1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2016 Rockchip Electronics Co., Ltd
4 *
5 * Based on kernel drivers/regulator/pwm-regulator.c
6 * Copyright (C) 2014 - STMicroelectronics Inc.
7 * Author: Lee Jones <lee.jones@linaro.org>
8 */
9
10#include <common.h>
11#include <dm.h>
12#include <errno.h>
13#include <log.h>
14#include <pwm.h>
15#include <asm/global_data.h>
16#include <dm/device_compat.h>
17#include <power/regulator.h>
18
19DECLARE_GLOBAL_DATA_PTR;
20
21struct pwm_regulator_info {
22	/* pwm id corresponding to the PWM driver */
23	int pwm_id;
24	/* the period of one PWM cycle */
25	int period_ns;
26	/*
27	 * the polarity of one PWM
28	 * 0: normal polarity
29	 * 1: inverted polarity
30	 */
31	bool polarity;
32	struct udevice *pwm;
33	/* initialize voltage of regulator */
34	int init_voltage;
35	/* the maximum voltage of regulator */
36	int max_voltage;
37	/* the minimum voltage of regulator */
38	int min_voltage;
39	/* the current voltage of regulator */
40	int volt_uV;
41};
42
43static int pwm_regulator_enable(struct udevice *dev, bool enable)
44{
45	struct pwm_regulator_info *priv = dev_get_priv(dev);
46
47	return pwm_set_enable(priv->pwm, priv->pwm_id, enable);
48}
49
50static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV)
51{
52	struct pwm_regulator_info *priv = dev_get_priv(dev);
53	int min_uV = priv->min_voltage;
54	int max_uV = priv->max_voltage;
55	int diff = max_uV - min_uV;
56
57	return ((req_uV * 100) - (min_uV * 100)) / diff;
58}
59
60static int pwm_regulator_get_voltage(struct udevice *dev)
61{
62	struct pwm_regulator_info *priv = dev_get_priv(dev);
63
64	return priv->volt_uV;
65}
66
67static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)
68{
69	struct pwm_regulator_info *priv = dev_get_priv(dev);
70	int duty_cycle;
71	int ret = 0;
72
73	duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
74
75	ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity);
76	if (ret) {
77		dev_err(dev, "Failed to init PWM\n");
78		return ret;
79	}
80
81	ret = pwm_set_config(priv->pwm, priv->pwm_id,
82			priv->period_ns, (priv->period_ns / 100) * duty_cycle);
83	if (ret) {
84		dev_err(dev, "Failed to configure PWM\n");
85		return ret;
86	}
87
88	priv->volt_uV = uvolt;
89
90	return ret;
91}
92
93static int pwm_regulator_of_to_plat(struct udevice *dev)
94{
95	struct pwm_regulator_info *priv = dev_get_priv(dev);
96	struct ofnode_phandle_args args;
97	int ret;
98
99	ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0, &args);
100	if (ret) {
101		debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
102		return ret;
103	}
104
105	priv->period_ns = args.args[1];
106	priv->polarity = args.args[2];
107
108	priv->init_voltage = dev_read_u32_default(dev, "regulator-init-microvolt", -1);
109	if (priv->init_voltage < 0) {
110		printf("Cannot find regulator pwm init_voltage\n");
111		return -EINVAL;
112	}
113
114	ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm);
115	if (ret) {
116		debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
117		return ret;
118	}
119
120	return 0;
121}
122
123static int pwm_regulator_probe(struct udevice *dev)
124{
125	struct pwm_regulator_info *priv = dev_get_priv(dev);
126	struct dm_regulator_uclass_plat *uc_pdata;
127
128	uc_pdata = dev_get_uclass_plat(dev);
129
130	uc_pdata->type = REGULATOR_TYPE_BUCK;
131	uc_pdata->mode_count = 0;
132	priv->max_voltage = uc_pdata->max_uV;
133	priv->min_voltage = uc_pdata->min_uV;
134
135	if (priv->init_voltage)
136		pwm_regulator_set_voltage(dev, priv->init_voltage);
137
138	return 0;
139}
140
141static const struct dm_regulator_ops pwm_regulator_ops = {
142	.get_value  = pwm_regulator_get_voltage,
143	.set_value  = pwm_regulator_set_voltage,
144	.set_enable = pwm_regulator_enable,
145};
146
147static const struct udevice_id pwm_regulator_ids[] = {
148	{ .compatible = "pwm-regulator" },
149	{ }
150};
151
152U_BOOT_DRIVER(pwm_regulator) = {
153	.name = "pwm_regulator",
154	.id = UCLASS_REGULATOR,
155	.ops = &pwm_regulator_ops,
156	.probe = pwm_regulator_probe,
157	.of_match = pwm_regulator_ids,
158	.of_to_plat	= pwm_regulator_of_to_plat,
159	.priv_auto	= sizeof(struct pwm_regulator_info),
160};
161