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   1 /*
   2  * wm831x-isink.c  --  Current sink driver for the WM831x series
   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/i2c.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/regulator/driver.h>
  22
  23 #include <linux/mfd/wm831x/core.h>
  24 #include <linux/mfd/wm831x/regulator.h>
  25 #include <linux/mfd/wm831x/pdata.h>
  26
  27 #define WM831X_ISINK_MAX_NAME 7
  28
  29 struct wm831x_isink {
  30         char name[WM831X_ISINK_MAX_NAME];
  31         struct regulator_desc desc;
  32         int reg;
  33         struct wm831x *wm831x;
  34         struct regulator_dev *regulator;
  35 };
  36
  37 static int wm831x_isink_enable(struct regulator_dev *rdev)
  38 {
  39         struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  40         struct wm831x *wm831x = isink->wm831x;
  41         int ret;
  42
  43         /* We have a two stage enable: first start the ISINK... */
  44         ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA,
  45                               WM831X_CS1_ENA);
  46         if (ret != 0)
  47                 return ret;
  48
  49         /* ...then enable drive */
  50         ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE,
  51                               WM831X_CS1_DRIVE);
  52         if (ret != 0)
  53                 wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
  54
  55         return ret;
  56
  57 }
  58
  59 static int wm831x_isink_disable(struct regulator_dev *rdev)
  60 {
  61         struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  62         struct wm831x *wm831x = isink->wm831x;
  63         int ret;
  64
  65         ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0);
  66         if (ret < 0)
  67                 return ret;
  68
  69         ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
  70         if (ret < 0)
  71                 return ret;
  72
  73         return ret;
  74
  75 }
  76
  77 static int wm831x_isink_is_enabled(struct regulator_dev *rdev)
  78 {
  79         struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  80         struct wm831x *wm831x = isink->wm831x;
  81         int ret;
  82
  83         ret = wm831x_reg_read(wm831x, isink->reg);
  84         if (ret < 0)
  85                 return ret;
  86
  87         if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) ==
  88             (WM831X_CS1_ENA | WM831X_CS1_DRIVE))
  89                 return 1;
  90         else
  91                 return 0;
  92 }
  93
  94 static int wm831x_isink_set_current(struct regulator_dev *rdev,
  95                                     int min_uA, int max_uA)
  96 {
  97         struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  98         struct wm831x *wm831x = isink->wm831x;
  99         int ret, i;
 100
 101         for (i = 0; i < ARRAY_SIZE(wm831x_isinkv_values); i++) {
 102                 int val = wm831x_isinkv_values[i];
 103                 if (min_uA >= val && val <= max_uA) {
 104                         ret = wm831x_set_bits(wm831x, isink->reg,
 105                                               WM831X_CS1_ISEL_MASK, i);
 106                         return ret;
 107                 }
 108         }
 109
 110         return -EINVAL;
 111 }
 112
 113 static int wm831x_isink_get_current(struct regulator_dev *rdev)
 114 {
 115         struct wm831x_isink *isink = rdev_get_drvdata(rdev);
 116         struct wm831x *wm831x = isink->wm831x;
 117         int ret;
 118
 119         ret = wm831x_reg_read(wm831x, isink->reg);
 120         if (ret < 0)
 121                 return ret;
 122
 123         ret &= WM831X_CS1_ISEL_MASK;
 124         if (ret > WM831X_ISINK_MAX_ISEL)
 125                 ret = WM831X_ISINK_MAX_ISEL;
 126
 127         return wm831x_isinkv_values[ret];
 128 }
 129
 130 static struct regulator_ops wm831x_isink_ops = {
 131         .is_enabled = wm831x_isink_is_enabled,
 132         .enable = wm831x_isink_enable,
 133         .disable = wm831x_isink_disable,
 134         .set_current_limit = wm831x_isink_set_current,
 135         .get_current_limit = wm831x_isink_get_current,
 136 };
 137
 138 static irqreturn_t wm831x_isink_irq(int irq, void *data)
 139 {
 140         struct wm831x_isink *isink = data;
 141
 142         regulator_notifier_call_chain(isink->regulator,
 143                                       REGULATOR_EVENT_OVER_CURRENT,
 144                                       NULL);
 145
 146         return IRQ_HANDLED;
 147 }
 148
 149
 150 static __devinit int wm831x_isink_probe(struct platform_device *pdev)
 151 {
 152         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 153         struct wm831x_pdata *pdata = wm831x->dev->platform_data;
 154         struct wm831x_isink *isink;
 155         int id = pdev->id % ARRAY_SIZE(pdata->isink);
 156         struct resource *res;
 157         int ret, irq;
 158
 159         dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);
 160
 161         if (pdata == NULL || pdata->isink[id] == NULL)
 162                 return -ENODEV;
 163
 164         isink = kzalloc(sizeof(struct wm831x_isink), GFP_KERNEL);
 165         if (isink == NULL) {
 166                 dev_err(&pdev->dev, "Unable to allocate private data\n");
 167                 return -ENOMEM;
 168         }
 169
 170         isink->wm831x = wm831x;
 171
 172         res = platform_get_resource(pdev, IORESOURCE_IO, 0);
 173         if (res == NULL) {
 174                 dev_err(&pdev->dev, "No I/O resource\n");
 175                 ret = -EINVAL;
 176                 goto err;
 177         }
 178         isink->reg = res->start;
 179
 180         /* For current parts this is correct; probably need to revisit
 181          * in future.
 182          */
 183         snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
 184         isink->desc.name = isink->name;
 185         isink->desc.id = id;
 186         isink->desc.ops = &wm831x_isink_ops;
 187         isink->desc.type = REGULATOR_CURRENT;
 188         isink->desc.owner = THIS_MODULE;
 189
 190         isink->regulator = regulator_register(&isink->desc, &pdev->dev,
 191                                              pdata->isink[id], isink);
 192         if (IS_ERR(isink->regulator)) {
 193                 ret = PTR_ERR(isink->regulator);
 194                 dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
 195                         id + 1, ret);
 196                 goto err;
 197         }
 198
 199         irq = platform_get_irq(pdev, 0);
 200         ret = wm831x_request_irq(wm831x, irq, wm831x_isink_irq,
 201                                  IRQF_TRIGGER_RISING, isink->name,
 202                                  isink);
 203         if (ret != 0) {
 204                 dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
 205                         irq, ret);
 206                 goto err_regulator;
 207         }
 208
 209         platform_set_drvdata(pdev, isink);
 210
 211         return 0;
 212
 213 err_regulator:
 214         regulator_unregister(isink->regulator);
 215 err:
 216         kfree(isink);
 217         return ret;
 218 }
 219
 220 static __devexit int wm831x_isink_remove(struct platform_device *pdev)
 221 {
 222         struct wm831x_isink *isink = platform_get_drvdata(pdev);
 223         struct wm831x *wm831x = isink->wm831x;
 224
 225         wm831x_free_irq(wm831x, platform_get_irq(pdev, 0), isink);
 226
 227         regulator_unregister(isink->regulator);
 228         kfree(isink);
 229
 230         return 0;
 231 }
 232
 233 static struct platform_driver wm831x_isink_driver = {
 234         .probe = wm831x_isink_probe,
 235         .remove = __devexit_p(wm831x_isink_remove),
 236         .driver         = {
 237                 .name   = "wm831x-isink",
 238         },
 239 };
 240
 241 static int __init wm831x_isink_init(void)
 242 {
 243         int ret;
 244         ret = platform_driver_register(&wm831x_isink_driver);
 245         if (ret != 0)
 246                 pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
 247
 248         return ret;
 249 }
 250 subsys_initcall(wm831x_isink_init);
 251
 252 static void __exit wm831x_isink_exit(void)
 253 {
 254         platform_driver_unregister(&wm831x_isink_driver);
 255 }
 256 module_exit(wm831x_isink_exit);
 257
 258 /* Module information */
 259 MODULE_AUTHOR("Mark Brown");
 260 MODULE_DESCRIPTION("WM831x current sink driver");
 261 MODULE_LICENSE("GPL");
 262 MODULE_ALIAS("platform:wm831x-isink");