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path: root/drivers/pwm/pwm-cros-ec.c
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2021-03-22pwm: cros-ec: Refuse requests with unsupported polarityUwe Kleine-König
The driver only supports normal polarity and so should refuse requests for inversed polarity. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22pwm: Always allocate PWM chip base ID dynamicallyUwe Kleine-König
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 <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-08-24pwm: cros-ec: Simplify EC error handlingGuenter Roeck
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 <u.kleine-koenig@pengutronix.de> Reviewed-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2020-08-24pwm: cros-ec: Accept more error codes from cros_ec_cmd_xfer_statusGuenter Roeck
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 <gwendal@chromium.org> Cc: Yu-Hsuan Hsu <yuhsuan@chromium.org> Cc: Prashant Malani <pmalani@chromium.org> Cc: Brian Norris <briannorris@chromium.org> Acked-by: Thierry Reding <thierry.reding@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
2019-12-09pwm: cros-ec: Cache duty cycle valueThierry Reding
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 <enric.balletbo@collabora.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-27Merge tag 'pwm/for-5.4-rc1' of ↵Linus Torvalds
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-König
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>
2019-09-02mfd / platform: cros_ec: Reorganize platform and mfd includesEnric Balletbo i Serra
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 <enric.balletbo@collabora.com> Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com> Acked-by: Chanwoo Choi <cw00.choi@samsung.com> Reviewed-by: Gwendal Grignou <gwendal@chromium.org> Tested-by: Gwendal Grignou <gwendal@chromium.org> Series changes: 3 - Fix dereferencing pointer to incomplete type 'struct cros_ec_dev' (lkp) Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-07-09pwm: cros-ec: Switch to SPDX identifierEnric Balletbo i Serra
Adopt the SPDX license identifier headers to ease license compliance management. Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-06pwm: cros-ec: Fix transposed param settingsNick Vaccaro
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 <nvaccaro@chromium.org> Reviewed-by: Brian Norris <briannorris@chromium.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-06pwm: cros-ec: Add __packed to prevent paddingBrian Norris
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 <briannorris@chromium.org> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-25pwm: Add ChromeOS EC PWM driverBrian Norris
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 <briannorris@chromium.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>