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>
33 #include <linux/acpi.h>
34 #include <linux/property.h>
35 #include <linux/gpio/consumer.h>
37 struct fixed_voltage_data {
38 struct regulator_desc desc;
39 struct regulator_dev *dev;
44 * of_get_fixed_voltage_config - extract fixed_voltage_config structure info
45 * @dev: device requesting for fixed_voltage_config
46 * @desc: regulator description
48 * Populates fixed_voltage_config structure by extracting data from device
49 * tree node, returns a pointer to the populated structure of NULL if memory
52 static struct fixed_voltage_config *
53 of_get_fixed_voltage_config(struct device *dev,
54 const struct regulator_desc *desc)
56 struct fixed_voltage_config *config;
57 struct device_node *np = dev->of_node;
58 struct regulator_init_data *init_data;
60 config = devm_kzalloc(dev, sizeof(struct fixed_voltage_config),
63 return ERR_PTR(-ENOMEM);
65 config->init_data = of_get_regulator_init_data(dev, dev->of_node, desc);
66 if (!config->init_data)
67 return ERR_PTR(-EINVAL);
69 init_data = config->init_data;
70 init_data->constraints.apply_uV = 0;
72 config->supply_name = init_data->constraints.name;
73 if (init_data->constraints.min_uV == init_data->constraints.max_uV) {
74 config->microvolts = init_data->constraints.min_uV;
77 "Fixed regulator specified with variable voltages\n");
78 return ERR_PTR(-EINVAL);
81 if (init_data->constraints.boot_on)
82 config->enabled_at_boot = true;
84 config->gpio = of_get_named_gpio(np, "gpio", 0);
85 if ((config->gpio < 0) && (config->gpio != -ENOENT))
86 return ERR_PTR(config->gpio);
88 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
90 config->enable_high = of_property_read_bool(np, "enable-active-high");
91 config->gpio_is_open_drain = of_property_read_bool(np,
94 if (of_find_property(np, "vin-supply", NULL))
95 config->input_supply = "vin";
101 * acpi_get_fixed_voltage_config - extract fixed_voltage_config structure info
102 * @dev: device requesting for fixed_voltage_config
103 * @desc: regulator description
105 * Populates fixed_voltage_config structure by extracting data through ACPI
106 * interface, returns a pointer to the populated structure of NULL if memory
109 static struct fixed_voltage_config *
110 acpi_get_fixed_voltage_config(struct device *dev,
111 const struct regulator_desc *desc)
113 struct fixed_voltage_config *config;
114 const char *supply_name;
115 struct gpio_desc *gpiod;
118 config = devm_kzalloc(dev, sizeof(*config), GFP_KERNEL);
120 return ERR_PTR(-ENOMEM);
122 ret = device_property_read_string(dev, "supply-name", &supply_name);
124 config->supply_name = supply_name;
126 gpiod = gpiod_get(dev, "gpio", GPIOD_ASIS);
128 return ERR_PTR(-ENODEV);
130 config->gpio = desc_to_gpio(gpiod);
131 config->enable_high = device_property_read_bool(dev,
132 "enable-active-high");
138 static struct regulator_ops fixed_voltage_ops = {
141 static int reg_fixed_voltage_probe(struct platform_device *pdev)
143 struct fixed_voltage_config *config;
144 struct fixed_voltage_data *drvdata;
145 struct regulator_config cfg = { };
148 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct fixed_voltage_data),
153 if (pdev->dev.of_node) {
154 config = of_get_fixed_voltage_config(&pdev->dev,
157 return PTR_ERR(config);
158 } else if (ACPI_HANDLE(&pdev->dev)) {
159 config = acpi_get_fixed_voltage_config(&pdev->dev,
162 return PTR_ERR(config);
164 config = dev_get_platdata(&pdev->dev);
170 drvdata->desc.name = devm_kstrdup(&pdev->dev,
173 if (drvdata->desc.name == NULL) {
174 dev_err(&pdev->dev, "Failed to allocate supply name\n");
177 drvdata->desc.type = REGULATOR_VOLTAGE;
178 drvdata->desc.owner = THIS_MODULE;
179 drvdata->desc.ops = &fixed_voltage_ops;
181 drvdata->desc.enable_time = config->startup_delay;
183 if (config->input_supply) {
184 drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
185 config->input_supply,
187 if (!drvdata->desc.supply_name) {
189 "Failed to allocate input supply\n");
194 if (config->microvolts)
195 drvdata->desc.n_voltages = 1;
197 drvdata->desc.fixed_uV = config->microvolts;
199 if (gpio_is_valid(config->gpio)) {
200 cfg.ena_gpio = config->gpio;
201 if (pdev->dev.of_node)
202 cfg.ena_gpio_initialized = true;
204 cfg.ena_gpio_invert = !config->enable_high;
205 if (config->enabled_at_boot) {
206 if (config->enable_high)
207 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
209 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
211 if (config->enable_high)
212 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
214 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
216 if (config->gpio_is_open_drain)
217 cfg.ena_gpio_flags |= GPIOF_OPEN_DRAIN;
219 cfg.dev = &pdev->dev;
220 cfg.init_data = config->init_data;
221 cfg.driver_data = drvdata;
222 cfg.of_node = pdev->dev.of_node;
224 drvdata->dev = devm_regulator_register(&pdev->dev, &drvdata->desc,
226 if (IS_ERR(drvdata->dev)) {
227 ret = PTR_ERR(drvdata->dev);
228 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
232 platform_set_drvdata(pdev, drvdata);
234 dev_dbg(&pdev->dev, "%s supplying %duV\n", drvdata->desc.name,
235 drvdata->desc.fixed_uV);
240 #if defined(CONFIG_OF)
241 static const struct of_device_id fixed_of_match[] = {
242 { .compatible = "regulator-fixed", },
245 MODULE_DEVICE_TABLE(of, fixed_of_match);
248 static struct platform_driver regulator_fixed_voltage_driver = {
249 .probe = reg_fixed_voltage_probe,
251 .name = "reg-fixed-voltage",
252 .of_match_table = of_match_ptr(fixed_of_match),
256 static int __init regulator_fixed_voltage_init(void)
258 return platform_driver_register(®ulator_fixed_voltage_driver);
260 subsys_initcall(regulator_fixed_voltage_init);
262 static void __exit regulator_fixed_voltage_exit(void)
264 platform_driver_unregister(®ulator_fixed_voltage_driver);
266 module_exit(regulator_fixed_voltage_exit);
268 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
269 MODULE_DESCRIPTION("Fixed voltage regulator");
270 MODULE_LICENSE("GPL");
271 MODULE_ALIAS("platform:reg-fixed-voltage");