u-boot/drivers/pwm/pwm-uclass.c
Kever Yang 0b60111aa6 power: regulator: pwm: support pwm polarity setting
The latest kernel PWM drivers enable the polarity settings. When system
run from U-Boot to kerenl, if there are differences in polarity set or
duty cycle, the PMW will re-init:
  close -> set polarity and duty cycle -> enable the PWM.
The power supply controled by pwm regulator may have voltage shaking,
which lead to the system not stable.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
2017-05-10 13:37:21 -06:00

46 lines
891 B
C

/*
* Copyright (c) 2016 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <pwm.h>
int pwm_set_invert(struct udevice *dev, uint channel, bool polarity)
{
struct pwm_ops *ops = pwm_get_ops(dev);
if (!ops->set_invert)
return -ENOSYS;
return ops->set_invert(dev, channel, polarity);
}
int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
uint duty_ns)
{
struct pwm_ops *ops = pwm_get_ops(dev);
if (!ops->set_config)
return -ENOSYS;
return ops->set_config(dev, channel, period_ns, duty_ns);
}
int pwm_set_enable(struct udevice *dev, uint channel, bool enable)
{
struct pwm_ops *ops = pwm_get_ops(dev);
if (!ops->set_enable)
return -ENOSYS;
return ops->set_enable(dev, channel, enable);
}
UCLASS_DRIVER(pwm) = {
.id = UCLASS_PWM,
.name = "pwm",
};