drivers/media/platform/amphion/vpu_helpers.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright 2020-2021 NXP
  */

 #include <linux/init.h>
 #include <linux/interconnect.h>
 #include <linux/ioctl.h>
 #include <linux/list.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include "vpu.h"
 #include "vpu_defs.h"
 #include "vpu_core.h"
 #include "vpu_rpc.h"
 #include "vpu_helpers.h"

 int vpu_helper_find_in_array_u8(const u8 *array, u32 size, u32 x)
 {
 	int i;

 	for (i = 0; i < size; i++) {
 		if (array[i] == x)
 			return i;
 	}

 	return 0;
 }

 bool vpu_helper_check_type(struct vpu_inst *inst, u32 type)
 {
 	const struct vpu_format *pfmt;

 	for (pfmt = inst->formats; pfmt->pixfmt; pfmt++) {
 		if (!vpu_iface_check_format(inst, pfmt->pixfmt))
 			continue;
 		if (pfmt->type == type)
 			return true;
 	}

 	return false;
 }

 const struct vpu_format *vpu_helper_find_format(struct vpu_inst *inst, u32 type, u32 pixelfmt)
 {
 	const struct vpu_format *pfmt;

 	if (!inst || !inst->formats)
 		return NULL;

 	if (!vpu_iface_check_format(inst, pixelfmt))
 		return NULL;

 	for (pfmt = inst->formats; pfmt->pixfmt; pfmt++) {
 		if (pfmt->pixfmt == pixelfmt && (!type || type == pfmt->type))
 			return pfmt;
 	}

 	return NULL;
 }

 const struct vpu_format *vpu_helper_find_sibling(struct vpu_inst *inst, u32 type, u32 pixelfmt)
 {
 	const struct vpu_format *fmt;
 	const struct vpu_format *sibling;

 	fmt = vpu_helper_find_format(inst, type, pixelfmt);
 	if (!fmt || !fmt->sibling)
 		return NULL;

 	sibling = vpu_helper_find_format(inst, type, fmt->sibling);
 	if (!sibling || sibling->sibling != fmt->pixfmt ||
 	    sibling->comp_planes != fmt->comp_planes)
 		return NULL;

 	return sibling;
 }

 bool vpu_helper_match_format(struct vpu_inst *inst, u32 type, u32 fmta, u32 fmtb)
 {
 	const struct vpu_format *sibling;

 	if (fmta == fmtb)
 		return true;

 	sibling = vpu_helper_find_sibling(inst, type, fmta);
 	if (sibling && sibling->pixfmt == fmtb)
 		return true;
 	return false;
 }

 const struct vpu_format *vpu_helper_enum_format(struct vpu_inst *inst, u32 type, int index)
 {
 	const struct vpu_format *pfmt;
 	int i = 0;

 	if (!inst || !inst->formats)
 		return NULL;

 	for (pfmt = inst->formats; pfmt->pixfmt; pfmt++) {
 		if (!vpu_iface_check_format(inst, pfmt->pixfmt))
 			continue;

 		if (pfmt->type == type) {
 			if (index == i)
 				return pfmt;
 			i++;
 		}
 	}

 	return NULL;
 }

 u32 vpu_helper_valid_frame_width(struct vpu_inst *inst, u32 width)
 {
 	const struct vpu_core_resources *res;

 	if (!inst)
 		return width;

 	res = vpu_get_resource(inst);
 	if (!res)
 		return width;
 	if (res->max_width)
 		width = clamp(width, res->min_width, res->max_width);
 	if (res->step_width)
 		width = ALIGN(width, res->step_width);

 	return width;
 }

 u32 vpu_helper_valid_frame_height(struct vpu_inst *inst, u32 height)
 {
 	const struct vpu_core_resources *res;

 	if (!inst)
 		return height;

 	res = vpu_get_resource(inst);
 	if (!res)
 		return height;
 	if (res->max_height)
 		height = clamp(height, res->min_height, res->max_height);
 	if (res->step_height)
 		height = ALIGN(height, res->step_height);

 	return height;
 }

 static u32 get_nv12_plane_size(u32 width, u32 height, int plane_no,
 			       u32 stride, u32 interlaced, u32 *pbl)
 {
 	u32 bytesperline;
 	u32 size = 0;

 	bytesperline = width;
 	if (pbl)
 		bytesperline = max(bytesperline, *pbl);
 	bytesperline = ALIGN(bytesperline, stride);
 	height = ALIGN(height, 2);
 	if (plane_no == 0)
 		size = bytesperline * height;
 	else if (plane_no == 1)
 		size = bytesperline * height >> 1;
 	if (pbl)
 		*pbl = bytesperline;

 	return size;
 }

 static u32 get_tiled_8l128_plane_size(u32 fmt, u32 width, u32 height, int plane_no,
 				      u32 stride, u32 interlaced, u32 *pbl)
 {
 	u32 ws = 3;
 	u32 hs = 7;
 	u32 bitdepth = 8;
 	u32 bytesperline;
 	u32 size = 0;

 	if (interlaced)
 		hs++;
 	if (fmt == V4L2_PIX_FMT_NV12M_10BE_8L128 || fmt == V4L2_PIX_FMT_NV12_10BE_8L128)
 		bitdepth = 10;
 	bytesperline = DIV_ROUND_UP(width * bitdepth, BITS_PER_BYTE);
 	if (pbl)
 		bytesperline = max(bytesperline, *pbl);
 	bytesperline = ALIGN(bytesperline, 1 << ws);
 	bytesperline = ALIGN(bytesperline, stride);
 	height = ALIGN(height, 1 << hs);
 	if (plane_no == 0)
 		size = bytesperline * height;
 	else if (plane_no == 1)
 		size = (bytesperline * ALIGN(height, 1 << (hs + 1))) >> 1;
 	if (pbl)
 		*pbl = bytesperline;

 	return size;
 }

 static u32 get_default_plane_size(u32 width, u32 height, int plane_no,
 				  u32 stride, u32 interlaced, u32 *pbl)
 {
 	u32 bytesperline;
 	u32 size = 0;

 	bytesperline = width;
 	if (pbl)
 		bytesperline = max(bytesperline, *pbl);
 	bytesperline = ALIGN(bytesperline, stride);
 	if (plane_no == 0)
 		size = bytesperline * height;
 	if (pbl)
 		*pbl = bytesperline;

 	return size;
 }

 u32 vpu_helper_get_plane_size(u32 fmt, u32 w, u32 h, int plane_no,
 			      u32 stride, u32 interlaced, u32 *pbl)
 {
 	switch (fmt) {
 	case V4L2_PIX_FMT_NV12:
 	case V4L2_PIX_FMT_NV12M:
 		return get_nv12_plane_size(w, h, plane_no, stride, interlaced, pbl);
 	case V4L2_PIX_FMT_NV12_8L128:
 	case V4L2_PIX_FMT_NV12M_8L128:
 	case V4L2_PIX_FMT_NV12_10BE_8L128:
 	case V4L2_PIX_FMT_NV12M_10BE_8L128:
 		return get_tiled_8l128_plane_size(fmt, w, h, plane_no, stride, interlaced, pbl);
 	default:
 		return get_default_plane_size(w, h, plane_no, stride, interlaced, pbl);
 	}
 }

 int vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
 				       u32 *rptr, u32 size, void *dst)
 {
 	u32 offset;
 	u32 start;
 	u32 end;
 	void *virt;

 	if (!stream_buffer || !rptr || !dst)
 		return -EINVAL;

 	if (!size)
 		return 0;

 	offset = *rptr;
 	start = stream_buffer->phys;
 	end = start + stream_buffer->length;
 	virt = stream_buffer->virt;

 	if (offset < start || offset > end)
 		return -EINVAL;

 	if (offset + size <= end) {
 		memcpy(dst, virt + (offset - start), size);
 	} else {
 		memcpy(dst, virt + (offset - start), end - offset);
 		memcpy(dst + end - offset, virt, size + offset - end);
 	}

 	*rptr = vpu_helper_step_walk(stream_buffer, offset, size);

 	return 0;
 }

 int vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
 				     u32 *wptr, u32 size, void *src)
 {
 	u32 offset;
 	u32 start;
 	u32 end;
 	void *virt;

 	if (!stream_buffer || !wptr || !src)
 		return -EINVAL;

 	if (!size)
 		return 0;

 	offset = *wptr;
 	start = stream_buffer->phys;
 	end = start + stream_buffer->length;
 	virt = stream_buffer->virt;
 	if (offset < start || offset > end)
 		return -EINVAL;

 	if (offset + size <= end) {
 		memcpy(virt + (offset - start), src, size);
 	} else {
 		memcpy(virt + (offset - start), src, end - offset);
 		memcpy(virt, src + end - offset, size + offset - end);
 	}

 	*wptr = vpu_helper_step_walk(stream_buffer, offset, size);

 	return 0;
 }

 int vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
 				    u32 *wptr, u8 val, u32 size)
 {
 	u32 offset;
 	u32 start;
 	u32 end;
 	void *virt;

 	if (!stream_buffer || !wptr)
 		return -EINVAL;

 	if (!size)
 		return 0;

 	offset = *wptr;
 	start = stream_buffer->phys;
 	end = start + stream_buffer->length;
 	virt = stream_buffer->virt;
 	if (offset < start || offset > end)
 		return -EINVAL;

 	if (offset + size <= end) {
 		memset(virt + (offset - start), val, size);
 	} else {
 		memset(virt + (offset - start), val, end - offset);
 		memset(virt, val, size + offset - end);
 	}

 	offset += size;
 	if (offset >= end)
 		offset -= stream_buffer->length;

 	*wptr = offset;

 	return 0;
 }

 u32 vpu_helper_get_free_space(struct vpu_inst *inst)
 {
 	struct vpu_rpc_buffer_desc desc;

 	if (vpu_iface_get_stream_buffer_desc(inst, &desc))
 		return 0;

 	if (desc.rptr > desc.wptr)
 		return desc.rptr - desc.wptr;
 	else if (desc.rptr < desc.wptr)
 		return (desc.end - desc.start + desc.rptr - desc.wptr);
 	else
 		return desc.end - desc.start;
 }

 u32 vpu_helper_get_used_space(struct vpu_inst *inst)
 {
 	struct vpu_rpc_buffer_desc desc;

 	if (vpu_iface_get_stream_buffer_desc(inst, &desc))
 		return 0;

 	if (desc.wptr > desc.rptr)
 		return desc.wptr - desc.rptr;
 	else if (desc.wptr < desc.rptr)
 		return (desc.end - desc.start + desc.wptr - desc.rptr);
 	else
 		return 0;
 }

 int vpu_helper_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct vpu_inst *inst = ctrl_to_inst(ctrl);

 	switch (ctrl->id) {
 	case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE:
 		ctrl->val = inst->min_buffer_cap;
 		break;
 	case V4L2_CID_MIN_BUFFERS_FOR_OUTPUT:
 		ctrl->val = inst->min_buffer_out;
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 int vpu_helper_find_startcode(struct vpu_buffer *stream_buffer,
 			      u32 pixelformat, u32 offset, u32 bytesused)
 {
 	u32 start_code;
 	int start_code_size;
 	u32 val = 0;
 	int i;
 	int ret = -EINVAL;

 	if (!stream_buffer || !stream_buffer->virt)
 		return -EINVAL;

 	switch (pixelformat) {
 	case V4L2_PIX_FMT_H264:
 		start_code_size = 4;
 		start_code = 0x00000001;
 		break;
 	default:
 		return 0;
 	}

 	for (i = 0; i < bytesused; i++) {
 		val = (val << 8) | vpu_helper_read_byte(stream_buffer, offset + i);
 		if (i < start_code_size - 1)
 			continue;
 		if (val == start_code) {
 			ret = i + 1 - start_code_size;
 			break;
 		}
 	}

 	return ret;
 }

 int vpu_find_dst_by_src(struct vpu_pair *pairs, u32 cnt, u32 src)
 {
 	u32 i;

 	if (!pairs || !cnt)
 		return -EINVAL;

 	for (i = 0; i < cnt; i++) {
 		if (pairs[i].src == src)
 			return pairs[i].dst;
 	}

 	return -EINVAL;
 }

 int vpu_find_src_by_dst(struct vpu_pair *pairs, u32 cnt, u32 dst)
 {
 	u32 i;

 	if (!pairs || !cnt)
 		return -EINVAL;

 	for (i = 0; i < cnt; i++) {
 		if (pairs[i].dst == dst)
 			return pairs[i].src;
 	}

 	return -EINVAL;
 }

 const char *vpu_id_name(u32 id)
 {
 	switch (id) {
 	case VPU_CMD_ID_NOOP: return "noop";
 	case VPU_CMD_ID_CONFIGURE_CODEC: return "configure codec";
 	case VPU_CMD_ID_START: return "start";
 	case VPU_CMD_ID_STOP: return "stop";
 	case VPU_CMD_ID_ABORT: return "abort";
 	case VPU_CMD_ID_RST_BUF: return "reset buf";
 	case VPU_CMD_ID_SNAPSHOT: return "snapshot";
 	case VPU_CMD_ID_FIRM_RESET: return "reset firmware";
 	case VPU_CMD_ID_UPDATE_PARAMETER: return "update parameter";
 	case VPU_CMD_ID_FRAME_ENCODE: return "encode frame";
 	case VPU_CMD_ID_SKIP: return "skip";
 	case VPU_CMD_ID_FS_ALLOC: return "alloc fb";
 	case VPU_CMD_ID_FS_RELEASE: return "release fb";
 	case VPU_CMD_ID_TIMESTAMP: return "timestamp";
 	case VPU_CMD_ID_DEBUG: return "debug";
 	case VPU_MSG_ID_RESET_DONE: return "reset done";
 	case VPU_MSG_ID_START_DONE: return "start done";
 	case VPU_MSG_ID_STOP_DONE: return "stop done";
 	case VPU_MSG_ID_ABORT_DONE: return "abort done";
 	case VPU_MSG_ID_BUF_RST: return "buf reset done";
 	case VPU_MSG_ID_MEM_REQUEST: return "mem request";
 	case VPU_MSG_ID_PARAM_UPD_DONE: return "param upd done";
 	case VPU_MSG_ID_FRAME_INPUT_DONE: return "frame input done";
 	case VPU_MSG_ID_ENC_DONE: return "encode done";
 	case VPU_MSG_ID_DEC_DONE: return "frame display";
 	case VPU_MSG_ID_FRAME_REQ: return "fb request";
 	case VPU_MSG_ID_FRAME_RELEASE: return "fb release";
 	case VPU_MSG_ID_SEQ_HDR_FOUND: return "seq hdr found";
 	case VPU_MSG_ID_RES_CHANGE: return "resolution change";
 	case VPU_MSG_ID_PIC_HDR_FOUND: return "pic hdr found";
 	case VPU_MSG_ID_PIC_DECODED: return "picture decoded";
 	case VPU_MSG_ID_PIC_EOS: return "eos";
 	case VPU_MSG_ID_FIFO_LOW: return "fifo low";
 	case VPU_MSG_ID_BS_ERROR: return "bs error";
 	case VPU_MSG_ID_UNSUPPORTED: return "unsupported";
 	case VPU_MSG_ID_FIRMWARE_XCPT: return "exception";
 	case VPU_MSG_ID_PIC_SKIPPED: return "skipped";
 	case VPU_MSG_ID_DBG_MSG: return "debug msg";
 	}
 	return "<unknown>";
 }

 const char *vpu_codec_state_name(enum vpu_codec_state state)
 {
 	switch (state) {
 	case VPU_CODEC_STATE_DEINIT: return "initialization";
 	case VPU_CODEC_STATE_CONFIGURED: return "configured";
 	case VPU_CODEC_STATE_START: return "start";
 	case VPU_CODEC_STATE_STARTED: return "started";
 	case VPU_CODEC_STATE_ACTIVE: return "active";
 	case VPU_CODEC_STATE_SEEK: return "seek";
 	case VPU_CODEC_STATE_STOP: return "stop";
 	case VPU_CODEC_STATE_DRAIN: return "drain";
 	case VPU_CODEC_STATE_DYAMIC_RESOLUTION_CHANGE: return "resolution change";
 	}
 	return "<unknown>";
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright 2020-2021 NXP
	*/

	#include <linux/init.h>
	#include <linux/interconnect.h>
	#include <linux/ioctl.h>
	#include <linux/list.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include "vpu.h"
	#include "vpu_defs.h"
	#include "vpu_core.h"
	#include "vpu_rpc.h"
	#include "vpu_helpers.h"

	int vpu_helper_find_in_array_u8(const u8 *array, u32 size, u32 x)
	{
	int i;

	for (i = 0; i < size; i++) {
	if (array[i] == x)
	return i;
	}

	return 0;
	}

	bool vpu_helper_check_type(struct vpu_inst *inst, u32 type)
	{
	const struct vpu_format *pfmt;

	for (pfmt = inst->formats; pfmt->pixfmt; pfmt++) {
	if (!vpu_iface_check_format(inst, pfmt->pixfmt))
	continue;
	if (pfmt->type == type)
	return true;
	}

	return false;
	}

	const struct vpu_format vpu_helper_find_format(struct vpu_inst inst, u32 type, u32 pixelfmt)
	{
	const struct vpu_format *pfmt;

	if (!inst \|\| !inst->formats)
	return NULL;

	if (!vpu_iface_check_format(inst, pixelfmt))
	return NULL;

	for (pfmt = inst->formats; pfmt->pixfmt; pfmt++) {
	if (pfmt->pixfmt == pixelfmt && (!type \|\| type == pfmt->type))
	return pfmt;
	}

	return NULL;
	}

	const struct vpu_format vpu_helper_find_sibling(struct vpu_inst inst, u32 type, u32 pixelfmt)
	{
	const struct vpu_format *fmt;
	const struct vpu_format *sibling;

	fmt = vpu_helper_find_format(inst, type, pixelfmt);
	if (!fmt \|\| !fmt->sibling)
	return NULL;

	sibling = vpu_helper_find_format(inst, type, fmt->sibling);
	if (!sibling \|\| sibling->sibling != fmt->pixfmt \|\|
	sibling->comp_planes != fmt->comp_planes)
	return NULL;

	return sibling;
	}

	bool vpu_helper_match_format(struct vpu_inst *inst, u32 type, u32 fmta, u32 fmtb)
	{
	const struct vpu_format *sibling;

	if (fmta == fmtb)
	return true;

	sibling = vpu_helper_find_sibling(inst, type, fmta);
	if (sibling && sibling->pixfmt == fmtb)
	return true;
	return false;
	}

	const struct vpu_format vpu_helper_enum_format(struct vpu_inst inst, u32 type, int index)
	{
	const struct vpu_format *pfmt;
	int i = 0;

	if (!inst \|\| !inst->formats)
	return NULL;

	for (pfmt = inst->formats; pfmt->pixfmt; pfmt++) {
	if (!vpu_iface_check_format(inst, pfmt->pixfmt))
	continue;

	if (pfmt->type == type) {
	if (index == i)
	return pfmt;
	i++;
	}
	}

	return NULL;
	}

	u32 vpu_helper_valid_frame_width(struct vpu_inst *inst, u32 width)
	{
	const struct vpu_core_resources *res;

	if (!inst)
	return width;

	res = vpu_get_resource(inst);
	if (!res)
	return width;
	if (res->max_width)
	width = clamp(width, res->min_width, res->max_width);
	if (res->step_width)
	width = ALIGN(width, res->step_width);

	return width;
	}

	u32 vpu_helper_valid_frame_height(struct vpu_inst *inst, u32 height)
	{
	const struct vpu_core_resources *res;

	if (!inst)
	return height;

	res = vpu_get_resource(inst);
	if (!res)
	return height;
	if (res->max_height)
	height = clamp(height, res->min_height, res->max_height);
	if (res->step_height)
	height = ALIGN(height, res->step_height);

	return height;
	}

	static u32 get_nv12_plane_size(u32 width, u32 height, int plane_no,
	u32 stride, u32 interlaced, u32 *pbl)
	{
	u32 bytesperline;
	u32 size = 0;

	bytesperline = width;
	if (pbl)
	bytesperline = max(bytesperline, *pbl);
	bytesperline = ALIGN(bytesperline, stride);
	height = ALIGN(height, 2);
	if (plane_no == 0)
	size = bytesperline * height;
	else if (plane_no == 1)
	size = bytesperline * height >> 1;
	if (pbl)
	*pbl = bytesperline;

	return size;
	}

	static u32 get_tiled_8l128_plane_size(u32 fmt, u32 width, u32 height, int plane_no,
	u32 stride, u32 interlaced, u32 *pbl)
	{
	u32 ws = 3;
	u32 hs = 7;
	u32 bitdepth = 8;
	u32 bytesperline;
	u32 size = 0;

	if (interlaced)
	hs++;
	if (fmt == V4L2_PIX_FMT_NV12M_10BE_8L128 \|\| fmt == V4L2_PIX_FMT_NV12_10BE_8L128)
	bitdepth = 10;
	bytesperline = DIV_ROUND_UP(width * bitdepth, BITS_PER_BYTE);
	if (pbl)
	bytesperline = max(bytesperline, *pbl);
	bytesperline = ALIGN(bytesperline, 1 << ws);
	bytesperline = ALIGN(bytesperline, stride);
	height = ALIGN(height, 1 << hs);
	if (plane_no == 0)
	size = bytesperline * height;
	else if (plane_no == 1)
	size = (bytesperline * ALIGN(height, 1 << (hs + 1))) >> 1;
	if (pbl)
	*pbl = bytesperline;

	return size;
	}

	static u32 get_default_plane_size(u32 width, u32 height, int plane_no,
	u32 stride, u32 interlaced, u32 *pbl)
	{
	u32 bytesperline;
	u32 size = 0;

	bytesperline = width;
	if (pbl)
	bytesperline = max(bytesperline, *pbl);
	bytesperline = ALIGN(bytesperline, stride);
	if (plane_no == 0)
	size = bytesperline * height;
	if (pbl)
	*pbl = bytesperline;

	return size;
	}

	u32 vpu_helper_get_plane_size(u32 fmt, u32 w, u32 h, int plane_no,
	u32 stride, u32 interlaced, u32 *pbl)
	{
	switch (fmt) {
	case V4L2_PIX_FMT_NV12:
	case V4L2_PIX_FMT_NV12M:
	return get_nv12_plane_size(w, h, plane_no, stride, interlaced, pbl);
	case V4L2_PIX_FMT_NV12_8L128:
	case V4L2_PIX_FMT_NV12M_8L128:
	case V4L2_PIX_FMT_NV12_10BE_8L128:
	case V4L2_PIX_FMT_NV12M_10BE_8L128:
	return get_tiled_8l128_plane_size(fmt, w, h, plane_no, stride, interlaced, pbl);
	default:
	return get_default_plane_size(w, h, plane_no, stride, interlaced, pbl);
	}
	}

	int vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
	u32 rptr, u32 size, void dst)
	{
	u32 offset;
	u32 start;
	u32 end;
	void *virt;

	if (!stream_buffer \|\| !rptr \|\| !dst)
	return -EINVAL;

	if (!size)
	return 0;

	offset = *rptr;
	start = stream_buffer->phys;
	end = start + stream_buffer->length;
	virt = stream_buffer->virt;

	if (offset < start \|\| offset > end)
	return -EINVAL;

	if (offset + size <= end) {
	memcpy(dst, virt + (offset - start), size);
	} else {
	memcpy(dst, virt + (offset - start), end - offset);
	memcpy(dst + end - offset, virt, size + offset - end);
	}

	*rptr = vpu_helper_step_walk(stream_buffer, offset, size);

	return 0;
	}

	int vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
	u32 wptr, u32 size, void src)
	{
	u32 offset;
	u32 start;
	u32 end;
	void *virt;

	if (!stream_buffer \|\| !wptr \|\| !src)
	return -EINVAL;

	if (!size)
	return 0;

	offset = *wptr;
	start = stream_buffer->phys;
	end = start + stream_buffer->length;
	virt = stream_buffer->virt;
	if (offset < start \|\| offset > end)
	return -EINVAL;

	if (offset + size <= end) {
	memcpy(virt + (offset - start), src, size);
	} else {
	memcpy(virt + (offset - start), src, end - offset);
	memcpy(virt, src + end - offset, size + offset - end);
	}

	*wptr = vpu_helper_step_walk(stream_buffer, offset, size);

	return 0;
	}

	int vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
	u32 *wptr, u8 val, u32 size)
	{
	u32 offset;
	u32 start;
	u32 end;
	void *virt;

	if (!stream_buffer \|\| !wptr)
	return -EINVAL;

	if (!size)
	return 0;

	offset = *wptr;
	start = stream_buffer->phys;
	end = start + stream_buffer->length;
	virt = stream_buffer->virt;
	if (offset < start \|\| offset > end)
	return -EINVAL;

	if (offset + size <= end) {
	memset(virt + (offset - start), val, size);
	} else {
	memset(virt + (offset - start), val, end - offset);
	memset(virt, val, size + offset - end);
	}

	offset += size;
	if (offset >= end)
	offset -= stream_buffer->length;

	*wptr = offset;

	return 0;
	}

	u32 vpu_helper_get_free_space(struct vpu_inst *inst)
	{
	struct vpu_rpc_buffer_desc desc;

	if (vpu_iface_get_stream_buffer_desc(inst, &desc))
	return 0;

	if (desc.rptr > desc.wptr)
	return desc.rptr - desc.wptr;
	else if (desc.rptr < desc.wptr)
	return (desc.end - desc.start + desc.rptr - desc.wptr);
	else
	return desc.end - desc.start;
	}

	u32 vpu_helper_get_used_space(struct vpu_inst *inst)
	{
	struct vpu_rpc_buffer_desc desc;

	if (vpu_iface_get_stream_buffer_desc(inst, &desc))
	return 0;

	if (desc.wptr > desc.rptr)
	return desc.wptr - desc.rptr;
	else if (desc.wptr < desc.rptr)
	return (desc.end - desc.start + desc.wptr - desc.rptr);
	else
	return 0;
	}

	int vpu_helper_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct vpu_inst *inst = ctrl_to_inst(ctrl);

	switch (ctrl->id) {
	case V4L2_CID_MIN_BUFFERS_FOR_CAPTURE:
	ctrl->val = inst->min_buffer_cap;
	break;
	case V4L2_CID_MIN_BUFFERS_FOR_OUTPUT:
	ctrl->val = inst->min_buffer_out;
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	int vpu_helper_find_startcode(struct vpu_buffer *stream_buffer,
	u32 pixelformat, u32 offset, u32 bytesused)
	{
	u32 start_code;
	int start_code_size;
	u32 val = 0;
	int i;
	int ret = -EINVAL;

	if (!stream_buffer \|\| !stream_buffer->virt)
	return -EINVAL;

	switch (pixelformat) {
	case V4L2_PIX_FMT_H264:
	start_code_size = 4;
	start_code = 0x00000001;
	break;
	default:
	return 0;
	}

	for (i = 0; i < bytesused; i++) {
	val = (val << 8) \| vpu_helper_read_byte(stream_buffer, offset + i);
	if (i < start_code_size - 1)
	continue;
	if (val == start_code) {
	ret = i + 1 - start_code_size;
	break;
	}
	}

	return ret;
	}

	int vpu_find_dst_by_src(struct vpu_pair *pairs, u32 cnt, u32 src)
	{
	u32 i;

	if (!pairs \|\| !cnt)
	return -EINVAL;

	for (i = 0; i < cnt; i++) {
	if (pairs[i].src == src)
	return pairs[i].dst;
	}

	return -EINVAL;
	}

	int vpu_find_src_by_dst(struct vpu_pair *pairs, u32 cnt, u32 dst)
	{
	u32 i;

	if (!pairs \|\| !cnt)
	return -EINVAL;

	for (i = 0; i < cnt; i++) {
	if (pairs[i].dst == dst)
	return pairs[i].src;
	}

	return -EINVAL;
	}

	const char *vpu_id_name(u32 id)
	{
	switch (id) {
	case VPU_CMD_ID_NOOP: return "noop";
	case VPU_CMD_ID_CONFIGURE_CODEC: return "configure codec";
	case VPU_CMD_ID_START: return "start";
	case VPU_CMD_ID_STOP: return "stop";
	case VPU_CMD_ID_ABORT: return "abort";
	case VPU_CMD_ID_RST_BUF: return "reset buf";
	case VPU_CMD_ID_SNAPSHOT: return "snapshot";
	case VPU_CMD_ID_FIRM_RESET: return "reset firmware";
	case VPU_CMD_ID_UPDATE_PARAMETER: return "update parameter";
	case VPU_CMD_ID_FRAME_ENCODE: return "encode frame";
	case VPU_CMD_ID_SKIP: return "skip";
	case VPU_CMD_ID_FS_ALLOC: return "alloc fb";
	case VPU_CMD_ID_FS_RELEASE: return "release fb";
	case VPU_CMD_ID_TIMESTAMP: return "timestamp";
	case VPU_CMD_ID_DEBUG: return "debug";
	case VPU_MSG_ID_RESET_DONE: return "reset done";
	case VPU_MSG_ID_START_DONE: return "start done";
	case VPU_MSG_ID_STOP_DONE: return "stop done";
	case VPU_MSG_ID_ABORT_DONE: return "abort done";
	case VPU_MSG_ID_BUF_RST: return "buf reset done";
	case VPU_MSG_ID_MEM_REQUEST: return "mem request";
	case VPU_MSG_ID_PARAM_UPD_DONE: return "param upd done";
	case VPU_MSG_ID_FRAME_INPUT_DONE: return "frame input done";
	case VPU_MSG_ID_ENC_DONE: return "encode done";
	case VPU_MSG_ID_DEC_DONE: return "frame display";
	case VPU_MSG_ID_FRAME_REQ: return "fb request";
	case VPU_MSG_ID_FRAME_RELEASE: return "fb release";
	case VPU_MSG_ID_SEQ_HDR_FOUND: return "seq hdr found";
	case VPU_MSG_ID_RES_CHANGE: return "resolution change";
	case VPU_MSG_ID_PIC_HDR_FOUND: return "pic hdr found";
	case VPU_MSG_ID_PIC_DECODED: return "picture decoded";
	case VPU_MSG_ID_PIC_EOS: return "eos";
	case VPU_MSG_ID_FIFO_LOW: return "fifo low";
	case VPU_MSG_ID_BS_ERROR: return "bs error";
	case VPU_MSG_ID_UNSUPPORTED: return "unsupported";
	case VPU_MSG_ID_FIRMWARE_XCPT: return "exception";
	case VPU_MSG_ID_PIC_SKIPPED: return "skipped";
	case VPU_MSG_ID_DBG_MSG: return "debug msg";
	}
	return "<unknown>";
	}

	const char *vpu_codec_state_name(enum vpu_codec_state state)
	{
	switch (state) {
	case VPU_CODEC_STATE_DEINIT: return "initialization";
	case VPU_CODEC_STATE_CONFIGURED: return "configured";
	case VPU_CODEC_STATE_START: return "start";
	case VPU_CODEC_STATE_STARTED: return "started";
	case VPU_CODEC_STATE_ACTIVE: return "active";
	case VPU_CODEC_STATE_SEEK: return "seek";
	case VPU_CODEC_STATE_STOP: return "stop";
	case VPU_CODEC_STATE_DRAIN: return "drain";
	case VPU_CODEC_STATE_DYAMIC_RESOLUTION_CHANGE: return "resolution change";
	}
	return "<unknown>";
	}