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path: root/drivers/pwm/pwm-imx27.c
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2019-12-09pwm: imx27: Cache duty cycle register valueThierry Reding
The hardware register containing the duty cycle value cannot be accessed when the PWM is disabled. This causes the ->get_state() callback to read back a duty cycle value of 0, which can confuse consumer drivers. Tested-by: Michal Vokáč <michal.vokac@ysoft.com> Tested-by: Adam Ford <aford173@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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>
2019-09-21pwm: imx: Document known limitationsUwe Kleine-König
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09pwm: imx27: Use devm_platform_ioremap_resource() to simplify codeAnson Huang
Use the new helper devm_platform_ioremap_resource() which wraps the platform_get_resource() and devm_ioremap_resource() together, to simplify the code. Signed-off-by: Anson Huang <Anson.Huang@nxp.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Mukesh Ojha <mojha@codeaurora.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04pwm: imx27: Only enable the clocks once in .get_state()Uwe Kleine-König
Currently the function pwm_imx27_get_state() of enables the clocks once unconditionally at the start, a second time if the PWM is enabled and disables unconditionally at the end. Simplify that to enable once at the start and disable conditionally at the end. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-01-16pwm: imx: Signedness bug in imx_pwm_get_state()Dan Carpenter
"ret" only holds zero and negative error codes. It needs to be signed for the error handling to work. Fixes: 9f4c8f9607c3 ("pwm: imx: Add ipg clock operation") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-01-16pwm: imx: Split into two driversUwe Kleine-König
The two PWM implementations called v1 (for i.MX1 and i.MX21) and v2 (for i.MX27 and later) have nothing in common apart from needing two clocks named "per" and "ipg" and being integrated in a SoC named i.MX. So split the file containing the two disjunct drivers into two files and two complete separate drivers. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> [thierry.reding@gmail.com: fix a modular build issue] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>