regulator: fixed: Use core GPIO enable support
[linux-3.10.git] / drivers / regulator / fixed.c
1 /*
2  * fixed.c
3  *
4  * Copyright 2008 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  * Copyright (c) 2009 Nokia Corporation
9  * Roger Quadros <ext-roger.quadros@nokia.com>
10  *
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/module.h>
24 #include <linux/platform_device.h>
25 #include <linux/regulator/driver.h>
26 #include <linux/regulator/fixed.h>
27 #include <linux/gpio.h>
28 #include <linux/slab.h>
29 #include <linux/of.h>
30 #include <linux/of_gpio.h>
31 #include <linux/regulator/of_regulator.h>
32 #include <linux/regulator/machine.h>
33
34 struct fixed_voltage_data {
35         struct regulator_desc desc;
36         struct regulator_dev *dev;
37         int microvolts;
38 };
39
40
41 /**
42  * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
43  * @dev: device requesting for fixed_voltage_config
44  *
45  * Populates fixed_voltage_config structure by extracting data from device
46  * tree node, returns a pointer to the populated structure of NULL if memory
47  * alloc fails.
48  */
49 static struct fixed_voltage_config *
50 of_get_fixed_voltage_config(struct device *dev)
51 {
52         struct fixed_voltage_config *config;
53         struct device_node *np = dev->of_node;
54         const __be32 *delay;
55         struct regulator_init_data *init_data;
56
57         config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
58                                                                  GFP_KERNEL);
59         if (!config)
60                 return ERR_PTR(-ENOMEM);
61
62         config->init_data = of_get_regulator_init_data(dev, dev->of_node);
63         if (!config->init_data)
64                 return ERR_PTR(-EINVAL);
65
66         init_data = config->init_data;
67         init_data->constraints.apply_uV = 0;
68
69         config->supply_name = init_data->constraints.name;
70         if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
71                 config->microvolts = init_data->constraints.min_uV;
72         } else {
73                 dev_err(dev,
74                          "Fixed regulator specified with variable voltages\n");
75                 return ERR_PTR(-EINVAL);
76         }
77
78         if (init_data->constraints.boot_on)
79                 config->enabled_at_boot = true;
80
81         config->gpio = of_get_named_gpio(np, "gpio", 0);
82         /*
83          * of_get_named_gpio() currently returns ENODEV rather than
84          * EPROBE_DEFER. This code attempts to be compatible with both
85          * for now; the ENODEV check can be removed once the API is fixed.
86          * of_get_named_gpio() doesn't differentiate between a missing
87          * property (which would be fine here, since the GPIO is optional)
88          * and some other error. Patches have been posted for both issues.
89          * Once they are check in, we should replace this with:
90          * if (config->gpio < 0 && config->gpio != -ENOENT)
91          */
92         if ((config->gpio == -ENODEV) || (config->gpio == -EPROBE_DEFER))
93                 return ERR_PTR(-EPROBE_DEFER);
94
95         delay = of_get_property(np, "startup-delay-us", NULL);
96         if (delay)
97                 config->startup_delay = be32_to_cpu(*delay);
98
99         if (of_find_property(np, "enable-active-high", NULL))
100                 config->enable_high = true;
101
102         if (of_find_property(np, "gpio-open-drain", NULL))
103                 config->gpio_is_open_drain = true;
104
105         return config;
106 }
107
108 static int fixed_voltage_get_voltage(struct regulator_dev *dev)
109 {
110         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
111
112         if (data->microvolts)
113                 return data->microvolts;
114         else
115                 return -EINVAL;
116 }
117
118 static int fixed_voltage_list_voltage(struct regulator_dev *dev,
119                                       unsigned selector)
120 {
121         struct fixed_voltage_data *data = rdev_get_drvdata(dev);
122
123         if (selector != 0)
124                 return -EINVAL;
125
126         return data->microvolts;
127 }
128
129 static struct regulator_ops fixed_voltage_ops = {
130         .get_voltage = fixed_voltage_get_voltage,
131         .list_voltage = fixed_voltage_list_voltage,
132 };
133
134 static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
135 {
136         struct fixed_voltage_config *config;
137         struct fixed_voltage_data *drvdata;
138         struct regulator_config cfg = { };
139         int ret;
140
141         if (pdev->dev.of_node) {
142                 config = of_get_fixed_voltage_config(&pdev->dev);
143                 if (IS_ERR(config))
144                         return PTR_ERR(config);
145         } else {
146                 config = pdev->dev.platform_data;
147         }
148
149         if (!config)
150                 return -ENOMEM;
151
152         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
153                                GFP_KERNEL);
154         if (drvdata == NULL) {
155                 dev_err(&pdev->dev, "Failed to allocate device data\n");
156                 ret = -ENOMEM;
157                 goto err;
158         }
159
160         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
161         if (drvdata->desc.name == NULL) {
162                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
163                 ret = -ENOMEM;
164                 goto err;
165         }
166         drvdata->desc.type = REGULATOR_VOLTAGE;
167         drvdata->desc.owner = THIS_MODULE;
168         drvdata->desc.ops = &fixed_voltage_ops;
169
170         drvdata->desc.enable_time = config->startup_delay;
171
172         if (config->microvolts)
173                 drvdata->desc.n_voltages = 1;
174
175         drvdata->microvolts = config->microvolts;
176
177         if (config->gpio >= 0)
178                 cfg.ena_gpio = config->gpio;
179         cfg.ena_gpio_invert = !config->enable_high;
180         if (config->enabled_at_boot) {
181                 if (config->enable_high) {
182                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
183                 } else {
184                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
185                 }
186         } else {
187                 if (config->enable_high) {
188                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
189                 } else {
190                         cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
191                 }
192         }
193         if (config->gpio_is_open_drain)
194                 cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
195
196         cfg.dev = &pdev->dev;
197         cfg.init_data = config->init_data;
198         cfg.driver_data = drvdata;
199         cfg.of_node = pdev->dev.of_node;
200
201         drvdata->dev = regulator_register(&drvdata->desc, &cfg);
202         if (IS_ERR(drvdata->dev)) {
203                 ret = PTR_ERR(drvdata->dev);
204                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
205                 goto err_name;
206         }
207
208         platform_set_drvdata(pdev, drvdata);
209
210         dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
211                 drvdata->microvolts);
212
213         return 0;
214
215 err_name:
216         kfree(drvdata->desc.name);
217 err:
218         return ret;
219 }
220
221 static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
222 {
223         struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
224
225         regulator_unregister(drvdata->dev);
226         kfree(drvdata->desc.name);
227
228         return 0;
229 }
230
231 #if defined(CONFIG_OF)
232 static const struct of_device_id fixed_of_match[] __devinitconst = {
233         { .compatible = "regulator-fixed", },
234         {},
235 };
236 MODULE_DEVICE_TABLE(of, fixed_of_match);
237 #endif
238
239 static struct platform_driver regulator_fixed_voltage_driver = {
240         .probe          = reg_fixed_voltage_probe,
241         .remove         = __devexit_p(reg_fixed_voltage_remove),
242         .driver         = {
243                 .name           = "reg-fixed-voltage",
244                 .owner          = THIS_MODULE,
245                 .of_match_table = of_match_ptr(fixed_of_match),
246         },
247 };
248
249 static int __init regulator_fixed_voltage_init(void)
250 {
251         return platform_driver_register(&regulator_fixed_voltage_driver);
252 }
253 subsys_initcall(regulator_fixed_voltage_init);
254
255 static void __exit regulator_fixed_voltage_exit(void)
256 {
257         platform_driver_unregister(&regulator_fixed_voltage_driver);
258 }
259 module_exit(regulator_fixed_voltage_exit);
260
261 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
262 MODULE_DESCRIPTION("Fixed voltage regulator");
263 MODULE_LICENSE("GPL");
264 MODULE_ALIAS("platform:reg-fixed-voltage");