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
19 DECLARE_GLOBAL_DATA_PTR;
20
21 struct 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
pwm_regulator_enable(struct udevice * dev,bool enable)43 static 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
pwm_voltage_to_duty_cycle_percentage(struct udevice * dev,int req_uV)50 static 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
pwm_regulator_get_voltage(struct udevice * dev)60 static 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
pwm_regulator_set_voltage(struct udevice * dev,int uvolt)67 static 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
pwm_regulator_of_to_plat(struct udevice * dev)93 static 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
pwm_regulator_probe(struct udevice * dev)123 static 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
141 static 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
147 static const struct udevice_id pwm_regulator_ids[] = {
148 { .compatible = "pwm-regulator" },
149 { }
150 };
151
152 U_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