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path: root/drivers/pwm/pwm-atmel.c
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* pwm: atmel: Use of_device_get_match_data()Thierry Reding2016-07-111-9/+2
| | | | | | Use of_device_get_match_data() instead of an open-coded variant. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: Fix checkpatch warningsThierry Reding2016-07-111-6/+7
| | | | | | | Avoid an overly long line by moving a comment around, and remove a use of else-after-return. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: Fix disabling of PWM channelsGuillermo Rodriguez2016-07-111-0/+10
| | | | | | | | | | | | | | When disabling a PWM channel, the PWM clock was being stopped immediately after writing to PWM_DIS. As a result, the disabling of the PWM channel did not complete properly, and the PWM output might be left at the wrong level. Fix this by waiting for the channel to be effectively disabled (by checking the PWM_SR register) before disabling the clock. Signed-off-by: Guillermo Rodriguez <guille.rodriguez@gmail.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Make use of pwm_get_xxx() helpers where appropriateBoris Brezillon2015-07-201-1/+1
| | | | | | | | | Use the pwm_get_xxx() helpers instead of directly accessing the fields in struct pwm_device. This will allow us to smoothly move to the atomic update approach. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: Add the pwm_is_enabled() helperBoris Brezillon2015-07-201-3/+3
| | | | | | | | | | Some PWM drivers are testing the PWMF_ENABLED flag. Create a helper function to hide the logic behind enabled test. This will allow us to smoothly move from the current approach to an atomic PWM update approach. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: Fix incorrect CDTY value after disablingAlexandre Belloni2015-06-121-0/+28
| | | | | | | | | | | | | pwm-leds calls .config() and .disable() in a row. This exhibits that it may happen that the channel gets disabled before CDTY has been updated with CUPD. The issue gets quite worse with long periods. So, ensure that at least one period has past before disabling the channel by polling ISR. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Tested-by: Gaël PORTAY <gael.portay@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: Fix incorrect CDTY value after enablingAlexandre Belloni2015-06-121-17/+18
| | | | | | | | | | CUPD is not flushed before enabling the channel so it will update CDTY/CPRD just after one period. So we always set CUPD, even when the channel is not enabled. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: Fix calculation of prescale valueNikolaus Voss2014-09-251-13/+11
| | | | | | | | | | | | | | The prescale value used for calculating the period was incremented afterwards, thus the resulting prescale value is by one too high. This resulted in a PWM frequency only half as high as requested. This patch moves the 64 bit division out of the prescale loop to correct the above issue and make the calculation more efficient. Signed-off-by: Nikolaus Voss <n.voss@weinmann-emt.de> Tested-by: Bo Shen <voice.shen@atmel.com> Acked-by: Bo Shen <voice.shen@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: set pwm_chip can_sleep flagAlexandre Belloni2014-05-211-0/+1
| | | | | | | | | atmel_pwm_config() calls clk_get_rate() which might sleep, so we need to set pwm_chip can_sleep flag. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: correct CDTY calculationAlexandre Belloni2014-03-181-1/+1
| | | | | | | | | | | | | | | From the datasheet, the actual duty cycle is: (period - (1 / clk) * CDTY) / period This actually correct the polarity of the PWM and solves the issue that pwm-leds exhibits: when setting a duty cycle of 0 and then disabling a channel, the level was wrong (1 when the polarity was normal and 0 when the polarity was inversed). Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel: Fix polarity handlingAlexandre Belloni2014-03-181-1/+6
| | | | | | | | | | | | | | | When atmel_pwm_config() calculates and then sets the prescaler, it is overwriting the channel's CMR register so we are losing the CPOL configuration. As atmel_pwm_config() is always called before enabling a channel, inverting the polarity doesn't work. Fix that by reading CMR first and only overwriting the prescaler bits. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel-pwm: Do not unprepare clock after successful registrationBo Shen2013-12-201-0/+2
| | | | | | | | When the PWM controller is registered successfully, the clock can not unprepare, so fix it. Signed-off-by: Bo Shen <voice.shen@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
* pwm: atmel-pwm: Add Atmel PWM controller driverBo Shen2013-12-171-0/+393
Add a PWM framework driver for the PWM controller found on Atmel SoCs. Signed-off-by: Bo Shen <voice.shen@atmel.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> [thierry.reding: coding style and other minor cleanups] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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