4 * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
8 * Copyright 2008 Wolfson Microelectronics PLC.
10 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
12 * Copyright (c) 2009 Nokia Corporation
13 * Roger Quadros <ext-roger.quadros@nokia.com>
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License as
17 * published by the Free Software Foundation; either version 2 of the
18 * License, or (at your option) any later version.
20 * This is useful for systems with mixed controllable and
21 * non-controllable regulators, as well as for allowing testing on
22 * systems with no controllable regulators.
25 #include <linux/err.h>
26 #include <linux/mutex.h>
27 #include <linux/module.h>
28 #include <linux/platform_device.h>
29 #include <linux/regulator/driver.h>
30 #include <linux/regulator/machine.h>
31 #include <linux/regulator/of_regulator.h>
32 #include <linux/regulator/gpio-regulator.h>
33 #include <linux/gpio.h>
34 #include <linux/slab.h>
36 #include <linux/of_gpio.h>
38 struct gpio_regulator_data {
39 struct regulator_desc desc;
40 struct regulator_dev *dev;
45 struct gpio_regulator_state *states;
51 static int gpio_regulator_get_value(struct regulator_dev *dev)
53 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
56 for (ptr = 0; ptr < data->nr_states; ptr++)
57 if (data->states[ptr].gpios == data->state)
58 return data->states[ptr].value;
63 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
64 int min_uV, int max_uV,
67 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
68 int ptr, target = 0, state, best_val = INT_MAX;
70 for (ptr = 0; ptr < data->nr_states; ptr++)
71 if (data->states[ptr].value < best_val &&
72 data->states[ptr].value >= min_uV &&
73 data->states[ptr].value <= max_uV) {
74 target = data->states[ptr].gpios;
75 best_val = data->states[ptr].value;
80 if (best_val == INT_MAX)
83 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
84 state = (target & (1 << ptr)) >> ptr;
85 gpio_set_value(data->gpios[ptr].gpio, state);
92 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
95 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
97 if (selector >= data->nr_states)
100 return data->states[selector].value;
103 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
104 int min_uA, int max_uA)
106 struct gpio_regulator_data *data = rdev_get_drvdata(dev);
107 int ptr, target = 0, state, best_val = 0;
109 for (ptr = 0; ptr < data->nr_states; ptr++)
110 if (data->states[ptr].value > best_val &&
111 data->states[ptr].value >= min_uA &&
112 data->states[ptr].value <= max_uA) {
113 target = data->states[ptr].gpios;
114 best_val = data->states[ptr].value;
120 for (ptr = 0; ptr < data->nr_gpios; ptr++) {
121 state = (target & (1 << ptr)) >> ptr;
122 gpio_set_value(data->gpios[ptr].gpio, state);
124 data->state = target;
129 static struct regulator_ops gpio_regulator_voltage_ops = {
130 .get_voltage = gpio_regulator_get_value,
131 .set_voltage = gpio_regulator_set_voltage,
132 .list_voltage = gpio_regulator_list_voltage,
135 struct gpio_regulator_config *
136 of_get_gpio_regulator_config(struct device *dev, struct device_node *np)
138 struct gpio_regulator_config *config;
139 struct property *prop;
141 int proplen, gpio, i;
143 config = devm_kzalloc(dev,
144 sizeof(struct gpio_regulator_config),
147 return ERR_PTR(-ENOMEM);
149 config->init_data = of_get_regulator_init_data(dev, np);
150 if (!config->init_data)
151 return ERR_PTR(-EINVAL);
153 config->supply_name = config->init_data->constraints.name;
155 if (of_property_read_bool(np, "enable-active-high"))
156 config->enable_high = true;
158 if (of_property_read_bool(np, "enable-at-boot"))
159 config->enabled_at_boot = true;
161 of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
163 config->enable_gpio = of_get_named_gpio(np, "enable-gpio", 0);
167 if (of_get_named_gpio(np, "gpios", i) < 0)
169 config->nr_gpios = i;
171 config->gpios = devm_kzalloc(dev,
172 sizeof(struct gpio) * config->nr_gpios,
175 return ERR_PTR(-ENOMEM);
177 for (i = 0; config->nr_gpios; i++) {
178 gpio = of_get_named_gpio(np, "gpios", i);
181 config->gpios[i].gpio = gpio;
185 prop = of_find_property(np, "states", NULL);
186 proplen = prop->length / sizeof(int);
188 config->states = devm_kzalloc(dev,
189 sizeof(struct gpio_regulator_state)
193 return ERR_PTR(-ENOMEM);
195 for (i = 0; i < proplen / 2; i++) {
196 config->states[i].value =
197 be32_to_cpup((int *)prop->value + (i * 2));
198 config->states[i].gpios =
199 be32_to_cpup((int *)prop->value + (i * 2 + 1));
201 config->nr_states = i;
203 of_property_read_string(np, "regulator-type", ®type);
205 if (!strncmp("voltage", regtype, 7))
206 config->type = REGULATOR_VOLTAGE;
207 else if (!strncmp("current", regtype, 7))
208 config->type = REGULATOR_CURRENT;
213 static struct regulator_ops gpio_regulator_current_ops = {
214 .get_current_limit = gpio_regulator_get_value,
215 .set_current_limit = gpio_regulator_set_current_limit,
218 static int __devinit gpio_regulator_probe(struct platform_device *pdev)
220 struct gpio_regulator_config *config = pdev->dev.platform_data;
221 struct device_node *np = pdev->dev.of_node;
222 struct gpio_regulator_data *drvdata;
223 struct regulator_config cfg = { };
227 config = of_get_gpio_regulator_config(&pdev->dev, np);
229 return PTR_ERR(config);
232 drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
234 if (drvdata == NULL) {
235 dev_err(&pdev->dev, "Failed to allocate device data\n");
239 drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
240 if (drvdata->desc.name == NULL) {
241 dev_err(&pdev->dev, "Failed to allocate supply name\n");
246 drvdata->gpios = kmemdup(config->gpios,
247 config->nr_gpios * sizeof(struct gpio),
249 if (drvdata->gpios == NULL) {
250 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
255 drvdata->states = kmemdup(config->states,
257 sizeof(struct gpio_regulator_state),
259 if (drvdata->states == NULL) {
260 dev_err(&pdev->dev, "Failed to allocate state data\n");
264 drvdata->nr_states = config->nr_states;
266 drvdata->desc.owner = THIS_MODULE;
267 drvdata->desc.enable_time = config->startup_delay;
269 /* handle regulator type*/
270 switch (config->type) {
271 case REGULATOR_VOLTAGE:
272 drvdata->desc.type = REGULATOR_VOLTAGE;
273 drvdata->desc.ops = &gpio_regulator_voltage_ops;
274 drvdata->desc.n_voltages = config->nr_states;
276 case REGULATOR_CURRENT:
277 drvdata->desc.type = REGULATOR_CURRENT;
278 drvdata->desc.ops = &gpio_regulator_current_ops;
281 dev_err(&pdev->dev, "No regulator type set\n");
287 drvdata->nr_gpios = config->nr_gpios;
288 ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
291 "Could not obtain regulator setting GPIOs: %d\n", ret);
295 /* build initial state from gpio init data. */
297 for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
298 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
301 drvdata->state = state;
303 cfg.dev = &pdev->dev;
304 cfg.init_data = config->init_data;
305 cfg.driver_data = drvdata;
307 if (config->enable_gpio >= 0)
308 cfg.ena_gpio = config->enable_gpio;
309 cfg.ena_gpio_invert = !config->enable_high;
310 if (config->enabled_at_boot) {
311 if (config->enable_high)
312 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
314 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
316 if (config->enable_high)
317 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_LOW;
319 cfg.ena_gpio_flags |= GPIOF_OUT_INIT_HIGH;
322 drvdata->dev = regulator_register(&drvdata->desc, &cfg);
323 if (IS_ERR(drvdata->dev)) {
324 ret = PTR_ERR(drvdata->dev);
325 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
329 platform_set_drvdata(pdev, drvdata);
334 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
336 kfree(drvdata->states);
338 kfree(drvdata->gpios);
340 kfree(drvdata->desc.name);
345 static int __devexit gpio_regulator_remove(struct platform_device *pdev)
347 struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
349 regulator_unregister(drvdata->dev);
351 gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
353 kfree(drvdata->states);
354 kfree(drvdata->gpios);
356 kfree(drvdata->desc.name);
361 static const struct of_device_id regulator_gpio_of_match[] __devinitconst = {
362 { .compatible = "regulator-gpio", },
366 static struct platform_driver gpio_regulator_driver = {
367 .probe = gpio_regulator_probe,
368 .remove = __devexit_p(gpio_regulator_remove),
370 .name = "gpio-regulator",
371 .owner = THIS_MODULE,
372 .of_match_table = regulator_gpio_of_match,
376 static int __init gpio_regulator_init(void)
378 return platform_driver_register(&gpio_regulator_driver);
380 subsys_initcall(gpio_regulator_init);
382 static void __exit gpio_regulator_exit(void)
384 platform_driver_unregister(&gpio_regulator_driver);
386 module_exit(gpio_regulator_exit);
388 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
389 MODULE_DESCRIPTION("gpio voltage regulator");
390 MODULE_LICENSE("GPL");
391 MODULE_ALIAS("platform:gpio-regulator");