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