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Mark Brown4b74ff62008-04-30 16:27:12 +01001/*
2 * fixed.c
3 *
4 * Copyright 2008 Wolfson Microelectronics PLC.
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
Roger Quadros86d98842009-08-06 19:37:29 +03008 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
10 *
Mark Brown4b74ff62008-04-30 16:27:12 +010011 * 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>
Paul Gortmaker65602c32011-07-17 16:28:23 -040023#include <linux/module.h>
Mark Brown4b74ff62008-04-30 16:27:12 +010024#include <linux/platform_device.h>
25#include <linux/regulator/driver.h>
26#include <linux/regulator/fixed.h>
Roger Quadros86d98842009-08-06 19:37:29 +030027#include <linux/gpio.h>
Adrian Huntereda79a32010-01-12 12:25:13 +020028#include <linux/delay.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090029#include <linux/slab.h>
Rajendra Nayakcef49102011-11-18 16:47:18 +053030#include <linux/of.h>
31#include <linux/of_gpio.h>
32#include <linux/regulator/of_regulator.h>
33#include <linux/regulator/machine.h>
Mark Brown4b74ff62008-04-30 16:27:12 +010034
35struct fixed_voltage_data {
36 struct regulator_desc desc;
37 struct regulator_dev *dev;
38 int microvolts;
Roger Quadros86d98842009-08-06 19:37:29 +030039 int gpio;
Adrian Huntereda79a32010-01-12 12:25:13 +020040 unsigned startup_delay;
Dmitry Torokhov8ab33432010-02-23 23:37:55 -080041 bool enable_high;
42 bool is_enabled;
Mark Brown4b74ff62008-04-30 16:27:12 +010043};
44
Rajendra Nayakcef49102011-11-18 16:47:18 +053045
46/**
47 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
48 * @dev: device requesting for fixed_voltage_config
49 *
50 * Populates fixed_voltage_config structure by extracting data from device
51 * tree node, returns a pointer to the populated structure of NULL if memory
52 * alloc fails.
53 */
Axel Linbc913962011-11-27 10:35:08 +080054static struct fixed_voltage_config *
55of_get_fixed_voltage_config(struct device *dev)
Rajendra Nayakcef49102011-11-18 16:47:18 +053056{
57 struct fixed_voltage_config *config;
58 struct device_node *np = dev->of_node;
59 const __be32 *delay;
60 struct regulator_init_data *init_data;
61
62 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
63 GFP_KERNEL);
64 if (!config)
65 return NULL;
66
Shawn Guod9a861c2011-12-01 17:21:06 +080067 config->init_data = of_get_regulator_init_data(dev, dev->of_node);
Axel Lin4b864af2011-11-26 20:19:19 +080068 if (!config->init_data)
69 return NULL;
70
Rajendra Nayakcef49102011-11-18 16:47:18 +053071 init_data = config->init_data;
Richard Zhao0c437c42012-01-04 11:07:29 +080072 init_data->constraints.apply_uV = 0;
Rajendra Nayakcef49102011-11-18 16:47:18 +053073
74 config->supply_name = init_data->constraints.name;
75 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
76 config->microvolts = init_data->constraints.min_uV;
77 } else {
78 dev_err(dev,
79 "Fixed regulator specified with variable voltages\n");
80 return NULL;
81 }
82
83 if (init_data->constraints.boot_on)
84 config->enabled_at_boot = true;
85
86 config->gpio = of_get_named_gpio(np, "gpio", 0);
87 delay = of_get_property(np, "startup-delay-us", NULL);
88 if (delay)
89 config->startup_delay = be32_to_cpu(*delay);
90
91 if (of_find_property(np, "enable-active-high", NULL))
92 config->enable_high = true;
93
94 return config;
95}
96
Mark Brown4b74ff62008-04-30 16:27:12 +010097static int fixed_voltage_is_enabled(struct regulator_dev *dev)
98{
Roger Quadros86d98842009-08-06 19:37:29 +030099 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
100
101 return data->is_enabled;
Mark Brown4b74ff62008-04-30 16:27:12 +0100102}
103
104static int fixed_voltage_enable(struct regulator_dev *dev)
105{
Roger Quadros86d98842009-08-06 19:37:29 +0300106 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
107
108 if (gpio_is_valid(data->gpio)) {
109 gpio_set_value_cansleep(data->gpio, data->enable_high);
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800110 data->is_enabled = true;
Roger Quadros86d98842009-08-06 19:37:29 +0300111 }
112
113 return 0;
114}
115
116static int fixed_voltage_disable(struct regulator_dev *dev)
117{
118 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
119
120 if (gpio_is_valid(data->gpio)) {
121 gpio_set_value_cansleep(data->gpio, !data->enable_high);
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800122 data->is_enabled = false;
Roger Quadros86d98842009-08-06 19:37:29 +0300123 }
124
Mark Brown4b74ff62008-04-30 16:27:12 +0100125 return 0;
126}
127
Mark Brown17133dc2010-01-28 10:21:05 +0000128static int fixed_voltage_enable_time(struct regulator_dev *dev)
129{
130 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
131
132 return data->startup_delay;
133}
134
Mark Brown4b74ff62008-04-30 16:27:12 +0100135static int fixed_voltage_get_voltage(struct regulator_dev *dev)
136{
137 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
138
Mark Brownaebe4952011-11-02 11:38:45 +0000139 if (data->microvolts)
140 return data->microvolts;
141 else
142 return -EINVAL;
Mark Brown4b74ff62008-04-30 16:27:12 +0100143}
144
Mark Brown9035cef2009-04-28 11:13:54 +0100145static int fixed_voltage_list_voltage(struct regulator_dev *dev,
146 unsigned selector)
147{
148 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
149
150 if (selector != 0)
151 return -EINVAL;
152
153 return data->microvolts;
154}
155
Mark Brown4b74ff62008-04-30 16:27:12 +0100156static struct regulator_ops fixed_voltage_ops = {
157 .is_enabled = fixed_voltage_is_enabled,
158 .enable = fixed_voltage_enable,
Roger Quadros86d98842009-08-06 19:37:29 +0300159 .disable = fixed_voltage_disable,
Mark Brown17133dc2010-01-28 10:21:05 +0000160 .enable_time = fixed_voltage_enable_time,
Mark Brown4b74ff62008-04-30 16:27:12 +0100161 .get_voltage = fixed_voltage_get_voltage,
Mark Brown9035cef2009-04-28 11:13:54 +0100162 .list_voltage = fixed_voltage_list_voltage,
Mark Brown4b74ff62008-04-30 16:27:12 +0100163};
164
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800165static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
Mark Brown4b74ff62008-04-30 16:27:12 +0100166{
Axel Lin22d881c2011-11-27 20:07:57 +0800167 struct fixed_voltage_config *config;
Mark Brown4b74ff62008-04-30 16:27:12 +0100168 struct fixed_voltage_data *drvdata;
169 int ret;
170
Rajendra Nayakcef49102011-11-18 16:47:18 +0530171 if (pdev->dev.of_node)
172 config = of_get_fixed_voltage_config(&pdev->dev);
Axel Lin22d881c2011-11-27 20:07:57 +0800173 else
174 config = pdev->dev.platform_data;
175
176 if (!config)
177 return -ENOMEM;
Rajendra Nayakcef49102011-11-18 16:47:18 +0530178
Mark Brown4b74ff62008-04-30 16:27:12 +0100179 drvdata = kzalloc(sizeof(struct fixed_voltage_data), GFP_KERNEL);
180 if (drvdata == NULL) {
Mark Brownc53ad7f2009-08-03 18:49:53 +0100181 dev_err(&pdev->dev, "Failed to allocate device data\n");
Mark Brown4b74ff62008-04-30 16:27:12 +0100182 ret = -ENOMEM;
183 goto err;
184 }
185
186 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
187 if (drvdata->desc.name == NULL) {
Mark Brownc53ad7f2009-08-03 18:49:53 +0100188 dev_err(&pdev->dev, "Failed to allocate supply name\n");
Mark Brown4b74ff62008-04-30 16:27:12 +0100189 ret = -ENOMEM;
190 goto err;
191 }
192 drvdata->desc.type = REGULATOR_VOLTAGE;
193 drvdata->desc.owner = THIS_MODULE;
Mark Brown9035cef2009-04-28 11:13:54 +0100194 drvdata->desc.ops = &fixed_voltage_ops;
Sascha Hauer1c37f8a2012-03-03 12:40:01 +0100195
196 if (config->microvolts)
197 drvdata->desc.n_voltages = 1;
Mark Brown4b74ff62008-04-30 16:27:12 +0100198
199 drvdata->microvolts = config->microvolts;
Roger Quadros86d98842009-08-06 19:37:29 +0300200 drvdata->gpio = config->gpio;
Adrian Huntereda79a32010-01-12 12:25:13 +0200201 drvdata->startup_delay = config->startup_delay;
Roger Quadros86d98842009-08-06 19:37:29 +0300202
203 if (gpio_is_valid(config->gpio)) {
204 drvdata->enable_high = config->enable_high;
205
206 /* FIXME: Remove below print warning
207 *
208 * config->gpio must be set to -EINVAL by platform code if
209 * GPIO control is not required. However, early adopters
210 * not requiring GPIO control may forget to initialize
211 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
212 * for GPIO control.
213 *
214 * This warning will be removed once there are a couple of users
215 * for this driver.
216 */
217 if (!config->gpio)
218 dev_warn(&pdev->dev,
219 "using GPIO 0 for regulator enable control\n");
220
221 ret = gpio_request(config->gpio, config->supply_name);
222 if (ret) {
223 dev_err(&pdev->dev,
224 "Could not obtain regulator enable GPIO %d: %d\n",
225 config->gpio, ret);
226 goto err_name;
227 }
228
229 /* set output direction without changing state
230 * to prevent glitch
231 */
232 drvdata->is_enabled = config->enabled_at_boot;
233 ret = drvdata->is_enabled ?
234 config->enable_high : !config->enable_high;
235
236 ret = gpio_direction_output(config->gpio, ret);
237 if (ret) {
238 dev_err(&pdev->dev,
239 "Could not configure regulator enable GPIO %d direction: %d\n",
240 config->gpio, ret);
241 goto err_gpio;
242 }
243
244 } else {
245 /* Regulator without GPIO control is considered
246 * always enabled
247 */
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800248 drvdata->is_enabled = true;
Roger Quadros86d98842009-08-06 19:37:29 +0300249 }
Mark Brown4b74ff62008-04-30 16:27:12 +0100250
Mark Brownbcf34022009-01-19 13:37:04 +0000251 drvdata->dev = regulator_register(&drvdata->desc, &pdev->dev,
Richard Zhao1bb50b22011-12-31 20:51:16 +0800252 config->init_data, drvdata,
253 pdev->dev.of_node);
Mark Brown4b74ff62008-04-30 16:27:12 +0100254 if (IS_ERR(drvdata->dev)) {
255 ret = PTR_ERR(drvdata->dev);
Mark Brownc53ad7f2009-08-03 18:49:53 +0100256 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
Roger Quadros86d98842009-08-06 19:37:29 +0300257 goto err_gpio;
Mark Brown4b74ff62008-04-30 16:27:12 +0100258 }
259
260 platform_set_drvdata(pdev, drvdata);
261
262 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
263 drvdata->microvolts);
264
265 return 0;
266
Roger Quadros86d98842009-08-06 19:37:29 +0300267err_gpio:
268 if (gpio_is_valid(config->gpio))
269 gpio_free(config->gpio);
Mark Brown4b74ff62008-04-30 16:27:12 +0100270err_name:
271 kfree(drvdata->desc.name);
272err:
273 kfree(drvdata);
274 return ret;
275}
276
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800277static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
Mark Brown4b74ff62008-04-30 16:27:12 +0100278{
279 struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
280
281 regulator_unregister(drvdata->dev);
Roger Quadros86d98842009-08-06 19:37:29 +0300282 if (gpio_is_valid(drvdata->gpio))
283 gpio_free(drvdata->gpio);
Dan Carpenter80099c72009-11-16 11:05:03 +0200284 kfree(drvdata->desc.name);
285 kfree(drvdata);
Roger Quadros86d98842009-08-06 19:37:29 +0300286
Mark Brown4b74ff62008-04-30 16:27:12 +0100287 return 0;
288}
289
Rajendra Nayakcef49102011-11-18 16:47:18 +0530290#if defined(CONFIG_OF)
291static const struct of_device_id fixed_of_match[] __devinitconst = {
292 { .compatible = "regulator-fixed", },
293 {},
294};
295MODULE_DEVICE_TABLE(of, fixed_of_match);
296#else
297#define fixed_of_match NULL
298#endif
299
Mark Brown4b74ff62008-04-30 16:27:12 +0100300static struct platform_driver regulator_fixed_voltage_driver = {
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800301 .probe = reg_fixed_voltage_probe,
302 .remove = __devexit_p(reg_fixed_voltage_remove),
Mark Brown4b74ff62008-04-30 16:27:12 +0100303 .driver = {
304 .name = "reg-fixed-voltage",
Dmitry Torokhov8ab33432010-02-23 23:37:55 -0800305 .owner = THIS_MODULE,
Rajendra Nayakcef49102011-11-18 16:47:18 +0530306 .of_match_table = fixed_of_match,
Mark Brown4b74ff62008-04-30 16:27:12 +0100307 },
308};
309
310static int __init regulator_fixed_voltage_init(void)
311{
312 return platform_driver_register(&regulator_fixed_voltage_driver);
313}
Mark Brown5a1b22b2009-04-27 18:21:18 +0100314subsys_initcall(regulator_fixed_voltage_init);
Mark Brown4b74ff62008-04-30 16:27:12 +0100315
316static void __exit regulator_fixed_voltage_exit(void)
317{
318 platform_driver_unregister(&regulator_fixed_voltage_driver);
319}
320module_exit(regulator_fixed_voltage_exit);
321
322MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
323MODULE_DESCRIPTION("Fixed voltage regulator");
324MODULE_LICENSE("GPL");
Mark Brown38c53c82009-04-28 11:13:55 +0100325MODULE_ALIAS("platform:reg-fixed-voltage");