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4a5d3013 LJ |
1 | /* |
2 | * Regulator driver for ST's PWM Regulators | |
3 | * | |
4 | * Copyright (C) 2014 - STMicroelectronics Inc. | |
5 | * | |
6 | * Author: Lee Jones <lee.jones@linaro.org> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/regulator/driver.h> | |
17 | #include <linux/regulator/machine.h> | |
18 | #include <linux/regulator/of_regulator.h> | |
19 | #include <linux/of.h> | |
20 | #include <linux/of_device.h> | |
21 | #include <linux/pwm.h> | |
22 | ||
23 | #define ST_PWM_REG_PERIOD 8448 | |
24 | ||
25 | struct st_pwm_regulator_pdata { | |
26 | const struct regulator_desc *desc; | |
27 | struct st_pwm_voltages *duty_cycle_table; | |
28 | }; | |
29 | ||
30 | struct st_pwm_regulator_data { | |
31 | const struct st_pwm_regulator_pdata *pdata; | |
32 | struct pwm_device *pwm; | |
33 | bool enabled; | |
34 | int state; | |
35 | }; | |
36 | ||
37 | struct st_pwm_voltages { | |
38 | unsigned int uV; | |
39 | unsigned int dutycycle; | |
40 | }; | |
41 | ||
d8eb6fa7 | 42 | static int st_pwm_regulator_get_voltage_sel(struct regulator_dev *dev) |
4a5d3013 LJ |
43 | { |
44 | struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
45 | ||
d8eb6fa7 | 46 | return drvdata->state; |
4a5d3013 LJ |
47 | } |
48 | ||
49 | static int st_pwm_regulator_set_voltage_sel(struct regulator_dev *dev, | |
50 | unsigned selector) | |
51 | { | |
52 | struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
53 | int dutycycle; | |
54 | int ret; | |
55 | ||
4a5d3013 LJ |
56 | dutycycle = (ST_PWM_REG_PERIOD / 100) * |
57 | drvdata->pdata->duty_cycle_table[selector].dutycycle; | |
58 | ||
59 | ret = pwm_config(drvdata->pwm, dutycycle, ST_PWM_REG_PERIOD); | |
60 | if (ret) { | |
61 | dev_err(&dev->dev, "Failed to configure PWM\n"); | |
62 | return ret; | |
63 | } | |
64 | ||
65 | drvdata->state = selector; | |
66 | ||
67 | if (!drvdata->enabled) { | |
68 | ret = pwm_enable(drvdata->pwm); | |
69 | if (ret) { | |
70 | dev_err(&dev->dev, "Failed to enable PWM\n"); | |
71 | return ret; | |
72 | } | |
73 | drvdata->enabled = true; | |
74 | } | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | static int st_pwm_regulator_list_voltage(struct regulator_dev *dev, | |
80 | unsigned selector) | |
81 | { | |
82 | struct st_pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
83 | ||
84 | if (selector >= dev->desc->n_voltages) | |
85 | return -EINVAL; | |
86 | ||
87 | return drvdata->pdata->duty_cycle_table[selector].uV; | |
88 | } | |
89 | ||
90 | static struct regulator_ops st_pwm_regulator_voltage_ops = { | |
91 | .set_voltage_sel = st_pwm_regulator_set_voltage_sel, | |
d8eb6fa7 | 92 | .get_voltage_sel = st_pwm_regulator_get_voltage_sel, |
4a5d3013 LJ |
93 | .list_voltage = st_pwm_regulator_list_voltage, |
94 | .map_voltage = regulator_map_voltage_iterate, | |
95 | }; | |
96 | ||
97 | static struct st_pwm_voltages b2105_duty_cycle_table[] = { | |
98 | { .uV = 1114000, .dutycycle = 0, }, | |
99 | { .uV = 1095000, .dutycycle = 10, }, | |
100 | { .uV = 1076000, .dutycycle = 20, }, | |
101 | { .uV = 1056000, .dutycycle = 30, }, | |
102 | { .uV = 1036000, .dutycycle = 40, }, | |
103 | { .uV = 1016000, .dutycycle = 50, }, | |
104 | /* WARNING: Values above 50% duty-cycle cause boot failures. */ | |
105 | }; | |
106 | ||
107 | static const struct regulator_desc b2105_desc = { | |
108 | .name = "b2105-pwm-regulator", | |
109 | .ops = &st_pwm_regulator_voltage_ops, | |
110 | .type = REGULATOR_VOLTAGE, | |
111 | .owner = THIS_MODULE, | |
112 | .n_voltages = ARRAY_SIZE(b2105_duty_cycle_table), | |
113 | .supply_name = "pwm", | |
114 | }; | |
115 | ||
116 | static const struct st_pwm_regulator_pdata b2105_info = { | |
117 | .desc = &b2105_desc, | |
118 | .duty_cycle_table = b2105_duty_cycle_table, | |
119 | }; | |
120 | ||
121 | static struct of_device_id st_pwm_of_match[] = { | |
122 | { .compatible = "st,b2105-pwm-regulator", .data = &b2105_info, }, | |
123 | { }, | |
124 | }; | |
125 | MODULE_DEVICE_TABLE(of, st_pwm_of_match); | |
126 | ||
127 | static int st_pwm_regulator_probe(struct platform_device *pdev) | |
128 | { | |
129 | struct st_pwm_regulator_data *drvdata; | |
130 | struct regulator_dev *regulator; | |
131 | struct regulator_config config = { }; | |
132 | struct device_node *np = pdev->dev.of_node; | |
133 | const struct of_device_id *of_match; | |
134 | ||
135 | if (!np) { | |
136 | dev_err(&pdev->dev, "Device Tree node missing\n"); | |
137 | return -EINVAL; | |
138 | } | |
139 | ||
140 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); | |
141 | if (!drvdata) | |
142 | return -ENOMEM; | |
143 | ||
144 | of_match = of_match_device(st_pwm_of_match, &pdev->dev); | |
145 | if (!of_match) { | |
146 | dev_err(&pdev->dev, "failed to match of device\n"); | |
147 | return -ENODEV; | |
148 | } | |
149 | drvdata->pdata = of_match->data; | |
150 | ||
151 | config.init_data = of_get_regulator_init_data(&pdev->dev, np); | |
152 | if (!config.init_data) | |
153 | return -ENOMEM; | |
154 | ||
155 | config.of_node = np; | |
156 | config.dev = &pdev->dev; | |
157 | config.driver_data = drvdata; | |
158 | ||
159 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); | |
160 | if (IS_ERR(drvdata->pwm)) { | |
161 | dev_err(&pdev->dev, "Failed to get PWM\n"); | |
162 | return PTR_ERR(drvdata->pwm); | |
163 | } | |
164 | ||
165 | regulator = devm_regulator_register(&pdev->dev, | |
166 | drvdata->pdata->desc, &config); | |
167 | if (IS_ERR(regulator)) { | |
168 | dev_err(&pdev->dev, "Failed to register regulator %s\n", | |
169 | drvdata->pdata->desc->name); | |
170 | return PTR_ERR(regulator); | |
171 | } | |
172 | ||
173 | return 0; | |
174 | } | |
175 | ||
176 | static struct platform_driver st_pwm_regulator_driver = { | |
177 | .driver = { | |
178 | .name = "st-pwm-regulator", | |
179 | .owner = THIS_MODULE, | |
180 | .of_match_table = of_match_ptr(st_pwm_of_match), | |
181 | }, | |
182 | .probe = st_pwm_regulator_probe, | |
183 | }; | |
184 | ||
185 | module_platform_driver(st_pwm_regulator_driver); | |
186 | ||
187 | MODULE_LICENSE("GPL"); | |
188 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
189 | MODULE_DESCRIPTION("ST PWM Regulator Driver"); | |
190 | MODULE_ALIAS("platform:st_pwm-regulator"); |