// SPDX-License-Identifier: GPL-2.0
/*
 * Device driver for leds in MAX5970 and MAX5978 IC
 *
 * Copyright (c) 2022 9elements GmbH
 *
 * Author: Patrick Rudolph <patrick.rudolph@9elements.com>
 */

#include <linux/bits.h>
#include <linux/container_of.h>
#include <linux/device.h>
#include <linux/leds.h>
#include <linux/mfd/max5970.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>

#define ldev_to_maxled(c)       container_of(c, struct max5970_led, cdev)

struct max5970_led {
        struct device *dev;
        struct regmap *regmap;
        struct led_classdev cdev;
        unsigned int index;
};

static int max5970_led_set_brightness(struct led_classdev *cdev,
                                      enum led_brightness brightness)
{
        struct max5970_led *ddata = ldev_to_maxled(cdev);
        int ret, val;

        /* Set/clear corresponding bit for given led index */
        val = !brightness ? BIT(ddata->index) : 0;

        ret = regmap_update_bits(ddata->regmap, MAX5970_REG_LED_FLASH, BIT(ddata->index), val);
        if (ret < 0)
                dev_err(cdev->dev, "failed to set brightness %d", ret);

        return ret;
}

static int max5970_led_probe(struct platform_device *pdev)
{
        struct fwnode_handle *child;
        struct device *dev = &pdev->dev;
        struct regmap *regmap;
        struct max5970_led *ddata;
        int ret = -ENODEV;

        regmap = dev_get_regmap(dev->parent, NULL);
        if (!regmap)
                return -ENODEV;

        struct fwnode_handle *led_node __free(fwnode_handle) =
                device_get_named_child_node(dev->parent, "leds");
        if (!led_node)
                return -ENODEV;

        fwnode_for_each_child_node(led_node, child) {
                u32 reg;

                if (fwnode_property_read_u32(child, "reg", &reg))
                        continue;

                if (reg >= MAX5970_NUM_LEDS) {
                        dev_err_probe(dev, -EINVAL, "invalid LED (%u >= %d)\n", reg, MAX5970_NUM_LEDS);
                        continue;
                }

                ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
                if (!ddata) {
                        fwnode_handle_put(child);
                        return -ENOMEM;
                }

                ddata->index = reg;
                ddata->regmap = regmap;
                ddata->dev = dev;

                if (fwnode_property_read_string(child, "label", &ddata->cdev.name))
                        ddata->cdev.name = fwnode_get_name(child);

                ddata->cdev.max_brightness = 1;
                ddata->cdev.brightness_set_blocking = max5970_led_set_brightness;
                ddata->cdev.default_trigger = "none";

                ret = devm_led_classdev_register(dev, &ddata->cdev);
                if (ret < 0) {
                        fwnode_handle_put(child);
                        return dev_err_probe(dev, ret, "Failed to initialize LED %u\n", reg);
                }
        }

        return ret;
}

static struct platform_driver max5970_led_driver = {
        .driver = {
                .name = "max5970-led",
        },
        .probe = max5970_led_probe,
};
module_platform_driver(max5970_led_driver);

MODULE_AUTHOR("Patrick Rudolph <patrick.rudolph@9elements.com>");
MODULE_AUTHOR("Naresh Solanki <Naresh.Solanki@9elements.com>");
MODULE_DESCRIPTION("MAX5970_hot-swap controller LED driver");
MODULE_LICENSE("GPL");