// SPDX-License-Identifier: GPL-2.0
// TI LM36274 LED chip family driver
// Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/leds.h>
#include <linux/leds-ti-lmu-common.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>

#include <linux/mfd/ti-lmu.h>
#include <linux/mfd/ti-lmu-register.h>

#include <uapi/linux/uleds.h>

#define LM36274_MAX_STRINGS     4
#define LM36274_BL_EN           BIT(4)

/**
 * struct lm36274
 * @pdev: platform device
 * @led_dev: led class device
 * @lmu_data: Register and setting values for common code
 * @regmap: Devices register map
 * @dev: Pointer to the devices device struct
 * @led_sources: The LED strings supported in this array
 * @num_leds: Number of LED strings are supported in this array
 */
struct lm36274 {
        struct platform_device *pdev;
        struct led_classdev led_dev;
        struct ti_lmu_bank lmu_data;
        struct regmap *regmap;
        struct device *dev;

        u32 led_sources[LM36274_MAX_STRINGS];
        int num_leds;
};

static int lm36274_brightness_set(struct led_classdev *led_cdev,
                                  enum led_brightness brt_val)
{
        struct lm36274 *chip = container_of(led_cdev, struct lm36274, led_dev);

        return ti_lmu_common_set_brightness(&chip->lmu_data, brt_val);
}

static int lm36274_init(struct lm36274 *chip)
{
        int enable_val = 0;
        int i;

        for (i = 0; i < chip->num_leds; i++)
                enable_val |= (1 << chip->led_sources[i]);

        if (!enable_val) {
                dev_err(chip->dev, "No LEDs were enabled\n");
                return -EINVAL;
        }

        enable_val |= LM36274_BL_EN;

        return regmap_write(chip->regmap, LM36274_REG_BL_EN, enable_val);
}

static int lm36274_parse_dt(struct lm36274 *chip,
                            struct led_init_data *init_data)
{
        struct device *dev = chip->dev;
        struct fwnode_handle *child;
        int ret;

        /* There should only be 1 node */
        if (device_get_child_node_count(dev) != 1)
                return -EINVAL;

        child = device_get_next_child_node(dev, NULL);

        init_data->fwnode = child;
        init_data->devicename = chip->pdev->name;
        /* for backwards compatibility when `label` property is not present */
        init_data->default_label = ":";

        chip->num_leds = fwnode_property_count_u32(child, "led-sources");
        if (chip->num_leds <= 0) {
                ret = -ENODEV;
                goto err;
        }

        ret = fwnode_property_read_u32_array(child, "led-sources",
                                             chip->led_sources, chip->num_leds);
        if (ret) {
                dev_err(dev, "led-sources property missing\n");
                goto err;
        }

        return 0;
err:
        fwnode_handle_put(child);
        return ret;
}

static int lm36274_probe(struct platform_device *pdev)
{
        struct ti_lmu *lmu = dev_get_drvdata(pdev->dev.parent);
        struct led_init_data init_data = {};
        struct lm36274 *chip;
        int ret;

        chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        chip->pdev = pdev;
        chip->dev = &pdev->dev;
        chip->regmap = lmu->regmap;
        platform_set_drvdata(pdev, chip);

        ret = lm36274_parse_dt(chip, &init_data);
        if (ret) {
                dev_err(chip->dev, "Failed to parse DT node\n");
                return ret;
        }

        ret = lm36274_init(chip);
        if (ret) {
                fwnode_handle_put(init_data.fwnode);
                dev_err(chip->dev, "Failed to init the device\n");
                return ret;
        }

        chip->lmu_data.regmap = chip->regmap;
        chip->lmu_data.max_brightness = MAX_BRIGHTNESS_11BIT;
        chip->lmu_data.msb_brightness_reg = LM36274_REG_BRT_MSB;
        chip->lmu_data.lsb_brightness_reg = LM36274_REG_BRT_LSB;

        chip->led_dev.max_brightness = MAX_BRIGHTNESS_11BIT;
        chip->led_dev.brightness_set_blocking = lm36274_brightness_set;

        ret = devm_led_classdev_register_ext(chip->dev, &chip->led_dev,
                                             &init_data);
        if (ret)
                dev_err(chip->dev, "Failed to register LED for node %pfw\n",
                        init_data.fwnode);

        fwnode_handle_put(init_data.fwnode);

        return ret;
}

static const struct of_device_id of_lm36274_leds_match[] = {
        { .compatible = "ti,lm36274-backlight", },
        {},
};
MODULE_DEVICE_TABLE(of, of_lm36274_leds_match);

static struct platform_driver lm36274_driver = {
        .probe  = lm36274_probe,
        .driver = {
                .name = "lm36274-leds",
                .of_match_table = of_lm36274_leds_match,
        },
};
module_platform_driver(lm36274_driver)

MODULE_DESCRIPTION("Texas Instruments LM36274 LED driver");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");