// SPDX-License-Identifier: GPL-2.0-only
/*
 * drivers/media/i2c/lm3646.c
 * General device driver for TI lm3646, Dual FLASH LED Driver
 *
 * Copyright (C) 2014 Texas Instruments
 *
 * Contact: Daniel Jeong <gshark.jeong@gmail.com>
 *                      Ldd-Mlp <ldd-mlp@list.ti.com>
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/videodev2.h>
#include <media/i2c/lm3646.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>

/* registers definitions */
#define REG_ENABLE              0x01
#define REG_TORCH_BR    0x05
#define REG_FLASH_BR    0x05
#define REG_FLASH_TOUT  0x04
#define REG_FLAG                0x08
#define REG_STROBE_SRC  0x06
#define REG_LED1_FLASH_BR 0x06
#define REG_LED1_TORCH_BR 0x07

#define MASK_ENABLE             0x03
#define MASK_TORCH_BR   0x70
#define MASK_FLASH_BR   0x0F
#define MASK_FLASH_TOUT 0x07
#define MASK_FLAG               0xFF
#define MASK_STROBE_SRC 0x80

/* Fault Mask */
#define FAULT_TIMEOUT   (1<<0)
#define FAULT_SHORT_CIRCUIT     (1<<1)
#define FAULT_UVLO              (1<<2)
#define FAULT_IVFM              (1<<3)
#define FAULT_OCP               (1<<4)
#define FAULT_OVERTEMP  (1<<5)
#define FAULT_NTC_TRIP  (1<<6)
#define FAULT_OVP               (1<<7)

enum led_mode {
        MODE_SHDN = 0x0,
        MODE_TORCH = 0x2,
        MODE_FLASH = 0x3,
};

/*
 * struct lm3646_flash
 *
 * @pdata: platform data
 * @regmap: reg. map for i2c
 * @lock: muxtex for serial access.
 * @led_mode: V4L2 LED mode
 * @ctrls_led: V4L2 controls
 * @subdev_led: V4L2 subdev
 * @mode_reg : mode register value
 */
struct lm3646_flash {
        struct device *dev;
        struct lm3646_platform_data *pdata;
        struct regmap *regmap;

        struct v4l2_ctrl_handler ctrls_led;
        struct v4l2_subdev subdev_led;

        u8 mode_reg;
};

#define to_lm3646_flash(_ctrl)  \
        container_of(_ctrl->handler, struct lm3646_flash, ctrls_led)

/* enable mode control */
static int lm3646_mode_ctrl(struct lm3646_flash *flash,
                            enum v4l2_flash_led_mode led_mode)
{
        switch (led_mode) {
        case V4L2_FLASH_LED_MODE_NONE:
                return regmap_write(flash->regmap,
                                    REG_ENABLE, flash->mode_reg | MODE_SHDN);
        case V4L2_FLASH_LED_MODE_TORCH:
                return regmap_write(flash->regmap,
                                    REG_ENABLE, flash->mode_reg | MODE_TORCH);
        case V4L2_FLASH_LED_MODE_FLASH:
                return regmap_write(flash->regmap,
                                    REG_ENABLE, flash->mode_reg | MODE_FLASH);
        }
        return -EINVAL;
}

/* V4L2 controls  */
static int lm3646_get_ctrl(struct v4l2_ctrl *ctrl)
{
        struct lm3646_flash *flash = to_lm3646_flash(ctrl);
        unsigned int reg_val;
        int rval;

        if (ctrl->id != V4L2_CID_FLASH_FAULT)
                return -EINVAL;

        rval = regmap_read(flash->regmap, REG_FLAG, &reg_val);
        if (rval < 0)
                return rval;

        ctrl->val = 0;
        if (reg_val & FAULT_TIMEOUT)
                ctrl->val |= V4L2_FLASH_FAULT_TIMEOUT;
        if (reg_val & FAULT_SHORT_CIRCUIT)
                ctrl->val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
        if (reg_val & FAULT_UVLO)
                ctrl->val |= V4L2_FLASH_FAULT_UNDER_VOLTAGE;
        if (reg_val & FAULT_IVFM)
                ctrl->val |= V4L2_FLASH_FAULT_INPUT_VOLTAGE;
        if (reg_val & FAULT_OCP)
                ctrl->val |= V4L2_FLASH_FAULT_OVER_CURRENT;
        if (reg_val & FAULT_OVERTEMP)
                ctrl->val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
        if (reg_val & FAULT_NTC_TRIP)
                ctrl->val |= V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE;
        if (reg_val & FAULT_OVP)
                ctrl->val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;

        return 0;
}

static int lm3646_set_ctrl(struct v4l2_ctrl *ctrl)
{
        struct lm3646_flash *flash = to_lm3646_flash(ctrl);
        unsigned int reg_val;
        int rval;

        switch (ctrl->id) {
        case V4L2_CID_FLASH_LED_MODE:

                if (ctrl->val != V4L2_FLASH_LED_MODE_FLASH)
                        return lm3646_mode_ctrl(flash, ctrl->val);
                /* switch to SHDN mode before flash strobe on */
                return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);

        case V4L2_CID_FLASH_STROBE_SOURCE:
                return regmap_update_bits(flash->regmap,
                                          REG_STROBE_SRC, MASK_STROBE_SRC,
                                          (ctrl->val) << 7);

        case V4L2_CID_FLASH_STROBE:

                /* read and check current mode of chip to start flash */
                rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
                if (rval < 0 || ((reg_val & MASK_ENABLE) != MODE_SHDN))
                        return rval;
                /* flash on */
                return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_FLASH);

        case V4L2_CID_FLASH_STROBE_STOP:

                /*
                 * flash mode will be turned automatically
                 * from FLASH mode to SHDN mode after flash duration timeout
                 * read and check current mode of chip to stop flash
                 */
                rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
                if (rval < 0)
                        return rval;
                if ((reg_val & MASK_ENABLE) == MODE_FLASH)
                        return lm3646_mode_ctrl(flash,
                                                V4L2_FLASH_LED_MODE_NONE);
                return rval;

        case V4L2_CID_FLASH_TIMEOUT:
                return regmap_update_bits(flash->regmap,
                                          REG_FLASH_TOUT, MASK_FLASH_TOUT,
                                          LM3646_FLASH_TOUT_ms_TO_REG
                                          (ctrl->val));

        case V4L2_CID_FLASH_INTENSITY:
                return regmap_update_bits(flash->regmap,
                                          REG_FLASH_BR, MASK_FLASH_BR,
                                          LM3646_TOTAL_FLASH_BRT_uA_TO_REG
                                          (ctrl->val));

        case V4L2_CID_FLASH_TORCH_INTENSITY:
                return regmap_update_bits(flash->regmap,
                                          REG_TORCH_BR, MASK_TORCH_BR,
                                          LM3646_TOTAL_TORCH_BRT_uA_TO_REG
                                          (ctrl->val) << 4);
        }

        return -EINVAL;
}

static const struct v4l2_ctrl_ops lm3646_led_ctrl_ops = {
        .g_volatile_ctrl = lm3646_get_ctrl,
        .s_ctrl = lm3646_set_ctrl,
};

static int lm3646_init_controls(struct lm3646_flash *flash)
{
        struct v4l2_ctrl *fault;
        struct v4l2_ctrl_handler *hdl = &flash->ctrls_led;
        const struct v4l2_ctrl_ops *ops = &lm3646_led_ctrl_ops;

        v4l2_ctrl_handler_init(hdl, 8);
        /* flash mode */
        v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_LED_MODE,
                               V4L2_FLASH_LED_MODE_TORCH, ~0x7,
                               V4L2_FLASH_LED_MODE_NONE);

        /* flash source */
        v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_STROBE_SOURCE,
                               0x1, ~0x3, V4L2_FLASH_STROBE_SOURCE_SOFTWARE);

        /* flash strobe */
        v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
        /* flash strobe stop */
        v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);

        /* flash strobe timeout */
        v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TIMEOUT,
                          LM3646_FLASH_TOUT_MIN,
                          LM3646_FLASH_TOUT_MAX,
                          LM3646_FLASH_TOUT_STEP, flash->pdata->flash_timeout);

        /* max flash current */
        v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_INTENSITY,
                          LM3646_TOTAL_FLASH_BRT_MIN,
                          LM3646_TOTAL_FLASH_BRT_MAX,
                          LM3646_TOTAL_FLASH_BRT_STEP,
                          LM3646_TOTAL_FLASH_BRT_MAX);

        /* max torch current */
        v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TORCH_INTENSITY,
                          LM3646_TOTAL_TORCH_BRT_MIN,
                          LM3646_TOTAL_TORCH_BRT_MAX,
                          LM3646_TOTAL_TORCH_BRT_STEP,
                          LM3646_TOTAL_TORCH_BRT_MAX);

        /* fault */
        fault = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_FAULT, 0,
                                  V4L2_FLASH_FAULT_OVER_VOLTAGE
                                  | V4L2_FLASH_FAULT_OVER_TEMPERATURE
                                  | V4L2_FLASH_FAULT_SHORT_CIRCUIT
                                  | V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
        if (fault != NULL)
                fault->flags |= V4L2_CTRL_FLAG_VOLATILE;

        if (hdl->error)
                return hdl->error;

        flash->subdev_led.ctrl_handler = hdl;
        return 0;
}

/* initialize device */
static const struct v4l2_subdev_ops lm3646_ops = {
        .core = NULL,
};

static const struct regmap_config lm3646_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0xFF,
};

static int lm3646_subdev_init(struct lm3646_flash *flash)
{
        struct i2c_client *client = to_i2c_client(flash->dev);
        int rval;

        v4l2_i2c_subdev_init(&flash->subdev_led, client, &lm3646_ops);
        flash->subdev_led.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        strscpy(flash->subdev_led.name, LM3646_NAME,
                sizeof(flash->subdev_led.name));
        rval = lm3646_init_controls(flash);
        if (rval)
                goto err_out;
        rval = media_entity_pads_init(&flash->subdev_led.entity, 0, NULL);
        if (rval < 0)
                goto err_out;
        flash->subdev_led.entity.function = MEDIA_ENT_F_FLASH;
        return rval;

err_out:
        v4l2_ctrl_handler_free(&flash->ctrls_led);
        return rval;
}

static int lm3646_init_device(struct lm3646_flash *flash)
{
        unsigned int reg_val;
        int rval;

        /* read the value of mode register to reduce redundant i2c accesses */
        rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
        if (rval < 0)
                return rval;
        flash->mode_reg = reg_val & 0xfc;

        /* output disable */
        rval = lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
        if (rval < 0)
                return rval;

        /*
         * LED1 flash current setting
         * LED2 flash current = Total(Max) flash current - LED1 flash current
         */
        rval = regmap_update_bits(flash->regmap,
                                  REG_LED1_FLASH_BR, 0x7F,
                                  LM3646_LED1_FLASH_BRT_uA_TO_REG
                                  (flash->pdata->led1_flash_brt));

        if (rval < 0)
                return rval;

        /*
         * LED1 torch current setting
         * LED2 torch current = Total(Max) torch current - LED1 torch current
         */
        rval = regmap_update_bits(flash->regmap,
                                  REG_LED1_TORCH_BR, 0x7F,
                                  LM3646_LED1_TORCH_BRT_uA_TO_REG
                                  (flash->pdata->led1_torch_brt));
        if (rval < 0)
                return rval;

        /* Reset flag register */
        return regmap_read(flash->regmap, REG_FLAG, &reg_val);
}

static int lm3646_probe(struct i2c_client *client)
{
        struct lm3646_flash *flash;
        struct lm3646_platform_data *pdata = dev_get_platdata(&client->dev);
        int rval;

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

        flash->regmap = devm_regmap_init_i2c(client, &lm3646_regmap);
        if (IS_ERR(flash->regmap))
                return PTR_ERR(flash->regmap);

        /* check device tree if there is no platform data */
        if (pdata == NULL) {
                pdata = devm_kzalloc(&client->dev,
                                     sizeof(struct lm3646_platform_data),
                                     GFP_KERNEL);
                if (pdata == NULL)
                        return -ENOMEM;
                /* use default data in case of no platform data */
                pdata->flash_timeout = LM3646_FLASH_TOUT_MAX;
                pdata->led1_torch_brt = LM3646_LED1_TORCH_BRT_MAX;
                pdata->led1_flash_brt = LM3646_LED1_FLASH_BRT_MAX;
        }
        flash->pdata = pdata;
        flash->dev = &client->dev;

        rval = lm3646_subdev_init(flash);
        if (rval < 0)
                return rval;

        rval = lm3646_init_device(flash);
        if (rval < 0)
                return rval;

        i2c_set_clientdata(client, flash);

        return 0;
}

static void lm3646_remove(struct i2c_client *client)
{
        struct lm3646_flash *flash = i2c_get_clientdata(client);

        v4l2_device_unregister_subdev(&flash->subdev_led);
        v4l2_ctrl_handler_free(&flash->ctrls_led);
        media_entity_cleanup(&flash->subdev_led.entity);
}

static const struct i2c_device_id lm3646_id_table[] = {
        { .name = LM3646_NAME },
        { }
};

MODULE_DEVICE_TABLE(i2c, lm3646_id_table);

static struct i2c_driver lm3646_i2c_driver = {
        .driver = {
                   .name = LM3646_NAME,
                   },
        .probe = lm3646_probe,
        .remove = lm3646_remove,
        .id_table = lm3646_id_table,
};

module_i2c_driver(lm3646_i2c_driver);

MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
MODULE_AUTHOR("Ldd Mlp <ldd-mlp@list.ti.com>");
MODULE_DESCRIPTION("Texas Instruments LM3646 Dual Flash LED driver");
MODULE_LICENSE("GPL");