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