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 struct regulator_ops wm8994_ldo1_ops = {
  81         .enable = wm8994_ldo_enable,
  82         .disable = wm8994_ldo_disable,
  83         .is_enabled = wm8994_ldo_is_enabled,
  84         .enable_time = wm8994_ldo_enable_time,
  85
  86         .list_voltage = regulator_list_voltage_linear,
  87         .map_voltage = regulator_map_voltage_linear,
  88         .get_voltage_sel = regulator_get_voltage_sel_regmap,
  89         .set_voltage_sel = regulator_set_voltage_sel_regmap,
  90 };
  91
  92 static int wm8994_ldo2_list_voltage(struct regulator_dev *rdev,
  93                                     unsigned int selector)
  94 {
  95         struct wm8994_ldo *ldo = rdev_get_drvdata(rdev);
  96
  97         if (selector > WM8994_LDO2_MAX_SELECTOR)
  98                 return -EINVAL;
  99
 100         switch (ldo->wm8994->type) {
 101         case WM8994:
 102                 return (selector * 100000) + 900000;
 103         case WM8958:
 104                 return (selector * 100000) + 1000000;
 105         case WM1811:
 106                 switch (selector) {
 107                 case 0:
 108                         return -EINVAL;
 109                 default:
 110                         return (selector * 100000) + 950000;
 111                 }
 112                 break;
 113         default:
 114                 return -EINVAL;
 115         }
 116 }
 117
 118 static struct regulator_ops wm8994_ldo2_ops = {
 119         .enable = wm8994_ldo_enable,
 120         .disable = wm8994_ldo_disable,
 121         .is_enabled = wm8994_ldo_is_enabled,
 122         .enable_time = wm8994_ldo_enable_time,
 123
 124         .list_voltage = wm8994_ldo2_list_voltage,
 125         .get_voltage_sel = regulator_get_voltage_sel_regmap,
 126         .set_voltage_sel = regulator_set_voltage_sel_regmap,
 127 };
 128
 129 static const struct regulator_desc wm8994_ldo_desc[] = {
 130         {
 131                 .name = "LDO1",
 132                 .id = 1,
 133                 .type = REGULATOR_VOLTAGE,
 134                 .n_voltages = WM8994_LDO1_MAX_SELECTOR + 1,
 135                 .vsel_reg = WM8994_LDO_1,
 136                 .vsel_mask = WM8994_LDO1_VSEL_MASK,
 137                 .ops = &wm8994_ldo1_ops,
 138                 .min_uV = 2400000,
 139                 .uV_step = 100000,
 140                 .owner = THIS_MODULE,
 141         },
 142         {
 143                 .name = "LDO2",
 144                 .id = 2,
 145                 .type = REGULATOR_VOLTAGE,
 146                 .n_voltages = WM8994_LDO2_MAX_SELECTOR + 1,
 147                 .vsel_reg = WM8994_LDO_2,
 148                 .vsel_mask = WM8994_LDO2_VSEL_MASK,
 149                 .ops = &wm8994_ldo2_ops,
 150                 .owner = THIS_MODULE,
 151         },
 152 };
 153
 154 static __devinit int wm8994_ldo_probe(struct platform_device *pdev)
 155 {
 156         struct wm8994 *wm8994 = dev_get_drvdata(pdev->dev.parent);
 157         struct wm8994_pdata *pdata = wm8994->dev->platform_data;
 158         int id = pdev->id % ARRAY_SIZE(pdata->ldo);
 159         struct regulator_config config = { };
 160         struct wm8994_ldo *ldo;
 161         int ret;
 162
 163         dev_dbg(&pdev->dev, "Probing LDO%d\n", id + 1);
 164
 165         ldo = devm_kzalloc(&pdev->dev, sizeof(struct wm8994_ldo), GFP_KERNEL);
 166         if (ldo == NULL) {
 167                 dev_err(&pdev->dev, "Unable to allocate private data\n");
 168                 return -ENOMEM;
 169         }
 170
 171         ldo->wm8994 = wm8994;
 172
 173         if (pdata->ldo[id].enable && gpio_is_valid(pdata->ldo[id].enable)) {
 174                 ldo->enable = pdata->ldo[id].enable;
 175
 176                 ret = gpio_request_one(ldo->enable, 0, "WM8994 LDO enable");
 177                 if (ret < 0) {
 178                         dev_err(&pdev->dev, "Failed to get enable GPIO: %d\n",
 179                                 ret);
 180                         goto err;
 181                 }
 182         } else
 183                 ldo->is_enabled = true;
 184
 185         config.dev = wm8994->dev;
 186         config.driver_data = ldo;
 187         config.regmap = wm8994->regmap;
 188         if (pdata)
 189                 config.init_data = pdata->ldo[id].init_data;
 190
 191         ldo->regulator = regulator_register(&wm8994_ldo_desc[id], &config);
 192         if (IS_ERR(ldo->regulator)) {
 193                 ret = PTR_ERR(ldo->regulator);
 194                 dev_err(wm8994->dev, "Failed to register LDO%d: %d\n",
 195                         id + 1, ret);
 196                 goto err_gpio;
 197         }
 198
 199         platform_set_drvdata(pdev, ldo);
 200
 201         return 0;
 202
 203 err_gpio:
 204         if (gpio_is_valid(ldo->enable))
 205                 gpio_free(ldo->enable);
 206 err:
 207         return ret;
 208 }
 209
 210 static __devexit int wm8994_ldo_remove(struct platform_device *pdev)
 211 {
 212         struct wm8994_ldo *ldo = platform_get_drvdata(pdev);
 213
 214         platform_set_drvdata(pdev, NULL);
 215
 216         regulator_unregister(ldo->regulator);
 217         if (gpio_is_valid(ldo->enable))
 218                 gpio_free(ldo->enable);
 219
 220         return 0;
 221 }
 222
 223 static struct platform_driver wm8994_ldo_driver = {
 224         .probe = wm8994_ldo_probe,
 225         .remove = __devexit_p(wm8994_ldo_remove),
 226         .driver         = {
 227                 .name   = "wm8994-ldo",
 228                 .owner  = THIS_MODULE,
 229         },
 230 };
 231
 232 static int __init wm8994_ldo_init(void)
 233 {
 234         int ret;
 235
 236         ret = platform_driver_register(&wm8994_ldo_driver);
 237         if (ret != 0)
 238                 pr_err("Failed to register Wm8994 GP LDO driver: %d\n", ret);
 239
 240         return ret;
 241 }
 242 subsys_initcall(wm8994_ldo_init);
 243
 244 static void __exit wm8994_ldo_exit(void)
 245 {
 246         platform_driver_unregister(&wm8994_ldo_driver);
 247 }
 248 module_exit(wm8994_ldo_exit);
 249
 250 /* Module information */
 251 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
 252 MODULE_DESCRIPTION("WM8994 LDO driver");
 253 MODULE_LICENSE("GPL");
 254 MODULE_ALIAS("platform:wm8994-ldo");