Pileus Git - ~andy/linux/blob - drivers/regulator/gpio-regulator.c

   1 /*
   2  * gpio-regulator.c
   3  *
   4  * Copyright 2011 Heiko Stuebner <heiko@sntech.de>
   5  *
   6  * based on fixed.c
   7  *
   8  * Copyright 2008 Wolfson Microelectronics PLC.
   9  *
  10  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  11  *
  12  * Copyright (c) 2009 Nokia Corporation
  13  * Roger Quadros <ext-roger.quadros@nokia.com>
  14  *
  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.
  19  *
  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.
  23  */
  24
  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/gpio-regulator.h>
  32 #include <linux/gpio.h>
  33 #include <linux/slab.h>
  34
  35 struct gpio_regulator_data {
  36         struct regulator_desc desc;
  37         struct regulator_dev *dev;
  38
  39         int enable_gpio;
  40         bool enable_high;
  41         bool is_enabled;
  42         unsigned startup_delay;
  43
  44         struct gpio *gpios;
  45         int nr_gpios;
  46
  47         struct gpio_regulator_state *states;
  48         int nr_states;
  49
  50         int state;
  51 };
  52
  53 static int gpio_regulator_is_enabled(struct regulator_dev *dev)
  54 {
  55         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
  56
  57         return data->is_enabled;
  58 }
  59
  60 static int gpio_regulator_enable(struct regulator_dev *dev)
  61 {
  62         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
  63
  64         if (gpio_is_valid(data->enable_gpio)) {
  65                 gpio_set_value_cansleep(data->enable_gpio, data->enable_high);
  66                 data->is_enabled = true;
  67         }
  68
  69         return 0;
  70 }
  71
  72 static int gpio_regulator_disable(struct regulator_dev *dev)
  73 {
  74         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
  75
  76         if (gpio_is_valid(data->enable_gpio)) {
  77                 gpio_set_value_cansleep(data->enable_gpio, !data->enable_high);
  78                 data->is_enabled = false;
  79         }
  80
  81         return 0;
  82 }
  83
  84 static int gpio_regulator_enable_time(struct regulator_dev *dev)
  85 {
  86         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
  87
  88         return data->startup_delay;
  89 }
  90
  91 static int gpio_regulator_get_value(struct regulator_dev *dev)
  92 {
  93         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
  94         int ptr;
  95
  96         for (ptr = 0; ptr < data->nr_states; ptr++)
  97                 if (data->states[ptr].gpios == data->state)
  98                         return data->states[ptr].value;
  99
 100         return -EINVAL;
 101 }
 102
 103 static int gpio_regulator_set_value(struct regulator_dev *dev,
 104                                         int min, int max, unsigned *selector)
 105 {
 106         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
 107         int ptr, target = 0, state, best_val = INT_MAX;
 108
 109         for (ptr = 0; ptr < data->nr_states; ptr++)
 110                 if (data->states[ptr].value < best_val &&
 111                     data->states[ptr].value >= min &&
 112                     data->states[ptr].value <= max) {
 113                         target = data->states[ptr].gpios;
 114                         best_val = data->states[ptr].value;
 115                         if (selector)
 116                                 *selector = ptr;
 117                 }
 118
 119         if (best_val == INT_MAX)
 120                 return -EINVAL;
 121
 122         for (ptr = 0; ptr < data->nr_gpios; ptr++) {
 123                 state = (target & (1 << ptr)) >> ptr;
 124                 gpio_set_value(data->gpios[ptr].gpio, state);
 125         }
 126         data->state = target;
 127
 128         return 0;
 129 }
 130
 131 static int gpio_regulator_set_voltage(struct regulator_dev *dev,
 132                                         int min_uV, int max_uV,
 133                                         unsigned *selector)
 134 {
 135         return gpio_regulator_set_value(dev, min_uV, max_uV, selector);
 136 }
 137
 138 static int gpio_regulator_list_voltage(struct regulator_dev *dev,
 139                                       unsigned selector)
 140 {
 141         struct gpio_regulator_data *data = rdev_get_drvdata(dev);
 142
 143         if (selector >= data->nr_states)
 144                 return -EINVAL;
 145
 146         return data->states[selector].value;
 147 }
 148
 149 static int gpio_regulator_set_current_limit(struct regulator_dev *dev,
 150                                         int min_uA, int max_uA)
 151 {
 152         return gpio_regulator_set_value(dev, min_uA, max_uA, NULL);
 153 }
 154
 155 static struct regulator_ops gpio_regulator_voltage_ops = {
 156         .is_enabled = gpio_regulator_is_enabled,
 157         .enable = gpio_regulator_enable,
 158         .disable = gpio_regulator_disable,
 159         .enable_time = gpio_regulator_enable_time,
 160         .get_voltage = gpio_regulator_get_value,
 161         .set_voltage = gpio_regulator_set_voltage,
 162         .list_voltage = gpio_regulator_list_voltage,
 163 };
 164
 165 static struct regulator_ops gpio_regulator_current_ops = {
 166         .is_enabled = gpio_regulator_is_enabled,
 167         .enable = gpio_regulator_enable,
 168         .disable = gpio_regulator_disable,
 169         .enable_time = gpio_regulator_enable_time,
 170         .get_current_limit = gpio_regulator_get_value,
 171         .set_current_limit = gpio_regulator_set_current_limit,
 172 };
 173
 174 static int __devinit gpio_regulator_probe(struct platform_device *pdev)
 175 {
 176         struct gpio_regulator_config *config = pdev->dev.platform_data;
 177         struct gpio_regulator_data *drvdata;
 178         struct regulator_config cfg = { };
 179         int ptr, ret, state;
 180
 181         drvdata = devm_kzalloc(&pdev->dev, sizeof(struct gpio_regulator_data),
 182                                GFP_KERNEL);
 183         if (drvdata == NULL) {
 184                 dev_err(&pdev->dev, "Failed to allocate device data\n");
 185                 return -ENOMEM;
 186         }
 187
 188         drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
 189         if (drvdata->desc.name == NULL) {
 190                 dev_err(&pdev->dev, "Failed to allocate supply name\n");
 191                 ret = -ENOMEM;
 192                 goto err;
 193         }
 194
 195         drvdata->gpios = kmemdup(config->gpios,
 196                                  config->nr_gpios * sizeof(struct gpio),
 197                                  GFP_KERNEL);
 198         if (drvdata->gpios == NULL) {
 199                 dev_err(&pdev->dev, "Failed to allocate gpio data\n");
 200                 ret = -ENOMEM;
 201                 goto err_name;
 202         }
 203
 204         drvdata->states = kmemdup(config->states,
 205                                   config->nr_states *
 206                                          sizeof(struct gpio_regulator_state),
 207                                   GFP_KERNEL);
 208         if (drvdata->states == NULL) {
 209                 dev_err(&pdev->dev, "Failed to allocate state data\n");
 210                 ret = -ENOMEM;
 211                 goto err_memgpio;
 212         }
 213         drvdata->nr_states = config->nr_states;
 214
 215         drvdata->desc.owner = THIS_MODULE;
 216
 217         /* handle regulator type*/
 218         switch (config->type) {
 219         case REGULATOR_VOLTAGE:
 220                 drvdata->desc.type = REGULATOR_VOLTAGE;
 221                 drvdata->desc.ops = &gpio_regulator_voltage_ops;
 222                 drvdata->desc.n_voltages = config->nr_states;
 223                 break;
 224         case REGULATOR_CURRENT:
 225                 drvdata->desc.type = REGULATOR_CURRENT;
 226                 drvdata->desc.ops = &gpio_regulator_current_ops;
 227                 break;
 228         default:
 229                 dev_err(&pdev->dev, "No regulator type set\n");
 230                 ret = -EINVAL;
 231                 goto err_memgpio;
 232                 break;
 233         }
 234
 235         drvdata->enable_gpio = config->enable_gpio;
 236         drvdata->startup_delay = config->startup_delay;
 237
 238         if (gpio_is_valid(config->enable_gpio)) {
 239                 drvdata->enable_high = config->enable_high;
 240
 241                 ret = gpio_request(config->enable_gpio, config->supply_name);
 242                 if (ret) {
 243                         dev_err(&pdev->dev,
 244                            "Could not obtain regulator enable GPIO %d: %d\n",
 245                                                 config->enable_gpio, ret);
 246                         goto err_memstate;
 247                 }
 248
 249                 /* set output direction without changing state
 250                  * to prevent glitch
 251                  */
 252                 if (config->enabled_at_boot) {
 253                         drvdata->is_enabled = true;
 254                         ret = gpio_direction_output(config->enable_gpio,
 255                                                     config->enable_high);
 256                 } else {
 257                         drvdata->is_enabled = false;
 258                         ret = gpio_direction_output(config->enable_gpio,
 259                                                     !config->enable_high);
 260                 }
 261
 262                 if (ret) {
 263                         dev_err(&pdev->dev,
 264                            "Could not configure regulator enable GPIO %d direction: %d\n",
 265                                                 config->enable_gpio, ret);
 266                         goto err_enablegpio;
 267                 }
 268         } else {
 269                 /* Regulator without GPIO control is considered
 270                  * always enabled
 271                  */
 272                 drvdata->is_enabled = true;
 273         }
 274
 275         drvdata->nr_gpios = config->nr_gpios;
 276         ret = gpio_request_array(drvdata->gpios, drvdata->nr_gpios);
 277         if (ret) {
 278                 dev_err(&pdev->dev,
 279                    "Could not obtain regulator setting GPIOs: %d\n", ret);
 280                 goto err_enablegpio;
 281         }
 282
 283         /* build initial state from gpio init data. */
 284         state = 0;
 285         for (ptr = 0; ptr < drvdata->nr_gpios; ptr++) {
 286                 if (config->gpios[ptr].flags & GPIOF_OUT_INIT_HIGH)
 287                         state |= (1 << ptr);
 288         }
 289         drvdata->state = state;
 290
 291         cfg.dev = &pdev->dev;
 292         cfg.init_data = config->init_data;
 293         cfg.driver_data = drvdata;
 294
 295         drvdata->dev = regulator_register(&drvdata->desc, &cfg);
 296         if (IS_ERR(drvdata->dev)) {
 297                 ret = PTR_ERR(drvdata->dev);
 298                 dev_err(&pdev->dev, "Failed to register regulator: %d\n", ret);
 299                 goto err_stategpio;
 300         }
 301
 302         platform_set_drvdata(pdev, drvdata);
 303
 304         return 0;
 305
 306 err_stategpio:
 307         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
 308 err_enablegpio:
 309         if (gpio_is_valid(config->enable_gpio))
 310                 gpio_free(config->enable_gpio);
 311 err_memstate:
 312         kfree(drvdata->states);
 313 err_memgpio:
 314         kfree(drvdata->gpios);
 315 err_name:
 316         kfree(drvdata->desc.name);
 317 err:
 318         return ret;
 319 }
 320
 321 static int __devexit gpio_regulator_remove(struct platform_device *pdev)
 322 {
 323         struct gpio_regulator_data *drvdata = platform_get_drvdata(pdev);
 324
 325         regulator_unregister(drvdata->dev);
 326
 327         gpio_free_array(drvdata->gpios, drvdata->nr_gpios);
 328
 329         kfree(drvdata->states);
 330         kfree(drvdata->gpios);
 331
 332         if (gpio_is_valid(drvdata->enable_gpio))
 333                 gpio_free(drvdata->enable_gpio);
 334
 335         kfree(drvdata->desc.name);
 336
 337         return 0;
 338 }
 339
 340 static struct platform_driver gpio_regulator_driver = {
 341         .probe          = gpio_regulator_probe,
 342         .remove         = __devexit_p(gpio_regulator_remove),
 343         .driver         = {
 344                 .name           = "gpio-regulator",
 345                 .owner          = THIS_MODULE,
 346         },
 347 };
 348
 349 static int __init gpio_regulator_init(void)
 350 {
 351         return platform_driver_register(&gpio_regulator_driver);
 352 }
 353 subsys_initcall(gpio_regulator_init);
 354
 355 static void __exit gpio_regulator_exit(void)
 356 {
 357         platform_driver_unregister(&gpio_regulator_driver);
 358 }
 359 module_exit(gpio_regulator_exit);
 360
 361 MODULE_AUTHOR("Heiko Stuebner <heiko@sntech.de>");
 362 MODULE_DESCRIPTION("gpio voltage regulator");
 363 MODULE_LICENSE("GPL");
 364 MODULE_ALIAS("platform:gpio-regulator");