linux/drivers/regulator/wm831x-isink.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2//
   3// wm831x-isink.c  --  Current sink driver for the WM831x series
   4//
   5// Copyright 2009 Wolfson Microelectronics PLC.
   6//
   7// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   8
   9#include <linux/module.h>
  10#include <linux/moduleparam.h>
  11#include <linux/init.h>
  12#include <linux/bitops.h>
  13#include <linux/err.h>
  14#include <linux/i2c.h>
  15#include <linux/platform_device.h>
  16#include <linux/regulator/driver.h>
  17#include <linux/slab.h>
  18
  19#include <linux/mfd/wm831x/core.h>
  20#include <linux/mfd/wm831x/regulator.h>
  21#include <linux/mfd/wm831x/pdata.h>
  22
  23#define WM831X_ISINK_MAX_NAME 7
  24
  25struct wm831x_isink {
  26        char name[WM831X_ISINK_MAX_NAME];
  27        struct regulator_desc desc;
  28        int reg;
  29        struct wm831x *wm831x;
  30        struct regulator_dev *regulator;
  31};
  32
  33static int wm831x_isink_enable(struct regulator_dev *rdev)
  34{
  35        struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  36        struct wm831x *wm831x = isink->wm831x;
  37        int ret;
  38
  39        /* We have a two stage enable: first start the ISINK... */
  40        ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA,
  41                              WM831X_CS1_ENA);
  42        if (ret != 0)
  43                return ret;
  44
  45        /* ...then enable drive */
  46        ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE,
  47                              WM831X_CS1_DRIVE);
  48        if (ret != 0)
  49                wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
  50
  51        return ret;
  52
  53}
  54
  55static int wm831x_isink_disable(struct regulator_dev *rdev)
  56{
  57        struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  58        struct wm831x *wm831x = isink->wm831x;
  59        int ret;
  60
  61        ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0);
  62        if (ret < 0)
  63                return ret;
  64
  65        ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
  66        if (ret < 0)
  67                return ret;
  68
  69        return ret;
  70
  71}
  72
  73static int wm831x_isink_is_enabled(struct regulator_dev *rdev)
  74{
  75        struct wm831x_isink *isink = rdev_get_drvdata(rdev);
  76        struct wm831x *wm831x = isink->wm831x;
  77        int ret;
  78
  79        ret = wm831x_reg_read(wm831x, isink->reg);
  80        if (ret < 0)
  81                return ret;
  82
  83        if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) ==
  84            (WM831X_CS1_ENA | WM831X_CS1_DRIVE))
  85                return 1;
  86        else
  87                return 0;
  88}
  89
  90static const struct regulator_ops wm831x_isink_ops = {
  91        .is_enabled = wm831x_isink_is_enabled,
  92        .enable = wm831x_isink_enable,
  93        .disable = wm831x_isink_disable,
  94        .set_current_limit = regulator_set_current_limit_regmap,
  95        .get_current_limit = regulator_get_current_limit_regmap,
  96};
  97
  98static irqreturn_t wm831x_isink_irq(int irq, void *data)
  99{
 100        struct wm831x_isink *isink = data;
 101
 102        regulator_lock(isink->regulator);
 103        regulator_notifier_call_chain(isink->regulator,
 104                                      REGULATOR_EVENT_OVER_CURRENT,
 105                                      NULL);
 106        regulator_unlock(isink->regulator);
 107
 108        return IRQ_HANDLED;
 109}
 110
 111
 112static int wm831x_isink_probe(struct platform_device *pdev)
 113{
 114        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 115        struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
 116        struct wm831x_isink *isink;
 117        int id = pdev->id % ARRAY_SIZE(pdata->isink);
 118        struct regulator_config config = { };
 119        struct resource *res;
 120        int ret, irq;
 121
 122        dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);
 123
 124        if (pdata == NULL || pdata->isink[id] == NULL)
 125                return -ENODEV;
 126
 127        isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
 128                             GFP_KERNEL);
 129        if (!isink)
 130                return -ENOMEM;
 131
 132        isink->wm831x = wm831x;
 133
 134        res = platform_get_resource(pdev, IORESOURCE_REG, 0);
 135        if (res == NULL) {
 136                dev_err(&pdev->dev, "No REG resource\n");
 137                ret = -EINVAL;
 138                goto err;
 139        }
 140        isink->reg = res->start;
 141
 142        /* For current parts this is correct; probably need to revisit
 143         * in future.
 144         */
 145        snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
 146        isink->desc.name = isink->name;
 147        isink->desc.id = id;
 148        isink->desc.ops = &wm831x_isink_ops;
 149        isink->desc.type = REGULATOR_CURRENT;
 150        isink->desc.owner = THIS_MODULE;
 151        isink->desc.curr_table = wm831x_isinkv_values,
 152        isink->desc.n_current_limits = ARRAY_SIZE(wm831x_isinkv_values),
 153        isink->desc.csel_reg = isink->reg,
 154        isink->desc.csel_mask = WM831X_CS1_ISEL_MASK,
 155
 156        config.dev = pdev->dev.parent;
 157        config.init_data = pdata->isink[id];
 158        config.driver_data = isink;
 159        config.regmap = wm831x->regmap;
 160
 161        isink->regulator = devm_regulator_register(&pdev->dev, &isink->desc,
 162                                                   &config);
 163        if (IS_ERR(isink->regulator)) {
 164                ret = PTR_ERR(isink->regulator);
 165                dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
 166                        id + 1, ret);
 167                goto err;
 168        }
 169
 170        irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
 171        ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 172                                        wm831x_isink_irq,
 173                                        IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 174                                        isink->name,
 175                                        isink);
 176        if (ret != 0) {
 177                dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
 178                        irq, ret);
 179                goto err;
 180        }
 181
 182        platform_set_drvdata(pdev, isink);
 183
 184        return 0;
 185
 186err:
 187        return ret;
 188}
 189
 190static struct platform_driver wm831x_isink_driver = {
 191        .probe = wm831x_isink_probe,
 192        .driver         = {
 193                .name   = "wm831x-isink",
 194        },
 195};
 196
 197static int __init wm831x_isink_init(void)
 198{
 199        int ret;
 200        ret = platform_driver_register(&wm831x_isink_driver);
 201        if (ret != 0)
 202                pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
 203
 204        return ret;
 205}
 206subsys_initcall(wm831x_isink_init);
 207
 208static void __exit wm831x_isink_exit(void)
 209{
 210        platform_driver_unregister(&wm831x_isink_driver);
 211}
 212module_exit(wm831x_isink_exit);
 213
 214/* Module information */
 215MODULE_AUTHOR("Mark Brown");
 216MODULE_DESCRIPTION("WM831x current sink driver");
 217MODULE_LICENSE("GPL");
 218MODULE_ALIAS("platform:wm831x-isink");
 219