// SPDX-License-Identifier: GPL-2.0-only
/*
 * LED driver for WM831x status LEDs
 *
 * Copyright(C) 2009 Wolfson Microelectronics PLC.
 */

#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/leds.h>
#include <linux/err.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/status.h>
#include <linux/module.h>


struct wm831x_status {
        struct led_classdev cdev;
        struct wm831x *wm831x;
        struct mutex mutex;

        spinlock_t value_lock;
        int reg;     /* Control register */
        int reg_val; /* Control register value */

        int blink;
        int blink_time;
        int blink_cyc;
        int src;
        enum led_brightness brightness;
};

#define to_wm831x_status(led_cdev) \
        container_of(led_cdev, struct wm831x_status, cdev)

static void wm831x_status_set(struct wm831x_status *led)
{
        unsigned long flags;

        mutex_lock(&led->mutex);

        led->reg_val &= ~(WM831X_LED_SRC_MASK | WM831X_LED_MODE_MASK |
                          WM831X_LED_DUTY_CYC_MASK | WM831X_LED_DUR_MASK);

        spin_lock_irqsave(&led->value_lock, flags);

        led->reg_val |= led->src << WM831X_LED_SRC_SHIFT;
        if (led->blink) {
                led->reg_val |= 2 << WM831X_LED_MODE_SHIFT;
                led->reg_val |= led->blink_time << WM831X_LED_DUR_SHIFT;
                led->reg_val |= led->blink_cyc;
        } else {
                if (led->brightness != LED_OFF)
                        led->reg_val |= 1 << WM831X_LED_MODE_SHIFT;
        }

        spin_unlock_irqrestore(&led->value_lock, flags);

        wm831x_reg_write(led->wm831x, led->reg, led->reg_val);

        mutex_unlock(&led->mutex);
}

static int wm831x_status_brightness_set(struct led_classdev *led_cdev,
                                         enum led_brightness value)
{
        struct wm831x_status *led = to_wm831x_status(led_cdev);
        unsigned long flags;

        spin_lock_irqsave(&led->value_lock, flags);
        led->brightness = value;
        if (value == LED_OFF)
                led->blink = 0;
        spin_unlock_irqrestore(&led->value_lock, flags);
        wm831x_status_set(led);

        return 0;
}

static int wm831x_status_blink_set(struct led_classdev *led_cdev,
                                   unsigned long *delay_on,
                                   unsigned long *delay_off)
{
        struct wm831x_status *led = to_wm831x_status(led_cdev);
        unsigned long flags;
        int ret = 0;

        /* Pick some defaults if we've not been given times */
        if (*delay_on == 0 && *delay_off == 0) {
                *delay_on = 250;
                *delay_off = 250;
        }

        spin_lock_irqsave(&led->value_lock, flags);

        /* We only have a limited selection of settings, see if we can
         * support the configuration we're being given */
        switch (*delay_on) {
        case 1000:
                led->blink_time = 0;
                break;
        case 250:
                led->blink_time = 1;
                break;
        case 125:
                led->blink_time = 2;
                break;
        case 62:
        case 63:
                /* Actually 62.5ms */
                led->blink_time = 3;
                break;
        default:
                ret = -EINVAL;
                break;
        }

        if (ret == 0) {
                switch (*delay_off / *delay_on) {
                case 1:
                        led->blink_cyc = 0;
                        break;
                case 3:
                        led->blink_cyc = 1;
                        break;
                case 4:
                        led->blink_cyc = 2;
                        break;
                case 8:
                        led->blink_cyc = 3;
                        break;
                default:
                        ret = -EINVAL;
                        break;
                }
        }

        if (ret == 0)
                led->blink = 1;
        else
                led->blink = 0;

        spin_unlock_irqrestore(&led->value_lock, flags);
        wm831x_status_set(led);

        return ret;
}

static const char * const led_src_texts[] = {
        "otp",
        "power",
        "charger",
        "soft",
};

static ssize_t src_show(struct device *dev,
                        struct device_attribute *attr, char *buf)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct wm831x_status *led = to_wm831x_status(led_cdev);
        int i;
        ssize_t ret = 0;

        mutex_lock(&led->mutex);

        for (i = 0; i < ARRAY_SIZE(led_src_texts); i++)
                if (i == led->src)
                        ret += sprintf(&buf[ret], "[%s] ", led_src_texts[i]);
                else
                        ret += sprintf(&buf[ret], "%s ", led_src_texts[i]);

        mutex_unlock(&led->mutex);

        ret += sprintf(&buf[ret], "\n");

        return ret;
}

static ssize_t src_store(struct device *dev,
                         struct device_attribute *attr,
                         const char *buf, size_t size)
{
        struct led_classdev *led_cdev = dev_get_drvdata(dev);
        struct wm831x_status *led = to_wm831x_status(led_cdev);
        int i;

        i = sysfs_match_string(led_src_texts, buf);
        if (i >= 0) {
                mutex_lock(&led->mutex);
                led->src = i;
                mutex_unlock(&led->mutex);
                wm831x_status_set(led);
        }

        return size;
}

static DEVICE_ATTR_RW(src);

static struct attribute *wm831x_status_attrs[] = {
        &dev_attr_src.attr,
        NULL
};
ATTRIBUTE_GROUPS(wm831x_status);

static int wm831x_status_probe(struct platform_device *pdev)
{
        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
        struct wm831x_pdata *chip_pdata;
        struct wm831x_status_pdata pdata;
        struct wm831x_status *drvdata;
        struct resource *res;
        int id = pdev->id % ARRAY_SIZE(chip_pdata->status);
        int ret;

        res = platform_get_resource(pdev, IORESOURCE_REG, 0);
        if (res == NULL) {
                dev_err(&pdev->dev, "No register resource\n");
                return -EINVAL;
        }

        drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status),
                               GFP_KERNEL);
        if (!drvdata)
                return -ENOMEM;

        drvdata->wm831x = wm831x;
        drvdata->reg = res->start;

        if (dev_get_platdata(wm831x->dev))
                chip_pdata = dev_get_platdata(wm831x->dev);
        else
                chip_pdata = NULL;

        memset(&pdata, 0, sizeof(pdata));
        if (chip_pdata && chip_pdata->status[id])
                memcpy(&pdata, chip_pdata->status[id], sizeof(pdata));
        else
                pdata.name = dev_name(&pdev->dev);

        mutex_init(&drvdata->mutex);
        spin_lock_init(&drvdata->value_lock);

        /* We cache the configuration register and read startup values
         * from it. */
        drvdata->reg_val = wm831x_reg_read(wm831x, drvdata->reg);

        if (drvdata->reg_val & WM831X_LED_MODE_MASK)
                drvdata->brightness = LED_FULL;
        else
                drvdata->brightness = LED_OFF;

        /* Set a default source if configured, otherwise leave the
         * current hardware setting.
         */
        if (pdata.default_src == WM831X_STATUS_PRESERVE) {
                drvdata->src = drvdata->reg_val;
                drvdata->src &= WM831X_LED_SRC_MASK;
                drvdata->src >>= WM831X_LED_SRC_SHIFT;
        } else {
                drvdata->src = pdata.default_src - 1;
        }

        drvdata->cdev.name = pdata.name;
        drvdata->cdev.default_trigger = pdata.default_trigger;
        drvdata->cdev.brightness_set_blocking = wm831x_status_brightness_set;
        drvdata->cdev.blink_set = wm831x_status_blink_set;
        drvdata->cdev.groups = wm831x_status_groups;

        ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
        if (ret < 0) {
                dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
                return ret;
        }

        platform_set_drvdata(pdev, drvdata);

        return 0;
}

static void wm831x_status_remove(struct platform_device *pdev)
{
        struct wm831x_status *drvdata = platform_get_drvdata(pdev);

        led_classdev_unregister(&drvdata->cdev);
}

static struct platform_driver wm831x_status_driver = {
        .driver = {
                   .name = "wm831x-status",
                   },
        .probe = wm831x_status_probe,
        .remove = wm831x_status_remove,
};

module_platform_driver(wm831x_status_driver);

MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x status LED driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-status");