NXP

6.2 ipu_csi_enc.c详细分析

2019-07-12 13:47发布

站内文章 / NXP MCU
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这个文件和ipu_prp_enc.c以及ipu_fg_overlay_sdc.c和ipu_bg_overlay_sdc.c几个文件的操作都是相似的，这几个文件可以一起查看。找到他们之间的区别， 1cam_data中使用的函数指针的不同; 2ipu_init_channel_buffer中地址的不同和width等不同。
在mxc_v4l2_capture.c中的mxc_v4l_open函数，里面有这样一个选择语句： if (strcmp(mxc_capture_inputs[cam->current_input].name, "CSI MEM") == 0) { #if defined(CONFIG_MXC_IPU_CSI_ENC) || defined(CONFIG_MXC_IPU_CSI_ENC_MODULE) err = csi_enc_select(cam); #endif } else if (strcmp(mxc_capture_inputs[cam->current_input].name, "CSI IC MEM") == 0) { #if defined(CONFIG_MXC_IPU_PRP_ENC) || defined(CONFIG_MXC_IPU_PRP_ENC_MODULE) err = prp_enc_select(cam); #endif }
如果匹配的mxc_capture_inputs[cam->current_input].name是"CSIMEM"的话，就会执行csi_enc_select函数，这个“CSIMEM”一般是用作overlay或者viewfinder，从CSI中获取到的数据，不经过IC，直接到达内存中。这个csi_enc_select函数就在ipu_csi_enc.c文件中，这个函数就是设置cam_data结构体中的几个函数指针所指向的函数。
1.csi_enc_select函数 int csi_enc_select(void *private) { cam_data *cam = (cam_data *) private; int err = 0; if (cam) { cam->enc_update_eba = csi_enc_eba_update; cam->enc_enable = csi_enc_enabling_tasks; cam->enc_disable = csi_enc_disabling_tasks; cam->enc_enable_csi = csi_enc_enable_csi; cam->enc_disable_csi = csi_enc_disable_csi; } else { err = -EIO; } return err; } EXPORT_SYMBOL(csi_enc_select);
2.csi_enc_enabling_tasks函数 当在mxc_v4l2_capture.c中的mxc_streamon函数中调用cam->enc_enable的话，就会调用到csi_enc_enabling_tasks函数。 static int csi_enc_enabling_tasks(void *private) { cam_data *cam = (cam_data *) private; int err = 0; uint32_t irq = (cam->csi == 0) ? IPU_IRQ_CSI0_OUT_EOF : IPU_IRQ_CSI1_OUT_EOF; CAMERA_TRACE("IPU:In csi_enc_enabling_tasks "); cam->dummy_frame.vaddress = dma_alloc_coherent(0, PAGE_ALIGN(cam->v2f.fmt.pix.sizeimage), &cam->dummy_frame.paddress, GFP_DMA | GFP_KERNEL); if (cam->dummy_frame.vaddress == 0) { pr_err("ERROR: v4l2 capture: Allocate dummy frame " "failed. "); return -ENOBUFS; } cam->dummy_frame.buffer.type = V4L2_BUF_TYPE_PRIVATE; cam->dummy_frame.buffer.length = PAGE_ALIGN(cam->v2f.fmt.pix.sizeimage); cam->dummy_frame.buffer.m.offset = cam->dummy_frame.paddress; ipu_clear_irq(cam->ipu, irq); err = ipu_request_irq( cam->ipu, irq, csi_enc_callback, 0, "Mxc Camera", cam); if (err != 0) { printk(KERN_ERR "Error registering rot irq "); return err; } err = csi_enc_setup(cam); if (err != 0) { printk(KERN_ERR "csi_enc_setup %d ", err); return err; } return err; }
这个函数与ipu_prp_enc.c中的不同就是首先会根据cam->csi号来选择一个对应的中断号，其他的步骤都是相似的，通过dma_alloc_coherent函数来为cam->dummy_frame.vaddress生成虚拟地址，然后填充这个cam->dummy_frame结构体。之后通过ipu_request_irq函数来为对应的中断号申请中断，同时中断处理函数为csi_enc_callback。之后调用csi_enc_setup函数。 static int csi_enc_setup(cam_data *cam) { ipu_channel_params_t params; u32 pixel_fmt; int err = 0, sensor_protocol = 0; dma_addr_t dummy = cam->dummy_frame.buffer.m.offset; ipu_channel_t chan = (cam->csi == 0) ? CSI_MEM0 : CSI_MEM1; #ifdef CONFIG_MXC_MIPI_CSI2 void *mipi_csi2_info; int ipu_id; int csi_id; #endif CAMERA_TRACE("In csi_enc_setup "); if (!cam) { printk(KERN_ERR "cam private is NULL "); return -ENXIO; } memset(¶ms, 0, sizeof(ipu_channel_params_t)); params.csi_mem.csi = cam->csi; sensor_protocol = ipu_csi_get_sensor_protocol(cam->ipu, cam->csi); switch (sensor_protocol) { case IPU_CSI_CLK_MODE_GATED_CLK: case IPU_CSI_CLK_MODE_NONGATED_CLK: case IPU_CSI_CLK_MODE_CCIR656_PROGRESSIVE: case IPU_CSI_CLK_MODE_CCIR1120_PROGRESSIVE_DDR: case IPU_CSI_CLK_MODE_CCIR1120_PROGRESSIVE_SDR: params.csi_mem.interlaced = false; break; case IPU_CSI_CLK_MODE_CCIR656_INTERLACED: case IPU_CSI_CLK_MODE_CCIR1120_INTERLACED_DDR: case IPU_CSI_CLK_MODE_CCIR1120_INTERLACED_SDR: params.csi_mem.interlaced = true; break; default: printk(KERN_ERR "sensor protocol unsupported "); return -EINVAL; } if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_YUV420) pixel_fmt = IPU_PIX_FMT_YUV420P; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_YVU420) pixel_fmt = IPU_PIX_FMT_YVU420P; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_YUV422P) pixel_fmt = IPU_PIX_FMT_YUV422P; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_UYVY) pixel_fmt = IPU_PIX_FMT_UYVY; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_YUYV) pixel_fmt = IPU_PIX_FMT_YUYV; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_NV12) pixel_fmt = IPU_PIX_FMT_NV12; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_BGR24) pixel_fmt = IPU_PIX_FMT_BGR24; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_RGB24) pixel_fmt = IPU_PIX_FMT_RGB24; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_RGB565) pixel_fmt = IPU_PIX_FMT_RGB565; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_BGR32) pixel_fmt = IPU_PIX_FMT_BGR32; else if (cam->v2f.fmt.pix.pixelformat == V4L2_PIX_FMT_RGB32) pixel_fmt = IPU_PIX_FMT_RGB32; else { printk(KERN_ERR "format not supported "); return -EINVAL; } #ifdef CONFIG_MXC_MIPI_CSI2 mipi_csi2_info = mipi_csi2_get_info(); if (mipi_csi2_info) { if (mipi_csi2_get_status(mipi_csi2_info)) { ipu_id = mipi_csi2_get_bind_ipu(mipi_csi2_info); csi_id = mipi_csi2_get_bind_csi(mipi_csi2_info); if (cam->ipu == ipu_get_soc(ipu_id) && cam->csi == csi_id) { params.csi_mem.mipi_en = true; params.csi_mem.mipi_vc = mipi_csi2_get_virtual_channel(mipi_csi2_info); params.csi_mem.mipi_id = mipi_csi2_get_datatype(mipi_csi2_info); mipi_csi2_pixelclk_enable(mipi_csi2_info); } else { params.csi_mem.mipi_en = false; params.csi_mem.mipi_vc = 0; params.csi_mem.mipi_id = 0; } } else { params.csi_mem.mipi_en = false; params.csi_mem.mipi_vc = 0; params.csi_mem.mipi_id = 0; } } #endif err = ipu_init_channel(cam->ipu, chan, ¶ms); if (err != 0) { printk(KERN_ERR "ipu_init_channel %d ", err); return err; } err = ipu_init_channel_buffer(cam->ipu, chan, IPU_OUTPUT_BUFFER, pixel_fmt, cam->v2f.fmt.pix.width, cam->v2f.fmt.pix.height, cam->v2f.fmt.pix.bytesperline, IPU_ROTATE_NONE, dummy, dummy, 0, cam->offset.u_offset, cam->offset.v_offset); if (err != 0) { printk(KERN_ERR "CSI_MEM output buffer "); return err; } err = ipu_enable_channel(cam->ipu, chan); if (err < 0) { printk(KERN_ERR "ipu_enable_channel CSI_MEM "); return err; } return err; }
在这个函数中，我们可以发现，设置的是ipu_channel_params_t联合中的csi_mem结构体。所以，这个文件所对应的channel就是CSI_MEMx。所以重点就是设置ipu_channel_params_t联合中的csi_mem结构体。 之后就是根据这个params参数通过ipu_init_channel函数来初始化channel，之后继续调用ipu_init_channel_buffer来初始化buffer参数。最后调用ipu_enable_channel函数来使能即可。
其他的步骤与ipu_prp_enc.c中基本相似，就不分析了。

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