNING: possible circular locking dependency detected [ 87.672327] 5.0.0 #7 Not tainted [ 87.675549] ------------------------------------------------------ [ 87.681723] bash/2986 is trying to acquire lock: [ 87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0 [ 87.694528] [ 87.694528] but task is already holding lock: [ 87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c [ 87.707405] [ 87.707405] which lock already depends on the new lock. [ 87.707405] [ 87.715574] [ 87.715574] the existing dependency chain (in reverse order) is: [ 87.723048] [ 87.723048] -> #1 (pwm_lock){+.+.}: [ 87.728017] __mutex_lock+0x70/0x7e4 [ 87.732108] mutex_lock_nested+0x1c/0x24 [ 87.736547] pwm_request_from_chip.part.6+0x34/0x74 [ 87.741940] pwm_request_from_chip+0x20/0x40 [ 87.746725] export_store+0x6c/0x1f4 [ 87.750820] dev_attr_store+0x18/0x28 [ 87.754998] sysfs_kf_write+0x54/0x64 [ 87.759175] kernfs_fop_write+0xe4/0x1e8 [ 87.763615] __vfs_write+0x40/0x184 [ 87.767619] vfs_write+0xa8/0x19c [ 87.771448] ksys_write+0x58/0xbc [ 87.775278] __arm64_sys_write+0x18/0x20 [ 87.779721] el0_svc_common+0xd0/0x124 [ 87.783986] el0_svc_compat_handler+0x1c/0x24 [ 87.788858] el0_svc_compat+0x8/0x18 [ 87.792947] [ 87.792947] -> #0 (kn->count#58){++++}: [ 87.798260] lock_acquire+0xc4/0x22c [ 87.802353] __kernfs_remove+0x258/0x2c4 [ 87.806790] kernfs_remove_by_name_ns+0x50/0xa0 [ 87.811836] remove_files.isra.1+0x38/0x78 [ 87.816447] sysfs_remove_group+0x48/0x98 [ 87.820971] sysfs_remove_groups+0x34/0x4c [ 87.825583] device_remove_attrs+0x6c/0x7c [ 87.830197] device_del+0x11c/0x33c [ 87.834201] device_unregister+0x14/0x2c [ 87.838638] pwmchip_sysfs_unexport+0x40/0x4c [ 87.843509] pwmchip_remove+0xf4/0x13c [ 87.847773] rcar_pwm_remove+0x28/0x34 [ 87.852039] platform_drv_remove+0x24/0x64 [ 87.856651] device_release_driver_internal+0x18c/0x21c [ 87.862391] device_release_driver+0x14/0x1c [ 87.867175] unbind_store+0xe0/0x124 [ 87.871265] drv_attr_store+0x20/0x30 [ 87.875442] sysfs_kf_write+0x54/0x64 [ 87.879618] kernfs_fop_write+0xe4/0x1e8 [ 87.884055] __vfs_write+0x40/0x184 [ 87.888057] vfs_write+0xa8/0x19c [ 87.891887] ksys_write+0x58/0xbc [ 87.895716] __arm64_sys_write+0x18/0x20 [ 87.900154] el0_svc_common+0xd0/0x124 [ 87.904417] el0_svc_compat_handler+0x1c/0x24 [ 87.909289] el0_svc_compat+0x8/0x18 [ 87.913378] [ 87.913378] other info that might help us debug this: [ 87.913378] [ 87.921374] Possible unsafe locking scenario: [ 87.921374] [ 87.927286] CPU0 CPU1 [ 87.931808] ---- ---- [ 87.936331] lock(pwm_lock); [ 87.939293] lock(kn->count#58); [ 87.945120] lock(pwm_lock); [ 87.950599] lock(kn->count#58); [ 87.953908] [ 87.953908] *** DEADLOCK *** [ 87.953908] [ 87.959821] 4 locks held by bash/2986: [ 87.963563] #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c [ 87.971044] #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8 [ 87.978872] #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c [ 87.988001] #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c [ 87.995481] [ 87.995481] stack backtrace: [ 87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7 [ 88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT) [ 88.012791] Call trace: [ 88.015235] dump_backtrace+0x0/0x190 [ 88.018891] show_stack+0x14/0x1c [ 88.022204] dump_stack+0xb0/0xec [ 88.025514] print_circular_bug.isra.32+0x1d0/0x2e0 [ 88.030385] __lock_acquire+0x1318/0x1864 [ 88.034388] lock_acquire+0xc4/0x22c [ 88.037958] __kernfs_remove+0x258/0x2c4 [ 88.041874] kernfs_remove_by_name_ns+0x50/0xa0 [ 88.046398] remove_files.isra.1+0x38/0x78 [ 88.050487] sysfs_remove_group+0x48/0x98 [ 88.054490] sysfs_remove_groups+0x34/0x4c [ 88.058580] device_remove_attrs+0x6c/0x7c [ 88.062671] device_del+0x11c/0x33c [ 88.066154] device_unregister+0x14/0x2c [ 88.070070] pwmchip_sysfs_unexport+0x40/0x4c [ 88.074421] pwmchip_remove+0xf4/0x13c [ 88.078163] rcar_pwm_remove+0x28/0x34 [ 88.081906] platform_drv_remove+0x24/0x64 [ 88.085996] device_release_driver_internal+0x18c/0x21c [ 88.091215] device_release_driver+0x14/0x1c [ 88.095478] unbind_store+0xe0/0x124 [ 88.099048] drv_attr_store+0x20/0x30 [ 88.102704] sysfs_kf_write+0x54/0x64 [ 88.106359] kernfs_fop_write+0xe4/0x1e8 [ 88.110275] __vfs_write+0x40/0x184 [ 88.113757] vfs_write+0xa8/0x19c [ 88.117065] ksys_write+0x58/0xbc [ 88.120374] __arm64_sys_write+0x18/0x20 [ 88.124291] el0_svc_common+0xd0/0x124 [ 88.128034] el0_svc_compat_handler+0x1c/0x24 [ 88.132384] el0_svc_compat+0x8/0x18 The sysfs unexport in pwmchip_remove() is completely asymmetric to what we do in pwmchip_add_with_polarity() and commit 0733424c9ba9 ("pwm: Unexport children before chip removal") is a strong indication that this was wrong to begin with. We should just move pwmchip_sysfs_unexport() where it belongs, which is right after pwmchip_sysfs_unexport_children(). In that case, we do not need separate functions anymore either. We also really want to remove sysfs irrespective of whether or not the chip will be removed as a result of pwmchip_remove(). We can only assume that the driver will be gone after that, so we shouldn't leave any dangling sysfs files around. This warning disappears if we move pwmchip_sysfs_unexport() to the top of pwmchip_remove(), pwmchip_sysfs_unexport_children(). That way it is also outside of the pwm_lock section, which indeed doesn't seem to be needed. Moving the pwmchip_sysfs_export() call outside of that section also seems fine and it'd be perfectly symmetric with pwmchip_remove() again. So, this patch fixes them. Signed-off-by: Phong Hoang <phong.hoang.wz@renesas.com> [shimoda: revise the commit log and code] Fixes: 76abbdde2d95 ("pwm: Add sysfs interface") Fixes: 0733424c9ba9 ("pwm: Unexport children before chip removal") Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Tested-by: Hoan Nguyen An <na-hoan@jinso.co.jp> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-17 23:54:23 +0000