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path: root/drivers/pwm/pwm-cros-ec.c
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2024-07-10pwm: cros-ec: Simplify device tree xlationUwe Kleine-König1-20/+12
The cros-ec device tree binding only uses #pwm-cells = <1>, and so there is no period provided in the device tree. Up to now this was handled by hardcoding the period to the only supported value in the custom xlate callback. Apart from that, the default xlate callback (i.e. of_pwm_xlate_with_flags()) handles this just fine (and better, e.g. by checking args->args_count >= 1 before accessing args->args[0]). To simplify make use of of_pwm_xlate_with_flags(), drop the custom callback and provide the default period in .probe() already. Apart from simplifying the driver this also drops the last non-core user of pwm_request_from_chip() and so makes further simplifications possible. Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]>
2024-07-10pwm: cros-ec: Don't care about consumers in .get_state()Uwe Kleine-König1-33/+1
The get_state() callback is never called (in a visible way) after there is a consumer for a pwm device. The core handles loosing the information about duty_cycle just fine. Simplify the driver accordingly. Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Link: https://lore.kernel.org/r/[email protected] [Drop kdoc comment for channel to make W=1 builds happy] Signed-off-by: Uwe Kleine-König <[email protected]>
2024-02-15pwm: cros-ec: Make use of devm_pwmchip_alloc() functionUwe Kleine-König1-20/+19
This prepares the pwm-cros-ec driver to further changes of the pwm core outlined in the commit introducing devm_pwmchip_alloc(). There is no intended semantical change and the driver should behave as before. The probe function had to be changed a bit because the number of PWMs must be determined before allocation of the pwm_chip and its private data now. Reviewed-by: Tzung-Bi Shih <[email protected]> Link: https://lore.kernel.org/r/b0afe9e25340f0a274ff3806687cf37a6cc31557.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
2024-02-15pwm: cros-ec: Make use of pwmchip_parent() accessorUwe Kleine-König1-1/+1
struct pwm_chip::dev is about to change. To not have to touch this driver in the same commit as struct pwm_chip::dev, use the accessor function provided for exactly this purpose. Reviewed-by: Tzung-Bi Shih <[email protected]> Link: https://lore.kernel.org/r/486c40609bd9e339d7e5576e2501f63111b59b8b.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
2024-02-15pwm: cros-ec: Change prototype of helpers to prepare further changesUwe Kleine-König1-7/+10
pwm_chip allocation and registration is about to change. For that the number of PWM devices must be known earlier in cros_ec_pwm_probe(). So make cros_ec_pwm_get_duty() and cros_ec_num_pwms() independent of struct cros_ec_pwm_device which is only available later. Reviewed-by: Tzung-Bi Shih <[email protected]> Link: https://lore.kernel.org/r/c0cfc75c1cba0f735555e0138387143ec101feb3.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
2024-02-15pwm: Drop useless member .of_pwm_n_cells of struct pwm_chipUwe Kleine-König1-1/+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 <[email protected]> Link: https://lore.kernel.org/r/53d8c545aa8f79a920358be9e72e382b3981bdc4.1704835845.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
2023-12-20pwm: cros-ec: Drop documentation for dropped struct memberUwe Kleine-König1-1/+0
Recently an unused member was removed from struct cros_ec_pwm_device, but the kernel doc wasn't adapted accordingly. Catch up and drop the documentation, too. Reported-by: kernel test robot <[email protected]> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ Fixes: 6c4406ce609f ("pwm: cros-ec: Drop unused member from driver private data") Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-12-20pwm: cros-ec: Drop unused member from driver private dataUwe Kleine-König1-1/+0
.dev is unused since the driver was introduced in commit 1f0d3bb02785 ("pwm: Add ChromeOS EC PWM driver"). Drop it. Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-10-13pwm: cros-ec: Simplify using devm_pwmchip_add() and dev_err_probe()Uwe Kleine-König1-25/+8
Using devm_pwmchip_add() allows to drop pwmchip_remove() from the remove function which makes this function empty. Then there is no user of drvdata left and platform_set_drvdata() can be dropped, too. Further simplify and improve error returning using dev_err_probe(). Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-10-13pwm: cros-ec: Put per-channel data into driver dataUwe Kleine-König1-24/+9
Instead of an allocation of a single u16 per channel, allocate them all in a single chunk which greatly reduces memory fragmentation and also the overhead to track the allocated memory. Also put the channel data in driver data where it's cheaper to determine the address (no function call involved, just a trivial pointer addition). This also allows to get rid of the request and free callbacks. The only cost is that the channel data is allocated early, and even for unused channels. Reviewed-by: Tzung-Bi Shih <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-10-13pwm: Manage owner assignment implicitly for driversUwe Kleine-König1-1/+0
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 <[email protected]> # Intel LPSS Reviewed-by: Florian Fainelli <[email protected]> # pwm-{bcm,brcm}*.c Acked-by: Jernej Skrabec <[email protected]> # sun4i Acked-by: Andi Shyti <[email protected]> Acked-by: Nobuhiro Iwamatsu <[email protected]> # pwm-visconti Acked-by: Heiko Stuebner <[email protected]> # pwm-rockchip Acked-by: Michael Walle <[email protected]> # pwm-sl28cpld Acked-by: Neil Armstrong <[email protected]> # pwm-meson Reviewed-by: Linus Walleij <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-07-24pwm: Explicitly include correct DT includesRob Herring1-0/+1
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <[email protected]> Reviewed-by: Nobuhiro Iwamatsu <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-07-21pwm: cros-ec: Consistently name pwm_chip variables "chip"Uwe Kleine-König1-5/+5
Most variables holding a pointer to a pwm_chip are called "chip" which is also the usual name in most other PWM drivers. Rename the two variables that have a different name to be called "chip", too, for consistency. Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-03-30pwm: cros-ec: Convert to platform remove callback returning voidUwe Kleine-König1-4/+2
The .remove() callback for a platform driver returns an int which makes many driver authors wrongly assume it's possible to do error handling by returning an error code. However the value returned is (mostly) ignored and this typically results in resource leaks. To improve here there is a quest to make the remove callback return void. In the first step of this quest all drivers are converted to .remove_new() which already returns void. Trivially convert this driver from always returning zero in the remove callback to the void returning variant. Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Guenter Roeck <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2023-03-23pwm: cros-ec: Explicitly set .polarity in .get_state()Uwe Kleine-König1-0/+1
The driver only supports normal polarity. Complete the implementation of .get_state() by setting .polarity accordingly. Reviewed-by: Guenter Roeck <[email protected]> Fixes: 1f0d3bb02785 ("pwm: Add ChromeOS EC PWM driver") Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2022-12-06pwm: cros-ec: Propagate errors in .get_state() to the callerUwe Kleine-König1-1/+1
.get_state() can return an error indication. Make use of it to propagate failing hardware accesses. Reviewed-by: Tzung-Bi Shih <[email protected]> Acked-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2022-12-06pwm: Make .get_state() callback return an error codeUwe Kleine-König1-3/+5
.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 <[email protected]> Reviewed-by: Baolin Wang <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Reviewed-by: Neil Armstrong <[email protected]> Reviewed-by: Nobuhiro Iwamatsu <[email protected]> Reviewed-by: Andre Przywara <[email protected]> Reviewed-by: Dave Stevenson <[email protected]> Acked-by: Douglas Anderson <[email protected]> Acked-by: Jernej Skrabec <[email protected]> Acked-by: Pavel Machek <[email protected]> Acked-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2022-05-20pwm: pwm-cros-ec: Add channel type supportFabio Baltieri1-15/+67
Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm types to the PWM cros_ec_pwm driver. This allows specifying one of these PWM channel by functionality, and let the EC firmware pick the correct channel, thus abstracting the hardware implementation from the kernel driver. To use it, define the node with the "google,cros-ec-pwm-type" compatible. Signed-off-by: Fabio Baltieri <[email protected]> Reviewed-by: Tzung-Bi Shih <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2021-09-02pwm: cros-ec: Don't check the return code of pwmchip_remove()Uwe Kleine-König1-1/+3
pwmchip_remove() returns always 0. Don't use the value to make it possible to eventually change the function to return void. Also the driver core ignores the return value of cros_ec_pwm_remove(). Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2021-03-22pwm: cros-ec: Refuse requests with unsupported polarityUwe Kleine-König1-0/+3
The driver only supports normal polarity and so should refuse requests for inversed polarity. Signed-off-by: Uwe Kleine-König <[email protected]> Acked-by: Enric Balletbo i Serra <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2021-03-22pwm: Always allocate PWM chip base ID dynamicallyUwe Kleine-König1-1/+0
Since commit 5e5da1e9fbee ("pwm: ab8500: Explicitly allocate pwm chip base dynamically") all drivers use dynamic ID allocation explicitly. New drivers are supposed to do the same, so remove support for driver specified base IDs and drop all assignments in the low-level drivers. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2020-08-24pwm: cros-ec: Simplify EC error handlingGuenter Roeck1-22/+4
With enhanced error reporting from cros_ec_cmd_xfer_status() in place, we can fully use it and no longer rely on EC error codes. Acked-by: Uwe Kleine-König <[email protected]> Reviewed-by: Brian Norris <[email protected]> Signed-off-by: Guenter Roeck <[email protected]> Signed-off-by: Enric Balletbo i Serra <[email protected]>
2020-08-24pwm: cros-ec: Accept more error codes from cros_ec_cmd_xfer_statusGuenter Roeck1-7/+22
Since commit c5cd2b47b203 ("platform/chrome: cros_ec_proto: Report command not supported") we can no longer assume that cros_ec_cmd_xfer_status() reports -EPROTO for all errors returned by the EC itself. A follow-up patch will change cros_ec_cmd_xfer_status() to report additional errors reported by the EC as distinguished Linux error codes. Handle this change by no longer assuming that only -EPROTO is used to report all errors returned by the EC itself. Instead, support both the old and the new error codes. Add a comment describing cros_ec_num_pwms() to explain its functionality. Cc: Gwendal Grignou <[email protected]> Cc: Yu-Hsuan Hsu <[email protected]> Cc: Prashant Malani <[email protected]> Cc: Brian Norris <[email protected]> Acked-by: Thierry Reding <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Signed-off-by: Guenter Roeck <[email protected]> Signed-off-by: Enric Balletbo i Serra <[email protected]>
2019-12-09pwm: cros-ec: Cache duty cycle valueThierry Reding1-4/+54
The ChromeOS embedded controller doesn't differentiate between disabled and duty cycle being 0. In order not to potentially confuse consumers, cache the duty cycle and return the cached value instead of the real value when the PWM is disabled. Tested-by: Enric Balletbo i Serra <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-09-27Merge tag 'pwm/for-5.4-rc1' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm Pull pwm updates from Thierry Reding: "Besides one new driver being added for the PWM controller found in various Spreadtrum SoCs, this series of changes brings a slew of, mostly minor, fixes and cleanups for existing drivers, as well as some enhancements to the core code. Lastly, Uwe is added to the PWM subsystem entry of the MAINTAINERS file, making official his role as a reviewer" * tag 'pwm/for-5.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (34 commits) MAINTAINERS: Add myself as reviewer for the PWM subsystem MAINTAINERS: Add patchwork link for PWM entry MAINTAINERS: Add a selection of PWM related keywords to the PWM entry pwm: mediatek: Add MT7629 compatible string dt-bindings: pwm: Update bindings for MT7629 SoC pwm: mediatek: Update license and switch to SPDX tag pwm: mediatek: Use pwm_mediatek as common prefix pwm: mediatek: Allocate the clks array dynamically pwm: mediatek: Remove the has_clks field pwm: mediatek: Drop the check for of_device_get_match_data() pwm: atmel: Consolidate driver data initialization pwm: atmel: Remove unneeded check for match data pwm: atmel: Remove platform_device_id and use only dt bindings pwm: stm32-lp: Add check in case requested period cannot be achieved pwm: Ensure pwm_apply_state() doesn't modify the state argument pwm: fsl-ftm: Don't update the state for the caller of pwm_apply_state() pwm: sun4i: Don't update the state for the caller of pwm_apply_state() pwm: rockchip: Don't update the state for the caller of pwm_apply_state() pwm: Let pwm_get_state() return the last implemented state pwm: Introduce local struct pwm_chip in pwm_apply_state() ...
2019-09-21pwm: Ensure pwm_apply_state() doesn't modify the state argumentUwe Kleine-König1-1/+1
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 <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-09-02mfd / platform: cros_ec: Reorganize platform and mfd includesEnric Balletbo i Serra1-2/+2
There is a bit of mess between cros-ec mfd includes and platform includes. For example, we have a linux/mfd/cros_ec.h include that exports the interface implemented in platform/chrome/cros_ec_proto.c. Or we have a linux/mfd/cros_ec_commands.h file that is non related to the multifunction device (in the sense that is not exporting any function of the mfd device). This causes crossed includes between mfd and platform/chrome subsystems and makes the code difficult to read, apart from creating 'curious' situations where a platform/chrome driver includes a linux/mfd/cros_ec.h file just to get the exported functions that are implemented in another platform/chrome driver. In order to have a better separation on what the cros-ec multifunction driver does and what the cros-ec core provides move and rework the affected includes doing: - Move cros_ec_commands.h to include/linux/platform_data/cros_ec_commands.h - Get rid of the parts that are implemented in the platform/chrome/cros_ec_proto.c driver from include/linux/mfd/cros_ec.h to a new file include/linux/platform_data/cros_ec_proto.h - Update all the drivers with the new includes, so - Drivers that only need to know about the protocol include - linux/platform_data/cros_ec_proto.h - linux/platform_data/cros_ec_commands.h - Drivers that need to know about the cros-ec mfd device also include - linux/mfd/cros_ec.h Signed-off-by: Enric Balletbo i Serra <[email protected]> Acked-by: Andy Shevchenko <[email protected]> Acked-by: Mark Brown <[email protected]> Acked-by: Wolfram Sang <[email protected]> Acked-by: Neil Armstrong <[email protected]> Acked-by: Alexandre Belloni <[email protected]> Acked-by: Jonathan Cameron <[email protected]> Acked-by: Benjamin Tissoires <[email protected]> Acked-by: Dmitry Torokhov <[email protected]> Acked-by: Sebastian Reichel <[email protected]> Acked-by: Chanwoo Choi <[email protected]> Reviewed-by: Gwendal Grignou <[email protected]> Tested-by: Gwendal Grignou <[email protected]> Series changes: 3 - Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp) Signed-off-by: Lee Jones <[email protected]>
2018-07-09pwm: cros-ec: Switch to SPDX identifierEnric Balletbo i Serra1-6/+3
Adopt the SPDX license identifier headers to ease license compliance management. Signed-off-by: Enric Balletbo i Serra <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-07-06pwm: cros-ec: Fix transposed param settingsNick Vaccaro1-2/+2
The __cros_ec_pwm_get_duty() routine was transposing the insize and outsize fields when calling cros_ec_cmd_xfer_status(). The original code worked without error due to size of the two particular parameter blocks passed to cros_ec_cmd_xfer_status(), so this change is not fixing an actual runtime problem, just correcting the calling usage. Signed-off-by: Nick Vaccaro <[email protected]> Reviewed-by: Brian Norris <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-09-06pwm: cros-ec: Add __packed to prevent paddingBrian Norris1-2/+2
While the particular usage in question is likely safe (struct cros_ec_command is 32-bit aligned, followed by <= 32-bit fields), it's been suggested this is not a great pattern to follow for the general case -- for example, if we follow a 'struct cros_ec_command' (which is 32-bit- but not 64-bit-aligned) with a struct that starts with a 64-bit type (e.g., u64), the compiler may add padding. Let's add __packed, to inform the compiler of our true intention -- to have no padding between these struct elements -- and to future proof for any refactorings that might occur. Signed-off-by: Brian Norris <[email protected]> Reviewed-by: Dmitry Torokhov <[email protected]> Reviewed-by: Guenter Roeck <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-07-25pwm: Add ChromeOS EC PWM driverBrian Norris1-0/+260
Use the new ChromeOS EC EC_CMD_PWM_{GET,SET}_DUTY commands to control one or more PWMs attached to the Embedded Controller. Because the EC allows us to modify the duty cycle (as a percentage, where U16_MAX is 100%) but not the period, we assign the period a fixed value of EC_PWM_MAX_DUTY and reject all attempts to change it. This driver supports only device tree at the moment, because that provides a very flexible way of describing the relationship between PWMs and their consumer devices (e.g., backlight). On a non-DT system, we'll probably want to use the non-GENERIC addressing (i.e., we'll need to make special device instances that will use EC_PWM_TYPE_KB_LIGHT or EC_PWM_TYPE_DISPLAY_LIGHT), as well as the relatively inflexible pwm_lookup infrastructure for matching devices. Defer that work for now. Signed-off-by: Brian Norris <[email protected]> Signed-off-by: Thierry Reding <[email protected]>