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[u-boot] / 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 };