Quelle  wm831x-isink.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
//
// wm831x-isink.c  --  Current sink driver for the WM831x series
//
// Copyright 2009 Wolfson Microelectronics PLC.
//
// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/slab.h>

#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/regulator.h>
#include <linux/mfd/wm831x/pdata.h>

#define WM831X_ISINK_MAX_NAME 7

struct wm831x_isink {
 char name[WM831X_ISINK_MAX_NAME];
 struct regulator_desc desc;
 int reg;
 struct wm831x *wm831x;
 struct regulator_dev *regulator;
};

static int wm831x_isink_enable(struct regulator_dev *rdev)
{
 struct wm831x_isink *isink = rdev_get_drvdata(rdev);
 struct wm831x *wm831x = isink->wm831x;
 int ret;

 /* We have a two stage enable: first start the ISINK... */
 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA,
         WM831X_CS1_ENA);
 if (ret != 0)
  return ret;

 /* ...then enable drive */
 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE,
         WM831X_CS1_DRIVE);
 if (ret != 0)
  wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);

 return ret;

}

static int wm831x_isink_disable(struct regulator_dev *rdev)
{
 struct wm831x_isink *isink = rdev_get_drvdata(rdev);
 struct wm831x *wm831x = isink->wm831x;
 int ret;

 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0);
 if (ret < 0)
  return ret;

 ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
 if (ret < 0)
  return ret;

 return ret;

}

static int wm831x_isink_is_enabled(struct regulator_dev *rdev)
{
 struct wm831x_isink *isink = rdev_get_drvdata(rdev);
 struct wm831x *wm831x = isink->wm831x;
 int ret;

 ret = wm831x_reg_read(wm831x, isink->reg);
 if (ret < 0)
  return ret;

 if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) ==
     (WM831X_CS1_ENA | WM831X_CS1_DRIVE))
  return 1;
 else
  return 0;
}

static const struct regulator_ops wm831x_isink_ops = {
 .is_enabled = wm831x_isink_is_enabled,
 .enable = wm831x_isink_enable,
 .disable = wm831x_isink_disable,
 .set_current_limit = regulator_set_current_limit_regmap,
 .get_current_limit = regulator_get_current_limit_regmap,
};

static irqreturn_t wm831x_isink_irq(int irq, void *data)
{
 struct wm831x_isink *isink = data;

 regulator_notifier_call_chain(isink->regulator,
          REGULATOR_EVENT_OVER_CURRENT,
          NULL);

 return IRQ_HANDLED;
}


static int wm831x_isink_probe(struct platform_device *pdev)
{
 struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
 struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
 struct wm831x_isink *isink;
 int id = pdev->id % ARRAY_SIZE(pdata->isink);
 struct regulator_config config = { };
 struct resource *res;
 int ret, irq;

 dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);

 if (pdata == NULL || pdata->isink[id] == NULL)
  return -ENODEV;

 isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
        GFP_KERNEL);
 if (!isink)
  return -ENOMEM;

 isink->wm831x = wm831x;

 res = platform_get_resource(pdev, IORESOURCE_REG, 0);
 if (res == NULL) {
  dev_err(&pdev->dev, "No REG resource\n");
  ret = -EINVAL;
  goto err;
 }
 isink->reg = res->start;

 /* For current parts this is correct; probably need to revisit
 * in future.
 */
 snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
 isink->desc.name = isink->name;
 isink->desc.id = id;
 isink->desc.ops = &wm831x_isink_ops;
 isink->desc.type = REGULATOR_CURRENT;
 isink->desc.owner = THIS_MODULE;
 isink->desc.curr_table = wm831x_isinkv_values;
 isink->desc.n_current_limits = ARRAY_SIZE(wm831x_isinkv_values);
 isink->desc.csel_reg = isink->reg;
 isink->desc.csel_mask = WM831X_CS1_ISEL_MASK;

 config.dev = pdev->dev.parent;
 config.init_data = pdata->isink[id];
 config.driver_data = isink;
 config.regmap = wm831x->regmap;

 isink->regulator = devm_regulator_register(&pdev->dev, &isink->desc,
         &config);
 if (IS_ERR(isink->regulator)) {
  ret = PTR_ERR(isink->regulator);
  dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
   id + 1, ret);
  goto err;
 }

 irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
 ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
     wm831x_isink_irq,
     IRQF_TRIGGER_RISING | IRQF_ONESHOT,
     isink->name,
     isink);
 if (ret != 0) {
  dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
   irq, ret);
  goto err;
 }

 platform_set_drvdata(pdev, isink);

 return 0;

err:
 return ret;
}

static struct platform_driver wm831x_isink_driver = {
 .probe = wm831x_isink_probe,
 .driver  = {
  .name = "wm831x-isink",
  .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 },
};

static int __init wm831x_isink_init(void)
{
 int ret;
 ret = platform_driver_register(&wm831x_isink_driver);
 if (ret != 0)
  pr_err("Failed to register WM831x ISINK driver: %d\n", ret);

 return ret;
}
subsys_initcall(wm831x_isink_init);

static void __exit wm831x_isink_exit(void)
{
 platform_driver_unregister(&wm831x_isink_driver);
}
module_exit(wm831x_isink_exit);

/* Module information */
MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM831x current sink driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-isink");