// 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");