aboutsummaryrefslogtreecommitdiff
path: root/drivers/pwm/pwm-bcm2835.c
AgeCommit message (Collapse)AuthorFilesLines
2021-05-25pwm: Simplify all drivers with explicit of_pwm_n_cells = 3Uwe Kleine-König1-2/+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]>
2021-04-09pwm: bcm2835: Free resources only after pwmchip_remove()Uwe Kleine-König1-1/+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: Florian Fainelli <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2021-03-22pwm: Always allocate PWM chip base ID dynamicallyUwe Kleine-König1-1/+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]>
2021-03-22pwm: bcm2835: Improve period and duty cycle calculationUwe Kleine-König1-8/+27
With an input clk rate bigger than 2000000000, scaler would have been zero which then would have resulted in a division by zero. Also the originally implemented algorithm divided by the result of a division. This nearly always looses precision. Consider a requested period of 1000000 ns. With an input clock frequency of 32786885 Hz the hardware was configured with an actual period of 983869.007 ns (PERIOD = 32258) while the hardware can provide 1000003.508 ns (PERIOD = 32787). And note if the input clock frequency was 32786886 Hz instead, the hardware was configured to 1016656.477 ns (PERIOD = 33333) while the optimal setting results in 1000003.477 ns (PERIOD = 32787). This patch implements proper range checking and only divides once for the calculation of period (and similar for duty_cycle). Signed-off-by: Uwe Kleine-König <[email protected]> Reviewed-by: Lino Sanfilippo <[email protected]> Tested-by: Lino Sanfilippo <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2020-12-17pwm: bcm2835: Support apply function for atomic configurationLino Sanfilippo1-45/+24
Use the newer .apply function of pwm_ops instead of .config, .enable, .disable and .set_polarity. This guarantees atomic changes of the pwm controller configuration. It also reduces the size of the driver. Since now period is a 64 bit value, add an extra check to reject periods that exceed the possible max value for the 32 bit register. This has been tested on a Raspberry PI 4. Signed-off-by: Lino Sanfilippo <[email protected]> Reviewed-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2020-12-17pwm: bcm2835: Convert to devm_platform_ioremap_resource()Yangtao Li1-3/+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]>
2020-09-24pwm: bcm2835: Simplify with dev_err_probe()Krzysztof Kozlowski1-7/+3
Common pattern of handling deferred probe can be simplified with dev_err_probe(). Less code and also it prints the error value. Signed-off-by: Krzysztof Kozlowski <[email protected]> Acked-by: Florian Fainelli <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2020-03-30pwm: bcm2835: Dynamically allocate baseFlorian Fainelli1-0/+1
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 <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Reviewed-by: Nicolas Saenz Julienne <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-09-21pwm: bcm2835: Suppress error message during deferred probeStefan Wahren1-2/+5
This suppresses error messages in case the PWM clock isn't ready yet. Signed-off-by: Stefan Wahren <[email protected]> Reviewed-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-09-21pwm: bcm2835: Fix period_ns range checkStefan Wahren1-4/+5
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 <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-09-21pwm: bcm2835: Suppress error message for invalid period_nsStefan Wahren1-4/+1
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 <[email protected]> Acked-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-06-26pwm: bcm2835: Improve precision of PWMSean Young1-3/+5
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 <[email protected]> Signed-off-by: Sean Young <[email protected]> Acked-by: Stefan Wahren <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2018-12-24pwm: bcm2835: Switch to SPDX identifierStefan Wahren1-4/+1
Adopt the SPDX license identifier headers to ease license compliance management. Cc: Bart Tanghe <[email protected]> Signed-off-by: Stefan Wahren <[email protected]> Reviewed-by: Eric Anholt <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-08-21pwm: bcm2835: Support for polarity setting via DTStefan Wahren1-0/+2
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 <[email protected]> Reviewed-by: Eric Anholt <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2015-12-16pwm: bcm2835: Fix email address specificationStefan Wahren1-1/+1
Signed-off-by: Stefan Wahren <[email protected]> Reviewed-by: Eric Anholt <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2015-12-16pwm: bcm2835: Prevent division by zeroStefan Wahren1-1/+9
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 <[email protected]> Reviewed-by: Eric Anholt <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2015-12-16pwm: bcm2835: Calculate scaler in ->config()Stefan Wahren1-5/+3
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 <[email protected]> Reviewed-by: Eric Anholt <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2014-11-17pwm: Add BCM2835 PWM driverBart Tanghe1-0/+205
Add PWM driver for Broadcom BCM2835 processor (Raspberry Pi) Signed-off-by: Bart Tanghe <[email protected]> Acked-by: Stephen Warren <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
Powered by cgit, Gruvboxed by Blaster4385.