drivers/regulator/wm831x-isink.c

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