drivers/media/v4l2-core/v4l2-flash-led-class.c - linux/kernel/git/bpf/bpf - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * V4L2 flash LED sub-device registration helpers.
  *
  *	Copyright (C) 2015 Samsung Electronics Co., Ltd
  *	Author: Jacek Anaszewski <j.anaszewski@samsung.com>
  */

 #include <linux/led-class-flash.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/property.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 && 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_sync(&v4l2_flash->fled_cdev->led_cdev,
 					brightness);
 	} else {
 		led_set_brightness_sync(v4l2_flash->iled_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;
 	}

 	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 ? &fled_cdev->led_cdev : NULL;
 	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_sync(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_sync(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;
 	struct led_classdev *led_cdev = fled_cdev ? &fled_cdev->led_cdev : NULL;
 	struct v4l2_ctrl_config *ctrl_cfg;
 	u32 mask;

 	/* 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->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 || WARN_ON(!(led_cdev->flags & LED_DEV_CAP_FLASH)))
 		return;

 	/* 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->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 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 (has_flash_op(fled_cdev, 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 (has_flash_op(fled_cdev, 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 (has_flash_op(fled_cdev, 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_kcalloc(v4l2_flash->sd.dev,
 					STROBE_SOURCE + 1,
 					sizeof(*v4l2_flash->ctrls),
 					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;

 	if (ctrls[TORCH_INTENSITY])
 		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 ? &fled_cdev->led_cdev : NULL;
 	struct led_classdev *led_cdev_ind = v4l2_flash->iled_cdev;
 	int ret = 0;

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

 	if (led_cdev) {
 		mutex_lock(&led_cdev->led_access);

 		led_sysfs_disable(led_cdev);
 		led_trigger_remove(led_cdev);

 		mutex_unlock(&led_cdev->led_access);
 	}

 	if (led_cdev_ind) {
 		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:
 	if (led_cdev) {
 		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 ? &fled_cdev->led_cdev : NULL;
 	struct led_classdev *led_cdev_ind = v4l2_flash->iled_cdev;
 	int ret = 0;

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

 	if (led_cdev) {
 		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 (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 const struct v4l2_subdev_internal_ops v4l2_flash_subdev_internal_ops = {
 	.open = v4l2_flash_open,
 	.close = v4l2_flash_close,
 };

 static const struct v4l2_subdev_ops v4l2_flash_subdev_ops;

 static struct v4l2_flash *__v4l2_flash_init(
 	struct device *dev, struct fwnode_handle *fwn,
 	struct led_classdev_flash *fled_cdev, struct led_classdev *iled_cdev,
 	const struct v4l2_flash_ops *ops, struct v4l2_flash_config *config)
 {
 	struct v4l2_flash *v4l2_flash;
 	struct v4l2_subdev *sd;
 	int ret;

 	if (!config)
 		return ERR_PTR(-EINVAL);

 	v4l2_flash = devm_kzalloc(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->fwnode = fwn ? fwn : dev_fwnode(dev);
 	v4l2_subdev_init(sd, &v4l2_flash_subdev_ops);
 	sd->internal_ops = &v4l2_flash_subdev_internal_ops;
 	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
 	strscpy(sd->name, config->dev_name, sizeof(sd->name));

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

 	sd->entity.function = MEDIA_ENT_F_FLASH;

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

 	fwnode_handle_get(sd->fwnode);

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

 	return v4l2_flash;

 err_async_register_sd:
 	fwnode_handle_put(sd->fwnode);
 	v4l2_ctrl_handler_free(sd->ctrl_handler);
 err_init_controls:
 	media_entity_cleanup(&sd->entity);

 	return ERR_PTR(ret);
 }

 struct v4l2_flash *v4l2_flash_init(
 	struct device *dev, struct fwnode_handle *fwn,
 	struct led_classdev_flash *fled_cdev,
 	const struct v4l2_flash_ops *ops,
 	struct v4l2_flash_config *config)
 {
 	return __v4l2_flash_init(dev, fwn, fled_cdev, NULL, ops, config);
 }
 EXPORT_SYMBOL_GPL(v4l2_flash_init);

 struct v4l2_flash *v4l2_flash_indicator_init(
 	struct device *dev, struct fwnode_handle *fwn,
 	struct led_classdev *iled_cdev,
 	struct v4l2_flash_config *config)
 {
 	return __v4l2_flash_init(dev, fwn, NULL, iled_cdev, NULL, config);
 }
 EXPORT_SYMBOL_GPL(v4l2_flash_indicator_init);

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

 	if (IS_ERR_OR_NULL(v4l2_flash))
 		return;

 	sd = &v4l2_flash->sd;

 	v4l2_async_unregister_subdev(sd);

 	fwnode_handle_put(sd->fwnode);

 	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");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* V4L2 flash LED sub-device registration helpers.
	*
	* Copyright (C) 2015 Samsung Electronics Co., Ltd
	* Author: Jacek Anaszewski <j.anaszewski@samsung.com>
	*/

	#include <linux/led-class-flash.h>
	#include <linux/module.h>
	#include <linux/mutex.h>
	#include <linux/property.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 && 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_sync(&v4l2_flash->fled_cdev->led_cdev,
	brightness);
	} else {
	led_set_brightness_sync(v4l2_flash->iled_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;
	}

	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 ? &fled_cdev->led_cdev : NULL;
	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_sync(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_sync(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;
	struct led_classdev *led_cdev = fled_cdev ? &fled_cdev->led_cdev : NULL;
	struct v4l2_ctrl_config *ctrl_cfg;
	u32 mask;

	/* 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->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 \|\| WARN_ON(!(led_cdev->flags & LED_DEV_CAP_FLASH)))
	return;

	/* 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->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 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 (has_flash_op(fled_cdev, 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 (has_flash_op(fled_cdev, 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 (has_flash_op(fled_cdev, 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_kcalloc(v4l2_flash->sd.dev,
	STROBE_SOURCE + 1,
	sizeof(*v4l2_flash->ctrls),
	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;

	if (ctrls[TORCH_INTENSITY])
	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 ? &fled_cdev->led_cdev : NULL;
	struct led_classdev *led_cdev_ind = v4l2_flash->iled_cdev;
	int ret = 0;

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

	if (led_cdev) {
	mutex_lock(&led_cdev->led_access);

	led_sysfs_disable(led_cdev);
	led_trigger_remove(led_cdev);

	mutex_unlock(&led_cdev->led_access);
	}

	if (led_cdev_ind) {
	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:
	if (led_cdev) {
	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 ? &fled_cdev->led_cdev : NULL;
	struct led_classdev *led_cdev_ind = v4l2_flash->iled_cdev;
	int ret = 0;

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

	if (led_cdev) {
	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 (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 const struct v4l2_subdev_internal_ops v4l2_flash_subdev_internal_ops = {
	.open = v4l2_flash_open,
	.close = v4l2_flash_close,
	};

	static const struct v4l2_subdev_ops v4l2_flash_subdev_ops;

	static struct v4l2_flash *__v4l2_flash_init(
	struct device dev, struct fwnode_handle fwn,
	struct led_classdev_flash fled_cdev, struct led_classdev iled_cdev,
	const struct v4l2_flash_ops ops, struct v4l2_flash_config config)
	{
	struct v4l2_flash *v4l2_flash;
	struct v4l2_subdev *sd;
	int ret;

	if (!config)
	return ERR_PTR(-EINVAL);

	v4l2_flash = devm_kzalloc(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->fwnode = fwn ? fwn : dev_fwnode(dev);
	v4l2_subdev_init(sd, &v4l2_flash_subdev_ops);
	sd->internal_ops = &v4l2_flash_subdev_internal_ops;
	sd->flags \|= V4L2_SUBDEV_FL_HAS_DEVNODE;
	strscpy(sd->name, config->dev_name, sizeof(sd->name));

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

	sd->entity.function = MEDIA_ENT_F_FLASH;

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

	fwnode_handle_get(sd->fwnode);

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

	return v4l2_flash;

	err_async_register_sd:
	fwnode_handle_put(sd->fwnode);
	v4l2_ctrl_handler_free(sd->ctrl_handler);
	err_init_controls:
	media_entity_cleanup(&sd->entity);

	return ERR_PTR(ret);
	}

	struct v4l2_flash *v4l2_flash_init(
	struct device dev, struct fwnode_handle fwn,
	struct led_classdev_flash *fled_cdev,
	const struct v4l2_flash_ops *ops,
	struct v4l2_flash_config *config)
	{
	return __v4l2_flash_init(dev, fwn, fled_cdev, NULL, ops, config);
	}
	EXPORT_SYMBOL_GPL(v4l2_flash_init);

	struct v4l2_flash *v4l2_flash_indicator_init(
	struct device dev, struct fwnode_handle fwn,
	struct led_classdev *iled_cdev,
	struct v4l2_flash_config *config)
	{
	return __v4l2_flash_init(dev, fwn, NULL, iled_cdev, NULL, config);
	}
	EXPORT_SYMBOL_GPL(v4l2_flash_indicator_init);

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

	if (IS_ERR_OR_NULL(v4l2_flash))
	return;

	sd = &v4l2_flash->sd;

	v4l2_async_unregister_subdev(sd);

	fwnode_handle_put(sd->fwnode);

	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");