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 <linux/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 int init_voltage;
36 /* the maximum voltage of regulator */
37 int max_voltage;
38 /* the minimum voltage of regulator */
39 int min_voltage;
40 /* the current voltage of regulator */
41 int volt_uV;
42 };
43
pwm_regulator_enable(struct udevice * dev,bool enable)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
pwm_voltage_to_duty_cycle_percentage(struct udevice * dev,int req_uV)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
pwm_regulator_get_voltage(struct udevice * dev)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
pwm_regulator_set_voltage(struct udevice * dev,int uvolt)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, (priv->period_ns / 100) * duty_cycle);
84 if (ret) {
85 dev_err(dev, "Failed to configure PWM\n");
86 return ret;
87 }
88
89 priv->volt_uV = uvolt;
90
91 return ret;
92 }
93
pwm_regulator_ofdata_to_platdata(struct udevice * dev)94 static int pwm_regulator_ofdata_to_platdata(struct udevice *dev)
95 {
96 struct pwm_regulator_info *priv = dev_get_priv(dev);
97 struct ofnode_phandle_args args;
98 int ret;
99
100 ret = dev_read_phandle_with_args(dev, "pwms", "#pwm-cells", 0, 0, &args);
101 if (ret) {
102 debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret);
103 return ret;
104 }
105
106 priv->period_ns = args.args[1];
107 priv->polarity = args.args[2];
108
109 priv->init_voltage = dev_read_u32_default(dev, "regulator-init-microvolt", -1);
110 if (priv->init_voltage < 0) {
111 debug("Cannot find 'regulator-init-microvolt'\n");
112
113 /*
114 * 1. Compatible legacy pwm-regulator driver on rkdevelop;
115 * 2. Give pwm-regulator default init voltage 1.1v;
116 */
117 priv->init_voltage = dev_read_u32_default(dev, "rockchip,pwm_voltage",
118 1100000);
119 }
120
121 ret = uclass_get_device_by_ofnode(UCLASS_PWM, args.node, &priv->pwm);
122 if (ret) {
123 debug("%s: Cannot get PWM: ret=%d\n", __func__, ret);
124 return ret;
125 }
126
127 return 0;
128 }
129
pwm_regulator_probe(struct udevice * dev)130 static int pwm_regulator_probe(struct udevice *dev)
131 {
132 struct pwm_regulator_info *priv = dev_get_priv(dev);
133 struct dm_regulator_uclass_platdata *uc_pdata;
134
135 uc_pdata = dev_get_uclass_platdata(dev);
136
137 uc_pdata->type = REGULATOR_TYPE_BUCK;
138 uc_pdata->mode_count = 0;
139 priv->max_voltage = uc_pdata->max_uV;
140 priv->min_voltage = uc_pdata->min_uV;
141
142 if (priv->init_voltage > 0) {
143 debug("pwm-regulator(%s): init %d uV\n",
144 dev->name, priv->init_voltage);
145 pwm_regulator_set_voltage(dev, priv->init_voltage);
146 }
147
148 return 0;
149 }
150
151 static const struct dm_regulator_ops pwm_regulator_ops = {
152 .get_value = pwm_regulator_get_voltage,
153 .set_value = pwm_regulator_set_voltage,
154 .set_enable = pwm_regulator_enable,
155 };
156
157 static const struct udevice_id pwm_regulator_ids[] = {
158 { .compatible = "pwm-regulator" },
159 { }
160 };
161
162 U_BOOT_DRIVER(pwm_regulator) = {
163 .name = "pwm_regulator",
164 .id = UCLASS_REGULATOR,
165 .ops = &pwm_regulator_ops,
166 .probe = pwm_regulator_probe,
167 .of_match = pwm_regulator_ids,
168 .ofdata_to_platdata = pwm_regulator_ofdata_to_platdata,
169 .priv_auto_alloc_size = sizeof(struct pwm_regulator_info),
170 };
171