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/*
* Copyright (C) 2016 Rockchip Electronics Co., Ltd
*
* Based on kernel drivers/regulator/pwm-regulator.c
* Copyright (C) 2014 - STMicroelectronics Inc.
* Author: Lee Jones <lee.jones@linaro.org>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <pwm.h>
#include <power/regulator.h>
#include <libfdt.h>
#include <fdt_support.h>
#include <fdtdec.h>
DECLARE_GLOBAL_DATA_PTR;
struct pwm_regulator_info {
/* pwm id corresponding to the PWM driver */
int pwm_id;
/* the period of one PWM cycle */
int period_ns;
struct udevice *pwm;
/* initialize voltage of regulator */
unsigned int init_voltage;
/* the maximum voltage of regulator */
unsigned int max_voltage;
/* the minimum voltage of regulator */
unsigned int min_voltage;
/* the current voltage of regulator */
unsigned int volt_uV;
};
static int pwm_regulator_enable(struct udevice *dev, bool enable)
{
struct pwm_regulator_info *priv = dev_get_priv(dev);
return pwm_set_enable(priv->pwm, priv->pwm_id, enable);
}
static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV)
{
struct pwm_regulator_info *priv = dev_get_priv(dev);
int min_uV = priv->min_voltage;
int max_uV = priv->max_voltage;
int diff = max_uV - min_uV;
return 100 - (((req_uV * 100) - (min_uV * 100)) / diff);
}
static int pwm_regulator_get_voltage(struct udevice *dev)
{
struct pwm_regulator_info *priv = dev_get_priv(dev);
return priv->volt_uV;
}
static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)
{
struct pwm_regulator_info *priv = dev_get_priv(dev);
int duty_cycle;
int ret = 0;
duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
ret = pwm_set_config(priv->pwm, priv->pwm_id,
(priv->period_ns / 100) * duty_cycle, priv->period_ns);
if (ret) {
dev_err(dev, "Failed to configure PWM\n");
return ret;
}
ret = pwm_set_enable(priv->pwm, priv->pwm_id, true);
if (ret) {
dev_err(dev, "Failed to enable PWM\n");
return ret;
}
priv->volt_uV = uvolt;
return ret;
}
static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
{
struct pwm_regulator_info *priv = dev_get_priv(dev);
struct fdtdec_phandle_args args;
const void *blob = gd->fdt_blob;
int node = dev->of_offset;
int ret;
ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells",
0, 0, &args);
if (ret) {
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->init_voltage = fdtdec_get_int(blob, node,
"regulator-init-microvolt", -1);
if (priv->init_voltage < 0) {
printf("Cannot find regulator pwm init_voltage\n");
return -EINVAL;
}
ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
if (ret) {
debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
return ret;
}
return 0;
}
static int pwm_regulator_probe(struct udevice *dev)
{
struct pwm_regulator_info *priv = dev_get_priv(dev);
struct dm_regulator_uclass_platdata *uc_pdata;
uc_pdata = dev_get_uclass_platdata(dev);
uc_pdata->type = REGULATOR_TYPE_BUCK;
uc_pdata->mode_count = 0;
priv->max_voltage = uc_pdata->max_uV;
priv->min_voltage = uc_pdata->min_uV;
if (priv->init_voltage)
pwm_regulator_set_voltage(dev, priv->init_voltage);
pwm_regulator_enable(dev, 1);
return 0;
}
static const struct dm_regulator_ops pwm_regulator_ops = {
.get_value = pwm_regulator_get_voltage,
.set_value = pwm_regulator_set_voltage,
.set_enable = pwm_regulator_enable,
};
static const struct udevice_id pwm_regulator_ids[] = {
{ .compatible = "pwm-regulator" },
{ }
};
U_BOOT_DRIVER(pwm_regulator) = {
.name = "pwm_regulator",
.id = UCLASS_REGULATOR,
.ops = &pwm_regulator_ops,
.probe = pwm_regulator_probe,
.of_match = pwm_regulator_ids,
.ofdata_to_platdata = pwm_regulator_ofdata_to_platdata,
.priv_auto_alloc_size = sizeof(struct pwm_regulator_info),
};