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