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power: regulator: pwm: support pwm polarity setting

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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>
This commit is contained in:
Kever Yang 2017-04-24 10:27:49 +08:00 committed by Simon Glass
parent a66726838e
commit 0b60111aa6
3 changed files with 43 additions and 2 deletions
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16
drivers/power/regulator/pwm_regulator.c
View file

@ -24,6 +24,12 @@ struct pwm_regulator_info {
int pwm_id;
/* the period of one PWM cycle */
int period_ns;
/*
* the polarity of one PWM
* 0: normal polarity
* 1: inverted polarity
*/
bool polarity;
struct udevice *pwm;
/* initialize voltage of regulator */
unsigned int init_voltage;
@ -49,7 +55,7 @@ static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV)
int max_uV = priv->max_voltage;
int diff = max_uV - min_uV;
return 100 - (((req_uV * 100) - (min_uV * 100)) / diff);
return ((req_uV * 100) - (min_uV * 100)) / diff;
}
static int pwm_regulator_get_voltage(struct udevice *dev)
@ -67,6 +73,12 @@ static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)
duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity);
if (ret) {
dev_err(dev, "Failed to init PWM\n");
return ret;
}
ret = pwm_set_config(priv->pwm, priv->pwm_id,
(priv->period_ns / 100) * duty_cycle, priv->period_ns);
if (ret) {
@ -97,9 +109,9 @@ static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
return ret;
}
/* TODO: pwm_id here from device tree if needed */
priv->period_ns = args.args[1];
priv->polarity = args.args[2];
priv->init_voltage = fdtdec_get_int(blob, node,
"regulator-init-microvolt", -1);

10
drivers/pwm/pwm-uclass.c
View file

@ -9,6 +9,16 @@
#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)
{

19
include/pwm.h
View file

@ -34,6 +34,15 @@ struct pwm_ops {
* @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)
@ -60,6 +69,16 @@ int pwm_set_config(struct udevice *dev, uint channel, uint period_ns,
*/
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);