mirror of
https://github.com/brain-hackers/u-boot-brain
synced 2024-08-20 08:58:52 +09:00
![Kever Yang](/assets/img/avatar_default.png)
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>
47 lines
891 B
C
47 lines
891 B
C
/*
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* Copyright (c) 2016 Google, Inc
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* Written by Simon Glass <sjg@chromium.org>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <dm.h>
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#include <pwm.h>
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int pwm_set_invert(struct udevice *dev, uint channel, bool polarity)
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{
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struct pwm_ops *ops = pwm_get_ops(dev);
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if (!ops->set_invert)
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return -ENOSYS;
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return ops->set_invert(dev, channel, polarity);
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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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struct pwm_ops *ops = pwm_get_ops(dev);
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if (!ops->set_config)
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return -ENOSYS;
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return ops->set_config(dev, channel, period_ns, duty_ns);
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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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struct pwm_ops *ops = pwm_get_ops(dev);
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if (!ops->set_enable)
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return -ENOSYS;
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return ops->set_enable(dev, channel, enable);
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}
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UCLASS_DRIVER(pwm) = {
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.id = UCLASS_PWM,
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.name = "pwm",
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};
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