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