drivers/regulator/wm831x-isink.c

   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
  25 struct 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
  33 static 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
  55 static 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
  73 static 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
  90 static 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
  98 static irqreturn_t wm831x_isink_irq(int irq, void *data)
  99 {
 100         struct wm831x_isink *isink = data;
 101
 102         regulator_notifier_call_chain(isink->regulator,
 103                                       REGULATOR_EVENT_OVER_CURRENT,
 104                                       NULL);
 105
 106         return IRQ_HANDLED;
 107 }
 108
 109
 110 static int wm831x_isink_probe(struct platform_device *pdev)
 111 {
 112         struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 113         struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
 114         struct wm831x_isink *isink;
 115         int id = pdev->id % ARRAY_SIZE(pdata->isink);
 116         struct regulator_config config = { };
 117         struct resource *res;
 118         int ret, irq;
 119
 120         dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);
 121
 122         if (pdata == NULL || pdata->isink[id] == NULL)
 123                 return -ENODEV;
 124
 125         isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
 126                              GFP_KERNEL);
 127         if (!isink)
 128                 return -ENOMEM;
 129
 130         isink->wm831x = wm831x;
 131
 132         res = platform_get_resource(pdev, IORESOURCE_REG, 0);
 133         if (res == NULL) {
 134                 dev_err(&pdev->dev, "No REG resource\n");
 135                 ret = -EINVAL;
 136                 goto err;
 137         }
 138         isink->reg = res->start;
 139
 140         /* For current parts this is correct; probably need to revisit
 141          * in future.
 142          */
 143         snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
 144         isink->desc.name = isink->name;
 145         isink->desc.id = id;
 146         isink->desc.ops = &wm831x_isink_ops;
 147         isink->desc.type = REGULATOR_CURRENT;
 148         isink->desc.owner = THIS_MODULE;
 149         isink->desc.curr_table = wm831x_isinkv_values,
 150         isink->desc.n_current_limits = ARRAY_SIZE(wm831x_isinkv_values),
 151         isink->desc.csel_reg = isink->reg,
 152         isink->desc.csel_mask = WM831X_CS1_ISEL_MASK,
 153
 154         config.dev = pdev->dev.parent;
 155         config.init_data = pdata->isink[id];
 156         config.driver_data = isink;
 157         config.regmap = wm831x->regmap;
 158
 159         isink->regulator = devm_regulator_register(&pdev->dev, &isink->desc,
 160                                                    &config);
 161         if (IS_ERR(isink->regulator)) {
 162                 ret = PTR_ERR(isink->regulator);
 163                 dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
 164                         id + 1, ret);
 165                 goto err;
 166         }
 167
 168         irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
 169         ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
 170                                         wm831x_isink_irq,
 171                                         IRQF_TRIGGER_RISING | IRQF_ONESHOT,
 172                                         isink->name,
 173                                         isink);
 174         if (ret != 0) {
 175                 dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
 176                         irq, ret);
 177                 goto err;
 178         }
 179
 180         platform_set_drvdata(pdev, isink);
 181
 182         return 0;
 183
 184 err:
 185         return ret;
 186 }
 187
 188 static struct platform_driver wm831x_isink_driver = {
 189         .probe = wm831x_isink_probe,
 190         .driver         = {
 191                 .name   = "wm831x-isink",
 192                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 193         },
 194 };
 195
 196 static int __init wm831x_isink_init(void)
 197 {
 198         int ret;
 199         ret = platform_driver_register(&wm831x_isink_driver);
 200         if (ret != 0)
 201                 pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
 202
 203         return ret;
 204 }
 205 subsys_initcall(wm831x_isink_init);
 206
 207 static void __exit wm831x_isink_exit(void)
 208 {
 209         platform_driver_unregister(&wm831x_isink_driver);
 210 }
 211 module_exit(wm831x_isink_exit);
 212
 213 /* Module information */
 214 MODULE_AUTHOR("Mark Brown");
 215 MODULE_DESCRIPTION("WM831x current sink driver");
 216 MODULE_LICENSE("GPL");
 217 MODULE_ALIAS("platform:wm831x-isink");