drivers/media/platform/vsp1/vsp1_sru.c - vendor/opensource/backports - Git at Google

 /*
  * vsp1_sru.c  --  R-Car VSP1 Super Resolution Unit
  *
  * Copyright (C) 2013 Renesas Corporation
  *
  * Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  */

 #include <linux/device.h>
 #include <linux/gfp.h>

 #include <media/v4l2-subdev.h>

 #include "vsp1.h"
 #include "vsp1_sru.h"

 #define SRU_MIN_SIZE				4U
 #define SRU_MAX_SIZE				8190U

 /* -----------------------------------------------------------------------------
  * Device Access
  */

 static inline u32 vsp1_sru_read(struct vsp1_sru *sru, u32 reg)
 {
 	return vsp1_read(sru->entity.vsp1, reg);
 }

 static inline void vsp1_sru_write(struct vsp1_sru *sru, u32 reg, u32 data)
 {
 	vsp1_write(sru->entity.vsp1, reg, data);
 }

 /* -----------------------------------------------------------------------------
  * Controls
  */

 #define V4L2_CID_VSP1_SRU_INTENSITY		(V4L2_CID_USER_BASE + 1)

 struct vsp1_sru_param {
 	u32 ctrl0;
 	u32 ctrl2;
 };

 #define VI6_SRU_CTRL0_PARAMS(p0, p1)			\
 	(((p0) << VI6_SRU_CTRL0_PARAM0_SHIFT) |		\
 	 ((p1) << VI6_SRU_CTRL0_PARAM1_SHIFT))

 #define VI6_SRU_CTRL2_PARAMS(p6, p7, p8)		\
 	(((p6) << VI6_SRU_CTRL2_PARAM6_SHIFT) |		\
 	 ((p7) << VI6_SRU_CTRL2_PARAM7_SHIFT) |		\
 	 ((p8) << VI6_SRU_CTRL2_PARAM8_SHIFT))

 static const struct vsp1_sru_param vsp1_sru_params[] = {
 	{
 		.ctrl0 = VI6_SRU_CTRL0_PARAMS(256, 4) | VI6_SRU_CTRL0_EN,
 		.ctrl2 = VI6_SRU_CTRL2_PARAMS(24, 40, 255),
 	}, {
 		.ctrl0 = VI6_SRU_CTRL0_PARAMS(256, 4) | VI6_SRU_CTRL0_EN,
 		.ctrl2 = VI6_SRU_CTRL2_PARAMS(8, 16, 255),
 	}, {
 		.ctrl0 = VI6_SRU_CTRL0_PARAMS(384, 5) | VI6_SRU_CTRL0_EN,
 		.ctrl2 = VI6_SRU_CTRL2_PARAMS(36, 60, 255),
 	}, {
 		.ctrl0 = VI6_SRU_CTRL0_PARAMS(384, 5) | VI6_SRU_CTRL0_EN,
 		.ctrl2 = VI6_SRU_CTRL2_PARAMS(12, 27, 255),
 	}, {
 		.ctrl0 = VI6_SRU_CTRL0_PARAMS(511, 6) | VI6_SRU_CTRL0_EN,
 		.ctrl2 = VI6_SRU_CTRL2_PARAMS(48, 80, 255),
 	}, {
 		.ctrl0 = VI6_SRU_CTRL0_PARAMS(511, 6) | VI6_SRU_CTRL0_EN,
 		.ctrl2 = VI6_SRU_CTRL2_PARAMS(16, 36, 255),
 	},
 };

 static int sru_s_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct vsp1_sru *sru =
 		container_of(ctrl->handler, struct vsp1_sru, ctrls);
 	const struct vsp1_sru_param *param;
 	u32 value;

 	switch (ctrl->id) {
 	case V4L2_CID_VSP1_SRU_INTENSITY:
 		param = &vsp1_sru_params[ctrl->val - 1];

 		value = vsp1_sru_read(sru, VI6_SRU_CTRL0);
 		value &= ~(VI6_SRU_CTRL0_PARAM0_MASK |
 			   VI6_SRU_CTRL0_PARAM1_MASK);
 		value |= param->ctrl0;
 		vsp1_sru_write(sru, VI6_SRU_CTRL0, value);

 		vsp1_sru_write(sru, VI6_SRU_CTRL2, param->ctrl2);
 		break;
 	}

 	return 0;
 }

 static const struct v4l2_ctrl_ops sru_ctrl_ops = {
 	.s_ctrl = sru_s_ctrl,
 };

 static const struct v4l2_ctrl_config sru_intensity_control = {
 	.ops = &sru_ctrl_ops,
 	.id = V4L2_CID_VSP1_SRU_INTENSITY,
 	.name = "Intensity",
 	.type = V4L2_CTRL_TYPE_INTEGER,
 	.min = 1,
 	.max = 6,
 	.def = 1,
 	.step = 1,
 };

 /* -----------------------------------------------------------------------------
  * V4L2 Subdevice Core Operations
  */

 static int sru_s_stream(struct v4l2_subdev *subdev, int enable)
 {
 	struct vsp1_sru *sru = to_sru(subdev);
 	struct v4l2_mbus_framefmt *input;
 	struct v4l2_mbus_framefmt *output;
 	u32 ctrl0;
 	int ret;

 	ret = vsp1_entity_set_streaming(&sru->entity, enable);
 	if (ret < 0)
 		return ret;

 	if (!enable)
 		return 0;

 	input = &sru->entity.formats[SRU_PAD_SINK];
 	output = &sru->entity.formats[SRU_PAD_SOURCE];

 	if (input->code == MEDIA_BUS_FMT_ARGB8888_1X32)
 		ctrl0 = VI6_SRU_CTRL0_PARAM2 | VI6_SRU_CTRL0_PARAM3
 		      | VI6_SRU_CTRL0_PARAM4;
 	else
 		ctrl0 = VI6_SRU_CTRL0_PARAM3;

 	if (input->width != output->width)
 		ctrl0 |= VI6_SRU_CTRL0_MODE_UPSCALE;

 	/* Take the control handler lock to ensure that the CTRL0 value won't be
 	 * changed behind our back by a set control operation.
 	 */
 	mutex_lock(sru->ctrls.lock);
 	ctrl0 |= vsp1_sru_read(sru, VI6_SRU_CTRL0)
 	       & (VI6_SRU_CTRL0_PARAM0_MASK | VI6_SRU_CTRL0_PARAM1_MASK);
 	mutex_unlock(sru->ctrls.lock);

 	vsp1_sru_write(sru, VI6_SRU_CTRL1, VI6_SRU_CTRL1_PARAM5);

 	return 0;
 }

 /* -----------------------------------------------------------------------------
  * V4L2 Subdevice Pad Operations
  */

 static int sru_enum_mbus_code(struct v4l2_subdev *subdev,
 			      struct v4l2_subdev_pad_config *cfg,
 			      struct v4l2_subdev_mbus_code_enum *code)
 {
 	static const unsigned int codes[] = {
 		MEDIA_BUS_FMT_ARGB8888_1X32,
 		MEDIA_BUS_FMT_AYUV8_1X32,
 	};
 	struct vsp1_sru *sru = to_sru(subdev);
 	struct v4l2_mbus_framefmt *format;

 	if (code->pad == SRU_PAD_SINK) {
 		if (code->index >= ARRAY_SIZE(codes))
 			return -EINVAL;

 		code->code = codes[code->index];
 	} else {
 		/* The SRU can't perform format conversion, the sink format is
 		 * always identical to the source format.
 		 */
 		if (code->index)
 			return -EINVAL;

 		format = vsp1_entity_get_pad_format(&sru->entity, cfg,
 						    SRU_PAD_SINK, code->which);
 		code->code = format->code;
 	}

 	return 0;
 }

 static int sru_enum_frame_size(struct v4l2_subdev *subdev,
 			       struct v4l2_subdev_pad_config *cfg,
 			       struct v4l2_subdev_frame_size_enum *fse)
 {
 	struct vsp1_sru *sru = to_sru(subdev);
 	struct v4l2_mbus_framefmt *format;

 	format = vsp1_entity_get_pad_format(&sru->entity, cfg,
 					    SRU_PAD_SINK, fse->which);

 	if (fse->index || fse->code != format->code)
 		return -EINVAL;

 	if (fse->pad == SRU_PAD_SINK) {
 		fse->min_width = SRU_MIN_SIZE;
 		fse->max_width = SRU_MAX_SIZE;
 		fse->min_height = SRU_MIN_SIZE;
 		fse->max_height = SRU_MAX_SIZE;
 	} else {
 		fse->min_width = format->width;
 		fse->min_height = format->height;
 		if (format->width <= SRU_MAX_SIZE / 2 &&
 		    format->height <= SRU_MAX_SIZE / 2) {
 			fse->max_width = format->width * 2;
 			fse->max_height = format->height * 2;
 		} else {
 			fse->max_width = format->width;
 			fse->max_height = format->height;
 		}
 	}

 	return 0;
 }

 static int sru_get_format(struct v4l2_subdev *subdev, struct v4l2_subdev_pad_config *cfg,
 			  struct v4l2_subdev_format *fmt)
 {
 	struct vsp1_sru *sru = to_sru(subdev);

 	fmt->format = *vsp1_entity_get_pad_format(&sru->entity, cfg, fmt->pad,
 						  fmt->which);

 	return 0;
 }

 static void sru_try_format(struct vsp1_sru *sru, struct v4l2_subdev_pad_config *cfg,
 			   unsigned int pad, struct v4l2_mbus_framefmt *fmt,
 			   enum v4l2_subdev_format_whence which)
 {
 	struct v4l2_mbus_framefmt *format;
 	unsigned int input_area;
 	unsigned int output_area;

 	switch (pad) {
 	case SRU_PAD_SINK:
 		/* Default to YUV if the requested format is not supported. */
 		if (fmt->code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
 		    fmt->code != MEDIA_BUS_FMT_AYUV8_1X32)
 			fmt->code = MEDIA_BUS_FMT_AYUV8_1X32;

 		fmt->width = clamp(fmt->width, SRU_MIN_SIZE, SRU_MAX_SIZE);
 		fmt->height = clamp(fmt->height, SRU_MIN_SIZE, SRU_MAX_SIZE);
 		break;

 	case SRU_PAD_SOURCE:
 		/* The SRU can't perform format conversion. */
 		format = vsp1_entity_get_pad_format(&sru->entity, cfg,
 						    SRU_PAD_SINK, which);
 		fmt->code = format->code;

 		/* We can upscale by 2 in both direction, but not independently.
 		 * Compare the input and output rectangles areas (avoiding
 		 * integer overflows on the output): if the requested output
 		 * area is larger than 1.5^2 the input area upscale by two,
 		 * otherwise don't scale.
 		 */
 		input_area = format->width * format->height;
 		output_area = min(fmt->width, SRU_MAX_SIZE)
 			    * min(fmt->height, SRU_MAX_SIZE);

 		if (fmt->width <= SRU_MAX_SIZE / 2 &&
 		    fmt->height <= SRU_MAX_SIZE / 2 &&
 		    output_area > input_area * 9 / 4) {
 			fmt->width = format->width * 2;
 			fmt->height = format->height * 2;
 		} else {
 			fmt->width = format->width;
 			fmt->height = format->height;
 		}
 		break;
 	}

 	fmt->field = V4L2_FIELD_NONE;
 	fmt->colorspace = V4L2_COLORSPACE_SRGB;
 }

 static int sru_set_format(struct v4l2_subdev *subdev, struct v4l2_subdev_pad_config *cfg,
 			  struct v4l2_subdev_format *fmt)
 {
 	struct vsp1_sru *sru = to_sru(subdev);
 	struct v4l2_mbus_framefmt *format;

 	sru_try_format(sru, cfg, fmt->pad, &fmt->format, fmt->which);

 	format = vsp1_entity_get_pad_format(&sru->entity, cfg, fmt->pad,
 					    fmt->which);
 	*format = fmt->format;

 	if (fmt->pad == SRU_PAD_SINK) {
 		/* Propagate the format to the source pad. */
 		format = vsp1_entity_get_pad_format(&sru->entity, cfg,
 						    SRU_PAD_SOURCE, fmt->which);
 		*format = fmt->format;

 		sru_try_format(sru, cfg, SRU_PAD_SOURCE, format, fmt->which);
 	}

 	return 0;
 }

 /* -----------------------------------------------------------------------------
  * V4L2 Subdevice Operations
  */

 static struct v4l2_subdev_video_ops sru_video_ops = {
 	.s_stream = sru_s_stream,
 };

 static struct v4l2_subdev_pad_ops sru_pad_ops = {
 	.enum_mbus_code = sru_enum_mbus_code,
 	.enum_frame_size = sru_enum_frame_size,
 	.get_fmt = sru_get_format,
 	.set_fmt = sru_set_format,
 };

 static struct v4l2_subdev_ops sru_ops = {
 	.video	= &sru_video_ops,
 	.pad    = &sru_pad_ops,
 };

 /* -----------------------------------------------------------------------------
  * Initialization and Cleanup
  */

 struct vsp1_sru *vsp1_sru_create(struct vsp1_device *vsp1)
 {
 	struct v4l2_subdev *subdev;
 	struct vsp1_sru *sru;
 	int ret;

 	sru = devm_kzalloc(vsp1->dev, sizeof(*sru), GFP_KERNEL);
 	if (sru == NULL)
 		return ERR_PTR(-ENOMEM);

 	sru->entity.type = VSP1_ENTITY_SRU;

 	ret = vsp1_entity_init(vsp1, &sru->entity, 2);
 	if (ret < 0)
 		return ERR_PTR(ret);

 	/* Initialize the V4L2 subdev. */
 	subdev = &sru->entity.subdev;
 	v4l2_subdev_init(subdev, &sru_ops);

 	subdev->entity.ops = &vsp1_media_ops;
 	subdev->internal_ops = &vsp1_subdev_internal_ops;
 	snprintf(subdev->name, sizeof(subdev->name), "%s sru",
 		 dev_name(vsp1->dev));
 	v4l2_set_subdevdata(subdev, sru);
 	subdev->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;

 	vsp1_entity_init_formats(subdev, NULL);

 	/* Initialize the control handler. */
 	v4l2_ctrl_handler_init(&sru->ctrls, 1);
 	v4l2_ctrl_new_custom(&sru->ctrls, &sru_intensity_control, NULL);

 	sru->entity.subdev.ctrl_handler = &sru->ctrls;

 	if (sru->ctrls.error) {
 		dev_err(vsp1->dev, "sru: failed to initialize controls\n");
 		ret = sru->ctrls.error;
 		vsp1_entity_destroy(&sru->entity);
 		return ERR_PTR(ret);
 	}

 	return sru;
 }
	/*
	* vsp1_sru.c -- R-Car VSP1 Super Resolution Unit
	*
	* Copyright (C) 2013 Renesas Corporation
	*
	* Contact: Laurent Pinchart (laurent.pinchart@ideasonboard.com)
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*/

	#include <linux/device.h>
	#include <linux/gfp.h>

	#include <media/v4l2-subdev.h>

	#include "vsp1.h"
	#include "vsp1_sru.h"

	#define SRU_MIN_SIZE 4U
	#define SRU_MAX_SIZE 8190U

	/* -----------------------------------------------------------------------------
	* Device Access
	*/

	static inline u32 vsp1_sru_read(struct vsp1_sru *sru, u32 reg)
	{
	return vsp1_read(sru->entity.vsp1, reg);
	}

	static inline void vsp1_sru_write(struct vsp1_sru *sru, u32 reg, u32 data)
	{
	vsp1_write(sru->entity.vsp1, reg, data);
	}

	/* -----------------------------------------------------------------------------
	* Controls
	*/

	#define V4L2_CID_VSP1_SRU_INTENSITY (V4L2_CID_USER_BASE + 1)

	struct vsp1_sru_param {
	u32 ctrl0;
	u32 ctrl2;
	};

	#define VI6_SRU_CTRL0_PARAMS(p0, p1) \
	(((p0) << VI6_SRU_CTRL0_PARAM0_SHIFT) \| \
	((p1) << VI6_SRU_CTRL0_PARAM1_SHIFT))

	#define VI6_SRU_CTRL2_PARAMS(p6, p7, p8) \
	(((p6) << VI6_SRU_CTRL2_PARAM6_SHIFT) \| \
	((p7) << VI6_SRU_CTRL2_PARAM7_SHIFT) \| \
	((p8) << VI6_SRU_CTRL2_PARAM8_SHIFT))

	static const struct vsp1_sru_param vsp1_sru_params[] = {
	{
	.ctrl0 = VI6_SRU_CTRL0_PARAMS(256, 4) \| VI6_SRU_CTRL0_EN,
	.ctrl2 = VI6_SRU_CTRL2_PARAMS(24, 40, 255),
	}, {
	.ctrl0 = VI6_SRU_CTRL0_PARAMS(256, 4) \| VI6_SRU_CTRL0_EN,
	.ctrl2 = VI6_SRU_CTRL2_PARAMS(8, 16, 255),
	}, {
	.ctrl0 = VI6_SRU_CTRL0_PARAMS(384, 5) \| VI6_SRU_CTRL0_EN,
	.ctrl2 = VI6_SRU_CTRL2_PARAMS(36, 60, 255),
	}, {
	.ctrl0 = VI6_SRU_CTRL0_PARAMS(384, 5) \| VI6_SRU_CTRL0_EN,
	.ctrl2 = VI6_SRU_CTRL2_PARAMS(12, 27, 255),
	}, {
	.ctrl0 = VI6_SRU_CTRL0_PARAMS(511, 6) \| VI6_SRU_CTRL0_EN,
	.ctrl2 = VI6_SRU_CTRL2_PARAMS(48, 80, 255),
	}, {
	.ctrl0 = VI6_SRU_CTRL0_PARAMS(511, 6) \| VI6_SRU_CTRL0_EN,
	.ctrl2 = VI6_SRU_CTRL2_PARAMS(16, 36, 255),
	},
	};

	static int sru_s_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct vsp1_sru *sru =
	container_of(ctrl->handler, struct vsp1_sru, ctrls);
	const struct vsp1_sru_param *param;
	u32 value;

	switch (ctrl->id) {
	case V4L2_CID_VSP1_SRU_INTENSITY:
	param = &vsp1_sru_params[ctrl->val - 1];

	value = vsp1_sru_read(sru, VI6_SRU_CTRL0);
	value &= ~(VI6_SRU_CTRL0_PARAM0_MASK \|
	VI6_SRU_CTRL0_PARAM1_MASK);
	value \|= param->ctrl0;
	vsp1_sru_write(sru, VI6_SRU_CTRL0, value);

	vsp1_sru_write(sru, VI6_SRU_CTRL2, param->ctrl2);
	break;
	}

	return 0;
	}

	static const struct v4l2_ctrl_ops sru_ctrl_ops = {
	.s_ctrl = sru_s_ctrl,
	};

	static const struct v4l2_ctrl_config sru_intensity_control = {
	.ops = &sru_ctrl_ops,
	.id = V4L2_CID_VSP1_SRU_INTENSITY,
	.name = "Intensity",
	.type = V4L2_CTRL_TYPE_INTEGER,
	.min = 1,
	.max = 6,
	.def = 1,
	.step = 1,
	};

	/* -----------------------------------------------------------------------------
	* V4L2 Subdevice Core Operations
	*/

	static int sru_s_stream(struct v4l2_subdev *subdev, int enable)
	{
	struct vsp1_sru *sru = to_sru(subdev);
	struct v4l2_mbus_framefmt *input;
	struct v4l2_mbus_framefmt *output;
	u32 ctrl0;
	int ret;

	ret = vsp1_entity_set_streaming(&sru->entity, enable);
	if (ret < 0)
	return ret;

	if (!enable)
	return 0;

	input = &sru->entity.formats[SRU_PAD_SINK];
	output = &sru->entity.formats[SRU_PAD_SOURCE];

	if (input->code == MEDIA_BUS_FMT_ARGB8888_1X32)
	ctrl0 = VI6_SRU_CTRL0_PARAM2 \| VI6_SRU_CTRL0_PARAM3
	\| VI6_SRU_CTRL0_PARAM4;
	else
	ctrl0 = VI6_SRU_CTRL0_PARAM3;

	if (input->width != output->width)
	ctrl0 \|= VI6_SRU_CTRL0_MODE_UPSCALE;

	/* Take the control handler lock to ensure that the CTRL0 value won't be
	* changed behind our back by a set control operation.
	*/
	mutex_lock(sru->ctrls.lock);
	ctrl0 \|= vsp1_sru_read(sru, VI6_SRU_CTRL0)
	& (VI6_SRU_CTRL0_PARAM0_MASK \| VI6_SRU_CTRL0_PARAM1_MASK);
	mutex_unlock(sru->ctrls.lock);

	vsp1_sru_write(sru, VI6_SRU_CTRL1, VI6_SRU_CTRL1_PARAM5);

	return 0;
	}

	/* -----------------------------------------------------------------------------
	* V4L2 Subdevice Pad Operations
	*/

	static int sru_enum_mbus_code(struct v4l2_subdev *subdev,
	struct v4l2_subdev_pad_config *cfg,
	struct v4l2_subdev_mbus_code_enum *code)
	{
	static const unsigned int codes[] = {
	MEDIA_BUS_FMT_ARGB8888_1X32,
	MEDIA_BUS_FMT_AYUV8_1X32,
	};
	struct vsp1_sru *sru = to_sru(subdev);
	struct v4l2_mbus_framefmt *format;

	if (code->pad == SRU_PAD_SINK) {
	if (code->index >= ARRAY_SIZE(codes))
	return -EINVAL;

	code->code = codes[code->index];
	} else {
	/* The SRU can't perform format conversion, the sink format is
	* always identical to the source format.
	*/
	if (code->index)
	return -EINVAL;

	format = vsp1_entity_get_pad_format(&sru->entity, cfg,
	SRU_PAD_SINK, code->which);
	code->code = format->code;
	}

	return 0;
	}

	static int sru_enum_frame_size(struct v4l2_subdev *subdev,
	struct v4l2_subdev_pad_config *cfg,
	struct v4l2_subdev_frame_size_enum *fse)
	{
	struct vsp1_sru *sru = to_sru(subdev);
	struct v4l2_mbus_framefmt *format;

	format = vsp1_entity_get_pad_format(&sru->entity, cfg,
	SRU_PAD_SINK, fse->which);

	if (fse->index \|\| fse->code != format->code)
	return -EINVAL;

	if (fse->pad == SRU_PAD_SINK) {
	fse->min_width = SRU_MIN_SIZE;
	fse->max_width = SRU_MAX_SIZE;
	fse->min_height = SRU_MIN_SIZE;
	fse->max_height = SRU_MAX_SIZE;
	} else {
	fse->min_width = format->width;
	fse->min_height = format->height;
	if (format->width <= SRU_MAX_SIZE / 2 &&
	format->height <= SRU_MAX_SIZE / 2) {
	fse->max_width = format->width * 2;
	fse->max_height = format->height * 2;
	} else {
	fse->max_width = format->width;
	fse->max_height = format->height;
	}
	}

	return 0;
	}

	static int sru_get_format(struct v4l2_subdev subdev, struct v4l2_subdev_pad_config cfg,
	struct v4l2_subdev_format *fmt)
	{
	struct vsp1_sru *sru = to_sru(subdev);

	fmt->format = *vsp1_entity_get_pad_format(&sru->entity, cfg, fmt->pad,
	fmt->which);

	return 0;
	}

	static void sru_try_format(struct vsp1_sru sru, struct v4l2_subdev_pad_config cfg,
	unsigned int pad, struct v4l2_mbus_framefmt *fmt,
	enum v4l2_subdev_format_whence which)
	{
	struct v4l2_mbus_framefmt *format;
	unsigned int input_area;
	unsigned int output_area;

	switch (pad) {
	case SRU_PAD_SINK:
	/* Default to YUV if the requested format is not supported. */
	if (fmt->code != MEDIA_BUS_FMT_ARGB8888_1X32 &&
	fmt->code != MEDIA_BUS_FMT_AYUV8_1X32)
	fmt->code = MEDIA_BUS_FMT_AYUV8_1X32;

	fmt->width = clamp(fmt->width, SRU_MIN_SIZE, SRU_MAX_SIZE);
	fmt->height = clamp(fmt->height, SRU_MIN_SIZE, SRU_MAX_SIZE);
	break;

	case SRU_PAD_SOURCE:
	/* The SRU can't perform format conversion. */
	format = vsp1_entity_get_pad_format(&sru->entity, cfg,
	SRU_PAD_SINK, which);
	fmt->code = format->code;

	/* We can upscale by 2 in both direction, but not independently.
	* Compare the input and output rectangles areas (avoiding
	* integer overflows on the output): if the requested output
	* area is larger than 1.5^2 the input area upscale by two,
	* otherwise don't scale.
	*/
	input_area = format->width * format->height;
	output_area = min(fmt->width, SRU_MAX_SIZE)
	* min(fmt->height, SRU_MAX_SIZE);

	if (fmt->width <= SRU_MAX_SIZE / 2 &&
	fmt->height <= SRU_MAX_SIZE / 2 &&
	output_area > input_area * 9 / 4) {
	fmt->width = format->width * 2;
	fmt->height = format->height * 2;
	} else {
	fmt->width = format->width;
	fmt->height = format->height;
	}
	break;
	}

	fmt->field = V4L2_FIELD_NONE;
	fmt->colorspace = V4L2_COLORSPACE_SRGB;
	}

	static int sru_set_format(struct v4l2_subdev subdev, struct v4l2_subdev_pad_config cfg,
	struct v4l2_subdev_format *fmt)
	{
	struct vsp1_sru *sru = to_sru(subdev);
	struct v4l2_mbus_framefmt *format;

	sru_try_format(sru, cfg, fmt->pad, &fmt->format, fmt->which);

	format = vsp1_entity_get_pad_format(&sru->entity, cfg, fmt->pad,
	fmt->which);
	*format = fmt->format;

	if (fmt->pad == SRU_PAD_SINK) {
	/* Propagate the format to the source pad. */
	format = vsp1_entity_get_pad_format(&sru->entity, cfg,
	SRU_PAD_SOURCE, fmt->which);
	*format = fmt->format;

	sru_try_format(sru, cfg, SRU_PAD_SOURCE, format, fmt->which);
	}

	return 0;
	}

	/* -----------------------------------------------------------------------------
	* V4L2 Subdevice Operations
	*/

	static struct v4l2_subdev_video_ops sru_video_ops = {
	.s_stream = sru_s_stream,
	};

	static struct v4l2_subdev_pad_ops sru_pad_ops = {
	.enum_mbus_code = sru_enum_mbus_code,
	.enum_frame_size = sru_enum_frame_size,
	.get_fmt = sru_get_format,
	.set_fmt = sru_set_format,
	};

	static struct v4l2_subdev_ops sru_ops = {
	.video = &sru_video_ops,
	.pad = &sru_pad_ops,
	};

	/* -----------------------------------------------------------------------------
	* Initialization and Cleanup
	*/

	struct vsp1_sru vsp1_sru_create(struct vsp1_device vsp1)
	{
	struct v4l2_subdev *subdev;
	struct vsp1_sru *sru;
	int ret;

	sru = devm_kzalloc(vsp1->dev, sizeof(*sru), GFP_KERNEL);
	if (sru == NULL)
	return ERR_PTR(-ENOMEM);

	sru->entity.type = VSP1_ENTITY_SRU;

	ret = vsp1_entity_init(vsp1, &sru->entity, 2);
	if (ret < 0)
	return ERR_PTR(ret);

	/* Initialize the V4L2 subdev. */
	subdev = &sru->entity.subdev;
	v4l2_subdev_init(subdev, &sru_ops);

	subdev->entity.ops = &vsp1_media_ops;
	subdev->internal_ops = &vsp1_subdev_internal_ops;
	snprintf(subdev->name, sizeof(subdev->name), "%s sru",
	dev_name(vsp1->dev));
	v4l2_set_subdevdata(subdev, sru);
	subdev->flags \|= V4L2_SUBDEV_FL_HAS_DEVNODE;

	vsp1_entity_init_formats(subdev, NULL);

	/* Initialize the control handler. */
	v4l2_ctrl_handler_init(&sru->ctrls, 1);
	v4l2_ctrl_new_custom(&sru->ctrls, &sru_intensity_control, NULL);

	sru->entity.subdev.ctrl_handler = &sru->ctrls;

	if (sru->ctrls.error) {
	dev_err(vsp1->dev, "sru: failed to initialize controls\n");
	ret = sru->ctrls.error;
	vsp1_entity_destroy(&sru->entity);
	return ERR_PTR(ret);
	}

	return sru;
	}