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path: root/drivers/pwm/pwm-lpc18xx-sct.c
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* pwm: lpc18xx-sct: Drop driver local lockingUwe Kleine-König2025-07-071-14/+0
| | | | | | | | | | | | Both mutexes are only used in one function each. These functions are only called by the .apply() callback. As the .apply() calls are serialized by the core since commit 1cc2e1faafb3 ("pwm: Add more locking") the mutexes have no effect apart from runtime overhead. Drop them. Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Vladimir Zapolskiy <[email protected]> Link: https://lore.kernel.org/r/4f7a2da37adbfe4743564245119045826d86eca6.1750788649.git.u.kleine-koenig@baylibre.com Signed-off-by: Uwe Kleine-König <[email protected]>
* pwm: Switch back to struct platform_driver::remove()Uwe Kleine-König2024-09-161-1/+1
| | | | | | | | | | | | | | | After commit 0edb555a65d1 ("platform: Make platform_driver::remove() return void") .remove() is (again) the right callback to implement for platform drivers. Convert all pwm drivers to use .remove(), with the eventual goal to drop struct platform_driver::remove_new(). As .remove() and .remove_new() have the same prototypes, conversion is done by just changing the structure member name in the driver initializer. Signed-off-by: Uwe Kleine-König <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Uwe Kleine-König <[email protected]>
* pwm: lpc18xx-sct: Make use of devm_pwmchip_alloc() functionUwe Kleine-König2024-02-191-9/+5
| | | | | | | | | This prepares the pwm-lpc18xx-sct 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. Link: https://lore.kernel.org/r/d480891340e927705843cd09e5777d4daaa6c9cc.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
* pwm: lpc18xx-sct: Prepare removing pwm_chip from driver dataUwe Kleine-König2024-02-191-7/+10
| | | | | | | | | | This prepares the driver for further changes that will drop struct pwm_chip chip from struct lpc18xx_pwm_chip. Use the pwm_chip as driver data instead of the lpc18xx_pwm_chip to get access to the pwm_chip in lpc18xx_pwm_remove() without using lpc18xx_pwm->chip. Link: https://lore.kernel.org/r/b7bf8c421ff754ec3e985ec6235f4ddd6e5e27a4.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
* pwm: lpc18xx-sct: Make use of pwmchip_parent() accessorUwe Kleine-König2024-02-191-3/+3
| | | | | | | | | 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. Link: https://lore.kernel.org/r/e4fb330c8dbf8fecd365afe3f8b33f8c7952eb38.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
* pwm: lpc18xx-sct: Drop hardly used member from driver private dataUwe Kleine-König2024-02-191-4/+1
| | | | | | | | | | The device pointer is only used once in lpc18xx_pwm_request(). There the pwm_chip is available, too, which has a pointer to the same structure. Replace the usage accordingly and drop the then write-only member variable. Link: https://lore.kernel.org/r/427a719a24dd7ff5ebbac3e260a1773c094c7489.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <[email protected]>
* pwm: lpc18xx-sct: Don't modify the cached period of other PWM outputsUwe Kleine-König2023-12-201-3/+1
| | | | | | | | | Even though the hardware only supports a single period for all PWM outputs, modifying the other (disabled) outputs's period is strange and wrong. Only the pwm core is supposed to update these values. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: Stop referencing pwm->chipThierry Reding2023-12-201-1/+1
| | | | | | | | Drivers have access to the chip via a function argument already, so there is no need to reference it via the PWM device. Reviewed-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: Manage owner assignment implicitly for driversUwe Kleine-König2023-10-131-1/+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]>
* pwm: lpc18xx-sct: Simplify using devm_clk_get_enabled()Uwe Kleine-König2023-07-281-25/+8
| | | | | | | | With devm_clk_get_enabled() the call to clk_disable_unprepare() can be dropped from the error path and the remove callback. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: Explicitly include correct DT includesRob Herring2023-07-241-0/+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]>
* pwm: lpc18xx-sct: Convert to platform remove callback returning voidUwe Kleine-König2023-03-301-4/+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]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Fix a comment to match codeUwe Kleine-König2022-12-061-1/+1
| | | | | | | | | | | lpc18xx_pwm_probe() only ensures clk_rate <= NSEC_PER_SEC, the following reasoning is right even under this slightly lesser condition. Fixes: 8933d30c5f46 ("pwm: lpc18xx: Fix period handling") Acked-by: Vladimir Zapolskiy <[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]>
* pwm: lpc18xx: Fix period handlingUwe Kleine-König2022-07-291-16/+31
| | | | | | | | | | | | | | | | | | | | | | | The calculation: val = (u64)NSEC_PER_SEC * LPC18XX_PWM_TIMER_MAX; do_div(val, lpc18xx_pwm->clk_rate); lpc18xx_pwm->max_period_ns = val; is bogus because with NSEC_PER_SEC = 1000000000, LPC18XX_PWM_TIMER_MAX = 0xffffffff and clk_rate < NSEC_PER_SEC this overflows the (on lpc18xx (i.e. ARM32) 32 bit wide) unsigned int .max_period_ns. This results (dependant of the actual clk rate) in an arbitrary limitation of the maximal period. E.g. for clkrate = 333333333 (Hz) we get max_period_ns = 9 instead of 12884901897. So make .max_period_ns an u64 and pass period and duty as u64 to not discard relevant digits. And also make use of mul_u64_u64_div_u64() which prevents all overflows assuming clk_rate < NSEC_PER_SEC. Fixes: 841e6f90bb78 ("pwm: NXP LPC18xx PWM/SCT driver") Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx: Convert to use dev_err_probe()Uwe Kleine-König2022-07-291-11/+9
| | | | | | | | | | This has various upsides: - It emits the symbolic name of the error code - It is silent in the EPROBE_DEFER case and properly sets the defer reason - It reduces the number of code lines slightly Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx: Implement .apply() callbackUwe Kleine-König2022-05-201-13/+30
| | | | | | | | | | | | To eventually get rid of all legacy drivers convert this driver to the modern world implementing .apply(). This pushes a variant of pwm_apply_legacy into the driver that was slightly simplified because the .set_polarity callback was a noop. There is no change in behavior. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Simplify driver by not using pwm_[gs]et_chip_data()Uwe Kleine-König2022-02-021-17/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The per-channel data is available directly in the driver data struct. So use it without making use of pwm_[gs]et_chip_data(). The relevant change introduced by this patch to lpc18xx_pwm_disable() at the assembler level (for an arm lpc18xx_defconfig build) is: push {r3, r4, r5, lr} mov r4, r0 mov r0, r1 mov r5, r1 bl 0 <pwm_get_chip_data> ldr r3, [r0, #0] changes to ldr r3, [r1, #8] push {r4, lr} add.w r3, r0, r3, lsl #2 ldr r3, [r3, #92] ; 0x5c So this reduces stack usage, has an improved runtime behavior because of better pipeline usage, doesn't branch to an external function and the generated code is a bit smaller occupying less memory. The codesize of lpc18xx_pwm_probe() is reduced by 32 bytes. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Reduce number of devm memory allocationsUwe Kleine-König2022-02-021-7/+5
| | | | | | | | | | | Each devm allocations has an overhead of 24 bytes to store the related struct devres_node additionally to the fragmentation of the allocator. So allocating 16 struct lpc18xx_pwm_data (which only hold a single int) adds quite some overhead. Instead put the per-channel data into the driver data struct and allocate it in one go. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Initialize driver data and hardware before pwmchip_add()Uwe Kleine-König2022-02-021-11/+9
| | | | | | | | | | | | | When a driver calls pwmchip_add() it has to be prepared to immediately get its callbacks called. So move allocation of driver data and hardware initialization before the call to pwmchip_add(). This fixes a potential NULL pointer exception and a race condition on register writes. Fixes: 841e6f90bb78 ("pwm: NXP LPC18xx PWM/SCT driver") Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: Simplify all drivers with explicit of_pwm_n_cells = 3Uwe Kleine-König2021-05-251-2/+0
| | | | | | | | | | | | | | 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 <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Free resources only after pwmchip_remove()Uwe Kleine-König2021-04-091-1/+3
| | | | | | | | | Before pwmchip_remove() returns the PWM is expected to be functional. So remove the pwmchip before disabling the clock. Signed-off-by: Uwe Kleine-König <[email protected]> Acked-by: Vladimir Zapolskiy <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: Always allocate PWM chip base ID dynamicallyUwe Kleine-König2021-03-221-1/+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]>
* pwm: lpc18xx-sct: remove unneeded semicolonYang Li2021-02-221-1/+1
| | | | | | | | | | | Eliminate the following coccicheck warning: ./drivers/pwm/pwm-lpc18xx-sct.c:292:2-3: Unneeded semicolon Reported-by: Abaci Robot <[email protected]> Signed-off-by: Yang Li <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Acked-by: Vladimir Zapolskiy <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Convert to devm_platform_ioremap_resource()Yangtao Li2020-12-171-3/+1
| | | | | | | | Use devm_platform_ioremap_resource() to simplify code. Signed-off-by: Yangtao Li <[email protected]> Reviewed-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 178Thomas Gleixner2019-05-301-4/+1
| | | | | | | | | | | | | | | | | | | | | | | Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 24 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Alexios Zavras <[email protected]> Reviewed-by: Steve Winslow <[email protected]> Reviewed-by: Allison Randal <[email protected]> Reviewed-by: Richard Fontana <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
* pwm: lpc18xx-sct: Don't reconfigure PWM in .request and .freeUwe Kleine-König2018-11-161-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | Regarding the .request case: The consumer might be interested in taking over the configured state from the boot loader. So the initially configured state should be retained. For the free case the PWM consumer is responsible for disabling the PWM before calling pwm_put() and there are three subcases to consider: a) The PWM is already off. Then there is no gain in disabling the PWM once more. b) The PWM is still running and there is a good reason for that. (Not sure this is a valid case, I cannot imagine such a good reason.) Then it is counterproductive to disable the PWM. c) The PWM is still running because the consumer failed to disable the PWM. Then the consumer needs fixing and there is little incentive to paper over the problem in the backend driver. This aligns the lpc18xx-sct driver to the other PWM drivers that also don't reconfigure the hardware in .request and .free. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc-18xx: use pwm_set_chip_data[email protected]2016-09-081-4/+8
| | | | | | | | | | | The lpc-18xx driver currently manipulates the pwm_device struct directly rather than using the pwm_set_chip_data() function. While the current method may save a clock cycle or two, using the explicit function call makes it more obvious that data is set to the local chip data pointer. Signed-off-by: Olliver Schinagl <[email protected]> Reviewed-by: Ariel D'Alessandro <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: Use pwm_get/set_xxx() helpers where appropriateBoris Brezillon2016-05-171-1/+1
| | | | | | | | | Use pwm_get/set_xxx() helpers instead of directly accessing the pwm->xxx field. Doing that will ease adaptation of the PWM framework to support atomic update. Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: lpc18xx-sct: Test clock rate to avoid division by 0Wolfram Sang2016-03-231-0/+5
| | | | | | | | | The clk API may return 0 on clk_get_rate(), so we should check the result before using it as a divisor. Signed-off-by: Wolfram Sang <[email protected]> Acked-by: Joachim Eastwood <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
* pwm: NXP LPC18xx PWM/SCT driverAriel D'Alessandro2015-09-091-0/+465
This commit adds support for NXP LPC18xx PWM/SCT. NXP LPC SoCs family, which includes LPC18xx/LPC43xx, provides a State Configurable Timer (SCT) which can be configured as a Pulse Width Modulator. Other SoCs in that family may share the same hardware. The PWM supports a total of 16 channels, but only 15 can be simultaneously requested. There's only one period, global to all the channels, thus PWM driver will refuse setting different values to it, unless there's only one channel requested. Signed-off-by: Ariel D'Alessandro <[email protected]> [[email protected]: remove excessive padding of fields] Signed-off-by: Thierry Reding <[email protected]>
generated by cgit (git 2.51.2) at 2025-11-30 15:32:42 +0000