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)
 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         selector <<= WM8994_LDO1_VSEL_SHIFT;
 115
 116         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_1,
 117                                WM8994_LDO1_VSEL_MASK, selector);
 118 }
 119
 120 static struct regulator_ops wm8994_ldo1_ops = {
 121         .enable = wm8994_ldo_enable,
 122         .disable = wm8994_ldo_disable,
 123         .is_enabled = wm8994_ldo_is_enabled,
 124         .enable_time = wm8994_ldo_enable_time,
 125
 126         .list_voltage = wm8994_ldo1_list_voltage,
 127         .get_voltage = wm8994_ldo1_get_voltage,
 128         .set_voltage = wm8994_ldo1_set_voltage,
 129 };
 130
 131 static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
 132                                     unsigned int selector)
 133 {
 134         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 135
 136         if (selector > WM8994_LDO2_MAX_SELECTOR)
 137                 return -EINVAL;
 138
 139         switch (ldo->wm8994->type) {
 140         case WM8994:
 141                 return (selector * 100000) + 900000;
 142         case WM8958:
 143                 return (selector * 100000) + 1000000;
 144         default:
 145                 return -EINVAL;
 146         }
 147 }
 148
 149 static int wm8994_ldo2_get_voltage(struct regulator_dev *rdev)
 150 {
 151         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 152         int val;
 153
 154         val = wm8994_reg_read(ldo->wm8994, WM8994_LDO_2);
 155         if (val < 0)
 156                 return val;
 157
 158         val = (val & WM8994_LDO2_VSEL_MASK) >> WM8994_LDO2_VSEL_SHIFT;
 159
 160         return wm8994_ldo2_list_voltage(rdev, val);
 161 }
 162
 163 static int wm8994_ldo2_set_voltage(struct regulator_dev *rdev,
 164                                    int min_uV, int max_uV)
 165 {
 166         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
 167         int selector, v;
 168
 169         switch (ldo->wm8994->type) {
 170         case WM8994:
 171                 selector = (min_uV - 900000) / 100000;
 172                 break;
 173         case WM8958:
 174                 selector = (min_uV - 1000000) / 100000;
 175                 break;
 176         default:
 177                 return -EINVAL;
 178         }
 179
 180         v = wm8994_ldo2_list_voltage(rdev, selector);
 181         if (v < 0 || v > max_uV)
 182                 return -EINVAL;
 183
 184         selector <<= WM8994_LDO2_VSEL_SHIFT;
 185
 186         return wm8994_set_bits(ldo->wm8994, WM8994_LDO_2,
 187                                WM8994_LDO2_VSEL_MASK, selector);
 188 }
 189
 190 static struct regulator_ops wm8994_ldo2_ops = {
 191         .enable = wm8994_ldo_enable,
 192         .disable = wm8994_ldo_disable,
 193         .is_enabled = wm8994_ldo_is_enabled,
 194         .enable_time = wm8994_ldo_enable_time,
 195
 196         .list_voltage = wm8994_ldo2_list_voltage,
 197         .get_voltage = wm8994_ldo2_get_voltage,
 198         .set_voltage = wm8994_ldo2_set_voltage,
 199 };
 200
 201 static struct regulator_desc wm8994_ldo_desc[] = {
 202         {
 203                 .name = "LDO1",
 204                 .id = 1,
 205                 .type = REGULATOR_VOLTAGE,
 206                 .n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
 207                 .ops = &wm8994_ldo1_ops,
 208                 .owner = THIS_MODULE,
 209         },
 210         {
 211                 .name = "LDO2",
 212                 .id = 2,
 213                 .type = REGULATOR_VOLTAGE,
 214                 .n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
 215                 .ops = &wm8994_ldo2_ops,
 216                 .owner = THIS_MODULE,
 217         },
 218 };
 219
 220 static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
 221 {
 222         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 223         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 224         int id = pdev->id % ARRAY_SIZE(pdata->ldo);
 225         struct wm8994_ldo *ldo;
 226         int ret;
 227
 228         dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
 229
 230         if (!pdata)
 231                 return -ENODEV;
 232
 233         ldo = kzalloc(sizeof(struct wm8994_ldo), GFP_KERNEL);
 234         if (ldo == NULL) {
 235                 dev_err(&pdev->dev, "Unable to allocate private data\n");
 236                 return -ENOMEM;
 237         }
 238
 239         ldo->wm8994 = wm8994;
 240
 241         if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
 242                 ldo->enable = pdata->ldo[id].enable;
 243
 244                 ret = gpio_request(ldo->enable, "WM8994 LDO enable");
 245                 if (ret < 0) {
 246                         dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
 247                                 ret);
 248                         goto err;
 249                 }
 250
 251                 ret = gpio_direction_output(ldo->enable, ldo->is_enabled);
 252                 if (ret < 0) {
 253                         dev_err(&pdev->dev, "Failed to set GPIO up: %d\n",
 254                                 ret);
 255                         goto err_gpio;
 256                 }
 257         } else
 258                 ldo->is_enabled = true;
 259
 260         ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &pdev->dev,
 261                                              pdata->ldo[id].init_data, ldo);
 262         if (IS_ERR(ldo->regulator)) {
 263                 ret = PTR_ERR(ldo->regulator);
 264                 dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
 265                         id + 1, ret);
 266                 goto err_gpio;
 267         }
 268
 269         platform_set_drvdata(pdev, ldo);
 270
 271         return 0;
 272
 273 err_gpio:
 274         if (gpio_is_valid(ldo->enable))
 275                 gpio_free(ldo->enable);
 276 err:
 277         kfree(ldo);
 278         return ret;
 279 }
 280
 281 static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
 282 {
 283         struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
 284
 285         platform_set_drvdata(pdev, NULL);
 286
 287         regulator_unregister(ldo->regulator);
 288         if (gpio_is_valid(ldo->enable))
 289                 gpio_free(ldo->enable);
 290         kfree(ldo);
 291
 292         return 0;
 293 }
 294
 295 static struct platform_driver wm8994_ldo_driver = {
 296         .probe = wm8994_ldo_probe,
 297         .remove = __devexit_p(wm8994_ldo_remove),
 298         .driver         = {
 299                 .name   = "wm8994-ldo",
 300                 .owner  = THIS_MODULE,
 301         },
 302 };
 303
 304 static int __init wm8994_ldo_init(void)
 305 {
 306         int ret;
 307
 308         ret = platform_driver_register(&wm8994_ldo_driver);
 309         if (ret != 0)
 310                 pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
 311
 312         return ret;
 313 }
 314 subsys_initcall(wm8994_ldo_init);
 315
 316 static void __exit wm8994_ldo_exit(void)
 317 {
 318         platform_driver_unregister(&wm8994_ldo_driver);
 319 }
 320 module_exit(wm8994_ldo_exit);
 321
 322 /* Module information */
 323 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 324 MODULE_DESCRIPTION("WM8994 LDO driver");
 325 MODULE_LICENSE("GPL");
 326 MODULE_ALIAS("platform:wm8994-ldo");