4 * Copyright 2008 Wolfson Microelectronics PLC.
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 * Copyright (c) 2009 Nokia Corporation
9 * Roger Quadros <ext-roger.quadros@nokia.com>
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.
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.
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>
30 #include <linux/of_gpio.h>
31 #include <linux/regulator/of_regulator.h>
32 #include <linux/regulator/machine.h>
34 struct fixed_voltage_data {
35 struct regulator_desc desc;
36 struct regulator_dev *dev;
39 unsigned startup_delay;
46 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
47 * @dev: device requesting for fixed_voltage_config
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
53 static struct fixed_voltage_config *
54 of_get_fixed_voltage_config(struct device *dev)
56 struct fixed_voltage_config *config;
57 struct device_node *np = dev->of_node;
59 struct regulator_init_data *init_data;
61 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
66 config->init_data = of_get_regulator_init_data(dev, dev->of_node);
67 if (!config->init_data)
70 init_data = config->init_data;
71 init_data->constraints.apply_uV = 0;
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;
78 "Fixed regulator specified with variable voltages\n");
82 if (init_data->constraints.boot_on)
83 config->enabled_at_boot = true;
85 config->gpio = of_get_named_gpio(np, "gpio", 0);
86 delay = of_get_property(np, "startup-delay-us", NULL);
88 config->startup_delay = be32_to_cpu(*delay);
90 if (of_find_property(np, "enable-active-high", NULL))
91 config->enable_high = true;
93 if (of_find_property(np, "gpio-open-drain", NULL))
94 config->gpio_is_open_drain = true;
99 static int fixed_voltage_is_enabled(struct regulator_dev *dev)
101 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
103 return data->is_enabled;
106 static int fixed_voltage_enable(struct regulator_dev *dev)
108 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
110 gpio_set_value_cansleep(data->gpio, data->enable_high);
111 data->is_enabled = true;
116 static int fixed_voltage_disable(struct regulator_dev *dev)
118 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
120 gpio_set_value_cansleep(data->gpio, !data->enable_high);
121 data->is_enabled = false;
126 static int fixed_voltage_enable_time(struct regulator_dev *dev)
128 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
130 return data->startup_delay;
133 static int fixed_voltage_get_voltage(struct regulator_dev *dev)
135 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
137 if (data->microvolts)
138 return data->microvolts;
143 static int fixed_voltage_list_voltage(struct regulator_dev *dev,
146 struct fixed_voltage_data *data = rdev_get_drvdata(dev);
151 return data->microvolts;
154 static struct regulator_ops fixed_voltage_gpio_ops = {
155 .is_enabled = fixed_voltage_is_enabled,
156 .enable = fixed_voltage_enable,
157 .disable = fixed_voltage_disable,
158 .enable_time = fixed_voltage_enable_time,
159 .get_voltage = fixed_voltage_get_voltage,
160 .list_voltage = fixed_voltage_list_voltage,
163 static struct regulator_ops fixed_voltage_ops = {
164 .get_voltage = fixed_voltage_get_voltage,
165 .list_voltage = fixed_voltage_list_voltage,
168 static int __devinit reg_fixed_voltage_probe(struct platform_device *pdev)
170 struct fixed_voltage_config *config;
171 struct fixed_voltage_data *drvdata;
172 struct regulator_config cfg = { };
175 if (pdev->dev.of_node)
176 config = of_get_fixed_voltage_config(&pdev->dev);
178 config = pdev->dev.platform_data;
183 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
185 if (drvdata == NULL) {
186 dev_err(&pdev->dev, "Failed to allocate device data\n");
191 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
192 if (drvdata->desc.name == NULL) {
193 dev_err(&pdev->dev, "Failed to allocate supply name\n");
197 drvdata->desc.type = REGULATOR_VOLTAGE;
198 drvdata->desc.owner = THIS_MODULE;
200 if (config->microvolts)
201 drvdata->desc.n_voltages = 1;
203 drvdata->microvolts = config->microvolts;
204 drvdata->gpio = config->gpio;
205 drvdata->startup_delay = config->startup_delay;
207 if (gpio_is_valid(config->gpio)) {
209 drvdata->enable_high = config->enable_high;
211 /* FIXME: Remove below print warning
213 * config->gpio must be set to -EINVAL by platform code if
214 * GPIO control is not required. However, early adopters
215 * not requiring GPIO control may forget to initialize
216 * config->gpio to -EINVAL. This will cause GPIO 0 to be used
219 * This warning will be removed once there are a couple of users
224 "using GPIO 0 for regulator enable control\n");
227 * set output direction without changing state
230 drvdata->is_enabled = config->enabled_at_boot;
231 ret = drvdata->is_enabled ?
232 config->enable_high : !config->enable_high;
233 gpio_flag = ret ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
235 if (config->gpio_is_open_drain)
236 gpio_flag |= GPIOF_OPEN_DRAIN;
238 ret = gpio_request_one(config->gpio, gpio_flag,
239 config->supply_name);
242 "Could not obtain regulator enable GPIO %d: %d\n",
247 drvdata->desc.ops = &fixed_voltage_gpio_ops;
250 drvdata->desc.ops = &fixed_voltage_ops;
253 cfg.dev = &pdev->dev;
254 cfg.init_data = config->init_data;
255 cfg.driver_data = drvdata;
256 cfg.of_node = pdev->dev.of_node;
258 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
259 if (IS_ERR(drvdata->dev)) {
260 ret = PTR_ERR(drvdata->dev);
261 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
265 platform_set_drvdata(pdev, drvdata);
267 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
268 drvdata->microvolts);
273 if (gpio_is_valid(config->gpio))
274 gpio_free(config->gpio);
276 kfree(drvdata->desc.name);
281 static int __devexit reg_fixed_voltage_remove(struct platform_device *pdev)
283 struct fixed_voltage_data *drvdata = platform_get_drvdata(pdev);
285 regulator_unregister(drvdata->dev);
286 if (gpio_is_valid(drvdata->gpio))
287 gpio_free(drvdata->gpio);
288 kfree(drvdata->desc.name);
293 #if defined(CONFIG_OF)
294 static const struct of_device_id fixed_of_match[] __devinitconst = {
295 { .compatible = "regulator-fixed", },
298 MODULE_DEVICE_TABLE(of, fixed_of_match);
300 #define fixed_of_match NULL
303 static struct platform_driver regulator_fixed_voltage_driver = {
304 .probe = reg_fixed_voltage_probe,
305 .remove = __devexit_p(reg_fixed_voltage_remove),
307 .name = "reg-fixed-voltage",
308 .owner = THIS_MODULE,
309 .of_match_table = fixed_of_match,
313 static int __init regulator_fixed_voltage_init(void)
315 return platform_driver_register(®ulator_fixed_voltage_driver);
317 subsys_initcall(regulator_fixed_voltage_init);
319 static void __exit regulator_fixed_voltage_exit(void)
321 platform_driver_unregister(®ulator_fixed_voltage_driver);
323 module_exit(regulator_fixed_voltage_exit);
325 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
326 MODULE_DESCRIPTION("Fixed voltage regulator");
327 MODULE_LICENSE("GPL");
328 MODULE_ALIAS("platform:reg-fixed-voltage");