regulator: core: Allow fixed enable_time to be set in the regulator_desc
[deliverable/linux.git] / drivers / regulator / fixed.c
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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 *
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8 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
10 *
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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>
65602c32 23#include <linux/module.h>
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24#include <linux/platform_device.h>
25#include <linux/regulator/driver.h>
26#include <linux/regulator/fixed.h>
86d9884b 27#include <linux/gpio.h>
5a0e3ad6 28#include <linux/slab.h>
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29#include <linux/of.h>
30#include <linux/of_gpio.h>
31#include <linux/regulator/of_regulator.h>
32#include <linux/regulator/machine.h>
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33
34struct fixed_voltage_data {
35 struct regulator_desc desc;
36 struct regulator_dev *dev;
37 int microvolts;
86d9884b 38 int gpio;
eda79a30 39 unsigned startup_delay;
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40 bool enable_high;
41 bool is_enabled;
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42};
43
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44
45/**
46 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
47 * @dev: device requesting for fixed_voltage_config
48 *
49 * Populates fixed_voltage_config structure by extracting data from device
50 * tree node, returns a pointer to the populated structure of NULL if memory
51 * alloc fails.
52 */
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53static struct fixed_voltage_config *
54of_get_fixed_voltage_config(struct device *dev)
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55{
56 struct fixed_voltage_config *config;
57 struct device_node *np = dev->of_node;
58 const __be32 *delay;
59 struct regulator_init_data *init_data;
60
61 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
62 GFP_KERNEL);
63 if (!config)
f141822b 64 return ERR_PTR(-ENOMEM);
cef49102 65
d9a861cc 66 config->init_data = of_get_regulator_init_data(dev, dev->of_node);
4b864af1 67 if (!config->init_data)
f141822b 68 return ERR_PTR(-EINVAL);
4b864af1 69
cef49102 70 init_data = config->init_data;
0c437c4a 71 init_data->constraints.apply_uV = 0;
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72
73 config->supply_name = init_data->constraints.name;
74 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
75 config->microvolts = init_data->constraints.min_uV;
76 } else {
77 dev_err(dev,
78 "Fixed regulator specified with variable voltages\n");
f141822b 79 return ERR_PTR(-EINVAL);
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80 }
81
82 if (init_data->constraints.boot_on)
83 config->enabled_at_boot = true;
84
85 config->gpio = of_get_named_gpio(np, "gpio", 0);
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86 /*
87 * of_get_named_gpio() currently returns ENODEV rather than
88 * EPROBE_DEFER. This code attempts to be compatible with both
89 * for now; the ENODEV check can be removed once the API is fixed.
90 * of_get_named_gpio() doesn't differentiate between a missing
91 * property (which would be fine here, since the GPIO is optional)
92 * and some other error. Patches have been posted for both issues.
93 * Once they are check in, we should replace this with:
94 * if (config->gpio < 0 && config->gpio != -ENOENT)
95 */
96 if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
97 return ERR_PTR(-EPROBE_DEFER);
98
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99 delay = of_get_property(np, "startup-delay-us", NULL);
100 if (delay)
101 config->startup_delay = be32_to_cpu(*delay);
102
103 if (of_find_property(np, "enable-active-high", NULL))
104 config->enable_high = true;
105
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106 if (of_find_property(np, "gpio-open-drain", NULL))
107 config->gpio_is_open_drain = true;
108
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109 return config;
110}
111
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112static int fixed_voltage_is_enabled(struct regulator_dev *dev)
113{
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114 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
115
116 return data->is_enabled;
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117}
118
119static int fixed_voltage_enable(struct regulator_dev *dev)
120{
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121 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
122
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123 gpio_set_value_cansleep(data->gpio, data->enable_high);
124 data->is_enabled = true;
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125
126 return 0;
127}
128
129static int fixed_voltage_disable(struct regulator_dev *dev)
130{
131 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
132
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133 gpio_set_value_cansleep(data->gpio, !data->enable_high);
134 data->is_enabled = false;
86d9884b 135
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136 return 0;
137}
138
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139static int fixed_voltage_enable_time(struct regulator_dev *dev)
140{
141 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
142
143 return data->startup_delay;
144}
145
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146static int fixed_voltage_get_voltage(struct regulator_dev *dev)
147{
148 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
149
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150 if (data->microvolts)
151 return data->microvolts;
152 else
153 return -EINVAL;
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154}
155
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156static int fixed_voltage_list_voltage(struct regulator_dev *dev,
157 unsigned selector)
158{
159 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
160
161 if (selector != 0)
162 return -EINVAL;
163
164 return data->microvolts;
165}
166
9d442061 167static struct regulator_ops fixed_voltage_gpio_ops = {
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168 .is_enabled = fixed_voltage_is_enabled,
169 .enable = fixed_voltage_enable,
86d9884b 170 .disable = fixed_voltage_disable,
17133dc8 171 .enable_time = fixed_voltage_enable_time,
4b74ff65 172 .get_voltage = fixed_voltage_get_voltage,
9035cefc 173 .list_voltage = fixed_voltage_list_voltage,
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174};
175
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176static struct regulator_ops fixed_voltage_ops = {
177 .get_voltage = fixed_voltage_get_voltage,
178 .list_voltage = fixed_voltage_list_voltage,
179};
180
8ab3343d 181static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
4b74ff65 182{
22d881c0 183 struct fixed_voltage_config *config;
4b74ff65 184 struct fixed_voltage_data *drvdata;
c172708d 185 struct regulator_config cfg = { };
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186 int ret;
187
f141822b 188 if (pdev->dev.of_node) {
cef49102 189 config = of_get_fixed_voltage_config(&pdev->dev);
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190 if (IS_ERR(config))
191 return PTR_ERR(config);
192 } else {
22d881c0 193 config = pdev->dev.platform_data;
f141822b 194 }
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195
196 if (!config)
197 return -ENOMEM;
cef49102 198
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199 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
200 GFP_KERNEL);
4b74ff65 201 if (drvdata == NULL) {
c53ad7fe 202 dev_err(&pdev->dev, "Failed to allocate device data\n");
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203 ret = -ENOMEM;
204 goto err;
205 }
206
207 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
208 if (drvdata->desc.name == NULL) {
c53ad7fe 209 dev_err(&pdev->dev, "Failed to allocate supply name\n");
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210 ret = -ENOMEM;
211 goto err;
212 }
213 drvdata->desc.type = REGULATOR_VOLTAGE;
214 drvdata->desc.owner = THIS_MODULE;
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215
216 if (config->microvolts)
217 drvdata->desc.n_voltages = 1;
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218
219 drvdata->microvolts = config->microvolts;
86d9884b 220 drvdata->gpio = config->gpio;
eda79a30 221 drvdata->startup_delay = config->startup_delay;
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222
223 if (gpio_is_valid(config->gpio)) {
a4d9f179 224 int gpio_flag;
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225 drvdata->enable_high = config->enable_high;
226
227 /* FIXME: Remove below print warning
228 *
229 * config->gpio must be set to -EINVAL by platform code if
230 * GPIO control is not required. However, early adopters
231 * not requiring GPIO control may forget to initialize
232 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
233 * for GPIO control.
234 *
235 * This warning will be removed once there are a couple of users
236 * for this driver.
237 */
238 if (!config->gpio)
239 dev_warn(&pdev->dev,
240 "using GPIO 0 for regulator enable control\n");
241
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242 /*
243 * set output direction without changing state
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244 * to prevent glitch
245 */
246 drvdata->is_enabled = config->enabled_at_boot;
247 ret = drvdata->is_enabled ?
248 config->enable_high : !config->enable_high;
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249 gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
250
251 if (config->gpio_is_open_drain)
252 gpio_flag |= GPIOF_OPEN_DRAIN;
86d9884b 253
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254 ret = gpio_request_one(config->gpio, gpio_flag,
255 config->supply_name);
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256 if (ret) {
257 dev_err(&pdev->dev,
a4d9f179 258 "Could not obtain regulator enable GPIO %d: %d\n",
86d9884b 259 config->gpio, ret);
a4d9f179 260 goto err_name;
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261 }
262
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263 drvdata->desc.ops = &fixed_voltage_gpio_ops;
264
86d9884b 265 } else {
9d442061 266 drvdata->desc.ops = &fixed_voltage_ops;
86d9884b 267 }
4b74ff65 268
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269 cfg.dev = &pdev->dev;
270 cfg.init_data = config->init_data;
271 cfg.driver_data = drvdata;
272 cfg.of_node = pdev->dev.of_node;
273
274 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
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275 if (IS_ERR(drvdata->dev)) {
276 ret = PTR_ERR(drvdata->dev);
c53ad7fe 277 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
86d9884b 278 goto err_gpio;
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279 }
280
281 platform_set_drvdata(pdev, drvdata);
282
283 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
284 drvdata->microvolts);
285
286 return 0;
287
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288err_gpio:
289 if (gpio_is_valid(config->gpio))
290 gpio_free(config->gpio);
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291err_name:
292 kfree(drvdata->desc.name);
293err:
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294 return ret;
295}
296
8ab3343d 297static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
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298{
299 struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
300
301 regulator_unregister(drvdata->dev);
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302 if (gpio_is_valid(drvdata->gpio))
303 gpio_free(drvdata->gpio);
80099c70 304 kfree(drvdata->desc.name);
86d9884b 305
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306 return 0;
307}
308
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309#if defined(CONFIG_OF)
310static const struct of_device_id fixed_of_match[] __devinitconst = {
311 { .compatible = "regulator-fixed", },
312 {},
313};
314MODULE_DEVICE_TABLE(of, fixed_of_match);
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315#endif
316
4b74ff65 317static struct platform_driver regulator_fixed_voltage_driver = {
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318 .probe = reg_fixed_voltage_probe,
319 .remove = __devexit_p(reg_fixed_voltage_remove),
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320 .driver = {
321 .name = "reg-fixed-voltage",
8ab3343d 322 .owner = THIS_MODULE,
abcfaf23 323 .of_match_table = of_match_ptr(fixed_of_match),
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324 },
325};
326
327static int __init regulator_fixed_voltage_init(void)
328{
329 return platform_driver_register(&regulator_fixed_voltage_driver);
330}
5a1b22be 331subsys_initcall(regulator_fixed_voltage_init);
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332
333static void __exit regulator_fixed_voltage_exit(void)
334{
335 platform_driver_unregister(&regulator_fixed_voltage_driver);
336}
337module_exit(regulator_fixed_voltage_exit);
338
339MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
340MODULE_DESCRIPTION("Fixed voltage regulator");
341MODULE_LICENSE("GPL");
38c53c89 342MODULE_ALIAS("platform:reg-fixed-voltage");
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