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_cansleep(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_cansleep(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         case WM1811:
 144                 switch (selector) {
 145                 case 0:
 146                         return -EINVAL;
 147                 default:
 148                         return (selector * 100000) + 950000;
 149                 }
 150                 break;
 151         default:
 152                 return -EINVAL;
 153         }
 154 }
 155
 156 static int wm8994_ldo2_get_voltage_sel(struct regulator_dev *rdev)
 157 {
 158         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 159         int val;
 160
 161         val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
 162         if (val < 0)
 163                 return val;
 164
 165         return (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
 166 }
 167
 168 static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
 169                                    int min_uV, int max_uV, unsigned *s)
 170 {
 171         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 172         int selector, v;
 173
 174         switch (ldo->wm8994->type) {
 175         case WM8994:
 176                 selector = (min_uV - 900000) / 100000;
 177                 break;
 178         case WM8958:
 179                 selector = (min_uV - 1000000) / 100000;
 180                 break;
 181         case WM1811:
 182                 selector = (min_uV - 950000) / 100000;
 183                 if (selector == 0)
 184                         selector = 1;
 185                 break;
 186         default:
 187                 return -EINVAL;
 188         }
 189
 190         v = wm8994_ldo2_list_voltage(rdev, selector);
 191         if (v < 0 || v > max_uV)
 192                 return -EINVAL;
 193
 194         *s = selector;
 195         selector <<= WM8994_LDO2_VSEL_SHIFT;
 196
 197         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
 198                                WM8994_LDO2_VSEL_MASK, selector);
 199 }
 200
 201 static struct regulator_ops wm8994_ldo2_ops = {
 202         .enable = wm8994_ldo_enable,
 203         .disable = wm8994_ldo_disable,
 204         .is_enabled = wm8994_ldo_is_enabled,
 205         .enable_time = wm8994_ldo_enable_time,
 206
 207         .list_voltage = wm8994_ldo2_list_voltage,
 208         .get_voltage_sel = wm8994_ldo2_get_voltage_sel,
 209         .set_voltage = wm8994_ldo2_set_voltage,
 210 };
 211
 212 static struct regulator_desc wm8994_ldo_desc[] = {
 213         {
 214                 .name = "LDO1",
 215                 .id = 1,
 216                 .type = REGULATOR_VOLTAGE,
 217                 .n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
 218                 .ops = &wm8994_ldo1_ops,
 219                 .owner = THIS_MODULE,
 220         },
 221         {
 222                 .name = "LDO2",
 223                 .id = 2,
 224                 .type = REGULATOR_VOLTAGE,
 225                 .n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
 226                 .ops = &wm8994_ldo2_ops,
 227                 .owner = THIS_MODULE,
 228         },
 229 };
 230
 231 static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
 232 {
 233         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 234         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 235         int id = pdev->id % ARRAY_SIZE(pdata->ldo);
 236         struct wm8994_ldo *ldo;
 237         int ret;
 238
 239         dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
 240
 241         if (!pdata)
 242                 return -ENODEV;
 243
 244         ldo = devm_kzalloc(&pdev->dev, sizeof(struct wm8994_ldo), GFP_KERNEL);
 245         if (ldo == NULL) {
 246                 dev_err(&pdev->dev, "Unable to allocate private data\n");
 247                 return -ENOMEM;
 248         }
 249
 250         ldo->wm8994 = wm8994;
 251
 252         if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
 253                 ldo->enable = pdata->ldo[id].enable;
 254
 255                 ret = gpio_request(ldo->enable, "WM8994 LDO enable");
 256                 if (ret < 0) {
 257                         dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
 258                                 ret);
 259                         goto err;
 260                 }
 261
 262                 ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
 263                 if (ret < 0) {
 264                         dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
 265                                 ret);
 266                         goto err_gpio;
 267                 }
 268         } else
 269                 ldo->is_enabled = true;
 270
 271         ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
 272                                              pdata->ldo[id].init_data, ldo, NULL);
 273         if (IS_ERR(ldo->regulator)) {
 274                 ret = PTR_ERR(ldo->regulator);
 275                 dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
 276                         id + 1, ret);
 277                 goto err_gpio;
 278         }
 279
 280         platform_set_drvdata(pdev, ldo);
 281
 282         return 0;
 283
 284 err_gpio:
 285         if (gpio_is_valid(ldo->enable))
 286                 gpio_free(ldo->enable);
 287 err:
 288         return ret;
 289 }
 290
 291 static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
 292 {
 293         struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
 294
 295         platform_set_drvdata(pdev, NULL);
 296
 297         regulator_unregister(ldo->regulator);
 298         if (gpio_is_valid(ldo->enable))
 299                 gpio_free(ldo->enable);
 300
 301         return 0;
 302 }
 303
 304 static struct platform_driver wm8994_ldo_driver = {
 305         .probe = wm8994_ldo_probe,
 306         .remove = __devexit_p(wm8994_ldo_remove),
 307         .driver         = {
 308                 .name   = "wm8994-ldo",
 309                 .owner  = THIS_MODULE,
 310         },
 311 };
 312
 313 static int __init wm8994_ldo_init(void)
 314 {
 315         int ret;
 316
 317         ret = platform_driver_register(&wm8994_ldo_driver);
 318         if (ret != 0)
 319                 pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
 320
 321         return ret;
 322 }
 323 subsys_initcall(wm8994_ldo_init);
 324
 325 static void __exit wm8994_ldo_exit(void)
 326 {
 327         platform_driver_unregister(&wm8994_ldo_driver);
 328 }
 329 module_exit(wm8994_ldo_exit);
 330
 331 /* Module information */
 332 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 333 MODULE_DESCRIPTION("WM8994 LDO driver");
 334 MODULE_LICENSE("GPL");
 335 MODULE_ALIAS("platform:wm8994-ldo");