/*
 * V4L2 flash LED sub-device registration helpers.
 *
 *      Copyright (C) 2015 Samsung Electronics Co., Ltd
 *      Author: Jacek Anaszewski <j.anaszewski@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/led-class-flash.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <media/v4l2-flash-led-class.h>

#define has_flash_op(v4l2_flash, op)                            \
        (v4l2_flash && v4l2_flash->ops->op)

#define call_flash_op(v4l2_flash, op, arg)                      \
                (has_flash_op(v4l2_flash, op) ?                 \
                        v4l2_flash->ops->op(v4l2_flash, arg) :  \
                        -EINVAL)

enum ctrl_init_data_id {
        LED_MODE,
        TORCH_INTENSITY,
        FLASH_INTENSITY,
        INDICATOR_INTENSITY,
        FLASH_TIMEOUT,
        STROBE_SOURCE,
        /*
         * Only above values are applicable to
         * the 'ctrls' array in the struct v4l2_flash.
         */
        FLASH_STROBE,
        STROBE_STOP,
        STROBE_STATUS,
        FLASH_FAULT,
        NUM_FLASH_CTRLS,
};

static enum led_brightness __intensity_to_led_brightness(
                                        struct v4l2_ctrl *ctrl, s32 intensity)
{
        intensity -= ctrl->minimum;
        intensity /= (u32) ctrl->step;

        /*
         * Indicator LEDs, unlike torch LEDs, are turned on/off basing on
         * the state of V4L2_CID_FLASH_INDICATOR_INTENSITY control only.
         * Therefore it must be possible to set it to 0 level which in
         * the LED subsystem reflects LED_OFF state.
         */
        if (ctrl->minimum)
                ++intensity;

        return intensity;
}

static s32 __led_brightness_to_intensity(struct v4l2_ctrl *ctrl,
                                         enum led_brightness brightness)
{
        /*
         * Indicator LEDs, unlike torch LEDs, are turned on/off basing on
         * the state of V4L2_CID_FLASH_INDICATOR_INTENSITY control only.
         * Do not decrement brightness read from the LED subsystem for
         * indicator LED as it may equal 0. For torch LEDs this function
         * is called only when V4L2_FLASH_LED_MODE_TORCH is set and the
         * brightness read is guaranteed to be greater than 0. In the mode
         * V4L2_FLASH_LED_MODE_NONE the cached torch intensity value is used.
         */
        if (ctrl->id != V4L2_CID_FLASH_INDICATOR_INTENSITY)
                --brightness;

        return (brightness * ctrl->step) + ctrl->minimum;
}

static void v4l2_flash_set_led_brightness(struct v4l2_flash *v4l2_flash,
                                        struct v4l2_ctrl *ctrl)
{
        struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
        enum led_brightness brightness;

        if (has_flash_op(v4l2_flash, intensity_to_led_brightness))
                brightness = call_flash_op(v4l2_flash,
                                        intensity_to_led_brightness,
                                        ctrl->val);
        else
                brightness = __intensity_to_led_brightness(ctrl, ctrl->val);
        /*
         * In case a LED Flash class driver provides ops for custom
         * brightness <-> intensity conversion, it also must have defined
         * related v4l2 control step == 1. In such a case a backward conversion
         * from led brightness to v4l2 intensity is required to find out the
         * the aligned intensity value.
         */
        if (has_flash_op(v4l2_flash, led_brightness_to_intensity))
                ctrl->val = call_flash_op(v4l2_flash,
                                        led_brightness_to_intensity,
                                        brightness);

        if (ctrl == ctrls[TORCH_INTENSITY]) {
                if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
                        return;

                led_set_brightness(&v4l2_flash->fled_cdev->led_cdev,
                                        brightness);
        } else {
                led_set_brightness(&v4l2_flash->iled_cdev->led_cdev,
                                        brightness);
        }
}

static int v4l2_flash_update_led_brightness(struct v4l2_flash *v4l2_flash,
                                        struct v4l2_ctrl *ctrl)
{
        struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
        struct led_classdev *led_cdev;
        int ret;

        if (ctrl == ctrls[TORCH_INTENSITY]) {
                /*
                 * Update torch brightness only if in TORCH_MODE. In other modes
                 * torch led is turned off, which would spuriously inform the
                 * user space that V4L2_CID_FLASH_TORCH_INTENSITY control value
                 * has changed to 0.
                 */
                if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
                        return 0;
                led_cdev = &v4l2_flash->fled_cdev->led_cdev;
        } else {
                led_cdev = &v4l2_flash->iled_cdev->led_cdev;
        }

        ret = led_update_brightness(led_cdev);
        if (ret < 0)
                return ret;

        if (has_flash_op(v4l2_flash, led_brightness_to_intensity))
                ctrl->val = call_flash_op(v4l2_flash,
                                                led_brightness_to_intensity,
                                                led_cdev->brightness);
        else
                ctrl->val = __led_brightness_to_intensity(ctrl,
                                                led_cdev->brightness);

        return 0;
}

static int v4l2_flash_g_volatile_ctrl(struct v4l2_ctrl *c)
{
        struct v4l2_flash *v4l2_flash = v4l2_ctrl_to_v4l2_flash(c);
        struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
        bool is_strobing;
        int ret;

        switch (c->id) {
        case V4L2_CID_FLASH_TORCH_INTENSITY:
        case V4L2_CID_FLASH_INDICATOR_INTENSITY:
                return v4l2_flash_update_led_brightness(v4l2_flash, c);
        case V4L2_CID_FLASH_INTENSITY:
                ret = led_update_flash_brightness(fled_cdev);
                if (ret < 0)
                        return ret;
                /*
                 * No conversion is needed as LED Flash class also uses
                 * microamperes for flash intensity units.
                 */
                c->val = fled_cdev->brightness.val;
                return 0;
        case V4L2_CID_FLASH_STROBE_STATUS:
                ret = led_get_flash_strobe(fled_cdev, &is_strobing);
                if (ret < 0)
                        return ret;
                c->val = is_strobing;
                return 0;
        case V4L2_CID_FLASH_FAULT:
                /* LED faults map directly to V4L2 flash faults */
                return led_get_flash_fault(fled_cdev, &c->val);
        default:
                return -EINVAL;
        }
}

static bool __software_strobe_mode_inactive(struct v4l2_ctrl **ctrls)
{
        return ((ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_FLASH) ||
                (ctrls[STROBE_SOURCE] && (ctrls[STROBE_SOURCE]->val !=
                                V4L2_FLASH_STROBE_SOURCE_SOFTWARE)));
}

static int v4l2_flash_s_ctrl(struct v4l2_ctrl *c)
{
        struct v4l2_flash *v4l2_flash = v4l2_ctrl_to_v4l2_flash(c);
        struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
        bool external_strobe;
        int ret = 0;

        switch (c->id) {
        case V4L2_CID_FLASH_LED_MODE:
                switch (c->val) {
                case V4L2_FLASH_LED_MODE_NONE:
                        led_set_brightness(led_cdev, LED_OFF);
                        return led_set_flash_strobe(fled_cdev, false);
                case V4L2_FLASH_LED_MODE_FLASH:
                        /* Turn the torch LED off */
                        led_set_brightness(led_cdev, LED_OFF);
                        if (ctrls[STROBE_SOURCE]) {
                                external_strobe = (ctrls[STROBE_SOURCE]->val ==
                                        V4L2_FLASH_STROBE_SOURCE_EXTERNAL);

                                ret = call_flash_op(v4l2_flash,
                                                external_strobe_set,
                                                external_strobe);
                        }
                        return ret;
                case V4L2_FLASH_LED_MODE_TORCH:
                        if (ctrls[STROBE_SOURCE]) {
                                ret = call_flash_op(v4l2_flash,
                                                external_strobe_set,
                                                false);
                                if (ret < 0)
                                        return ret;
                        }
                        /* Stop flash strobing */
                        ret = led_set_flash_strobe(fled_cdev, false);
                        if (ret < 0)
                                return ret;

                        v4l2_flash_set_led_brightness(v4l2_flash,
                                                        ctrls[TORCH_INTENSITY]);
                        return 0;
                }
                break;
        case V4L2_CID_FLASH_STROBE_SOURCE:
                external_strobe = (c->val == V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
                /*
                 * For some hardware arrangements setting strobe source may
                 * affect torch mode. Therefore, if not in the flash mode,
                 * cache only this setting. It will be applied upon switching
                 * to flash mode.
                 */
                if (ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_FLASH)
                        return 0;

                return call_flash_op(v4l2_flash, external_strobe_set,
                                        external_strobe);
        case V4L2_CID_FLASH_STROBE:
                if (__software_strobe_mode_inactive(ctrls))
                        return -EBUSY;
                return led_set_flash_strobe(fled_cdev, true);
        case V4L2_CID_FLASH_STROBE_STOP:
                if (__software_strobe_mode_inactive(ctrls))
                        return -EBUSY;
                return led_set_flash_strobe(fled_cdev, false);
        case V4L2_CID_FLASH_TIMEOUT:
                /*
                 * No conversion is needed as LED Flash class also uses
                 * microseconds for flash timeout units.
                 */
                return led_set_flash_timeout(fled_cdev, c->val);
        case V4L2_CID_FLASH_INTENSITY:
                /*
                 * No conversion is needed as LED Flash class also uses
                 * microamperes for flash intensity units.
                 */
                return led_set_flash_brightness(fled_cdev, c->val);
        case V4L2_CID_FLASH_TORCH_INTENSITY:
        case V4L2_CID_FLASH_INDICATOR_INTENSITY:
                v4l2_flash_set_led_brightness(v4l2_flash, c);
                return 0;
        }

        return -EINVAL;
}

static const struct v4l2_ctrl_ops v4l2_flash_ctrl_ops = {
        .g_volatile_ctrl = v4l2_flash_g_volatile_ctrl,
        .s_ctrl = v4l2_flash_s_ctrl,
};

static void __lfs_to_v4l2_ctrl_config(struct led_flash_setting *s,
                                struct v4l2_ctrl_config *c)
{
        c->min = s->min;
        c->max = s->max;
        c->step = s->step;
        c->def = s->val;
}

static void __fill_ctrl_init_data(struct v4l2_flash *v4l2_flash,
                          struct v4l2_flash_config *flash_cfg,
                          struct v4l2_flash_ctrl_data *ctrl_init_data)
{
        struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
        const struct led_flash_ops *fled_cdev_ops = fled_cdev->ops;
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        struct v4l2_ctrl_config *ctrl_cfg;
        u32 mask;

        /* Init FLASH_FAULT ctrl data */
        if (flash_cfg->flash_faults) {
                ctrl_init_data[FLASH_FAULT].cid = V4L2_CID_FLASH_FAULT;
                ctrl_cfg = &ctrl_init_data[FLASH_FAULT].config;
                ctrl_cfg->id = V4L2_CID_FLASH_FAULT;
                ctrl_cfg->max = flash_cfg->flash_faults;
                ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
                                  V4L2_CTRL_FLAG_READ_ONLY;
        }

        /* Init FLASH_LED_MODE ctrl data */
        mask = 1 << V4L2_FLASH_LED_MODE_NONE |
               1 << V4L2_FLASH_LED_MODE_TORCH;
        if (led_cdev->flags & LED_DEV_CAP_FLASH)
                mask |= 1 << V4L2_FLASH_LED_MODE_FLASH;

        ctrl_init_data[LED_MODE].cid = V4L2_CID_FLASH_LED_MODE;
        ctrl_cfg = &ctrl_init_data[LED_MODE].config;
        ctrl_cfg->id = V4L2_CID_FLASH_LED_MODE;
        ctrl_cfg->max = V4L2_FLASH_LED_MODE_TORCH;
        ctrl_cfg->menu_skip_mask = ~mask;
        ctrl_cfg->def = V4L2_FLASH_LED_MODE_NONE;
        ctrl_cfg->flags = 0;

        /* Init TORCH_INTENSITY ctrl data */
        ctrl_init_data[TORCH_INTENSITY].cid = V4L2_CID_FLASH_TORCH_INTENSITY;
        ctrl_cfg = &ctrl_init_data[TORCH_INTENSITY].config;
        __lfs_to_v4l2_ctrl_config(&flash_cfg->torch_intensity, ctrl_cfg);
        ctrl_cfg->id = V4L2_CID_FLASH_TORCH_INTENSITY;
        ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
                          V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;

        /* Init INDICATOR_INTENSITY ctrl data */
        if (v4l2_flash->iled_cdev) {
                ctrl_init_data[INDICATOR_INTENSITY].cid =
                                        V4L2_CID_FLASH_INDICATOR_INTENSITY;
                ctrl_cfg = &ctrl_init_data[INDICATOR_INTENSITY].config;
                __lfs_to_v4l2_ctrl_config(&flash_cfg->indicator_intensity,
                                          ctrl_cfg);
                ctrl_cfg->id = V4L2_CID_FLASH_INDICATOR_INTENSITY;
                ctrl_cfg->min = 0;
                ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
                                  V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
        }

        if (!(led_cdev->flags & LED_DEV_CAP_FLASH))
                return;

        /* Init FLASH_STROBE ctrl data */
        ctrl_init_data[FLASH_STROBE].cid = V4L2_CID_FLASH_STROBE;
        ctrl_cfg = &ctrl_init_data[FLASH_STROBE].config;
        ctrl_cfg->id = V4L2_CID_FLASH_STROBE;

        /* Init STROBE_STOP ctrl data */
        ctrl_init_data[STROBE_STOP].cid = V4L2_CID_FLASH_STROBE_STOP;
        ctrl_cfg = &ctrl_init_data[STROBE_STOP].config;
        ctrl_cfg->id = V4L2_CID_FLASH_STROBE_STOP;

        /* Init FLASH_STROBE_SOURCE ctrl data */
        if (flash_cfg->has_external_strobe) {
                mask = (1 << V4L2_FLASH_STROBE_SOURCE_SOFTWARE) |
                       (1 << V4L2_FLASH_STROBE_SOURCE_EXTERNAL);
                ctrl_init_data[STROBE_SOURCE].cid =
                                        V4L2_CID_FLASH_STROBE_SOURCE;
                ctrl_cfg = &ctrl_init_data[STROBE_SOURCE].config;
                ctrl_cfg->id = V4L2_CID_FLASH_STROBE_SOURCE;
                ctrl_cfg->max = V4L2_FLASH_STROBE_SOURCE_EXTERNAL;
                ctrl_cfg->menu_skip_mask = ~mask;
                ctrl_cfg->def = V4L2_FLASH_STROBE_SOURCE_SOFTWARE;
        }

        /* Init STROBE_STATUS ctrl data */
        if (fled_cdev_ops->strobe_get) {
                ctrl_init_data[STROBE_STATUS].cid =
                                        V4L2_CID_FLASH_STROBE_STATUS;
                ctrl_cfg = &ctrl_init_data[STROBE_STATUS].config;
                ctrl_cfg->id = V4L2_CID_FLASH_STROBE_STATUS;
                ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
                                  V4L2_CTRL_FLAG_READ_ONLY;
        }

        /* Init FLASH_TIMEOUT ctrl data */
        if (fled_cdev_ops->timeout_set) {
                ctrl_init_data[FLASH_TIMEOUT].cid = V4L2_CID_FLASH_TIMEOUT;
                ctrl_cfg = &ctrl_init_data[FLASH_TIMEOUT].config;
                __lfs_to_v4l2_ctrl_config(&fled_cdev->timeout, ctrl_cfg);
                ctrl_cfg->id = V4L2_CID_FLASH_TIMEOUT;
        }

        /* Init FLASH_INTENSITY ctrl data */
        if (fled_cdev_ops->flash_brightness_set) {
                ctrl_init_data[FLASH_INTENSITY].cid = V4L2_CID_FLASH_INTENSITY;
                ctrl_cfg = &ctrl_init_data[FLASH_INTENSITY].config;
                __lfs_to_v4l2_ctrl_config(&fled_cdev->brightness, ctrl_cfg);
                ctrl_cfg->id = V4L2_CID_FLASH_INTENSITY;
                ctrl_cfg->flags = V4L2_CTRL_FLAG_VOLATILE |
                                  V4L2_CTRL_FLAG_EXECUTE_ON_WRITE;
        }
}

static int v4l2_flash_init_controls(struct v4l2_flash *v4l2_flash,
                                struct v4l2_flash_config *flash_cfg)

{
        struct v4l2_flash_ctrl_data *ctrl_init_data;
        struct v4l2_ctrl *ctrl;
        struct v4l2_ctrl_config *ctrl_cfg;
        int i, ret, num_ctrls = 0;

        v4l2_flash->ctrls = devm_kzalloc(v4l2_flash->sd.dev,
                                        sizeof(*v4l2_flash->ctrls) *
                                        (STROBE_SOURCE + 1), GFP_KERNEL);
        if (!v4l2_flash->ctrls)
                return -ENOMEM;

        /* allocate memory dynamically so as not to exceed stack frame size */
        ctrl_init_data = kcalloc(NUM_FLASH_CTRLS, sizeof(*ctrl_init_data),
                                        GFP_KERNEL);
        if (!ctrl_init_data)
                return -ENOMEM;

        __fill_ctrl_init_data(v4l2_flash, flash_cfg, ctrl_init_data);

        for (i = 0; i < NUM_FLASH_CTRLS; ++i)
                if (ctrl_init_data[i].cid)
                        ++num_ctrls;

        v4l2_ctrl_handler_init(&v4l2_flash->hdl, num_ctrls);

        for (i = 0; i < NUM_FLASH_CTRLS; ++i) {
                ctrl_cfg = &ctrl_init_data[i].config;
                if (!ctrl_init_data[i].cid)
                        continue;

                if (ctrl_cfg->id == V4L2_CID_FLASH_LED_MODE ||
                    ctrl_cfg->id == V4L2_CID_FLASH_STROBE_SOURCE)
                        ctrl = v4l2_ctrl_new_std_menu(&v4l2_flash->hdl,
                                                &v4l2_flash_ctrl_ops,
                                                ctrl_cfg->id,
                                                ctrl_cfg->max,
                                                ctrl_cfg->menu_skip_mask,
                                                ctrl_cfg->def);
                else
                        ctrl = v4l2_ctrl_new_std(&v4l2_flash->hdl,
                                                &v4l2_flash_ctrl_ops,
                                                ctrl_cfg->id,
                                                ctrl_cfg->min,
                                                ctrl_cfg->max,
                                                ctrl_cfg->step,
                                                ctrl_cfg->def);

                if (ctrl)
                        ctrl->flags |= ctrl_cfg->flags;

                if (i <= STROBE_SOURCE)
                        v4l2_flash->ctrls[i] = ctrl;
        }

        kfree(ctrl_init_data);

        if (v4l2_flash->hdl.error) {
                ret = v4l2_flash->hdl.error;
                goto error_free_handler;
        }

        v4l2_ctrl_handler_setup(&v4l2_flash->hdl);

        v4l2_flash->sd.ctrl_handler = &v4l2_flash->hdl;

        return 0;

error_free_handler:
        v4l2_ctrl_handler_free(&v4l2_flash->hdl);
        return ret;
}

static int __sync_device_with_v4l2_controls(struct v4l2_flash *v4l2_flash)
{
        struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
        struct v4l2_ctrl **ctrls = v4l2_flash->ctrls;
        int ret = 0;

        v4l2_flash_set_led_brightness(v4l2_flash, ctrls[TORCH_INTENSITY]);

        if (ctrls[INDICATOR_INTENSITY])
                v4l2_flash_set_led_brightness(v4l2_flash,
                                                ctrls[INDICATOR_INTENSITY]);

        if (ctrls[FLASH_TIMEOUT]) {
                ret = led_set_flash_timeout(fled_cdev,
                                        ctrls[FLASH_TIMEOUT]->val);
                if (ret < 0)
                        return ret;
        }

        if (ctrls[FLASH_INTENSITY]) {
                ret = led_set_flash_brightness(fled_cdev,
                                        ctrls[FLASH_INTENSITY]->val);
                if (ret < 0)
                        return ret;
        }

        /*
         * For some hardware arrangements setting strobe source may affect
         * torch mode. Synchronize strobe source setting only if not in torch
         * mode. For torch mode case it will get synchronized upon switching
         * to flash mode.
         */
        if (ctrls[STROBE_SOURCE] &&
            ctrls[LED_MODE]->val != V4L2_FLASH_LED_MODE_TORCH)
                ret = call_flash_op(v4l2_flash, external_strobe_set,
                                        ctrls[STROBE_SOURCE]->val);

        return ret;
}

/*
 * V4L2 subdev internal operations
 */

static int v4l2_flash_open(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
        struct v4l2_flash *v4l2_flash = v4l2_subdev_to_v4l2_flash(sd);
        struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        struct led_classdev_flash *iled_cdev = v4l2_flash->iled_cdev;
        struct led_classdev *led_cdev_ind = NULL;
        int ret = 0;

        if (!v4l2_fh_is_singular(&fh->vfh))
                return 0;

        mutex_lock(&led_cdev->led_access);

        led_sysfs_disable(led_cdev);
        led_trigger_remove(led_cdev);

        mutex_unlock(&led_cdev->led_access);

        if (iled_cdev) {
                led_cdev_ind = &iled_cdev->led_cdev;

                mutex_lock(&led_cdev_ind->led_access);

                led_sysfs_disable(led_cdev_ind);
                led_trigger_remove(led_cdev_ind);

                mutex_unlock(&led_cdev_ind->led_access);
        }

        ret = __sync_device_with_v4l2_controls(v4l2_flash);
        if (ret < 0)
                goto out_sync_device;

        return 0;
out_sync_device:
        mutex_lock(&led_cdev->led_access);
        led_sysfs_enable(led_cdev);
        mutex_unlock(&led_cdev->led_access);

        if (led_cdev_ind) {
                mutex_lock(&led_cdev_ind->led_access);
                led_sysfs_enable(led_cdev_ind);
                mutex_unlock(&led_cdev_ind->led_access);
        }

        return ret;
}

static int v4l2_flash_close(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh)
{
        struct v4l2_flash *v4l2_flash = v4l2_subdev_to_v4l2_flash(sd);
        struct led_classdev_flash *fled_cdev = v4l2_flash->fled_cdev;
        struct led_classdev *led_cdev = &fled_cdev->led_cdev;
        struct led_classdev_flash *iled_cdev = v4l2_flash->iled_cdev;
        int ret = 0;

        if (!v4l2_fh_is_singular(&fh->vfh))
                return 0;

        mutex_lock(&led_cdev->led_access);

        if (v4l2_flash->ctrls[STROBE_SOURCE])
                ret = v4l2_ctrl_s_ctrl(v4l2_flash->ctrls[STROBE_SOURCE],
                                V4L2_FLASH_STROBE_SOURCE_SOFTWARE);
        led_sysfs_enable(led_cdev);

        mutex_unlock(&led_cdev->led_access);

        if (iled_cdev) {
                struct led_classdev *led_cdev_ind = &iled_cdev->led_cdev;

                mutex_lock(&led_cdev_ind->led_access);
                led_sysfs_enable(led_cdev_ind);
                mutex_unlock(&led_cdev_ind->led_access);
        }

        return ret;
}

static const struct v4l2_subdev_internal_ops v4l2_flash_subdev_internal_ops = {
        .open = v4l2_flash_open,
        .close = v4l2_flash_close,
};

static const struct v4l2_subdev_core_ops v4l2_flash_core_ops = {
        .queryctrl = v4l2_subdev_queryctrl,
        .querymenu = v4l2_subdev_querymenu,
};

static const struct v4l2_subdev_ops v4l2_flash_subdev_ops = {
        .core = &v4l2_flash_core_ops,
};

struct v4l2_flash *v4l2_flash_init(
        struct device *dev, struct device_node *of_node,
        struct led_classdev_flash *fled_cdev,
        struct led_classdev_flash *iled_cdev,
        const struct v4l2_flash_ops *ops,
        struct v4l2_flash_config *config)
{
        struct v4l2_flash *v4l2_flash;
        struct led_classdev *led_cdev;
        struct v4l2_subdev *sd;
        int ret;

        if (!fled_cdev || !ops || !config)
                return ERR_PTR(-EINVAL);

        led_cdev = &fled_cdev->led_cdev;

        v4l2_flash = devm_kzalloc(led_cdev->dev, sizeof(*v4l2_flash),
                                        GFP_KERNEL);
        if (!v4l2_flash)
                return ERR_PTR(-ENOMEM);

        sd = &v4l2_flash->sd;
        v4l2_flash->fled_cdev = fled_cdev;
        v4l2_flash->iled_cdev = iled_cdev;
        v4l2_flash->ops = ops;
        sd->dev = dev;
        sd->of_node = of_node;
        v4l2_subdev_init(sd, &v4l2_flash_subdev_ops);
        sd->internal_ops = &v4l2_flash_subdev_internal_ops;
        sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
        strlcpy(sd->name, config->dev_name, sizeof(sd->name));

        ret = media_entity_init(&sd->entity, 0, NULL, 0);
        if (ret < 0)
                return ERR_PTR(ret);

        sd->entity.type = MEDIA_ENT_T_V4L2_SUBDEV_FLASH;

        ret = v4l2_flash_init_controls(v4l2_flash, config);
        if (ret < 0)
                goto err_init_controls;

        if (sd->of_node)
                of_node_get(sd->of_node);
        else
                of_node_get(led_cdev->dev->of_node);

        ret = v4l2_async_register_subdev(sd);
        if (ret < 0)
                goto err_async_register_sd;

        return v4l2_flash;

err_async_register_sd:
        of_node_put(led_cdev->dev->of_node);
        v4l2_ctrl_handler_free(sd->ctrl_handler);
err_init_controls:
        media_entity_cleanup(&sd->entity);

        return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(v4l2_flash_init);

void v4l2_flash_release(struct v4l2_flash *v4l2_flash)
{
        struct v4l2_subdev *sd;
        struct led_classdev *led_cdev;

        if (IS_ERR_OR_NULL(v4l2_flash))
                return;

        sd = &v4l2_flash->sd;
        led_cdev = &v4l2_flash->fled_cdev->led_cdev;

        v4l2_async_unregister_subdev(sd);

        if (sd->of_node)
                of_node_put(sd->of_node);
        else
                of_node_put(led_cdev->dev->of_node);

        v4l2_ctrl_handler_free(sd->ctrl_handler);
        media_entity_cleanup(&sd->entity);
}
EXPORT_SYMBOL_GPL(v4l2_flash_release);

MODULE_AUTHOR("Jacek Anaszewski <j.anaszewski@samsung.com>");
MODULE_DESCRIPTION("V4L2 Flash sub-device helpers");
MODULE_LICENSE("GPL v2");