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path: root/drivers/pwm/pwm-pca9685.c
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2015-11-06pwm-pca9685: enable ACPI device found on Galileo Gen2Andy Shevchenko1-4/+16
There is a chip connected to i2c bus on Intel Galileo Gen2 board. Enable it via ACPI ID INT3492. Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm-pca9685: Support changing the output frequencyClemens Gruber1-1/+64
Previously, period_ns and duty_ns were only used to determine the ratio of ON and OFF time, the default frequency of 200 Hz was never changed. The PCA9685 however is capable of changing the PWM output frequency, which is expected when changing the period. This patch configures the prescaler accordingly, using the formula and notes provided in the PCA9685 datasheet. Bounds checking for the minimum and maximum frequencies, last updated in revision v.4 of said datasheet, is also added. The prescaler is only touched if the period changed, because we have to put the chip into sleep mode to unlock the prescale register. If it is changed, the PWM output frequency changes for all outputs, because there is one prescaler per chip. This is documented in the PCA9685 datasheet and in the comments. If the duty cycle is not changed at the same time as the period, then we restart the PWM output using the duty cycle to period ratio from before the period change. When using LEDs for example, previously set brightness levels stay the same when the frequency changes. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm-pca9685: Fix several driver bugsClemens Gruber1-0/+24
Problems: - When duty_ns == period_ns, the full OFF bit was not cleared and the PWM output of the PCA9685 stayed off. - When duty_ns == period_ns and the catch-all channel was used, the ALL_LED_OFF_L register was not cleared. - The full ON bit was not cleared when setting the OFF time, therefore the exact OFF time was ignored when setting a duty_ns < period_ns Solution: Clear both OFF registers when setting full ON and clear the full ON bit when changing the OFF registers. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm: pca9685: Drop owner assignmentKrzysztof Kozlowski1-1/+0
i2c_driver does not need to set an owner because i2c_register_driver() will set it. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-11pwm: pca9685: Constify struct regmap_configKrzysztof Kozlowski1-1/+1
The regmap_config struct may be const because it is not modified by the driver and regmap_init() accepts pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-27pwm: pca9685: Fix wrong argument to set MODE1_SLEEP bitAxel Lin1-2/+3
Current code actually does not set MODE1_SLEEP bit because the new value for bitmask (0x1) is wrong. To set MODE1_SLEEP bit, we should pass MODE1_SLEEP as the new value for bitmask. Signed-off-by: Axel Lin <axel.lin@ingics.com> Reviewed-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-12pwm: Fill in missing .owner fieldsThierry Reding1-0/+1
Some drivers don't set the .owner fields of the struct device_driver or struct pwm_ops, which causes the module usage count to become wrong. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-12pwm: add pca9685 driverSteffen Trumtrar1-0/+298
Add pwm driver for the NXP pca9685 16 channel pwm-led controller. The driver is really barebones at this stage. E.g. the OE' pin and therefore the corresponding registers are not supported. The driver was tested on a HW where this pin is tied to GND. Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> [thierry.reding@gmail.com: style and whitespace cleanups] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>