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path: root/drivers/pwm/pwm-bcm2835.c
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2020-03-30pwm: bcm2835: Dynamically allocate baseFlorian Fainelli
The newer 2711 and 7211 chips have two PWM controllers and failure to dynamically allocate the PWM base would prevent the second PWM controller instance being probed for succeeding with an -EEXIST error from alloc_pwms(). Fixes: e5a06dc5ac1f ("pwm: Add BCM2835 PWM driver") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21pwm: bcm2835: Suppress error message during deferred probeStefan Wahren
This suppresses error messages in case the PWM clock isn't ready yet. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21pwm: bcm2835: Fix period_ns range checkStefan Wahren
The range check for period_ns was written under assumption of a fixed PWM clock. With clk-bcm2835 driver the PWM clock is a dynamic one. So fix this by doing the range check on the period register value. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21pwm: bcm2835: Suppress error message for invalid period_nsStefan Wahren
The PWM config can be triggered via sysfs, so we better suppress the error message in case of an invalid period to avoid kernel log spamming. Signed-off-by: Stefan Wahren <wahrenst@gmx.net> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: bcm2835: Improve precision of PWMSean Young
If sending IR with carrier of 455kHz using the pwm-ir-tx driver, the carrier ends up being 476kHz. The clock is set to bcm2835-pwm with a rate of 10MHz. A carrier of 455kHz has a period of 2198ns, but the arithmetic truncates this to 2100ns rather than 2200ns. So, use DIV_ROUND_CLOSEST() to reduce rounding errors, and we have a much more accurate carrier of 454.5kHz. Reported-by: Andreas Christ <andreas@christ-faesch.ch> Signed-off-by: Sean Young <sean@mess.org> Acked-by: Stefan Wahren <wahrenst@gmx.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-12-24pwm: bcm2835: Switch to SPDX identifierStefan Wahren
Adopt the SPDX license identifier headers to ease license compliance management. Cc: Bart Tanghe <bart.tanghe@thomasmore.be> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21pwm: bcm2835: Support for polarity setting via DTStefan Wahren
This adds support for the third (optional) pwm cell to specify the polarity, which is needed by display backlights for example. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: bcm2835: Fix email address specificationStefan Wahren
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: bcm2835: Prevent division by zeroStefan Wahren
It's possible that the PWM clock becomes an orphan. So better check the result of clk_get_rate() in order to prevent a division by zero. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: bcm2835: Calculate scaler in ->config()Stefan Wahren
Currently pwm-bcm2835 assumes a fixed clock rate and stores the resulting scaler in the driver structure. But with the upcoming PWM clock support for clk-bcm2835 the rate could change, so calculate the scaler in the ->config() callback. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-11-17pwm: Add BCM2835 PWM driverBart Tanghe
Add PWM driver for Broadcom BCM2835 processor (Raspberry Pi) Signed-off-by: Bart Tanghe <bart.tanghe@thomasmore.be> Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>