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1 | /* |
2 | * fixed.c | |
3 | * | |
4 | * Copyright 2008 Wolfson Microelectronics PLC. | |
5 | * | |
6 | * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> | |
7 | * | |
86d9884b RQ |
8 | * Copyright (c) 2009 Nokia Corporation |
9 | * Roger Quadros <ext-roger.quadros@nokia.com> | |
10 | * | |
4b74ff65 MB |
11 | * This program is free software; you can redistribute it and/or |
12 | * modify it under the terms of the GNU General Public License as | |
13 | * published by the Free Software Foundation; either version 2 of the | |
14 | * License, or (at your option) any later version. | |
15 | * | |
16 | * This is useful for systems with mixed controllable and | |
17 | * non-controllable regulators, as well as for allowing testing on | |
18 | * systems with no controllable regulators. | |
19 | */ | |
20 | ||
21 | #include <linux/err.h> | |
22 | #include <linux/mutex.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/regulator/driver.h> | |
25 | #include <linux/regulator/fixed.h> | |
86d9884b | 26 | #include <linux/gpio.h> |
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27 | |
28 | struct fixed_voltage_data { | |
29 | struct regulator_desc desc; | |
30 | struct regulator_dev *dev; | |
31 | int microvolts; | |
86d9884b RQ |
32 | int gpio; |
33 | unsigned enable_high:1; | |
34 | unsigned is_enabled:1; | |
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35 | }; |
36 | ||
37 | static int fixed_voltage_is_enabled(struct regulator_dev *dev) | |
38 | { | |
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39 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
40 | ||
41 | return data->is_enabled; | |
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42 | } |
43 | ||
44 | static int fixed_voltage_enable(struct regulator_dev *dev) | |
45 | { | |
86d9884b RQ |
46 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); |
47 | ||
48 | if (gpio_is_valid(data->gpio)) { | |
49 | gpio_set_value_cansleep(data->gpio, data->enable_high); | |
50 | data->is_enabled = 1; | |
51 | } | |
52 | ||
53 | return 0; | |
54 | } | |
55 | ||
56 | static int fixed_voltage_disable(struct regulator_dev *dev) | |
57 | { | |
58 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
59 | ||
60 | if (gpio_is_valid(data->gpio)) { | |
61 | gpio_set_value_cansleep(data->gpio, !data->enable_high); | |
62 | data->is_enabled = 0; | |
63 | } | |
64 | ||
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65 | return 0; |
66 | } | |
67 | ||
68 | static int fixed_voltage_get_voltage(struct regulator_dev *dev) | |
69 | { | |
70 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
71 | ||
72 | return data->microvolts; | |
73 | } | |
74 | ||
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75 | static int fixed_voltage_list_voltage(struct regulator_dev *dev, |
76 | unsigned selector) | |
77 | { | |
78 | struct fixed_voltage_data *data = rdev_get_drvdata(dev); | |
79 | ||
80 | if (selector != 0) | |
81 | return -EINVAL; | |
82 | ||
83 | return data->microvolts; | |
84 | } | |
85 | ||
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86 | static struct regulator_ops fixed_voltage_ops = { |
87 | .is_enabled = fixed_voltage_is_enabled, | |
88 | .enable = fixed_voltage_enable, | |
86d9884b | 89 | .disable = fixed_voltage_disable, |
4b74ff65 | 90 | .get_voltage = fixed_voltage_get_voltage, |
9035cefc | 91 | .list_voltage = fixed_voltage_list_voltage, |
4b74ff65 MB |
92 | }; |
93 | ||
94 | static int regulator_fixed_voltage_probe(struct platform_device *pdev) | |
95 | { | |
96 | struct fixed_voltage_config *config = pdev->dev.platform_data; | |
97 | struct fixed_voltage_data *drvdata; | |
98 | int ret; | |
99 | ||
100 | drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL); | |
101 | if (drvdata == NULL) { | |
c53ad7fe | 102 | dev_err(&pdev->dev, "Failed to allocate device data\n"); |
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103 | ret = -ENOMEM; |
104 | goto err; | |
105 | } | |
106 | ||
107 | drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL); | |
108 | if (drvdata->desc.name == NULL) { | |
c53ad7fe | 109 | dev_err(&pdev->dev, "Failed to allocate supply name\n"); |
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110 | ret = -ENOMEM; |
111 | goto err; | |
112 | } | |
113 | drvdata->desc.type = REGULATOR_VOLTAGE; | |
114 | drvdata->desc.owner = THIS_MODULE; | |
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115 | drvdata->desc.ops = &fixed_voltage_ops; |
116 | drvdata->desc.n_voltages = 1; | |
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117 | |
118 | drvdata->microvolts = config->microvolts; | |
86d9884b RQ |
119 | drvdata->gpio = config->gpio; |
120 | ||
121 | if (gpio_is_valid(config->gpio)) { | |
122 | drvdata->enable_high = config->enable_high; | |
123 | ||
124 | /* FIXME: Remove below print warning | |
125 | * | |
126 | * config->gpio must be set to -EINVAL by platform code if | |
127 | * GPIO control is not required. However, early adopters | |
128 | * not requiring GPIO control may forget to initialize | |
129 | * config->gpio to -EINVAL. This will cause GPIO 0 to be used | |
130 | * for GPIO control. | |
131 | * | |
132 | * This warning will be removed once there are a couple of users | |
133 | * for this driver. | |
134 | */ | |
135 | if (!config->gpio) | |
136 | dev_warn(&pdev->dev, | |
137 | "using GPIO 0 for regulator enable control\n"); | |
138 | ||
139 | ret = gpio_request(config->gpio, config->supply_name); | |
140 | if (ret) { | |
141 | dev_err(&pdev->dev, | |
142 | "Could not obtain regulator enable GPIO %d: %d\n", | |
143 | config->gpio, ret); | |
144 | goto err_name; | |
145 | } | |
146 | ||
147 | /* set output direction without changing state | |
148 | * to prevent glitch | |
149 | */ | |
150 | drvdata->is_enabled = config->enabled_at_boot; | |
151 | ret = drvdata->is_enabled ? | |
152 | config->enable_high : !config->enable_high; | |
153 | ||
154 | ret = gpio_direction_output(config->gpio, ret); | |
155 | if (ret) { | |
156 | dev_err(&pdev->dev, | |
157 | "Could not configure regulator enable GPIO %d direction: %d\n", | |
158 | config->gpio, ret); | |
159 | goto err_gpio; | |
160 | } | |
161 | ||
162 | } else { | |
163 | /* Regulator without GPIO control is considered | |
164 | * always enabled | |
165 | */ | |
166 | drvdata->is_enabled = 1; | |
167 | } | |
4b74ff65 | 168 | |
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169 | drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev, |
170 | config->init_data, drvdata); | |
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171 | if (IS_ERR(drvdata->dev)) { |
172 | ret = PTR_ERR(drvdata->dev); | |
c53ad7fe | 173 | dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret); |
86d9884b | 174 | goto err_gpio; |
4b74ff65 MB |
175 | } |
176 | ||
177 | platform_set_drvdata(pdev, drvdata); | |
178 | ||
179 | dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name, | |
180 | drvdata->microvolts); | |
181 | ||
182 | return 0; | |
183 | ||
86d9884b RQ |
184 | err_gpio: |
185 | if (gpio_is_valid(config->gpio)) | |
186 | gpio_free(config->gpio); | |
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187 | err_name: |
188 | kfree(drvdata->desc.name); | |
189 | err: | |
190 | kfree(drvdata); | |
191 | return ret; | |
192 | } | |
193 | ||
194 | static int regulator_fixed_voltage_remove(struct platform_device *pdev) | |
195 | { | |
196 | struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev); | |
197 | ||
198 | regulator_unregister(drvdata->dev); | |
86d9884b RQ |
199 | if (gpio_is_valid(drvdata->gpio)) |
200 | gpio_free(drvdata->gpio); | |
80099c70 DC |
201 | kfree(drvdata->desc.name); |
202 | kfree(drvdata); | |
86d9884b | 203 | |
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204 | return 0; |
205 | } | |
206 | ||
207 | static struct platform_driver regulator_fixed_voltage_driver = { | |
208 | .probe = regulator_fixed_voltage_probe, | |
209 | .remove = regulator_fixed_voltage_remove, | |
210 | .driver = { | |
211 | .name = "reg-fixed-voltage", | |
212 | }, | |
213 | }; | |
214 | ||
215 | static int __init regulator_fixed_voltage_init(void) | |
216 | { | |
217 | return platform_driver_register(®ulator_fixed_voltage_driver); | |
218 | } | |
5a1b22be | 219 | subsys_initcall(regulator_fixed_voltage_init); |
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220 | |
221 | static void __exit regulator_fixed_voltage_exit(void) | |
222 | { | |
223 | platform_driver_unregister(®ulator_fixed_voltage_driver); | |
224 | } | |
225 | module_exit(regulator_fixed_voltage_exit); | |
226 | ||
227 | MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>"); | |
228 | MODULE_DESCRIPTION("Fixed voltage regulator"); | |
229 | MODULE_LICENSE("GPL"); | |
38c53c89 | 230 | MODULE_ALIAS("platform:reg-fixed-voltage"); |