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fefa713b18
The PWM device provided by Chrome OS EC doesn't really support anything other than setting a relative duty cycle. To support it as a backlight, this patch makes the PWM period optional in the device tree and pretends the valid brightness range is its period_ns. Also adds a sandbox test for a PWM channel that has a fixed period, checking that the resulting duty_cycle matches on a set_config() even if the requested period_ns can't be set. Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com> Reviewed-by: Simon Glass <sjg@chromium.org>
99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* header file for pwm driver.
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*
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* Copyright 2016 Google Inc.
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* Copyright (c) 2011 samsung electronics
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* Donghwa Lee <dh09.lee@samsung.com>
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*/
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#ifndef _pwm_h_
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#define _pwm_h_
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struct udevice;
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/* struct pwm_ops: Operations for the PWM uclass */
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struct pwm_ops {
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/**
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* set_config() - Set the PWM configuration
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*
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* Change both the PWM device's period and it's duty period if
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* possible. Otherwise, set an appropriate duty period that best
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* matches the given period_ns / duty_ns ratio for the device.
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*
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* @dev: PWM device to update
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* @channel: PWM channel to update
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* @period_ns: PWM period in nanoseconds
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* @duty_ns: PWM duty period in nanoseconds
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* @return 0 if OK, -ve on error
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*/
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int (*set_config)(struct udevice *dev, uint channel, uint period_ns,
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uint duty_ns);
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/**
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* set_enable() - Enable or disable the PWM
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*
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* @dev: PWM device to update
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* @channel: PWM channel to update
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* @enable: true to enable, false to disable
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* @return 0 if OK, -ve on error
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*/
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int (*set_enable)(struct udevice *dev, uint channel, bool enable);
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/**
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* set_invert() - Set the PWM invert
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*
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* @dev: PWM device to update
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* @channel: PWM channel to update
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* @polarity: true to invert, false to keep normal polarity
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* @return 0 if OK, -ve on error
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*/
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int (*set_invert)(struct udevice *dev, uint channel, bool polarity);
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};
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#define pwm_get_ops(dev) ((struct pwm_ops *)(dev)->driver->ops)
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/**
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* pwm_set_config() - Set the PWM configuration
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*
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* Change both the PWM device's period and it's duty period if
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* possible. Otherwise, set an appropriate duty period that best
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* matches the given period_ns / duty_ns ratio for the device.
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*
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* @dev: PWM device to update
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* @channel: PWM channel to update
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* @period_ns: PWM period in nanoseconds
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* @duty_ns: PWM duty period in nanoseconds
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* @return 0 if OK, -ve on error
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*/
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int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
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uint duty_ns);
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/**
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* pwm_set_enable() - Enable or disable the PWM
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*
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* @dev: PWM device to update
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* @channel: PWM channel to update
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* @enable: true to enable, false to disable
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* @return 0 if OK, -ve on error
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*/
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int pwm_set_enable(struct udevice *dev, uint channel, bool enable);
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/**
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* pwm_set_invert() - Set pwm default polarity
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*
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* @dev: PWM device to update
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* @channel: PWM channel to update
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* @polarity: true to invert, false to keep normal polarity
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* @return 0 if OK, -ve on error
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*/
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int pwm_set_invert(struct udevice *dev, uint channel, bool polarity);
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/* Legacy interface */
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#ifndef CONFIG_DM_PWM
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int pwm_init (int pwm_id, int div, int invert);
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int pwm_config (int pwm_id, int duty_ns, int period_ns);
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int pwm_enable (int pwm_id);
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void pwm_disable (int pwm_id);
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#endif
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#endif /* _pwm_h_ */
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