mirror of
https://github.com/AsahiLinux/u-boot
synced 2024-12-29 22:43:10 +00:00
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+ */
|
|
/*
|
|
* header file for pwm driver.
|
|
*
|
|
* Copyright 2016 Google Inc.
|
|
* Copyright (c) 2011 samsung electronics
|
|
* Donghwa Lee <dh09.lee@samsung.com>
|
|
*/
|
|
|
|
#ifndef _pwm_h_
|
|
#define _pwm_h_
|
|
|
|
struct udevice;
|
|
|
|
/* struct pwm_ops: Operations for the PWM uclass */
|
|
struct pwm_ops {
|
|
/**
|
|
* set_config() - Set the PWM configuration
|
|
*
|
|
* Change both the PWM device's period and it's duty period if
|
|
* possible. Otherwise, set an appropriate duty period that best
|
|
* matches the given period_ns / duty_ns ratio for the device.
|
|
*
|
|
* @dev: PWM device to update
|
|
* @channel: PWM channel to update
|
|
* @period_ns: PWM period in nanoseconds
|
|
* @duty_ns: PWM duty period in nanoseconds
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int (*set_config)(struct udevice *dev, uint channel, uint period_ns,
|
|
uint duty_ns);
|
|
|
|
/**
|
|
* set_enable() - Enable or disable the PWM
|
|
*
|
|
* @dev: PWM device to update
|
|
* @channel: PWM channel to update
|
|
* @enable: true to enable, false to disable
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int (*set_enable)(struct udevice *dev, uint channel, bool enable);
|
|
/**
|
|
* set_invert() - Set the PWM invert
|
|
*
|
|
* @dev: PWM device to update
|
|
* @channel: PWM channel to update
|
|
* @polarity: true to invert, false to keep normal polarity
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int (*set_invert)(struct udevice *dev, uint channel, bool polarity);
|
|
};
|
|
|
|
#define pwm_get_ops(dev) ((struct pwm_ops *)(dev)->driver->ops)
|
|
|
|
/**
|
|
* pwm_set_config() - Set the PWM configuration
|
|
*
|
|
* Change both the PWM device's period and it's duty period if
|
|
* possible. Otherwise, set an appropriate duty period that best
|
|
* matches the given period_ns / duty_ns ratio for the device.
|
|
*
|
|
* @dev: PWM device to update
|
|
* @channel: PWM channel to update
|
|
* @period_ns: PWM period in nanoseconds
|
|
* @duty_ns: PWM duty period in nanoseconds
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
|
|
uint duty_ns);
|
|
|
|
/**
|
|
* pwm_set_enable() - Enable or disable the PWM
|
|
*
|
|
* @dev: PWM device to update
|
|
* @channel: PWM channel to update
|
|
* @enable: true to enable, false to disable
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int pwm_set_enable(struct udevice *dev, uint channel, bool enable);
|
|
|
|
/**
|
|
* pwm_set_invert() - Set pwm default polarity
|
|
*
|
|
* @dev: PWM device to update
|
|
* @channel: PWM channel to update
|
|
* @polarity: true to invert, false to keep normal polarity
|
|
* @return 0 if OK, -ve on error
|
|
*/
|
|
int pwm_set_invert(struct udevice *dev, uint channel, bool polarity);
|
|
|
|
/* Legacy interface */
|
|
#ifndef CONFIG_DM_PWM
|
|
int pwm_init (int pwm_id, int div, int invert);
|
|
int pwm_config (int pwm_id, int duty_ns, int period_ns);
|
|
int pwm_enable (int pwm_id);
|
|
void pwm_disable (int pwm_id);
|
|
#endif
|
|
|
|
#endif /* _pwm_h_ */
|