// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
//
// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>

#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/leds.h>
#include <linux/module.h>
#include <linux/platform_data/mlxreg.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

/* Codes for LEDs. */
#define MLXREG_LED_OFFSET_BLINK_3HZ     0x01 /* Offset from solid: 3Hz blink */
#define MLXREG_LED_OFFSET_BLINK_6HZ     0x02 /* Offset from solid: 6Hz blink */
#define MLXREG_LED_IS_OFF               0x00 /* Off */
#define MLXREG_LED_RED_SOLID            0x05 /* Solid red */
#define MLXREG_LED_GREEN_SOLID          0x0D /* Solid green */
#define MLXREG_LED_AMBER_SOLID          0x09 /* Solid amber */
#define MLXREG_LED_BLINK_3HZ            167 /* ~167 msec off/on - HW support */
#define MLXREG_LED_BLINK_6HZ            83 /* ~83 msec off/on - HW support */
#define MLXREG_LED_CAPABILITY_CLEAR     GENMASK(31, 8) /* Clear mask */

/**
 * struct mlxreg_led_data - led control data:
 *
 * @data: led configuration data;
 * @led_cdev: led class data;
 * @base_color: base led color (other colors have constant offset from base);
 * @data_parent: pointer to private device control data of parent;
 * @led_cdev_name: class device name
 */
struct mlxreg_led_data {
        struct mlxreg_core_data *data;
        struct led_classdev led_cdev;
        u8 base_color;
        void *data_parent;
        char led_cdev_name[MLXREG_CORE_LABEL_MAX_SIZE];
};

#define cdev_to_priv(c) container_of(c, struct mlxreg_led_data, led_cdev)

/**
 * struct mlxreg_led_priv_data - platform private data:
 *
 * @pdev: platform device;
 * @pdata: platform data;
 * @access_lock: mutex for attribute IO access;
 */
struct mlxreg_led_priv_data {
        struct platform_device *pdev;
        struct mlxreg_core_platform_data *pdata;
        struct mutex access_lock; /* protect IO operations */
};

static int
mlxreg_led_store_hw(struct mlxreg_led_data *led_data, u8 vset)
{
        struct mlxreg_led_priv_data *priv = led_data->data_parent;
        struct mlxreg_core_platform_data *led_pdata = priv->pdata;
        struct mlxreg_core_data *data = led_data->data;
        u32 regval;
        u32 nib;
        int ret;

        /*
         * Each LED is controlled through low or high nibble of the relevant
         * register byte. Register offset is specified by off parameter.
         * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
         * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
         * green.
         * Parameter mask specifies which nibble is used for specific LED: mask
         * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
         * higher nibble (bits from 4 to 7).
         */
        mutex_lock(&priv->access_lock);

        ret = regmap_read(led_pdata->regmap, data->reg, &regval);
        if (ret)
                goto access_error;

        nib = (ror32(data->mask, data->bit) == 0xf0) ? rol32(vset, data->bit) :
              rol32(vset, data->bit + 4);
        regval = (regval & data->mask) | nib;

        ret = regmap_write(led_pdata->regmap, data->reg, regval);

access_error:
        mutex_unlock(&priv->access_lock);

        return ret;
}

static enum led_brightness
mlxreg_led_get_hw(struct mlxreg_led_data *led_data)
{
        struct mlxreg_led_priv_data *priv = led_data->data_parent;
        struct mlxreg_core_platform_data *led_pdata = priv->pdata;
        struct mlxreg_core_data *data = led_data->data;
        u32 regval;
        int err;

        /*
         * Each LED is controlled through low or high nibble of the relevant
         * register byte. Register offset is specified by off parameter.
         * Parameter vset provides color code: 0x0 for off, 0x5 for solid red,
         * 0x6 for 3Hz blink red, 0xd for solid green, 0xe for 3Hz blink
         * green.
         * Parameter mask specifies which nibble is used for specific LED: mask
         * 0xf0 - lower nibble is to be used (bits from 0 to 3), mask 0x0f -
         * higher nibble (bits from 4 to 7).
         */
        err = regmap_read(led_pdata->regmap, data->reg, &regval);
        if (err < 0) {
                dev_warn(led_data->led_cdev.dev, "Failed to get current brightness, error: %d\n",
                         err);
                /* Assume the LED is OFF */
                return LED_OFF;
        }

        regval = regval & ~data->mask;
        regval = (ror32(data->mask, data->bit) == 0xf0) ? ror32(regval,
                 data->bit) : ror32(regval, data->bit + 4);
        if (regval >= led_data->base_color &&
            regval <= (led_data->base_color + MLXREG_LED_OFFSET_BLINK_6HZ))
                return LED_FULL;

        return LED_OFF;
}

static int
mlxreg_led_brightness_set(struct led_classdev *cled, enum led_brightness value)
{
        struct mlxreg_led_data *led_data = cdev_to_priv(cled);

        if (value)
                return mlxreg_led_store_hw(led_data, led_data->base_color);
        else
                return mlxreg_led_store_hw(led_data, MLXREG_LED_IS_OFF);
}

static enum led_brightness
mlxreg_led_brightness_get(struct led_classdev *cled)
{
        struct mlxreg_led_data *led_data = cdev_to_priv(cled);

        return mlxreg_led_get_hw(led_data);
}

static int
mlxreg_led_blink_set(struct led_classdev *cled, unsigned long *delay_on,
                     unsigned long *delay_off)
{
        struct mlxreg_led_data *led_data = cdev_to_priv(cled);
        int err;

        /*
         * HW supports two types of blinking: full (6Hz) and half (3Hz).
         * For delay on/off zero LED is setting to solid color. For others
         * combination blinking is to be controlled by the software timer.
         */
        if (!(*delay_on == 0 && *delay_off == 0) &&
            !(*delay_on == MLXREG_LED_BLINK_3HZ &&
              *delay_off == MLXREG_LED_BLINK_3HZ) &&
            !(*delay_on == MLXREG_LED_BLINK_6HZ &&
              *delay_off == MLXREG_LED_BLINK_6HZ))
                return -EINVAL;

        if (*delay_on == MLXREG_LED_BLINK_6HZ)
                err = mlxreg_led_store_hw(led_data, led_data->base_color +
                                          MLXREG_LED_OFFSET_BLINK_6HZ);
        else if (*delay_on == MLXREG_LED_BLINK_3HZ)
                err = mlxreg_led_store_hw(led_data, led_data->base_color +
                                          MLXREG_LED_OFFSET_BLINK_3HZ);
        else
                err = mlxreg_led_store_hw(led_data, led_data->base_color);

        return err;
}

static int mlxreg_led_config(struct mlxreg_led_priv_data *priv)
{
        struct mlxreg_core_platform_data *led_pdata = priv->pdata;
        struct mlxreg_core_data *data = led_pdata->data;
        struct mlxreg_led_data *led_data;
        struct led_classdev *led_cdev;
        enum led_brightness brightness;
        u32 regval;
        int i;
        int err;

        for (i = 0; i < led_pdata->counter; i++, data++) {
                led_data = devm_kzalloc(&priv->pdev->dev, sizeof(*led_data),
                                        GFP_KERNEL);
                if (!led_data)
                        return -ENOMEM;

                if (data->capability) {
                        err = regmap_read(led_pdata->regmap, data->capability,
                                          &regval);
                        if (err) {
                                dev_err(&priv->pdev->dev, "Failed to query capability register\n");
                                return err;
                        }
                        if (!(regval & data->bit))
                                continue;
                        /*
                         * Field "bit" can contain one capability bit in 0 byte
                         * and offset bit in 1-3 bytes. Clear capability bit and
                         * keep only offset bit.
                         */
                        data->bit &= MLXREG_LED_CAPABILITY_CLEAR;
                }

                led_cdev = &led_data->led_cdev;
                led_data->data_parent = priv;
                if (strstr(data->label, "red") ||
                    strstr(data->label, "orange")) {
                        brightness = LED_OFF;
                        led_data->base_color = MLXREG_LED_RED_SOLID;
                } else if (strstr(data->label, "amber")) {
                        brightness = LED_OFF;
                        led_data->base_color = MLXREG_LED_AMBER_SOLID;
                } else {
                        brightness = LED_OFF;
                        led_data->base_color = MLXREG_LED_GREEN_SOLID;
                }
                snprintf(led_data->led_cdev_name, sizeof(led_data->led_cdev_name),
                         "mlxreg:%s", data->label);
                led_cdev->name = led_data->led_cdev_name;
                led_cdev->brightness = brightness;
                led_cdev->max_brightness = LED_ON;
                led_cdev->brightness_set_blocking =
                                                mlxreg_led_brightness_set;
                led_cdev->brightness_get = mlxreg_led_brightness_get;
                led_cdev->blink_set = mlxreg_led_blink_set;
                led_cdev->flags = LED_CORE_SUSPENDRESUME;
                led_data->data = data;
                err = devm_led_classdev_register(&priv->pdev->dev, led_cdev);
                if (err)
                        return err;

                if (led_cdev->brightness)
                        mlxreg_led_brightness_set(led_cdev,
                                                  led_cdev->brightness);
                dev_info(led_cdev->dev, "label: %s, mask: 0x%02x, offset:0x%02x\n",
                         data->label, data->mask, data->reg);
        }

        return 0;
}

static int mlxreg_led_probe(struct platform_device *pdev)
{
        struct mlxreg_core_platform_data *led_pdata;
        struct mlxreg_led_priv_data *priv;
        int err;

        led_pdata = dev_get_platdata(&pdev->dev);
        if (!led_pdata) {
                dev_err(&pdev->dev, "Failed to get platform data.\n");
                return -EINVAL;
        }

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

        err = devm_mutex_init(&pdev->dev, &priv->access_lock);
        if (err)
                return err;

        priv->pdev = pdev;
        priv->pdata = led_pdata;

        return mlxreg_led_config(priv);
}

static struct platform_driver mlxreg_led_driver = {
        .driver = {
            .name = "leds-mlxreg",
        },
        .probe = mlxreg_led_probe,
};

module_platform_driver(mlxreg_led_driver);

MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("Mellanox LED regmap driver");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_ALIAS("platform:leds-mlxreg");