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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 | struct udevice *pwm; | |
28 | /* initialize voltage of regulator */ | |
29 | unsigned int init_voltage; | |
30 | /* the maximum voltage of regulator */ | |
31 | unsigned int max_voltage; | |
32 | /* the minimum voltage of regulator */ | |
33 | unsigned int min_voltage; | |
34 | /* the current voltage of regulator */ | |
35 | unsigned int volt_uV; | |
36 | }; | |
37 | ||
38 | static int pwm_regulator_enable(struct udevice *dev, bool enable) | |
39 | { | |
40 | struct pwm_regulator_info *priv = dev_get_priv(dev); | |
41 | ||
42 | return pwm_set_enable(priv->pwm, priv->pwm_id, enable); | |
43 | } | |
44 | ||
45 | static int pwm_voltage_to_duty_cycle_percentage(struct udevice *dev, int req_uV) | |
46 | { | |
47 | struct pwm_regulator_info *priv = dev_get_priv(dev); | |
48 | int min_uV = priv->min_voltage; | |
49 | int max_uV = priv->max_voltage; | |
50 | int diff = max_uV - min_uV; | |
51 | ||
52 | return 100 - (((req_uV * 100) - (min_uV * 100)) / diff); | |
53 | } | |
54 | ||
55 | static int pwm_regulator_get_voltage(struct udevice *dev) | |
56 | { | |
57 | struct pwm_regulator_info *priv = dev_get_priv(dev); | |
58 | ||
59 | return priv->volt_uV; | |
60 | } | |
61 | ||
62 | static int pwm_regulator_set_voltage(struct udevice *dev, int uvolt) | |
63 | { | |
64 | struct pwm_regulator_info *priv = dev_get_priv(dev); | |
65 | int duty_cycle; | |
66 | int ret = 0; | |
67 | ||
68 | duty_cycle = pwm_voltage_to_duty_cycle_percentage(dev, uvolt); | |
69 | ||
70 | ret = pwm_set_config(priv->pwm, priv->pwm_id, | |
71 | (priv->period_ns / 100) * duty_cycle, priv->period_ns); | |
72 | if (ret) { | |
73 | dev_err(dev, "Failed to configure PWM\n"); | |
74 | return ret; | |
75 | } | |
76 | ||
77 | ret = pwm_set_enable(priv->pwm, priv->pwm_id, true); | |
78 | if (ret) { | |
79 | dev_err(dev, "Failed to enable PWM\n"); | |
80 | return ret; | |
81 | } | |
82 | priv->volt_uV = uvolt; | |
83 | return ret; | |
84 | } | |
85 | ||
86 | static int pwm_regulator_ofdata_to_platdata(struct udevice *dev) | |
87 | { | |
88 | struct pwm_regulator_info *priv = dev_get_priv(dev); | |
89 | struct fdtdec_phandle_args args; | |
90 | const void *blob = gd->fdt_blob; | |
91 | int node = dev->of_offset; | |
92 | int ret; | |
93 | ||
94 | ret = fdtdec_parse_phandle_with_args(blob, node, "pwms", "#pwm-cells", | |
95 | 0, 0, &args); | |
96 | if (ret) { | |
97 | debug("%s: Cannot get PWM phandle: ret=%d\n", __func__, ret); | |
98 | return ret; | |
99 | } | |
100 | /* TODO: pwm_id here from device tree if needed */ | |
101 | ||
102 | priv->period_ns = args.args[1]; | |
103 | ||
104 | priv->init_voltage = fdtdec_get_int(blob, node, | |
105 | "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_of_offset(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 | ||
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 | pwm_regulator_enable(dev, 1); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static const struct dm_regulator_ops pwm_regulator_ops = { | |
141 | .get_value = pwm_regulator_get_voltage, | |
142 | .set_value = pwm_regulator_set_voltage, | |
143 | .set_enable = pwm_regulator_enable, | |
144 | }; | |
145 | ||
146 | static const struct udevice_id pwm_regulator_ids[] = { | |
147 | { .compatible = "pwm-regulator" }, | |
148 | { } | |
149 | }; | |
150 | ||
151 | U_BOOT_DRIVER(pwm_regulator) = { | |
152 | .name = "pwm_regulator", | |
153 | .id = UCLASS_REGULATOR, | |
154 | .ops = &pwm_regulator_ops, | |
155 | .probe = pwm_regulator_probe, | |
156 | .of_match = pwm_regulator_ids, | |
157 | .ofdata_to_platdata = pwm_regulator_ofdata_to_platdata, | |
158 | .priv_auto_alloc_size = sizeof(struct pwm_regulator_info), | |
159 | }; |