linux/drivers/regulator/wm831x-isink.c
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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#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
  30struct 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
  38static 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
  60static 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
  78static 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
  95static 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
 114static 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
 131static 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
 139static 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
 151static __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 regulator_config config = { };
 158        struct resource *res;
 159        int ret, irq;
 160
 161        dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);
 162
 163        if (pdata == NULL || pdata->isink[id] == NULL)
 164                return -ENODEV;
 165
 166        isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
 167                             GFP_KERNEL);
 168        if (isink == NULL) {
 169                dev_err(&pdev->dev, "Unable to allocate private data\n");
 170                return -ENOMEM;
 171        }
 172
 173        isink->wm831x = wm831x;
 174
 175        res = platform_get_resource(pdev, IORESOURCE_REG, 0);
 176        if (res == NULL) {
 177                dev_err(&pdev->dev, "No REG resource\n");
 178                ret = -EINVAL;
 179                goto err;
 180        }
 181        isink->reg = res->start;
 182
 183        /* For current parts this is correct; probably need to revisit
 184         * in future.
 185         */
 186        snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
 187        isink->desc.name = isink->name;
 188        isink->desc.id = id;
 189        isink->desc.ops = &wm831x_isink_ops;
 190        isink->desc.type = REGULATOR_CURRENT;
 191        isink->desc.owner = THIS_MODULE;
 192
 193        config.dev = pdev->dev.parent;
 194        config.init_data = pdata->isink[id];
 195        config.driver_data = isink;
 196
 197        isink->regulator = regulator_register(&isink->desc, &config);
 198        if (IS_ERR(isink->regulator)) {
 199                ret = PTR_ERR(isink->regulator);
 200                dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
 201                        id + 1, ret);
 202                goto err;
 203        }
 204
 205        irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
 206        ret = request_threaded_irq(irq, NULL, wm831x_isink_irq,
 207                                   IRQF_TRIGGER_RISING, isink->name, isink);
 208        if (ret != 0) {
 209                dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
 210                        irq, ret);
 211                goto err_regulator;
 212        }
 213
 214        platform_set_drvdata(pdev, isink);
 215
 216        return 0;
 217
 218err_regulator:
 219        regulator_unregister(isink->regulator);
 220err:
 221        return ret;
 222}
 223
 224static __devexit int wm831x_isink_remove(struct platform_device *pdev)
 225{
 226        struct wm831x_isink *isink = platform_get_drvdata(pdev);
 227
 228        platform_set_drvdata(pdev, NULL);
 229
 230        free_irq(wm831x_irq(isink->wm831x, platform_get_irq(pdev, 0)), isink);
 231
 232        regulator_unregister(isink->regulator);
 233
 234        return 0;
 235}
 236
 237static struct platform_driver wm831x_isink_driver = {
 238        .probe = wm831x_isink_probe,
 239        .remove = __devexit_p(wm831x_isink_remove),
 240        .driver         = {
 241                .name   = "wm831x-isink",
 242                .owner  = THIS_MODULE,
 243        },
 244};
 245
 246static int __init wm831x_isink_init(void)
 247{
 248        int ret;
 249        ret = platform_driver_register(&wm831x_isink_driver);
 250        if (ret != 0)
 251                pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
 252
 253        return ret;
 254}
 255subsys_initcall(wm831x_isink_init);
 256
 257static void __exit wm831x_isink_exit(void)
 258{
 259        platform_driver_unregister(&wm831x_isink_driver);
 260}
 261module_exit(wm831x_isink_exit);
 262
 263/* Module information */
 264MODULE_AUTHOR("Mark Brown");
 265MODULE_DESCRIPTION("WM831x current sink driver");
 266MODULE_LICENSE("GPL");
 267MODULE_ALIAS("platform:wm831x-isink");
 268
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