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diff --git a/IMX6ULL/doc_pic/13_V4L2/05_MIPI摄像头驱动程序分析.md b/IMX6ULL/doc_pic/13_V4L2/05_MIPI摄像头驱动程序分析.md
index 16bd487..412154c 100644
--- a/IMX6ULL/doc_pic/13_V4L2/05_MIPI摄像头驱动程序分析.md
+++ b/IMX6ULL/doc_pic/13_V4L2/05_MIPI摄像头驱动程序分析.md
@@ -395,7 +395,692 @@ vi ./device/config/chips/v853/configs/100ask/linux-4.9/sys_partition.fex
 
 
 
+## 4. subdev和media子系统
+
+### 4.1 subdev和media子系统的引入
+
+#### 4.1.1 subdev的引入
+
+##### 1. 简单驱动
+
+对于比较简单的摄像头，我们把它当做一个整体，它的核心就是一个video_device。以前面讲过的虚拟驱动程序为例，它的源码位于如下目录：
+
+![image-20240229155411136](pic/v853/45_virtual_video.png)
+
+这个驱动程序的核心是video_device，如下：
+
+![image-20240229155308464](pic/v853/44_virtual_video.png)
+
+在整个驱动程序中，没有subdev，没有media子系统。
+
+
+
+##### 2. UVC驱动
+
+USB摄像头稍微复杂一点，它的内部有各类Unit或Terminal，如下图所示：
+
+![image-20230725082453370](pic/07_uvc_topology.png)
+
+但是这些Unit或Terminal的独立性不强，并且它们遵守UVC规范，没必要单独为它们编写驱动程序。在UVC驱动程序里，每一个Unit或Terminal都有一个"struct uvc_entity"结构体，每一个"struct uvc_entity"里面也都有一个"struct v4l2_subdev"，如下图所示：
+
+![image-20240229160615863](pic/v853/46_subdev_in_uvc_entity.png)
+
+但是，这些subdev没有什么作用，它们的ops函数都是空的：
+
+![image-20240229160728283](pic/v853/47_ops_of_uvc_subdev.png)
+
+
+
+##### 3. 复杂驱动
+
+下图是使用v853 mipi摄像头时，涉及的内部结构或内部流程：
+
+![](pic/v853/07_media0_entity.png)
+
+内部涉及的模块非常多，这些模块相对独立，有必要单独给这些模块编写驱动程序。
+
+这些模块被抽象为subdev，原因有2：
+
+* 屏蔽硬件操作的细节，有些模块是I2C接口的，有些模块是SPI接口的，它们都被封装为subdev
+* 方便内核使用、APP使用：可以在内核里调用subdev的函数，也可以在用户空间调用subdev的函数：很多厂家不愿意公开ISP的源码，只能在驱动层面提供最简单的subdev，然后通过APP调用subdev的基本读写函数进行复杂的设置。
+
+subdev结构体如下：
+
+![image-20240229111816717](pic/v853/42_subdev_ops.png)
+
+里面有各类ops结构体，比如core、tuner、audio、video等等。编写subdev驱动程序时，核心就是实现各类ops结构体的函数。
+
+以上图中第1个模块gc2053为例，它的代码为"drivers\media\platform\sunxi-vin\modules\sensor\gc2053_mipi.c"，核心结构体如下：
+
+![image-20240229161428666](pic/v853/48_gc2053_ops.png)
+
+#### 4.1.2 media子系统的引入
+
+即使我们给每一个子模块都编写了驱动程序，都构造了subdev，但是它们之间的相互关系怎么表示？如下图：
+
+* 每一个模块都构造了subdev
+* 但是，框图里黑色箭头所表示的关系如何描述？
+  * 比如，从"格式解析"模块出来的数据，到底是输出到"ISP0"还是"ISP1"？用户如何选择？
+  * 当我们指定"格式解析"模块输出的数据格式后，是否也要同步指定ISP0或ISP1模块的输入数据格式？
+
+![image-20240301081736905](pic/v853/49_media_import.png)
+
+这就需要引入media子系统，简化如下：
+
+![image-20240301103416668](pic/v853/50_media_concept.png)
+
+怎么操作上图的各个对象？使用subdev。subdev里含有各个对象的操作函数。
+
+怎么表示上图的各个对象之间的关系？使用media子系统。在media子系统里，
+
+* 每个对象都是一个media_entity
+* media_entity有media_pad，可以认为是端点（不能简单认为是硬件引脚），有source pad（输出数据），sink pad（输入数据）
+* media_entity之间的连接被称为media_link
+* media_link仅仅表示两个media_entity之间的连接，要构成一个完整的数据通道，需要多个系列的连接，这被称为pipeline
+* media子系统的作用就在于管理"拓扑关系"，就是各个对象的连接关系。
+
+
+
+把V853的拓扑图精简一下：
+
+![image-20240226162803343](pic/v853/29_v853_video0.png)
+
+怎么表示上图的各个对象？使用media子系统，media子系统的作用在于管理"拓扑关系"，就是各个对象的连接关系。
+
+怎么操作上图的各个对象？使用subdev。subdev里含有各个对象的操作函数。
+
+
+
+命令示例：
+
+```shell
+media-ctl -v -l '"gc2053_mipi":0->"sunxi_mipi.0":0[1]'
+v4l2-ctl -D -d /dev/v4l-subdev0
+```
+
+
+
+### 4.2 subdev概览与数据结构
+
+#### 4.2.1 实例
+
+以`drivers\media\platform\sunxi-vin\modules\sensor\gc2053_mipi.c`为例：
+
+```c
+sensor_probe
+    /* 分配sensor_info结构体,里面含有v4l2_subdev */
+    struct v4l2_subdev *sd;	
+	struct sensor_info *info;
+
+    info = kzalloc(sizeof(struct sensor_info), GFP_KERNEL);
+	sd = &info->sd;
+
+    cci_dev_probe_helper(sd, client, &sensor_ops, &cci_drv[sensor_dev_id++]);
+		v4l2_i2c_subdev_init(sd, client, sensor_ops);
+			v4l2_subdev_init(sd, ops);
+```
+
+![image-20240302143026115](pic/v853/52_v4l2_subdev_init.png)
+
+#### 4.2.2 数据结构
+
+一个模块对应一个subdev，怎么操作这个模块？subdev里面有ops：
+
+![image-20240229111816717](pic/v853/42_subdev_ops.png)
+
+
+
+怎么管理多个subdev？必定是放入一个链表里：
+
+![image-20240302144353536](pic/v853/53_v4l2_device.png)
+
+
+
+### 4.3 media子系统概览与数据结构
+
+#### 4.3.1 拓扑结构
+
+对于V853精简的拓扑图：
+
+![image-20240226162803343](pic/v853/29_v853_video0.png)
+
+在media子系统里，怎么表示上面的各个entity的关系？以最左边2个entity为例，结构体如下：
+
+![image-20240301180519100](pic/v853/51_media_topo.png)
+
+
+
+#### 4.3.2 数据结构
+
+一个media子系统使用"struct media_device"来表示，结构体如下：
+
+![image-20240227121132964](pic/v853/37_media_device.png)
+
+media_device里有多个entity，它使用"struct media_entity"来表示：
+
+![image-20240227174116166](pic/v853/38_media_entity.png)
+
+media_entity里有多个pad，它使用"struct media_pad"来表示：
+
+![image-20240227174428532](pic/v853/39_media_pad.png)
+
+entity通过pad跟其他entity相连，这被称为link，它使用"media_link"来表示：
+
+![image-20240227175654194](pic/v853/40_media_link.png)
+
+两个entity之间的连接，被称为link；多个已经使能的link构成一条完整的数据通道，这被称为pipeline。驱动程序在进行streamon操作时，有些驱动会调用"media_entity_pipeline_start"函数，类似下面的代码：
+
+```c
+ret = media_entity_pipeline_start(sensor, camif->m_pipeline);
+```
+
+第1个参数是第1个entity，第2个参数就是pipeline（它在media_entity_pipeline_start函数内部构造）。
+
+media_entity_pipeline_start的目的，是从第1个entity开始，遍历所有的link，把已经使能的link都执行"link_validate"。
+
+media_entity_pipeline_start内部，是按照深度优先来操作entity的，以下图为例：
+
+* 有两条pipeline：e0->e1->e2->e3，e0->e1->e4->e5
+* 先遍历e0->e1->e2->e3这条pipeline，调用e3、e2的"link_validate"
+* 再遍历e0->e1->e4->e5这条pipeline，调用e5、e4的"link_validate"
+* 接着处理e1，调用它的"link_validate"
+* 最后处理e0，它没有sink pad，无需调用它的"link_validate"
+
+![image-20240228154108145](pic/v853/41_pipeline_start.png)
 
 
 
 
+
+#### 4.3.3 media子系统和subdev的关系
+
+内核空间，v4l2_subdev里含有media_entity，两者都很容易找到对方：
+
+![image-20240229150632621](pic/v853/43_entity_subdev.png)
+
+从entity找到subdev，使用以下代码：
+
+```shell
+#define media_entity_to_v4l2_subdev(ent) \
+	container_of(ent, struct v4l2_subdev, entity)
+```
+
+
+
+用户空间里，怎么从entity找到对应的/dev/v4l-subdevX？参考`v4l-utils-1.20.0\utils\media-ctl\libmediactl.c`
+
+```c
+// 1. open /dev/media0
+media->fd = open(media->devnode, O_RDWR);
+
+// 2.循环调用ioctl(MEDIA_IOC_ENUM_ENTITIES), 得到每一个entity的信息
+entity = &media->entities[media->entities_count];
+memset(entity, 0, sizeof(*entity));
+entity->fd = -1;
+entity->info.id = id | MEDIA_ENT_ID_FLAG_NEXT;
+entity->media = media;
+
+// entity->info类型为: struct media_entity_desc info; 
+// 里面含有major, minor
+ret = ioctl(media->fd, MEDIA_IOC_ENUM_ENTITIES, &entity->info);
+
+
+// 3. 使用media_get_devname_sysfs函数获得entity对应的设备节点
+// 根据主设备号、次设备号在/sys/dev/char目录下找到类似这样的文件: /sys/dev/char/81:2
+// 它是一个连接文件,连接到：../../devices/platform/soc/5800800.vind/video4linux/v4l-subdev0
+// /dev/v4l-subdev0就是这个entity对应的设备节点
+// APP的media_entity.devname[32]里就是"/dev/v4l-subdev0"
+static int media_get_devname_sysfs(struct media_entity *entity);
+```
+
+
+
+### 4.4 subdev的注册与使用
+
+#### 4.4.1 内核注册过程
+
+subdev里含有模块的操作函数，谁调用这些函数？
+
+* 内核调用：subdev完全可以不暴露给用户，在摄像头驱动程序内部"偷偷地"调用subdev的函数，用户感觉不到subdev的存在。
+* APP调用：对于比较复杂的硬件，驱动程序应该"让用户有办法调节各类参数"，比如ISP模块几乎都是闭源的，对它的设置只能通过APP进行。这类subdev的函数，应该暴露给用户，用户可以调用它们。
+
+在内核里，subdev的注册过程为分为2步：
+
+* v4l2_device_register_subdev: 把subdev放入v4l2_device的链表
+
+  ```c
+  int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
+  				struct v4l2_subdev *sd);
+  ```
+
+* v4l2_device_register_subdev_nodes：遍历v4l2_device链表里各个subdev，如果它想暴露给APP，就把它注册为普通字符设备
+
+  ```c
+  int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev);
+  
+  // 调用过程如下
+  v4l2_device_register_subdev_nodes
+  	struct video_device *vdev;
+  	vdev->fops = &v4l2_subdev_fops;
+  	err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
+  					      sd->owner);
+  		name_base = "v4l-subdev";
+  		vdev->cdev->ops = &v4l2_fops;
+  		ret = cdev_add(vdev->cdev, MKDEV(VIDEO_MAJOR, vdev->minor), 1);
+  ```
+
+  
+
+v4l2_device_register_subdev_nodes的注册过程涉及2个结构体：
+
+* file_operations：
+  ![image-20240226145649608](pic/v853/25_v4l2_fops.png)
+
+* v4l2_file_operations：
+  ![image-20240226145739108](pic/v853/26_subdev_fops.png)
+
+
+
+APP对/dev/v4l-subdev*这类的设备进行ioctl操作时，内核里流程如下：
+
+```shell
+App:   ioctl
+--------------
+kernel: 
+v4l2_fops.unlocked_ioctl, 即v4l2_ioctl
+	ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
+		v4l2_subdev_fops.unlocked_ioctl, 即subdev_ioctl
+			video_usercopy(file, cmd, arg, subdev_do_ioctl);
+```
+
+![image-20240226150254845](pic/v853/27_subdev_do_ioctl.png)
+
+
+
+#### 4.4.2 内核态使用subdev
+
+可以直接调用subdev里的操作函数，也可以使用下面的宏：
+
+```c
+#define v4l2_subdev_call(sd, o, f, args...)				\
+	(!(sd) ? -ENODEV : (((sd)->ops->o && (sd)->ops->o->f) ?	\
+		(sd)->ops->o->f((sd), ##args) : -ENOIOCTLCMD))
+```
+
+
+
+#### 4.4.3 用户态使用subdev
+
+APP可以打开设备文件/dev/v4l-subdevX，执行ioctl调用驱动里面的各个ops函数，调用关系如下：
+
+##### 1. v4l2_subdev_core_ops
+
+* VIDIOC_SUBSCRIBE_EVENT：APP订阅感兴趣的事件，导致core->subscribe_event被调用
+* VIDIOC_UNSUBSCRIBE_EVENT：APP取消兴趣，导致core->unsubscribe_event被调用
+* VIDIOC_DBG_G_REGISTER：调试作用，读寄存器，导致core->g_register被调用
+* VIDIOC_DBG_S_REGISTER：调试作用，写寄存器，导致core->s_register被调用
+* VIDIOC_LOG_STATUS：调试作用，打印调试信息，导致core->log_status被调用
+
+##### 2. v4l2_subdev_video_ops
+
+* VIDIOC_SUBDEV_G_FRAME_INTERVAL：获得帧间隔，导致video->g_frame_interval被调用
+* VIDIOC_SUBDEV_S_FRAME_INTERVAL：设置帧间隔，导致video->s_frame_interval被调用
+* VIDIOC_SUBDEV_QUERY_DV_TIMINGS：导致video->query_dv_timings被调用
+* VIDIOC_SUBDEV_G_DV_TIMINGS：导致video->g_dv_timings被调用
+* VIDIOC_SUBDEV_S_DV_TIMINGS：导致video->s_dv_timings被调用
+
+
+
+##### 3. v4l2_subdev_pad_ops
+
+* VIDIOC_SUBDEV_G_FMT：导致pad->get_fmt被调用
+* VIDIOC_SUBDEV_S_FMT：导致pad->set_fmt被调用
+* VIDIOC_SUBDEV_G_CROP/VIDIOC_SUBDEV_G_SELECTION：导致pad->get_selection被调用
+* VIDIOC_SUBDEV_S_CROP/VIDIOC_SUBDEV_S_SELECTION：导致pad->set_selection被调用
+* VIDIOC_SUBDEV_ENUM_MBUS_CODE：导致pad->enum_mbus_code被调用
+* VIDIOC_SUBDEV_ENUM_FRAME_SIZE：导致pad->enum_frame_size被调用
+* VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL：导致pad->enum_frame_interval被调用
+* VIDIOC_G_EDID：导致pad->get_edid被调用
+* VIDIOC_S_EDID：导致pad->set_edid被调用
+* VIDIOC_SUBDEV_DV_TIMINGS_CAP：导致pad->dv_timings_cap被调用
+* VIDIOC_SUBDEV_ENUM_DV_TIMINGS：导致pad->enum_dv_timings被调用
+
+驱动内部调用：
+
+* v4l2_subdev_link_validate：导致pad->link_validate被调用
+* v4l2_subdev_alloc_pad_config：导致pad->init_cfg被调用
+
+
+
+### 4.5 media子系统的注册与使用
+
+#### 4.5.1 内核注册过程
+
+在内核里，media子系统的注册过程为：
+
+```shell
+media_device_register
+	__media_device_register
+		struct media_devnode *devnode;
+		devnode->fops = &media_device_fops;
+		ret = media_devnode_register(mdev, devnode, owner);
+        	cdev_init(&devnode->cdev, &media_devnode_fops);
+        	ret = cdev_add(&devnode->cdev, MKDEV(MAJOR(media_dev_t), devnode->minor), 1);
+```
+
+上述注册过程涉及2个结构体：
+
+* file_operations：
+  ![image-20240226120253801](pic/v853/17_media_file_ops.png)
+
+* media_file_operations：
+  ![image-20240226120400612](pic/v853/18_media_device_fops.png)
+
+
+
+APP对/dev/media0这类的设备进行ioctl操作时，内核里流程如下：
+
+```shell
+App:   ioctl
+--------------
+kernel: 
+media_devnode_fops.unlocked_ioctl, 即media_ioctl
+	__media_ioctl(filp, cmd, arg, devnode->fops->ioctl);
+		media_device_ioctl
+			const struct media_ioctl_info *info;
+			info = &ioctl_info[_IOC_NR(cmd)];
+			ret = info->arg_from_user(karg, arg, cmd);
+			ret = info->fn(dev, karg);
+			ret = info->arg_to_user(arg, karg, cmd);
+```
+
+核心在于ioctl_info：
+
+![image-20240226120856997](pic/v853/19_ioctl_info.png)
+
+
+
+
+
+#### 4.5.2 调用关系
+
+APP使用media子系统时，除了open之外，就只涉及5个ioctl：
+
+* MEDIA_IOC_DEVICE_INFO
+* MEDIA_IOC_ENUM_ENTITIES
+* MEDIA_IOC_ENUM_LINKS
+* MEDIA_IOC_SETUP_LINK
+* MEDIA_IOC_G_TOPOLOGY
+
+这5个ioctl将导致内核中如下函数被调用（drivers\media\media-device.c）：
+
+![image-20240227111537846](pic/v853/30_media_ioctl.png)
+
+
+
+##### 1.MEDIA_IOC_DEVICE_INFO
+
+这个ioctl被用来获得/dev/mediaX的设备信息，设备信息结构体如下
+![image-20240226121103122](pic/v853/20_media_device_info.png)
+
+APP代码如下：
+
+```c
+	memset(&media->info, 0, sizeof(media->info)); // struct media_device_info info;
+	ret = ioctl(media->fd, MEDIA_IOC_DEVICE_INFO, &media->info);
+```
+
+驱动中对应核心代码如下：
+
+![image-20240227112019964](pic/v853/31_media_device_get_info.png)
+
+
+
+##### 2. MEDIA_IOC_ENUM_ENTITIES
+
+这个ioctl被用来获得指定entity的信息，APP参考代码为
+![image-20240226142620054](pic/v853/21_enum_entity.png)
+
+驱动中对应核心代码如下：
+
+![image-20240227112316647](pic/v853/32_media_device_enum_entities.png)
+
+
+
+##### 3. MEDIA_IOC_ENUM_LINKS
+
+这个ioctl被用来枚举enity的link，APP参考代码为
+![image-20240226142751821](pic/v853/22_enum_link.png)
+
+驱动中对应核心代码如下：
+
+![image-20240227114208829](pic/v853/34_media_device_enum_links.png)
+
+
+
+##### 4. MEDIA_IOC_SETUP_LINK
+
+这个ioctl被用来设置link，把源pad、目的pad之间的连接激活（active），或者闲置（inactive），APP示例代码为：
+![image-20240226142927131](pic/v853/23_setup_link.png)
+
+APP传入的flags的取值有2种：
+
+* 0：闲置link
+* 1：激活link
+
+内核里link的flag有如下取值：
+
+![image-20240227112910542](pic/v853/33_media_link_flag.png)
+
+如果这个link的flag不是MEDIA_LINK_FL_IMMUTABLE的话，就可以去更改它的bit0状态：激活或闲置。
+
+
+
+驱动中对应核心代码如下：
+
+![image-20240227115855695](pic/v853/35_media_device_setup_link.png)
+
+##### 5. MEDIA_IOC_G_TOPOLOGY
+
+这个ioctl被用来获得整体的拓扑图，包括entities、interfaces、pads、links的信息，示例代码如下
+
+![image-20240226144452444](pic/v853/24_get_topology.png)
+
+驱动中对应核心代码如下，只要APP提供了对应的buffer，它就可以复制对应的信息，比如entities、interfaces、pads、links的信息：
+
+![image-20240227120707559](pic/v853/36_media_device_get_topology.png)
+
+* 
+
+### 4.6 v4l2-utils使用详解
+
+v4l2-utils中含有多个APP，比如：
+
+- [DVBv5_Tools](https://www.linuxtv.org/wiki/index.php/DVBv5_Tools): tools to scan, zap and do other neat things with DVB devices;
+- ir-keytable: Dump, Load or Modify ir receiver input tables;
+- ir-ctl: A swiss-knife tool to handle raw IR and to set lirc options;
+- media-ctl: Tool to handle media controller devices;
+- qv4l2: QT v4l2 control panel application;
+- v4l2-compliance: Tool to test v4l2 API compliance of drivers;
+- v4l2-ctl: tool to control v4l2 controls from the cmdline;
+- v4l2-dbg: tool to directly get and set registers of v4l2 devices;
+- v4l2-sysfs-path: checks the media devices installed on a machine and the corresponding device nodes;
+- xc3028-firmware: Xceive XC2028/3028 tuner module firmware manipulation tool;
+- cx18-ctl: tool to handle cx18 based devices (deprecated in favor of v4l2-ctl);
+- ivtv-ctl: tool to handle ivtv based devices (deprecated in favor of v4l2-ctl);
+- rds-ctl: tool to handle RDS radio devices;
+- decode_tm6000: ancillary tool to decodes tm6000 proprietary format streams;
+- cec-ctl: tool to control CEC devices from the command line;
+- cec-follower: tool used to emulate CEC followers;
+- cec-compliance: tool to test CEC API compliance of drivers and remote CEC devices;
+
+
+
+media-ctl使用方法为：
+
+```shell
+media-ctl --help
+media-ctl [options]
+-d, --device dev        Media device name (default: /dev/media0)
+                        If <dev> starts with a digit, then /dev/media<dev> is used.
+                        If <dev> doesn't exist, then find a media device that
+                        reports a bus info string equal to <dev>.
+-e, --entity name       Print the device name associated with the given entity
+-V, --set-v4l2 v4l2     Comma-separated list of formats to setup
+    --get-v4l2 pad      Print the active format on a given pad
+    --get-dv pad        Print detected and current DV timings on a given pad
+    --set-dv pad        Configure DV timings on a given pad
+-h, --help              Show verbose help and exit
+-i, --interactive       Modify links interactively
+-l, --links links       Comma-separated list of link descriptors to setup
+    --known-mbus-fmts   List known media bus formats and their numeric values
+-p, --print-topology    Print the device topology. If an entity
+                        is specified through the -e option, print
+                        information for that entity only.
+    --print-dot         Print the device topology as a dot graph
+-r, --reset             Reset all links to inactive
+-v, --verbose           Be verbose
+
+Links and formats are defined as
+        links           = link { ',' link } ;
+        link            = pad '->' pad '[' flags ']' ;
+        pad             = entity ':' pad-number ;
+        entity          = entity-number | ( '"' entity-name '"' ) ;
+
+        v4l2            = pad '[' v4l2-properties ']' ;
+        v4l2-properties = v4l2-property { ',' v4l2-property } ;
+        v4l2-property   = v4l2-mbusfmt | v4l2-crop | v4l2-interval
+                        | v4l2-compose | v4l2-interval ;
+        v4l2-mbusfmt    = 'fmt:' fcc '/' size ; { 'field:' v4l2-field ; } { 'colorspace:' v4l2-colorspace ; }
+                           { 'xfer:' v4l2-xfer-func ; } { 'ycbcr-enc:' v4l2-ycbcr-enc-func ; }
+                           { 'quantization:' v4l2-quant ; }
+        v4l2-crop       = 'crop:' rectangle ;
+        v4l2-compose    = 'compose:' rectangle ;
+        v4l2-interval   = '@' numerator '/' denominator ;
+
+        rectangle       = '(' left ',' top, ')' '/' size ;
+        size            = width 'x' height ;
+
+where the fields are
+        entity-number   Entity numeric identifier
+        entity-name     Entity name (string)
+        pad-number      Pad numeric identifier
+        flags           Link flags (0: inactive, 1: active)
+        fcc             Format FourCC
+        width           Image width in pixels
+        height          Image height in pixels
+        numerator       Frame interval numerator
+        denominator     Frame interval denominator
+        v4l2-field      One of the following:
+                        any
+                        none
+                        top
+                        bottom
+                        interlaced
+                        seq-tb
+                        seq-bt
+                        alternate
+                        interlaced-tb
+                        interlaced-bt
+        v4l2-colorspace One of the following:
+                        default
+                        smpte170m
+                        smpte240m
+                        rec709
+                        unknown
+                        470m
+                        470bg
+                        jpeg
+                        srgb
+                        oprgb
+                        bt2020
+                        raw
+                        dcip3
+        v4l2-xfer-func  One of the following:
+                        default
+                        709
+                        srgb
+                        oprgb
+                        smpte240m
+                        none
+                        dcip3
+                        smpte2084
+        v4l2-quant      One of the following:
+                        default
+                        full-range
+                        lim-range
+```
+
+
+
+v4l2-ctl使用方法如下：
+
+```shell
+v4l2-ctl --help
+
+General/Common options:
+  --all              display all information available
+  -C, --get-ctrl <ctrl>[,<ctrl>...]
+                     get the value of the controls [VIDIOC_G_EXT_CTRLS]
+  -c, --set-ctrl <ctrl>=<val>[,<ctrl>=<val>...]
+                     set the value of the controls [VIDIOC_S_EXT_CTRLS]
+  -D, --info         show driver info [VIDIOC_QUERYCAP]
+  -d, --device <dev> use device <dev> instead of /dev/video0
+                     if <dev> starts with a digit, then /dev/video<dev> is used
+                     Otherwise if -z was specified earlier, then <dev> is the entity name
+                     or interface ID (if prefixed with 0x) as found in the topology of the
+                     media device with the bus info string as specified by the -z option.
+  -e, --out-device <dev> use device <dev> for output streams instead of the
+                     default device as set with --device
+                     if <dev> starts with a digit, then /dev/video<dev> is used
+                     Otherwise if -z was specified earlier, then <dev> is the entity name
+                     or interface ID (if prefixed with 0x) as found in the topology of the
+                     media device with the bus info string as specified by the -z option.
+  -E, --export-device <dev> use device <dev> for exporting DMA buffers
+                     if <dev> starts with a digit, then /dev/video<dev> is used
+                     Otherwise if -z was specified earlier, then <dev> is the entity name
+                     or interface ID (if prefixed with 0x) as found in the topology of the
+                     media device with the bus info string as specified by the -z option.
+  -z, --media-bus-info <bus-info>
+                     find the media device with the given bus info string. If set, then
+                     -d, -e and -E options can use the entity name or interface ID to refer
+                     to the device nodes.
+  -h, --help         display this help message
+  --help-all         all options
+  --help-io          input/output options
+  --help-meta        metadata format options
+  --help-misc        miscellaneous options
+  --help-overlay     overlay format options
+  --help-sdr         SDR format options
+  --help-selection   crop/selection options
+  --help-stds        standards and other video timings options
+  --help-streaming   streaming options
+  --help-subdev      sub-device options
+  --help-tuner       tuner/modulator options
+  --help-vbi         VBI format options
+  --help-vidcap      video capture format options
+  --help-vidout      vidout output format options
+  --help-edid        edid handling options
+  -k, --concise      be more concise if possible.
+  -l, --list-ctrls   display all controls and their values [VIDIOC_QUERYCTRL]
+  -L, --list-ctrls-menus
+                     display all controls and their menus [VIDIOC_QUERYMENU]
+  -r, --subset <ctrl>[,<offset>,<size>]+
+                     the subset of the N-dimensional array to get/set for control <ctrl>,
+                     for every dimension an (<offset>, <size>) tuple is given.
+  -w, --wrapper      use the libv4l2 wrapper library.
+  --list-devices     list all v4l devices. If -z was given, then list just the
+                     devices of the media device with the bus info string as
+                     specified by the -z option.
+  --log-status       log the board status in the kernel log [VIDIOC_LOG_STATUS]
+  --get-priority     query the current access priority [VIDIOC_G_PRIORITY]
+  --set-priority <prio>
+                     set the new access priority [VIDIOC_S_PRIORITY]
+                     <prio> is 1 (background), 2 (interactive) or 3 (record)
+  --silent           only set the result code, do not print any messages
+  --sleep <secs>     sleep <secs>, call QUERYCAP and close the file handle
+  --verbose          turn on verbose ioctl status reporting
+```
+
+
+
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diff --git a/IMX6ULL/doc_pic/13_V4L2/pic/v853/51_media_topo.png b/IMX6ULL/doc_pic/13_V4L2/pic/v853/51_media_topo.png
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diff --git a/IMX6ULL/doc_pic/13_V4L2/pic/v853/52_v4l2_subdev_init.png b/IMX6ULL/doc_pic/13_V4L2/pic/v853/52_v4l2_subdev_init.png
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diff --git a/IMX6ULL/doc_pic/13_V4L2/pic/v853/53_v4l2_device.png b/IMX6ULL/doc_pic/13_V4L2/pic/v853/53_v4l2_device.png
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diff --git a/IMX6ULL/doc_pic/13_V4L2/笔记.md b/IMX6ULL/doc_pic/13_V4L2/笔记.md
index b719236..a882ce9 100644
--- a/IMX6ULL/doc_pic/13_V4L2/笔记.md
+++ b/IMX6ULL/doc_pic/13_V4L2/笔记.md
@@ -1113,6 +1113,17 @@ vin_md_register_core_entity
 
 
 
+设备树里vinc@0,4,8,12的status都是okay，但是vinc@4,8里：
+
+```shell
+vinc4_rear_sensor_sel = <1>;
+vinc8_rear_sensor_sel = <1>;
+```
+
+并没有sensor 1，所以没有创建出对应的subdev，没有创建出对应的/dev/video4,8
+
+
+
 ### 10.8 vin_video0
 
 drivers/media/platform/sunxi-vin/vin-video/vin_video.c
@@ -1120,8 +1131,7 @@ drivers/media/platform/sunxi-vin/vin-video/vin_video.c
 ![image-20240220185958332](pic/v853/13_vin_cap_internal_ops.png)
 
 ```shell
-vin_capture_subdev_registered
-	if (vin_init_video(sd->v4l2_dev, &vinc->vid_cap)) 
+vin_init_video
         snprintf(cap->vdev.name, sizeof(cap->vdev.name),
             "vin_video%d", cap->vinc->id);
         cap->vdev.fops = &vin_fops;
@@ -1156,3 +1166,6 @@ sd->internal_ops何时被调用？
 
 
 
+## 12. 其他
+
+v4l2-event：自定义事件调试 https://blog.csdn.net/qq_34341546/article/details/131329503
\ No newline at end of file
diff --git a/README.md b/README.md
index e4ca450..fb39f6c 100644
--- a/README.md
+++ b/README.md
@@ -853,6 +853,15 @@ git clone https://e.coding.net/weidongshan/linux/doc_and_source_for_drivers.git
   [05-2-3]_搭建V853开发环境_自制单板系统
   ```
 
+* 2024.03.02 发布"摄像头驱动"
+
+  ```shell
+  [05-3-1]_subdev和media子系统的引入
+  [05-3-2]_subdev概览与数据结构
+  [05-3-3]_media子系统概览与数据结构
+  [05-3-4]_subdev的注册
+  ```
+