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[people/ms/u-boot.git] / drivers / power / regulator / pwm_regulator.c
1 /*
2 * Copyright (C) 2016 Rockchip Electronics Co., Ltd
3 *
4 * Based on kernel drivers/regulator/pwm-regulator.c
5 * Copyright (C) 2014 - STMicroelectronics Inc.
6 * Author: Lee Jones <lee.jones@linaro.org>
7 *
8 * SPDX-License-Identifier: GPL-2.0+
9 */
10
11 #include <common.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <pwm.h>
15 #include <power/regulator.h>
16 #include <libfdt.h>
17 #include <fdt_support.h>
18 #include <fdtdec.h>
19
20 DECLARE_GLOBAL_DATA_PTR;
21
22 struct pwm_regulator_info {
23 /* pwm id corresponding to the PWM driver */
24 int pwm_id;
25 /* the period of one PWM cycle */
26 int period_ns;
27 /*
28 * the polarity of one PWM
29 * 0: normal polarity
30 * 1: inverted polarity
31 */
32 bool polarity;
33 struct udevice *pwm;
34 /* initialize voltage of regulator */
35 unsigned int init_voltage;
36 /* the maximum voltage of regulator */
37 unsigned int max_voltage;
38 /* the minimum voltage of regulator */
39 unsigned int min_voltage;
40 /* the current voltage of regulator */
41 unsigned int volt_uV;
42 };
43
44 static int pwm_regulator_enable(struct udevice *dev, bool enable)
45 {
46 struct pwm_regulator_info *priv = dev_get_priv(dev);
47
48 return pwm_set_enable(priv->pwm, priv->pwm_id, enable);
49 }
50
51 static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV)
52 {
53 struct pwm_regulator_info *priv = dev_get_priv(dev);
54 int min_uV = priv->min_voltage;
55 int max_uV = priv->max_voltage;
56 int diff = max_uV - min_uV;
57
58 return ((req_uV * 100) - (min_uV * 100)) / diff;
59 }
60
61 static int pwm_regulator_get_voltage(struct udevice *dev)
62 {
63 struct pwm_regulator_info *priv = dev_get_priv(dev);
64
65 return priv->volt_uV;
66 }
67
68 static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt)
69 {
70 struct pwm_regulator_info *priv = dev_get_priv(dev);
71 int duty_cycle;
72 int ret = 0;
73
74 duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt);
75
76 ret = pwm_set_invert(priv->pwm, priv->pwm_id, priv->polarity);
77 if (ret) {
78 dev_err(dev, "Failed to init PWM\n");
79 return ret;
80 }
81
82 ret = pwm_set_config(priv->pwm, priv->pwm_id,
83 (priv->period_ns / 100) * duty_cycle, priv->period_ns);
84 if (ret) {
85 dev_err(dev, "Failed to configure PWM\n");
86 return ret;
87 }
88
89 ret = pwm_set_enable(priv->pwm, priv->pwm_id, true);
90 if (ret) {
91 dev_err(dev, "Failed to enable PWM\n");
92 return ret;
93 }
94 priv->volt_uV = uvolt;
95 return ret;
96 }
97
98 static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
99 {
100 struct pwm_regulator_info *priv = dev_get_priv(dev);
101 struct fdtdec_phandle_args args;
102 const void *blob = gd->fdt_blob;
103 int node = dev_of_offset(dev);
104 int ret;
105
106 ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells",
107 0, 0, &args);
108 if (ret) {
109 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
110 return ret;
111 }
112
113 priv->period_ns = args.args[1];
114 priv->polarity = args.args[2];
115
116 priv->init_voltage = fdtdec_get_int(blob, node,
117 "regulator-init-microvolt", -1);
118 if (priv->init_voltage < 0) {
119 printf("Cannot find regulator pwm init_voltage\n");
120 return -EINVAL;
121 }
122
123 ret = uclass_get_device_by_of_offset(UCLASS_PWM, args.node, &priv->pwm);
124 if (ret) {
125 debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
126 return ret;
127 }
128
129 return 0;
130 }
131
132 static int pwm_regulator_probe(struct udevice *dev)
133 {
134 struct pwm_regulator_info *priv = dev_get_priv(dev);
135 struct dm_regulator_uclass_platdata *uc_pdata;
136
137 uc_pdata = dev_get_uclass_platdata(dev);
138
139 uc_pdata->type = REGULATOR_TYPE_BUCK;
140 uc_pdata->mode_count = 0;
141 priv->max_voltage = uc_pdata->max_uV;
142 priv->min_voltage = uc_pdata->min_uV;
143
144 if (priv->init_voltage)
145 pwm_regulator_set_voltage(dev, priv->init_voltage);
146
147 pwm_regulator_enable(dev, 1);
148
149 return 0;
150 }
151
152 static const struct dm_regulator_ops pwm_regulator_ops = {
153 .get_value = pwm_regulator_get_voltage,
154 .set_value = pwm_regulator_set_voltage,
155 .set_enable = pwm_regulator_enable,
156 };
157
158 static const struct udevice_id pwm_regulator_ids[] = {
159 { .compatible = "pwm-regulator" },
160 { }
161 };
162
163 U_BOOT_DRIVER(pwm_regulator) = {
164 .name = "pwm_regulator",
165 .id = UCLASS_REGULATOR,
166 .ops = &pwm_regulator_ops,
167 .probe = pwm_regulator_probe,
168 .of_match = pwm_regulator_ids,
169 .ofdata_to_platdata = pwm_regulator_ofdata_to_platdata,
170 .priv_auto_alloc_size = sizeof(struct pwm_regulator_info),
171 };