lwn.git/drivers/pwm/pwm-atmel.c, branch v6.6-rc3

pwm: atmel: Simplify using devm functions

2023-07-28T08:15:44+00:00

For all resources used by the driver there is a devm variant to allocate these. This simplifies the error path in the probe callback and allows to drop the remove callback. While at it also use dev_err_probe() to compact returning an error. With the remove callback gone, there is no user of driver data left, so the call to platform_set_drvdata() can also be dropped. Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding

pwm: atmel: Enable clk when pwm already enabled in bootloader

2023-07-24T11:28:13+00:00

The driver would never call clk_enable() if the PWM channel was already enabled in bootloader which lead to dump the warning message "the PWM clock already disabled" when turning off the PWM channel. Add atmel_pwm_enable_clk_if_on() in probe function to enable clock if the PWM channel was already enabled in bootloader. Signed-off-by: Guiting Shen Reviewed-by: Claudiu Beznea Signed-off-by: Thierry Reding

pwm: Explicitly include correct DT includes

2023-07-24T11:28:05+00:00

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 Reviewed-by: Nobuhiro Iwamatsu Acked-by: Uwe Kleine-König Reviewed-by: Tzung-Bi Shih Signed-off-by: Thierry Reding

docs: update some straggling Documentation/arm references

2023-06-16T14:31:47+00:00

The Arm documentation has moved to Documentation/arch/arm; update the last remaining references to match. Cc: Dmitry Torokhov Cc: Chen-Yu Tsai Cc: Samuel Holland Cc: Thierry Reding Acked-by: Nicolas Ferre Acked-by: Jernej Skrabec Acked-by: Greg Kroah-Hartman Acked-by: Uwe Kleine-König # for pwm Signed-off-by: Jonathan Corbet

pwm: atmel: Convert to platform remove callback returning void

2023-03-30T14:26:23+00:00

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 Reviewed-by: Claudiu Beznea Signed-off-by: Thierry Reding

pwm: Make .get_state() callback return an error code

2022-12-06T11:46:22+00:00

.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 Reviewed-by: Baolin Wang Reviewed-by: Tzung-Bi Shih Reviewed-by: Neil Armstrong Reviewed-by: Nobuhiro Iwamatsu Reviewed-by: Andre Przywara Reviewed-by: Dave Stevenson Acked-by: Douglas Anderson Acked-by: Jernej Skrabec Acked-by: Pavel Machek Acked-by: Conor Dooley Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding

pwm: atmel: Remove redundant initialization of variable timeout

2022-02-24T12:54:05+00:00

The variable timeout is being initialized with a value that is never read, it is being re-assigned the same value later on. Remove the redundant initialization and keep the latter assignment because it's closer to the use of the variable. Signed-off-by: Colin Ian King Reviewed-by: Uwe Kleine-König Signed-off-by: Thierry Reding

pwm: atmel: Drop unused header

2021-11-05T10:51:40+00:00

Since commit 52eaba4cedbd ("pwm: atmel: Rework tracking updates pending in hardware") the driver doesn't make use of mutexes any more, so the header defining these doesn't need to be included. Signed-off-by: Uwe Kleine-König Acked-by: Alexandre Belloni Acked-by: Claudiu Beznea Signed-off-by: Thierry Reding

pwm: atmel: Rework tracking updates pending in hardware

2021-09-02T19:35:09+00:00

This improves the driver's behavior in several ways: - The lock is held for shorter periods and so a channel that is currently waited for doesn't block disabling another channel. - It's easier to understand because the procedure is split into more semantic units and documentation is improved - A channel is only set to pending when such an event is actually scheduled in hardware (by writing the CUPD register). - Also wait in .get_state() to report the last configured state instead of (maybe) the previous one. This fixes the read back duty cycle and so prevents a warning being emitted when PWM_DEBUG is on. Tested on an AriettaG25. Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding

pwm: Simplify all drivers with explicit of_pwm_n_cells = 3

2021-05-25T16:19:15+00:00

With the previous commit there is no need for the lowlevel driver any more to specify it it uses two or three cells. So simplify accordingly. The only non-trival change affects the pwm-rockchip driver: It used to only support three cells if the hardware supports polarity. Now the default number depends on the device tree which has to match hardware anyhow (and if it doesn't the error is just a bit delayed as a PWM handle with an inverted setting is catched when pwm_apply_state() is called). Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding