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_sel(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         return (val & WM8994_LDO1_VSEL_MASK) >> WM8994_LDO1_VSEL_SHIFT;
  99 }
 100
 101 static int wm8994_ldo1_set_voltage(struct regulator_dev *rdev,
 102                                    int min_uV, int max_uV, unsigned *s)
 103 {
 104         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 105         int selector, v;
 106
 107         selector = (min_uV - 2400000) / 100000;
 108         v = wm8994_ldo1_list_voltage(rdev, selector);
 109         if (v < 0 || v > max_uV)
 110                 return -EINVAL;
 111
 112         *s = selector;
 113         selector <<= WM8994_LDO1_VSEL_SHIFT;
 114
 115         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_1,
 116                                WM8994_LDO1_VSEL_MASK, selector);
 117 }
 118
 119 static struct regulator_ops wm8994_ldo1_ops = {
 120         .enable = wm8994_ldo_enable,
 121         .disable = wm8994_ldo_disable,
 122         .is_enabled = wm8994_ldo_is_enabled,
 123         .enable_time = wm8994_ldo_enable_time,
 124
 125         .list_voltage = wm8994_ldo1_list_voltage,
 126         .get_voltage_sel = wm8994_ldo1_get_voltage_sel,
 127         .set_voltage = wm8994_ldo1_set_voltage,
 128 };
 129
 130 static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
 131                                     unsigned int selector)
 132 {
 133         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 134
 135         if (selector > WM8994_LDO2_MAX_SELECTOR)
 136                 return -EINVAL;
 137
 138         switch (ldo->wm8994->type) {
 139         case WM8994:
 140                 return (selector * 100000) + 900000;
 141         case WM8958:
 142                 return (selector * 100000) + 1000000;
 143         default:
 144                 return -EINVAL;
 145         }
 146 }
 147
 148 static int wm8994_ldo2_get_voltage_sel(struct regulator_dev *rdev)
 149 {
 150         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 151         int val;
 152
 153         val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
 154         if (val < 0)
 155                 return val;
 156
 157         return (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
 158 }
 159
 160 static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
 161                                    int min_uV, int max_uV, unsigned *s)
 162 {
 163         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 164         int selector, v;
 165
 166         switch (ldo->wm8994->type) {
 167         case WM8994:
 168                 selector = (min_uV - 900000) / 100000;
 169                 break;
 170         case WM8958:
 171                 selector = (min_uV - 1000000) / 100000;
 172                 break;
 173         default:
 174                 return -EINVAL;
 175         }
 176
 177         v = wm8994_ldo2_list_voltage(rdev, selector);
 178         if (v < 0 || v > max_uV)
 179                 return -EINVAL;
 180
 181         *s = selector;
 182         selector <<= WM8994_LDO2_VSEL_SHIFT;
 183
 184         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
 185                                WM8994_LDO2_VSEL_MASK, selector);
 186 }
 187
 188 static struct regulator_ops wm8994_ldo2_ops = {
 189         .enable = wm8994_ldo_enable,
 190         .disable = wm8994_ldo_disable,
 191         .is_enabled = wm8994_ldo_is_enabled,
 192         .enable_time = wm8994_ldo_enable_time,
 193
 194         .list_voltage = wm8994_ldo2_list_voltage,
 195         .get_voltage_sel = wm8994_ldo2_get_voltage_sel,
 196         .set_voltage = wm8994_ldo2_set_voltage,
 197 };
 198
 199 static struct regulator_desc wm8994_ldo_desc[] = {
 200         {
 201                 .name = "LDO1",
 202                 .id = 1,
 203                 .type = REGULATOR_VOLTAGE,
 204                 .n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
 205                 .ops = &wm8994_ldo1_ops,
 206                 .owner = THIS_MODULE,
 207         },
 208         {
 209                 .name = "LDO2",
 210                 .id = 2,
 211                 .type = REGULATOR_VOLTAGE,
 212                 .n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
 213                 .ops = &wm8994_ldo2_ops,
 214                 .owner = THIS_MODULE,
 215         },
 216 };
 217
 218 static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
 219 {
 220         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 221         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 222         int id = pdev->id % ARRAY_SIZE(pdata->ldo);
 223         struct wm8994_ldo *ldo;
 224         int ret;
 225
 226         dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
 227
 228         if (!pdata)
 229                 return -ENODEV;
 230
 231         ldo = kzalloc(sizeof(struct wm8994_ldo), GFP_KERNEL);
 232         if (ldo == NULL) {
 233                 dev_err(&pdev->dev, "Unable to allocate private data\n");
 234                 return -ENOMEM;
 235         }
 236
 237         ldo->wm8994 = wm8994;
 238
 239         if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
 240                 ldo->enable = pdata->ldo[id].enable;
 241
 242                 ret = gpio_request(ldo->enable, "WM8994 LDO enable");
 243                 if (ret < 0) {
 244                         dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
 245                                 ret);
 246                         goto err;
 247                 }
 248
 249                 ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
 250                 if (ret < 0) {
 251                         dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
 252                                 ret);
 253                         goto err_gpio;
 254                 }
 255         } else
 256                 ldo->is_enabled = true;
 257
 258         ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
 259                                              pdata->ldo[id].init_data, ldo);
 260         if (IS_ERR(ldo->regulator)) {
 261                 ret = PTR_ERR(ldo->regulator);
 262                 dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
 263                         id + 1, ret);
 264                 goto err_gpio;
 265         }
 266
 267         platform_set_drvdata(pdev, ldo);
 268
 269         return 0;
 270
 271 err_gpio:
 272         if (gpio_is_valid(ldo->enable))
 273                 gpio_free(ldo->enable);
 274 err:
 275         kfree(ldo);
 276         return ret;
 277 }
 278
 279 static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
 280 {
 281         struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
 282
 283         platform_set_drvdata(pdev, NULL);
 284
 285         regulator_unregister(ldo->regulator);
 286         if (gpio_is_valid(ldo->enable))
 287                 gpio_free(ldo->enable);
 288         kfree(ldo);
 289
 290         return 0;
 291 }
 292
 293 static struct platform_driver wm8994_ldo_driver = {
 294         .probe = wm8994_ldo_probe,
 295         .remove = __devexit_p(wm8994_ldo_remove),
 296         .driver         = {
 297                 .name   = "wm8994-ldo",
 298                 .owner  = THIS_MODULE,
 299         },
 300 };
 301
 302 static int __init wm8994_ldo_init(void)
 303 {
 304         int ret;
 305
 306         ret = platform_driver_register(&wm8994_ldo_driver);
 307         if (ret != 0)
 308                 pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
 309
 310         return ret;
 311 }
 312 subsys_initcall(wm8994_ldo_init);
 313
 314 static void __exit wm8994_ldo_exit(void)
 315 {
 316         platform_driver_unregister(&wm8994_ldo_driver);
 317 }
 318 module_exit(wm8994_ldo_exit);
 319
 320 /* Module information */
 321 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 322 MODULE_DESCRIPTION("WM8994 LDO driver");
 323 MODULE_LICENSE("GPL");
 324 MODULE_ALIAS("platform:wm8994-ldo");