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aa66cc66 CZ |
1 | /* |
2 | * Regulator driver for 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 | struct pwm_regulator_data { | |
24 | struct regulator_desc desc; | |
25 | struct pwm_voltages *duty_cycle_table; | |
26 | struct pwm_device *pwm; | |
27 | bool enabled; | |
28 | int state; | |
29 | }; | |
30 | ||
31 | struct pwm_voltages { | |
32 | unsigned int uV; | |
33 | unsigned int dutycycle; | |
34 | }; | |
35 | ||
36 | static int pwm_regulator_get_voltage_sel(struct regulator_dev *dev) | |
37 | { | |
38 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
39 | ||
40 | return drvdata->state; | |
41 | } | |
42 | ||
43 | static int pwm_regulator_set_voltage_sel(struct regulator_dev *dev, | |
44 | unsigned selector) | |
45 | { | |
46 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
47 | unsigned int pwm_reg_period; | |
48 | int dutycycle; | |
49 | int ret; | |
50 | ||
51 | pwm_reg_period = pwm_get_period(drvdata->pwm); | |
52 | ||
53 | dutycycle = (pwm_reg_period * | |
54 | drvdata->duty_cycle_table[selector].dutycycle) / 100; | |
55 | ||
56 | ret = pwm_config(drvdata->pwm, dutycycle, pwm_reg_period); | |
57 | if (ret) { | |
58 | dev_err(&dev->dev, "Failed to configure PWM\n"); | |
59 | return ret; | |
60 | } | |
61 | ||
62 | drvdata->state = selector; | |
63 | ||
64 | if (!drvdata->enabled) { | |
65 | ret = pwm_enable(drvdata->pwm); | |
66 | if (ret) { | |
67 | dev_err(&dev->dev, "Failed to enable PWM\n"); | |
68 | return ret; | |
69 | } | |
70 | drvdata->enabled = true; | |
71 | } | |
72 | ||
73 | return 0; | |
74 | } | |
75 | ||
76 | static int pwm_regulator_list_voltage(struct regulator_dev *dev, | |
77 | unsigned selector) | |
78 | { | |
79 | struct pwm_regulator_data *drvdata = rdev_get_drvdata(dev); | |
80 | ||
81 | if (selector >= drvdata->desc.n_voltages) | |
82 | return -EINVAL; | |
83 | ||
84 | return drvdata->duty_cycle_table[selector].uV; | |
85 | } | |
86 | ||
87 | static struct regulator_ops pwm_regulator_voltage_ops = { | |
88 | .set_voltage_sel = pwm_regulator_set_voltage_sel, | |
89 | .get_voltage_sel = pwm_regulator_get_voltage_sel, | |
90 | .list_voltage = pwm_regulator_list_voltage, | |
91 | .map_voltage = regulator_map_voltage_iterate, | |
92 | }; | |
93 | ||
94 | static const struct regulator_desc pwm_regulator_desc = { | |
95 | .name = "pwm-regulator", | |
96 | .ops = &pwm_regulator_voltage_ops, | |
97 | .type = REGULATOR_VOLTAGE, | |
98 | .owner = THIS_MODULE, | |
99 | .supply_name = "pwm", | |
100 | }; | |
101 | ||
102 | static int pwm_regulator_probe(struct platform_device *pdev) | |
103 | { | |
104 | struct pwm_regulator_data *drvdata; | |
105 | struct property *prop; | |
106 | struct regulator_dev *regulator; | |
107 | struct regulator_config config = { }; | |
108 | struct device_node *np = pdev->dev.of_node; | |
109 | int length, ret; | |
110 | ||
111 | if (!np) { | |
112 | dev_err(&pdev->dev, "Device Tree node missing\n"); | |
113 | return -EINVAL; | |
114 | } | |
115 | ||
116 | drvdata = devm_kzalloc(&pdev->dev, sizeof(*drvdata), GFP_KERNEL); | |
117 | if (!drvdata) | |
118 | return -ENOMEM; | |
119 | ||
120 | memcpy(&drvdata->desc, &pwm_regulator_desc, sizeof(pwm_regulator_desc)); | |
121 | ||
122 | /* determine the number of voltage-table */ | |
123 | prop = of_find_property(np, "voltage-table", &length); | |
124 | if (!prop) { | |
125 | dev_err(&pdev->dev, "No voltage-table\n"); | |
126 | return -EINVAL; | |
127 | } | |
128 | ||
129 | if ((length < sizeof(*drvdata->duty_cycle_table)) || | |
130 | (length % sizeof(*drvdata->duty_cycle_table))) { | |
131 | dev_err(&pdev->dev, "voltage-table length(%d) is invalid\n", | |
132 | length); | |
133 | return -EINVAL; | |
134 | } | |
135 | ||
136 | drvdata->desc.n_voltages = length / sizeof(*drvdata->duty_cycle_table); | |
137 | ||
138 | drvdata->duty_cycle_table = devm_kzalloc(&pdev->dev, | |
139 | length, GFP_KERNEL); | |
140 | if (!drvdata->duty_cycle_table) | |
141 | return -ENOMEM; | |
142 | ||
143 | /* read voltage table from DT property */ | |
144 | ret = of_property_read_u32_array(np, "voltage-table", | |
145 | (u32 *)drvdata->duty_cycle_table, | |
146 | length / sizeof(u32)); | |
147 | if (ret < 0) { | |
148 | dev_err(&pdev->dev, "read voltage-table failed\n"); | |
149 | return ret; | |
150 | } | |
151 | ||
072e78b1 JMC |
152 | config.init_data = of_get_regulator_init_data(&pdev->dev, np, |
153 | &drvdata->desc); | |
aa66cc66 CZ |
154 | if (!config.init_data) |
155 | return -ENOMEM; | |
156 | ||
157 | config.of_node = np; | |
158 | config.dev = &pdev->dev; | |
159 | config.driver_data = drvdata; | |
160 | ||
161 | drvdata->pwm = devm_pwm_get(&pdev->dev, NULL); | |
162 | if (IS_ERR(drvdata->pwm)) { | |
163 | dev_err(&pdev->dev, "Failed to get PWM\n"); | |
164 | return PTR_ERR(drvdata->pwm); | |
165 | } | |
166 | ||
167 | regulator = devm_regulator_register(&pdev->dev, | |
168 | &drvdata->desc, &config); | |
169 | if (IS_ERR(regulator)) { | |
170 | dev_err(&pdev->dev, "Failed to register regulator %s\n", | |
171 | drvdata->desc.name); | |
172 | return PTR_ERR(regulator); | |
173 | } | |
174 | ||
175 | return 0; | |
176 | } | |
177 | ||
178 | static const struct of_device_id pwm_of_match[] = { | |
179 | { .compatible = "pwm-regulator" }, | |
180 | { }, | |
181 | }; | |
182 | MODULE_DEVICE_TABLE(of, pwm_of_match); | |
183 | ||
184 | static struct platform_driver pwm_regulator_driver = { | |
185 | .driver = { | |
186 | .name = "pwm-regulator", | |
aa66cc66 CZ |
187 | .of_match_table = of_match_ptr(pwm_of_match), |
188 | }, | |
189 | .probe = pwm_regulator_probe, | |
190 | }; | |
191 | ||
192 | module_platform_driver(pwm_regulator_driver); | |
193 | ||
194 | MODULE_LICENSE("GPL"); | |
195 | MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org>"); | |
196 | MODULE_DESCRIPTION("PWM Regulator Driver"); | |
197 | MODULE_ALIAS("platform:pwm-regulator"); |