drivers/regulator/wm8994-regulator.c

   1 /*
   2  * wm8994-regulator.c  --  Regulator driver for the WM8994
   3  *
   4  * Copyright 2009 Wolfson Microelectronics PLC.
   5  *
   6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7  *
   8  *  This program is free software; you can redistribute  it and/or modify it
   9  *  under  the terms of  the GNU General  Public License as published by the
  10  *  Free Software Foundation;  either version 2 of the  License, or (at your
  11  *  option) any later version.
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/moduleparam.h>
  16 #include <linux/init.h>
  17 #include <linux/bitops.h>
  18 #include <linux/err.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/regulator/driver.h>
  21 #include <linux/gpio.h>
  22 #include <linux/slab.h>
  23
  24 #include <linux/mfd/wm8994/core.h>
  25 #include <linux/mfd/wm8994/registers.h>
  26 #include <linux/mfd/wm8994/pdata.h>
  27
  28 struct wm8994_ldo {
  29         int enable;
  30         bool is_enabled;
  31         struct regulator_dev *regulator;
  32         struct wm8994 *wm8994;
  33 };
  34
  35 #define WM8994_LDO1_MAX_SELECTOR 0x7
  36 #define WM8994_LDO2_MAX_SELECTOR 0x3
  37
  38 static int wm8994_ldo_enable(struct regulator_dev *rdev)
  39 {
  40         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  41
  42         /* If we have no soft control assume that the LDO is always enabled. */
  43         if (!ldo->enable)
  44                 return 0;
  45
  46         gpio_set_value(ldo->enable, 1);
  47         ldo->is_enabled = true;
  48
  49         return 0;
  50 }
  51
  52 static int wm8994_ldo_disable(struct regulator_dev *rdev)
  53 {
  54         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  55
  56         /* If we have no soft control assume that the LDO is always enabled. */
  57         if (!ldo->enable)
  58                 return -EINVAL;
  59
  60         gpio_set_value(ldo->enable, 0);
  61         ldo->is_enabled = false;
  62
  63         return 0;
  64 }
  65
  66 static int wm8994_ldo_is_enabled(struct regulator_dev *rdev)
  67 {
  68         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  69
  70         return ldo->is_enabled;
  71 }
  72
  73 static int wm8994_ldo_enable_time(struct regulator_dev *rdev)
  74 {
  75         /* 3ms is fairly conservative but this shouldn't be too performance
  76          * critical; can be tweaked per-system if required. */
  77         return 3000;
  78 }
  79
  80 static int wm8994_ldo1_list_voltage(struct regulator_dev *rdev,
  81                                     unsigned int selector)
  82 {
  83         if (selector > WM8994_LDO1_MAX_SELECTOR)
  84                 return -EINVAL;
  85
  86         return (selector * 100000) + 2400000;
  87 }
  88
  89 static int wm8994_ldo1_get_voltage(struct regulator_dev *rdev)
  90 {
  91         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  92         int val;
  93
  94         val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_1);
  95         if (val < 0)
  96                 return val;
  97
  98         val = (val & WM8994_LDO1_VSEL_MASK) >> WM8994_LDO1_VSEL_SHIFT;
  99
 100         return wm8994_ldo1_list_voltage(rdev, val);
 101 }
 102
 103 static int wm8994_ldo1_set_voltage(struct regulator_dev *rdev,
 104                                    int min_uV, int max_uV, unsigned *s)
 105 {
 106         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 107         int selector, v;
 108
 109         selector = (min_uV - 2400000) / 100000;
 110         v = wm8994_ldo1_list_voltage(rdev, selector);
 111         if (v < 0 || v > max_uV)
 112                 return -EINVAL;
 113
 114         *s = selector;
 115         selector <<= WM8994_LDO1_VSEL_SHIFT;
 116
 117         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_1,
 118                                WM8994_LDO1_VSEL_MASK, selector);
 119 }
 120
 121 static struct regulator_ops wm8994_ldo1_ops = {
 122         .enable = wm8994_ldo_enable,
 123         .disable = wm8994_ldo_disable,
 124         .is_enabled = wm8994_ldo_is_enabled,
 125         .enable_time = wm8994_ldo_enable_time,
 126
 127         .list_voltage = wm8994_ldo1_list_voltage,
 128         .get_voltage = wm8994_ldo1_get_voltage,
 129         .set_voltage = wm8994_ldo1_set_voltage,
 130 };
 131
 132 static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
 133                                     unsigned int selector)
 134 {
 135         if (selector > WM8994_LDO2_MAX_SELECTOR)
 136                 return -EINVAL;
 137
 138         return (selector * 100000) + 900000;
 139 }
 140
 141 static int wm8994_ldo2_get_voltage(struct regulator_dev *rdev)
 142 {
 143         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 144         int val;
 145
 146         val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
 147         if (val < 0)
 148                 return val;
 149
 150         val = (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
 151
 152         return wm8994_ldo2_list_voltage(rdev, val);
 153 }
 154
 155 static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
 156                                    int min_uV, int max_uV, unsigned *s)
 157 {
 158         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 159         int selector, v;
 160
 161         selector = (min_uV - 900000) / 100000;
 162         v = wm8994_ldo2_list_voltage(rdev, selector);
 163         if (v < 0 || v > max_uV)
 164                 return -EINVAL;
 165
 166         *s = selector;
 167         selector <<= WM8994_LDO2_VSEL_SHIFT;
 168
 169         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
 170                                WM8994_LDO2_VSEL_MASK, selector);
 171 }
 172
 173 static struct regulator_ops wm8994_ldo2_ops = {
 174         .enable = wm8994_ldo_enable,
 175         .disable = wm8994_ldo_disable,
 176         .is_enabled = wm8994_ldo_is_enabled,
 177         .enable_time = wm8994_ldo_enable_time,
 178
 179         .list_voltage = wm8994_ldo2_list_voltage,
 180         .get_voltage = wm8994_ldo2_get_voltage,
 181         .set_voltage = wm8994_ldo2_set_voltage,
 182 };
 183
 184 static struct regulator_desc wm8994_ldo_desc[] = {
 185         {
 186                 .name = "LDO1",
 187                 .id = 1,
 188                 .type = REGULATOR_VOLTAGE,
 189                 .n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
 190                 .ops = &wm8994_ldo1_ops,
 191                 .owner = THIS_MODULE,
 192         },
 193         {
 194                 .name = "LDO2",
 195                 .id = 2,
 196                 .type = REGULATOR_VOLTAGE,
 197                 .n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
 198                 .ops = &wm8994_ldo2_ops,
 199                 .owner = THIS_MODULE,
 200         },
 201 };
 202
 203 static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
 204 {
 205         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 206         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 207         int id = pdev->id % ARRAY_SIZE(pdata->ldo);
 208         struct wm8994_ldo *ldo;
 209         int ret;
 210
 211         dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
 212
 213         if (!pdata)
 214                 return -ENODEV;
 215
 216         ldo = kzalloc(sizeof(struct wm8994_ldo), GFP_KERNEL);
 217         if (ldo == NULL) {
 218                 dev_err(&pdev->dev, "Unable to allocate private data\n");
 219                 return -ENOMEM;
 220         }
 221
 222         ldo->wm8994 = wm8994;
 223
 224         if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
 225                 ldo->enable = pdata->ldo[id].enable;
 226
 227                 ret = gpio_request(ldo->enable, "WM8994 LDO enable");
 228                 if (ret < 0) {
 229                         dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
 230                                 ret);
 231                         goto err;
 232                 }
 233
 234                 ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
 235                 if (ret < 0) {
 236                         dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
 237                                 ret);
 238                         goto err_gpio;
 239                 }
 240         } else
 241                 ldo->is_enabled = true;
 242
 243         ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
 244                                              pdata->ldo[id].init_data, ldo);
 245         if (IS_ERR(ldo->regulator)) {
 246                 ret = PTR_ERR(ldo->regulator);
 247                 dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
 248                         id + 1, ret);
 249                 goto err_gpio;
 250         }
 251
 252         platform_set_drvdata(pdev, ldo);
 253
 254         return 0;
 255
 256 err_gpio:
 257         if (gpio_is_valid(ldo->enable))
 258                 gpio_free(ldo->enable);
 259 err:
 260         kfree(ldo);
 261         return ret;
 262 }
 263
 264 static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
 265 {
 266         struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
 267
 268         platform_set_drvdata(pdev, NULL);
 269
 270         regulator_unregister(ldo->regulator);
 271         if (gpio_is_valid(ldo->enable))
 272                 gpio_free(ldo->enable);
 273         kfree(ldo);
 274
 275         return 0;
 276 }
 277
 278 static struct platform_driver wm8994_ldo_driver = {
 279         .probe = wm8994_ldo_probe,
 280         .remove = __devexit_p(wm8994_ldo_remove),
 281         .driver         = {
 282                 .name   = "wm8994-ldo",
 283                 .owner  = THIS_MODULE,
 284         },
 285 };
 286
 287 static int __init wm8994_ldo_init(void)
 288 {
 289         int ret;
 290
 291         ret = platform_driver_register(&wm8994_ldo_driver);
 292         if (ret != 0)
 293                 pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
 294
 295         return ret;
 296 }
 297 subsys_initcall(wm8994_ldo_init);
 298
 299 static void __exit wm8994_ldo_exit(void)
 300 {
 301         platform_driver_unregister(&wm8994_ldo_driver);
 302 }
 303 module_exit(wm8994_ldo_exit);
 304
 305 /* Module information */
 306 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 307 MODULE_DESCRIPTION("WM8994 LDO driver");
 308 MODULE_LICENSE("GPL");
 309 MODULE_ALIAS("platform:wm8994-ldo");