泛全志芯片内核G2D模块sample深究

1. g2d 模块概述

g2d 主要功能：
1）旋转：支持90、180、270旋转；
2）镜像反转：H / V;
3) scale：放缩
4）格式转换：yuv 转 rgb 等，多种格式相互间转换；
5）透明叠加功能：实现两个rgb图片叠加；
6）矩形填充，等诸多功能；

2. g2d 配置
1）源码目录：tina-v853-docker/kernel/linux-4.9/drivers/char/sunxi_g2d

2）make kernel_menuconfig 配置

Device Drivers > Character devices > sunxi g2d driver
按空格键选中【*】

3）Device Tree 设备树配置
sun8iw21p1.dtsi路径：
tina-v853-docker/kernel/linux-4.9/arch/arm/boot/dts/sun8iw21p1.dtsi

		g2d: g2d@05410000 {
			compatible = "allwinner,sunxi-g2d";
			reg = 0x0 0x05410000 0x0 0xbffff>;
			interrupts = GIC_SPI 89 IRQ_TYPE_LEVEL_HIGH>;
			clocks = &clk_g2d>;
			iommus = &mmu_aw 3 1>;
			status = "okay";
		};

status 要设定为“okay” 状态。

4）重新编译内核

mkernel
make -j1 V=s
pack

使用烧录工具PhoenixSuit 将路径：tina-v853-docker/out/v851s/lizard/openwrt/v851s_linux_lizard_uart0.img 下的img 镜像烧录到开发板。

adb shell 打开控制终端查看设备节点G2D：

5）通过G2D 设备节点，对g2d 进行操作

static int SampleG2d_G2dOpen(SAMPLE_G2D_CTX *p_g2d_ctx)
{
    int ret = 0;
    p_g2d_ctx->mG2dFd = open("/dev/g2d", O_RDWR, 0);
    if (p_g2d_ctx->mG2dFd 0)
    {
        aloge("fatal error! open /dev/g2d failed");
        ret = -1;
    }
    return ret;
}

3. 详解 eyesee-mpp 中g2d sample 具体应用
1）eyesee-mpp 中 g2d sample 编译与执行请参考另一篇帖子
链接文本

2）g2d sample 目录

3）运用 g2d 进行rotation，scale，格式转换
具体实现：将 nv21 格式的1920×1080图转换成rgb888 格式并放缩为640×360 大小。具体用到两个功能，格式转换和放缩。
步骤如下：
1））根据1920×1080 nv21 格式以及 640×360 rgb888 格式申请虚拟地址空间以及转换成物理地址（注意：g2d 转换是在物理地址中完成的）

1920×1080 nv21 格式空间大小（输入文件）：

Y 占 19201080 = 2073600 字节
UV 占 19201080 / 2 = 1036800 字节

640×360 rgb888 格式空间大小（输出文件）：
RGB 占 6403603 = 691200 字节

另外：虚拟地址转换成物理地址使用如下函数：

g2d_getPhyAddrByVirAddr（）

申请虚拟空间并转换成物理空间完整函数如下：
在文件 tina-v853-docker/platform/allwinner/eyesee-mpp/middleware/sun8iw21/sample/sample_g2d/sample_g2d.c/sample_g2d.c 中

static int PrepareFrmBuff(SAMPLE_G2D_CTX *p_g2d_ctx)
{
    SampleG2dConfig *pConfig = NULL;
    unsigned int size = 0;

    pConfig = &p_g2d_ctx->mConfigPara;
    
    p_g2d_ctx->src_frm_info.frm_width = pConfig->mSrcWidth;
    p_g2d_ctx->src_frm_info.frm_height =  pConfig->mSrcHeight;

    p_g2d_ctx->dst_frm_info.frm_width = pConfig->mDstWidth;
    p_g2d_ctx->dst_frm_info.frm_height = pConfig->mDstHeight;

    size = ALIGN(p_g2d_ctx->src_frm_info.frm_width, 16)*ALIGN(p_g2d_ctx->src_frm_info.frm_height, 16);
    if(pConfig->mPicFormat == MM_PIXEL_FORMAT_YVU_SEMIPLANAR_420 || pConfig->mPicFormat == MM_PIXEL_FORMAT_YUV_SEMIPLANAR_420)
    {
        p_g2d_ctx->src_frm_info.p_vir_addr[0] = (void *)g2d_allocMem(size);
        if(NULL == p_g2d_ctx->src_frm_info.p_vir_addr[0])
        {
            aloge("malloc_src_frm_y_mem_failed");
            return -1;
        }

        p_g2d_ctx->src_frm_info.p_vir_addr[1] = (void *)g2d_allocMem(size/2);
        if(NULL == p_g2d_ctx->src_frm_info.p_vir_addr[1])
        {
            g2d_freeMem(p_g2d_ctx->src_frm_info.p_vir_addr[0]);
            aloge("malloc_src_frm_c_mem_failed");    
            return -1;
        }

        p_g2d_ctx->src_frm_info.p_phy_addr[0] = (void *)g2d_getPhyAddrByVirAddr(p_g2d_ctx->src_frm_info.p_vir_addr[0]); 
        p_g2d_ctx->src_frm_info.p_phy_addr[1] = (void *)g2d_getPhyAddrByVirAddr(p_g2d_ctx->src_frm_info.p_vir_addr[1]);
    }

	if(pConfig->mDstPicFormat == MM_PIXEL_FORMAT_RGB_888)
	{
		size = p_g2d_ctx->dst_frm_info.frm_width * p_g2d_ctx->dst_frm_info.frm_height * 3;
		p_g2d_ctx->dst_frm_info.p_vir_addr[0] = (void *)g2d_allocMem(size);
		if(NULL == p_g2d_ctx->dst_frm_info.p_vir_addr[0])
		{
			if(p_g2d_ctx->src_frm_info.p_vir_addr[0] != NULL)
			{
				g2d_freeMem(p_g2d_ctx->src_frm_info.p_vir_addr[0]); 
			}
			if(p_g2d_ctx->src_frm_info.p_vir_addr[1] != NULL)
			{
				g2d_freeMem(p_g2d_ctx->src_frm_info.p_vir_addr[1]);
			}
			aloge("malloc_dst_frm_y_mem_failed");
			return -1;
		}
		p_g2d_ctx->dst_frm_info.p_phy_addr[0] = (void *)g2d_getPhyAddrByVirAddr(p_g2d_ctx->dst_frm_info.p_vir_addr[0]); 
	}

    return 0; 
}

2））通过fopen 传菜间两个文件句柄，fd_in fd_out 用来操作输入输出两个文件资源

        p_g2d_ctx->fd_in = fopen(p_g2d_ctx->mConfigPara.SrcFile,"r");
        if(NULL == p_g2d_ctx->fd_in)
        {
            aloge("open src file failed");
            ret = -1;
            goto _err2;
        }
        fseek(p_g2d_ctx->fd_in, 0, SEEK_SET);

            p_g2d_ctx->fd_out = fopen(p_g2d_ctx->mConfigPara.DstFile, "wb");
            if (NULL == p_g2d_ctx->fd_out)
            {
                aloge("open out file failed");
                ret = -1;
                goto _err2;
            }
            fseek(p_g2d_ctx->fd_out, 0, SEEK_SET);

3））读出 1920×1080 nv21 图资放入 虚拟空间

read_len = p_g2d_ctx->src_frm_info.frm_width * p_g2d_ctx->src_frm_info.frm_height;
        if(pConfig->mPicFormat == MM_PIXEL_FORMAT_YVU_SEMIPLANAR_420|| pConfig->mPicFormat == MM_PIXEL_FORMAT_YUV_SEMIPLANAR_420)
        {
            size1 = fread(p_g2d_ctx->src_frm_info.p_vir_addr[0] , 1, read_len, p_g2d_ctx->fd_in);
            if(size1 != read_len)
            {
                aloge("read_y_data_frm_src_file_invalid");
            }
            size2 = fread(p_g2d_ctx->src_frm_info.p_vir_addr[1], 1, read_len /2, p_g2d_ctx->fd_in);
            if(size2 != read_len/2)
            {
                aloge("read_c_data_frm_src_file_invalid");
            }

            fclose(p_g2d_ctx->fd_in);

            g2d_flushCache((void *)p_g2d_ctx->src_frm_info.p_vir_addr[0], read_len);
            g2d_flushCache((void *)p_g2d_ctx->src_frm_info.p_vir_addr[1], read_len/2);
        }

4））打开g2d 初始化，并开始转换

ret = SampleG2d_G2dOpen(p_g2d_ctx);
    if (ret 0)
    {
        aloge("fatal error! open /dev/g2d fail!");
        goto _err2;
    }
    ret = SampleG2d_G2dConvert(p_g2d_ctx);
    if (ret 0)
    {
        aloge("fatal error! g2d convert fail!");
        goto _close_g2d;
    }
//具体转化函数：

static int SampleG2d_G2dConvert_scale(SAMPLE_G2D_CTX *p_g2d_ctx)
{
    int ret = 0;
    g2d_blt_h blit;
    g2d_fmt_enh eSrcFormat, eDstFormat; 
    SampleG2dConfig *pConfig = NULL;

    pConfig = &p_g2d_ctx->mConfigPara;

    ret = convert_PIXEL_FORMAT_E_to_g2d_fmt_enh(pConfig->mPicFormat, &eSrcFormat);
    if(ret!=SUCCESS)
    {
        aloge("fatal error! src pixel format[0x%x] is invalid!", pConfig->mPicFormat);
        return -1;
    }
    ret = convert_PIXEL_FORMAT_E_to_g2d_fmt_enh(pConfig->mDstPicFormat, &eDstFormat);
    if(ret!=SUCCESS)
    {
        aloge("fatal error! dst pixel format[0x%x] is invalid!", pConfig->mPicFormat);
        return -1;
    }

    //config blit
    memset(&blit, 0, sizeof(g2d_blt_h));

    if(0 != pConfig->mDstRotate)
    {
        aloge("fatal_err: rotation can't be performed when do scaling");
    }

    blit.flag_h = G2D_BLT_NONE_H;       // angle rotation used
//    switch(pConfig->mDstRotate)
//    {
//        case 0:
//            blit.flag_h = G2D_BLT_NONE_H;   //G2D_ROT_0, G2D_BLT_NONE_H
//            break;
//        case 90:
//            blit.flag_h = G2D_ROT_90;
//            break;
//        case 180:
//            blit.flag_h = G2D_ROT_180;
//            break;
//        case 270:
//            blit.flag_h = G2D_ROT_270;
//            break;
//        default:
//            aloge("fatal error! rotation[%d] is invalid!", pConfig->mDstRotate);
//            blit.flag_h = G2D_BLT_NONE_H;
//            break;
//    }
    //blit.src_image_h.bbuff = 1;
    //blit.src_image_h.color = 0xff;
    blit.src_image_h.format = eSrcFormat;
    blit.src_image_h.laddr[0] = (unsigned int)p_g2d_ctx->src_frm_info.p_phy_addr[0];
    blit.src_image_h.laddr[1] = (unsigned int)p_g2d_ctx->src_frm_info.p_phy_addr[1];
    blit.src_image_h.laddr[2] = (unsigned int)p_g2d_ctx->src_frm_info.p_phy_addr[2];
    //blit.src_image_h.haddr[] = 
    blit.src_image_h.width = p_g2d_ctx->src_frm_info.frm_width;
    blit.src_image_h.height = p_g2d_ctx->src_frm_info.frm_height;
    blit.src_image_h.align[0] = 0;
    blit.src_image_h.align[1] = 0;
    blit.src_image_h.align[2] = 0;
    blit.src_image_h.clip_rect.x = pConfig->mSrcRectX;
    blit.src_image_h.clip_rect.y = pConfig->mSrcRectY;
    blit.src_image_h.clip_rect.w = pConfig->mSrcRectW;
    blit.src_image_h.clip_rect.h = pConfig->mSrcRectH;
    blit.src_image_h.gamut = G2D_BT601;
    blit.src_image_h.bpremul = 0;
    //blit.src_image_h.alpha = 0xff;
    blit.src_image_h.mode = G2D_PIXEL_ALPHA;   //G2D_PIXEL_ALPHA, G2D_GLOBAL_ALPHA
    blit.src_image_h.fd = -1;
    blit.src_image_h.use_phy_addr = 1;

    //blit.dst_image_h.bbuff = 1;
    //blit.dst_image_h.color = 0xff;
    blit.dst_image_h.format = eDstFormat;
    blit.dst_image_h.laddr[0] = (unsigned int)p_g2d_ctx->dst_frm_info.p_phy_addr[0];
    blit.dst_image_h.laddr[1] = (unsigned int)p_g2d_ctx->dst_frm_info.p_phy_addr[1];
    blit.dst_image_h.laddr[2] = (unsigned int)p_g2d_ctx->dst_frm_info.p_phy_addr[2];
    //blit.dst_image_h.haddr[] = 
    blit.dst_image_h.width = p_g2d_ctx->dst_frm_info.frm_width;
    blit.dst_image_h.height = p_g2d_ctx->dst_frm_info.frm_height;
    blit.dst_image_h.align[0] = 0;
    blit.dst_image_h.align[1] = 0;
    blit.dst_image_h.align[2] = 0;
    blit.dst_image_h.clip_rect.x = pConfig->mDstRectX;
    blit.dst_image_h.clip_rect.y = pConfig->mDstRectY;
    blit.dst_image_h.clip_rect.w = pConfig->mDstRectW;
    blit.dst_image_h.clip_rect.h = pConfig->mDstRectH;
    blit.dst_image_h.gamut = G2D_BT601;
    blit.dst_image_h.bpremul = 0;
    //blit.dst_image_h.alpha = 0xff;
    blit.dst_image_h.mode = G2D_PIXEL_ALPHA;   //G2D_PIXEL_ALPHA, G2D_GLOBAL_ALPHA
    blit.dst_image_h.fd = -1;
    blit.dst_image_h.use_phy_addr = 1;

    ret = ioctl(p_g2d_ctx->mG2dFd, G2D_CMD_BITBLT_H, (unsigned long)&blit);
    if(ret 0)
    {
        aloge("fatal error! bit-block(image) transfer failed[%d]", ret);
        system("cd /sys/class/sunxi_dump;echo 0x14A8000,0x14A8100 > dump;cat dump");
    }

    return ret;
} 

5））转化完成后将640×360 rgb888 图资通过fd_out句柄存储起来

if(pConfig->mDstPicFormat == MM_PIXEL_FORMAT_RGB_888)
        {
            out_len = p_g2d_ctx->dst_frm_info.frm_width * p_g2d_ctx->dst_frm_info.frm_height *3;
            g2d_flushCache((void *)p_g2d_ctx->dst_frm_info.p_vir_addr[0], out_len);

            fwrite(p_g2d_ctx->dst_frm_info.p_vir_addr[0], 1, out_len, p_g2d_ctx->fd_out);
        }

4. 总结转化步骤

通过步骤3中的模块化分析，可以看出g2d 转化大概分为一下步骤：

1）为打开 iomen 初始化；
2）为src以及dst图资申请虚拟地址空间并转换成物理地址空间；
3）将src图资放入虚拟地址空间，然后自动映射到物理地址空间；
4）打开g2d 设备节点进行转换（最重要的一环，可以通过手册分析具体怎么转换的）；
5）将转换好的dst图资保存起来；

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