kernel/linux.git/drivers/pwm, branch v4.14.286

pwm: lp3943: Fix duty calculation in case period was clamped

2022-06-14T14:53:56+00:00

[ Upstream commit 5e3b07ca5cc78cd4a987e78446849e41288d87cb ] The hardware only supports periods <= 1.6 ms and if a bigger period is requested it is clamped to 1.6 ms. In this case duty_cycle might be bigger than 1.6 ms and then the duty cycle register is written with a value bigger than LP3943_MAX_DUTY. So clamp duty_cycle accordingly. Fixes: af66b3c0934e ("pwm: Add LP3943 PWM driver") Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: lpc18xx-sct: Initialize driver data and hardware before pwmchip_add()

2022-04-20T07:08:19+00:00

[ Upstream commit 0401f24cd238ae200a23a13925f98de3d2c883b8 ] 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 Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: rockchip: Don't modify HW state in .remove() callback

2021-09-26T11:37:30+00:00

[ Upstream commit 9d768cd7fd42bb0be16f36aec48548fca5260759 ] A consumer is expected to disable a PWM before calling pwm_put(). And if they didn't there is hopefully a good reason (or the consumer needs fixing). Also if disabling an enabled PWM was the right thing to do, this should better be done in the framework instead of in each low level driver. Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered

2021-09-26T11:37:29+00:00

commit 3d2813fb17e5fd0d73c1d1442ca0192bde4af10e upstream. This fixes a race condition: After pwmchip_add() is called there might already be a consumer and then modifying the hardware behind the consumer's back is bad. So set the default before. (Side-note: I don't know what this register setting actually does, if this modifies the polarity there is an inconsistency because the inversed polarity isn't considered if the PWM is already running during .probe().) Fixes: acfd92fdfb93 ("pwm: lpc32xx: Set PWM_PIN_LEVEL bit to default value") Cc: Sylvain Lemieux Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Greg Kroah-Hartman

pwm: tegra: Don't modify HW state in .remove callback

2021-07-20T14:17:52+00:00

[ Upstream commit 86f7fa71cd830d18d7ebcaf719dffd5ddfe1acdd ] A consumer is expected to disable a PWM before calling pwm_put(). And if they didn't there is hopefully a good reason (or the consumer needs fixing). Also if disabling an enabled PWM was the right thing to do, this should better be done in the framework instead of in each low level driver. So drop the hardware modification from the .remove() callback. Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: spear: Don't modify HW state in .remove callback

2021-07-20T14:17:51+00:00

[ Upstream commit b601a18f12383001e7a8da238de7ca1559ebc450 ] A consumer is expected to disable a PWM before calling pwm_put(). And if they didn't there is hopefully a good reason (or the consumer needs fixing). Also if disabling an enabled PWM was the right thing to do, this should better be done in the framework instead of in each low level driver. So drop the hardware modification from the .remove() callback. Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()

2021-03-03T17:22:48+00:00

[ Upstream commit d5d8d675865ccddfe4da26c85f22c55cec663bf2 ] If rockchip_pwm_probe() fails to register a PWM device it calls clk_unprepare() for the device's PWM clock, without having first disabled the clock and before jumping to an error handler that also unprepares it. This is likely to produce warnings from the kernel about the clock being unprepared when it is still enabled, and then being unprepared when it has already been unprepared. Prevent these warnings by removing this unnecessary call to clk_unprepare(). Fixes: 48cf973cae33 ("pwm: rockchip: Avoid glitches on already running PWMs") Signed-off-by: Simon South Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: lp3943: Dynamically allocate PWM chip base

2020-12-29T12:47:03+00:00

[ Upstream commit 1f0f1e80fdd3aa9631f6c22cda4f8550cfcfcc3e ] When there are other PWM controllers enabled along with pwm-lp3943, pwm-lp3942 is failing to probe with -EEXIST error. This is because other PWM controllers are probed first and assigned PWM base 0 and pwm-lp3943 is requesting for 0 again. In order to avoid this, assign the chip base with -1, so that it is dynamically allocated. Fixes: af66b3c0934e ("pwm: Add LP3943 PWM driver") Signed-off-by: Lokesh Vutla Reviewed-by: Uwe Kleine-König Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: zx: Add missing cleanup in error path

2020-12-29T12:47:03+00:00

[ Upstream commit 269effd03f6142df4c74814cfdd5f0b041b30bf9 ] zx_pwm_probe() called clk_prepare_enable() before; this must be undone in the error path. Fixes: 4836193c435c ("pwm: Add ZTE ZX PWM device driver") Signed-off-by: Uwe Kleine-König Acked-by: Shawn Guo Signed-off-by: Thierry Reding Signed-off-by: Sasha Levin

pwm: lpss: Add range limit check for the base_unit register value

2020-10-29T08:07:05+00:00

[ Upstream commit ef9f60daab309558c8bb3e086a9a11ee40bd6061 ] When the user requests a high enough period ns value, then the calculations in pwm_lpss_prepare() might result in a base_unit value of 0. But according to the data-sheet the way the PWM controller works is that each input clock-cycle the base_unit gets added to a N bit counter and that counter overflowing determines the PWM output frequency. Adding 0 to the counter is a no-op. The data-sheet even explicitly states that writing 0 to the base_unit bits will result in the PWM outputting a continuous 0 signal. When the user requestes a low enough period ns value, then the calculations in pwm_lpss_prepare() might result in a base_unit value which is bigger then base_unit_range - 1. Currently the codes for this deals with this by applying a mask: base_unit &= (base_unit_range - 1); But this means that we let the value overflow the range, we throw away the higher bits and store whatever value is left in the lower bits into the register leading to a random output frequency, rather then clamping the output frequency to the highest frequency which the hardware can do. This commit fixes both issues by clamping the base_unit value to be between 1 and (base_unit_range - 1). Fixes: 684309e5043e ("pwm: lpss: Avoid potential overflow of base_unit") Reviewed-by: Andy Shevchenko Acked-by: Thierry Reding Signed-off-by: Hans de Goede Link: https://patchwork.freedesktop.org/patch/msgid/20200903112337.4113-5-hdegoede@redhat.com Signed-off-by: Sasha Levin