IMX461，imx6q芯片

imx6q 包含两路ipu ，支持四路csi同时输入，支持四路mipi/csi-2,两路parallel;
ipu0-csi0,ipu1-csi1,是mipi/parallel 复用通道；

可以通过设置图2的寄存器进行切换

设备树中对video channel 配置
v4l2_cap_0 {
compatible = “fsl,imx6q-v4l2-capture”;
ipu_id = <0>;
csi_id = <0>;
mclk_source = <0>;
status = “okay”;
};

v4l2_cap_1 {compatible = "fsl,imx6q-v4l2-capture";ipu_id = <0>;csi_id = <1>;mclk_source = <0>;status = "okay";};v4l2_cap_2 {compatible = "fsl,imx6q-v4l2-capture";ipu_id = <1>;csi_id = <0>;mclk_source = <0>;status = "okay";};v4l2_cap_3 {compatible = "fsl,imx6q-v4l2-capture";ipu_id = <1>;csi_id = <1>;mclk_source = <0>;status = "okay";};

当应用层操作video设备进行图像采集时需要设置
ioctl(fd_capture_v4l, VIDIOC_S_INPUT, &g_input)；

static struct v4l2_input mxc_capture_inputs[MXC_V4L2_CAPTURE_NUM_INPUTS] = {{ .index = 0, .name = "CSI IC MEM", .type = V4L2_INPUT_TYPE_CAMERA, .audioset = 0, .tuner = 0, .std = V4L2_STD_UNKNOWN, .status = 0, },{ .index = 1, .name = "CSI MEM", .type = V4L2_INPUT_TYPE_CAMERA, .audioset = 0, .tuner = 0, .std = V4L2_STD_UNKNOWN, .status = V4L2_IN_ST_NO_POWER, },};

当index设置0 表示图像采集经过ipu IC，index为1 表示camera图像不经过IC

此处的input设置还关系到取景框的设置：
struct v4l2_cropcap cropcap;
struct v4l2_crop crop;
struct v4l2_format fmt;

在mxc_v4l2_capture.c 文件中

static int mxc_v4l2_s_fmt(cam_data *cam, struct v4l2_format *f){int retval = 0;int size = 0;int bytesperline = 0;int *width, *height;pr_debug("In MVC: mxc_v4l2_s_fmtn");switch (f->type) {case V4L2_BUF_TYPE_VIDEO_CAPTURE:pr_debug(" type=V4L2_BUF_TYPE_VIDEO_CAPTUREn");if (!valid_mode(f->fmt.pix.pixelformat)) {pr_err("ERROR: v4l2 capture: mxc_v4l2_s_fmt: format " "not supportedn");return -EINVAL;}/* * Force the capture window resolution to be crop bounds * for CSI MEM input mode. */if (strcmp(mxc_capture_inputs[cam->current_input].name, "CSI MEM") == 0) {f->fmt.pix.width = cam->crop_current.width;f->fmt.pix.height = cam->crop_current.height;}return retval;}

如果设置 input 为 CSI MEM 模式 struct v4l2_format fmt 的 width 和height将无效；
如果input 设置为 CSI IC MEM 模式 struct v4l2_crop crop设置的width和height将无效

注意：

当使用ipu进行图像的采集和显示时，如果设置input为 CSI IC MEM 模式程序将出错，因为采集和显示同时使用到ipu IC硬件将会冲突；input 设置为 CSI MEM 采集和显示正常，，此时只有显示用到ipu IC 硬件；（此问题困扰了我好久） ；