// SPDX-License-Identifier: GPL-2.0
// Flash and torch driver for Texas Instruments LM3601X LED
// Flash driver chip family
// Copyright (C) 2018 Texas Instruments Incorporated - https://www.ti.com/

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/leds.h>
#include <linux/led-class-flash.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/slab.h>

#define LM3601X_LED_IR          0x0
#define LM3601X_LED_TORCH       0x1

/* Registers */
#define LM3601X_ENABLE_REG      0x01
#define LM3601X_CFG_REG         0x02
#define LM3601X_LED_FLASH_REG   0x03
#define LM3601X_LED_TORCH_REG   0x04
#define LM3601X_FLAGS_REG       0x05
#define LM3601X_DEV_ID_REG      0x06

#define LM3601X_SW_RESET        BIT(7)

/* Enable Mode bits */
#define LM3601X_MODE_STANDBY    0x00
#define LM3601X_MODE_IR_DRV     BIT(0)
#define LM3601X_MODE_TORCH      BIT(1)
#define LM3601X_MODE_STROBE     (BIT(0) | BIT(1))
#define LM3601X_STRB_EN         BIT(2)
#define LM3601X_STRB_EDGE_TRIG  BIT(3)
#define LM3601X_IVFM_EN         BIT(4)

#define LM36010_BOOST_LIMIT_28  BIT(5)
#define LM36010_BOOST_FREQ_4MHZ BIT(6)
#define LM36010_BOOST_MODE_PASS BIT(7)

/* Flag Mask */
#define LM3601X_FLASH_TIME_OUT  BIT(0)
#define LM3601X_UVLO_FAULT      BIT(1)
#define LM3601X_THERM_SHUTDOWN  BIT(2)
#define LM3601X_THERM_CURR      BIT(3)
#define LM36010_CURR_LIMIT      BIT(4)
#define LM3601X_SHORT_FAULT     BIT(5)
#define LM3601X_IVFM_TRIP       BIT(6)
#define LM36010_OVP_FAULT       BIT(7)

#define LM3601X_MAX_TORCH_I_UA  376000
#define LM3601X_MIN_TORCH_I_UA  2400
#define LM3601X_TORCH_REG_DIV   2965

#define LM3601X_MAX_STROBE_I_UA 1500000
#define LM3601X_MIN_STROBE_I_UA 11000
#define LM3601X_STROBE_REG_DIV  11800

#define LM3601X_TIMEOUT_MASK    0x1e
#define LM3601X_ENABLE_MASK     (LM3601X_MODE_IR_DRV | LM3601X_MODE_TORCH)

#define LM3601X_LOWER_STEP_US   40000
#define LM3601X_UPPER_STEP_US   200000
#define LM3601X_MIN_TIMEOUT_US  40000
#define LM3601X_MAX_TIMEOUT_US  1600000
#define LM3601X_TIMEOUT_XOVER_US 400000

enum lm3601x_type {
        CHIP_LM36010 = 0,
        CHIP_LM36011,
};

/**
 * struct lm3601x_led - private lm3601x LED data
 * @fled_cdev: flash LED class device pointer
 * @client: Pointer to the I2C client
 * @regmap: Devices register map
 * @lock: Lock for reading/writing the device
 * @flash_timeout: the timeout for the flash
 * @last_flag: last known flags register value
 * @torch_current_max: maximum current for the torch
 * @flash_current_max: maximum current for the flash
 * @max_flash_timeout: maximum timeout for the flash
 * @led_mode: The mode to enable either IR or Torch
 */
struct lm3601x_led {
        struct led_classdev_flash fled_cdev;
        struct i2c_client *client;
        struct regmap *regmap;
        struct mutex lock;

        unsigned int flash_timeout;
        unsigned int last_flag;

        u32 torch_current_max;
        u32 flash_current_max;
        u32 max_flash_timeout;

        u32 led_mode;
};

static const struct reg_default lm3601x_regmap_defs[] = {
        { LM3601X_ENABLE_REG, 0x20 },
        { LM3601X_CFG_REG, 0x15 },
        { LM3601X_LED_FLASH_REG, 0x00 },
        { LM3601X_LED_TORCH_REG, 0x00 },
};

static bool lm3601x_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case LM3601X_FLAGS_REG:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config lm3601x_regmap = {
        .reg_bits = 8,
        .val_bits = 8,

        .max_register = LM3601X_DEV_ID_REG,
        .reg_defaults = lm3601x_regmap_defs,
        .num_reg_defaults = ARRAY_SIZE(lm3601x_regmap_defs),
        .cache_type = REGCACHE_MAPLE,
        .volatile_reg = lm3601x_volatile_reg,
};

static struct lm3601x_led *fled_cdev_to_led(struct led_classdev_flash *fled_cdev)
{
        return container_of(fled_cdev, struct lm3601x_led, fled_cdev);
}

static int lm3601x_read_faults(struct lm3601x_led *led)
{
        int flags_val;
        int ret;

        ret = regmap_read(led->regmap, LM3601X_FLAGS_REG, &flags_val);
        if (ret < 0)
                return -EIO;

        led->last_flag = 0;

        if (flags_val & LM36010_OVP_FAULT)
                led->last_flag |= LED_FAULT_OVER_VOLTAGE;

        if (flags_val & (LM3601X_THERM_SHUTDOWN | LM3601X_THERM_CURR))
                led->last_flag |= LED_FAULT_OVER_TEMPERATURE;

        if (flags_val & LM3601X_SHORT_FAULT)
                led->last_flag |= LED_FAULT_SHORT_CIRCUIT;

        if (flags_val & LM36010_CURR_LIMIT)
                led->last_flag |= LED_FAULT_OVER_CURRENT;

        if (flags_val & LM3601X_UVLO_FAULT)
                led->last_flag |= LED_FAULT_UNDER_VOLTAGE;

        if (flags_val & LM3601X_IVFM_TRIP)
                led->last_flag |= LED_FAULT_INPUT_VOLTAGE;

        if (flags_val & LM3601X_THERM_SHUTDOWN)
                led->last_flag |= LED_FAULT_LED_OVER_TEMPERATURE;

        return led->last_flag;
}

static int lm3601x_brightness_set(struct led_classdev *cdev,
                                        enum led_brightness brightness)
{
        struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(cdev);
        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
        int ret, led_mode_val;

        mutex_lock(&led->lock);

        ret = lm3601x_read_faults(led);
        if (ret < 0)
                goto out;

        if (led->led_mode == LM3601X_LED_TORCH)
                led_mode_val = LM3601X_MODE_TORCH;
        else
                led_mode_val = LM3601X_MODE_IR_DRV;

        if (brightness == LED_OFF) {
                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
                                        led_mode_val, LED_OFF);
                goto out;
        }

        ret = regmap_write(led->regmap, LM3601X_LED_TORCH_REG, brightness - 1);
        if (ret < 0)
                goto out;

        ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
                                LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
                                led_mode_val);
out:
        mutex_unlock(&led->lock);
        return ret;
}

static int lm3601x_strobe_set(struct led_classdev_flash *fled_cdev,
                                bool state)
{
        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
        int timeout_reg_val;
        int current_timeout;
        int ret;

        mutex_lock(&led->lock);

        ret = regmap_read(led->regmap, LM3601X_CFG_REG, &current_timeout);
        if (ret < 0)
                goto out;

        if (led->flash_timeout >= LM3601X_TIMEOUT_XOVER_US)
                timeout_reg_val = led->flash_timeout / LM3601X_UPPER_STEP_US + 0x07;
        else
                timeout_reg_val = led->flash_timeout / LM3601X_LOWER_STEP_US - 0x01;

        if (led->flash_timeout != current_timeout)
                ret = regmap_update_bits(led->regmap, LM3601X_CFG_REG,
                                        LM3601X_TIMEOUT_MASK, timeout_reg_val);

        if (state)
                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
                                        LM3601X_MODE_TORCH | LM3601X_MODE_IR_DRV,
                                        LM3601X_MODE_STROBE);
        else
                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
                                        LM3601X_MODE_STROBE, LED_OFF);

        ret = lm3601x_read_faults(led);
out:
        mutex_unlock(&led->lock);
        return ret;
}

static int lm3601x_flash_brightness_set(struct led_classdev_flash *fled_cdev,
                                        u32 brightness)
{
        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
        u8 brightness_val;
        int ret;

        mutex_lock(&led->lock);
        ret = lm3601x_read_faults(led);
        if (ret < 0)
                goto out;

        if (brightness == LED_OFF) {
                ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
                                        LM3601X_MODE_STROBE, LED_OFF);
                goto out;
        }

        brightness_val = brightness / LM3601X_STROBE_REG_DIV;

        ret = regmap_write(led->regmap, LM3601X_LED_FLASH_REG, brightness_val);
out:
        mutex_unlock(&led->lock);
        return ret;
}

static int lm3601x_flash_timeout_set(struct led_classdev_flash *fled_cdev,
                                u32 timeout)
{
        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);

        mutex_lock(&led->lock);

        led->flash_timeout = timeout;

        mutex_unlock(&led->lock);

        return 0;
}

static int lm3601x_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
{
        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);
        int strobe_state;
        int ret;

        mutex_lock(&led->lock);

        ret = regmap_read(led->regmap, LM3601X_ENABLE_REG, &strobe_state);
        if (ret < 0)
                goto out;

        *state = strobe_state & LM3601X_MODE_STROBE;

out:
        mutex_unlock(&led->lock);
        return ret;
}

static int lm3601x_flash_fault_get(struct led_classdev_flash *fled_cdev,
                                u32 *fault)
{
        struct lm3601x_led *led = fled_cdev_to_led(fled_cdev);

        lm3601x_read_faults(led);

        *fault = led->last_flag;

        return 0;
}

static const struct led_flash_ops flash_ops = {
        .flash_brightness_set   = lm3601x_flash_brightness_set,
        .strobe_set             = lm3601x_strobe_set,
        .strobe_get             = lm3601x_strobe_get,
        .timeout_set            = lm3601x_flash_timeout_set,
        .fault_get              = lm3601x_flash_fault_get,
};

static int lm3601x_register_leds(struct lm3601x_led *led,
                                 struct fwnode_handle *fwnode)
{
        struct led_classdev *led_cdev;
        struct led_flash_setting *setting;
        struct led_init_data init_data = {};

        led->fled_cdev.ops = &flash_ops;

        setting = &led->fled_cdev.timeout;
        setting->min = LM3601X_MIN_TIMEOUT_US;
        setting->max = led->max_flash_timeout;
        setting->step = LM3601X_LOWER_STEP_US;
        setting->val = led->max_flash_timeout;

        setting = &led->fled_cdev.brightness;
        setting->min = LM3601X_MIN_STROBE_I_UA;
        setting->max = led->flash_current_max;
        setting->step = LM3601X_TORCH_REG_DIV;
        setting->val = led->flash_current_max;

        led_cdev = &led->fled_cdev.led_cdev;
        led_cdev->brightness_set_blocking = lm3601x_brightness_set;
        led_cdev->max_brightness =
                        DIV_ROUND_UP(led->torch_current_max - LM3601X_MIN_TORCH_I_UA + 1,
                                     LM3601X_TORCH_REG_DIV);
        led_cdev->flags |= LED_DEV_CAP_FLASH;

        init_data.fwnode = fwnode;
        init_data.devicename = led->client->name;
        init_data.default_label = (led->led_mode == LM3601X_LED_TORCH) ?
                                        "torch" : "infrared";
        return devm_led_classdev_flash_register_ext(&led->client->dev,
                                                &led->fled_cdev, &init_data);
}

static int lm3601x_parse_node(struct lm3601x_led *led,
                              struct fwnode_handle **fwnode)
{
        struct fwnode_handle *child = NULL;
        int ret = -ENODEV;

        child = device_get_next_child_node(&led->client->dev, child);
        if (!child) {
                dev_err(&led->client->dev, "No LED Child node\n");
                return ret;
        }

        ret = fwnode_property_read_u32(child, "reg", &led->led_mode);
        if (ret) {
                dev_err(&led->client->dev, "reg DT property missing\n");
                goto out_err;
        }

        if (led->led_mode > LM3601X_LED_TORCH ||
            led->led_mode < LM3601X_LED_IR) {
                dev_warn(&led->client->dev, "Invalid led mode requested\n");
                ret = -EINVAL;
                goto out_err;
        }

        ret = fwnode_property_read_u32(child, "led-max-microamp",
                                        &led->torch_current_max);
        if (ret) {
                dev_warn(&led->client->dev,
                        "led-max-microamp DT property missing\n");
                goto out_err;
        }

        if (led->torch_current_max > LM3601X_MAX_TORCH_I_UA) {
                dev_warn(&led->client->dev,
                         "Max torch current set too high (%d vs %d)\n",
                         led->torch_current_max,
                         LM3601X_MAX_TORCH_I_UA);
                led->torch_current_max = LM3601X_MAX_TORCH_I_UA;
        }

        ret = fwnode_property_read_u32(child, "flash-max-microamp",
                                &led->flash_current_max);
        if (ret) {
                dev_warn(&led->client->dev,
                         "flash-max-microamp DT property missing\n");
                goto out_err;
        }

        ret = fwnode_property_read_u32(child, "flash-max-timeout-us",
                                &led->max_flash_timeout);
        if (ret) {
                dev_warn(&led->client->dev,
                         "flash-max-timeout-us DT property missing\n");
                goto out_err;
        }

        *fwnode = child;

out_err:
        fwnode_handle_put(child);
        return ret;
}

static int lm3601x_probe(struct i2c_client *client)
{
        struct lm3601x_led *led;
        struct fwnode_handle *fwnode;
        int ret;

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

        led->client = client;
        i2c_set_clientdata(client, led);

        ret = lm3601x_parse_node(led, &fwnode);
        if (ret)
                return -ENODEV;

        led->regmap = devm_regmap_init_i2c(client, &lm3601x_regmap);
        if (IS_ERR(led->regmap)) {
                ret = PTR_ERR(led->regmap);
                dev_err(&client->dev,
                        "Failed to allocate register map: %d\n", ret);
                return ret;
        }

        ret = regmap_write(led->regmap, LM3601X_DEV_ID_REG, LM3601X_SW_RESET);
        if (ret)
                dev_warn(&client->dev, "Failed to reset the LED controller\n");

        mutex_init(&led->lock);

        return lm3601x_register_leds(led, fwnode);
}

static void lm3601x_remove(struct i2c_client *client)
{
        struct lm3601x_led *led = i2c_get_clientdata(client);
        int ret;

        ret = regmap_update_bits(led->regmap, LM3601X_ENABLE_REG,
                                 LM3601X_ENABLE_MASK, LM3601X_MODE_STANDBY);
        if (ret)
                dev_warn(&client->dev,
                         "Failed to put into standby (%pe)\n", ERR_PTR(ret));
}

static const struct i2c_device_id lm3601x_id[] = {
        { "LM36010", CHIP_LM36010 },
        { "LM36011", CHIP_LM36011 },
        { }
};
MODULE_DEVICE_TABLE(i2c, lm3601x_id);

static const struct of_device_id of_lm3601x_leds_match[] = {
        { .compatible = "ti,lm36010", },
        { .compatible = "ti,lm36011", },
        { }
};
MODULE_DEVICE_TABLE(of, of_lm3601x_leds_match);

static struct i2c_driver lm3601x_i2c_driver = {
        .driver = {
                .name = "lm3601x",
                .of_match_table = of_lm3601x_leds_match,
        },
        .probe = lm3601x_probe,
        .remove = lm3601x_remove,
        .id_table = lm3601x_id,
};
module_i2c_driver(lm3601x_i2c_driver);

MODULE_DESCRIPTION("Texas Instruments Flash Lighting driver for LM3601X");
MODULE_AUTHOR("Dan Murphy <dmurphy@ti.com>");
MODULE_LICENSE("GPL v2");