linux V4L2子系统——v4l2的结构体（3）之v4l2_subdev
2024-05-23 06:06:29
linux V4L2子系统——v4l2的结构体（3）之v4l2_subdev
备注：
1. Kernel版本：5.4
2. 使用工具：Source Insight 4.0
文章目录
- linux V4L2子系统——v4l2的结构体（3）之v4l2_subdev
- 简介
- 定义
- struct v4l2_subdev
- struct v4l2_subdev_ops
- struct v4l2_subdev_core_ops
- struct v4l2_subdev_tuner_ops
- struct v4l2_subdev_audio_ops
- struct v4l2_subdev_video_ops
- struct v4l2_subdev_pad_ops
简介
子设备，负责实现具体的功能。可将其抽象为具体的某一摄像头传感器，如OV7740、OV7251、OV5640等。
每一个子设备驱动都必须有一个 v4l2_subdev 结构体，这个结构体可以作为独立的简单子设备存在，也可以嵌入到更大的结构体（自定义的子设备结构体）里面。通常会有一个由内核设置的低层次结构体（i2c_client，也就是上面说的 i2c 设备），它包含了一些设备数据，要调用 v4l2_set_subdevdata 来设置子设备私有数据指针指向它，这样的话就可以很方便的从 subdev 找到相关的 I2C 设备数据（这个要编程实现的时候才能够了解它的用意）。另外也需要设置低级别结构的私有数据指针指向 v4l2_subdev 结构体，方便从低级别的结构体访问 v4l2_subdev 结构体，达到双向访问的目的，对于 i2c_client 来说，可以用 i2c_set_clientdata 函数来设置，其它的需使用与之相应的函数来完成设置。
定义
struct v4l2_subdev
//源码：include/media/v4l2-subdev.h/* Set this flag if this subdev is a i2c device. */
#define V4L2_SUBDEV_FL_IS_I2C (1U << 0) // 从设备是I2C设备
/* Set this flag if this subdev is a spi device. */
#define V4L2_SUBDEV_FL_IS_SPI (1U << 1) // 从设备是SPI设备
/* Set this flag if this subdev needs a device node. */
#define V4L2_SUBDEV_FL_HAS_DEVNODE (1U << 2) // 从设备需要设备节点
/** Set this flag if this subdev generates events.* Note controls can send events, thus drivers exposing controls* should set this flag.*/
#define V4L2_SUBDEV_FL_HAS_EVENTS (1U << 3) // 从设备会产生事件/*** struct v4l2_subdev - describes a V4L2 sub-device** @entity: pointer to &struct media_entity* @list: List of sub-devices* @owner: The owner is the same as the driver's &struct device owner.* @owner_v4l2_dev: true if the &sd->owner matches the owner of @v4l2_dev->dev* owner. Initialized by v4l2_device_register_subdev().* @flags: subdev flags. Can be:* %V4L2_SUBDEV_FL_IS_I2C - Set this flag if this subdev is a i2c device;* %V4L2_SUBDEV_FL_IS_SPI - Set this flag if this subdev is a spi device;* %V4L2_SUBDEV_FL_HAS_DEVNODE - Set this flag if this subdev needs a* device node;* %V4L2_SUBDEV_FL_HAS_EVENTS - Set this flag if this subdev generates* events.** @v4l2_dev: pointer to struct &v4l2_device* @ops: pointer to struct &v4l2_subdev_ops* @internal_ops: pointer to struct &v4l2_subdev_internal_ops.* Never call these internal ops from within a driver!* @ctrl_handler: The control handler of this subdev. May be NULL.* @name: Name of the sub-device. Please notice that the name must be unique.* @grp_id: can be used to group similar subdevs. Value is driver-specific* @dev_priv: pointer to private data* @host_priv: pointer to private data used by the device where the subdev* is attached.* @devnode: subdev device node* @dev: pointer to the physical device, if any* @fwnode: The fwnode_handle of the subdev, usually the same as* either dev->of_node->fwnode or dev->fwnode (whichever is non-NULL).* @async_list: Links this subdev to a global subdev_list or @notifier->done* list.* @asd: Pointer to respective &struct v4l2_async_subdev.* @notifier: Pointer to the managing notifier.* @subdev_notifier: A sub-device notifier implicitly registered for the sub-* device using v4l2_device_register_sensor_subdev().* @pdata: common part of subdevice platform data** Each instance of a subdev driver should create this struct, either* stand-alone or embedded in a larger struct.** This structure should be initialized by v4l2_subdev_init() or one of* its variants: v4l2_spi_subdev_init(), v4l2_i2c_subdev_init().*/
struct v4l2_subdev {
#if defined(CONFIG_MEDIA_CONTROLLER)struct media_entity entity;
#endifstruct list_head list; // 子设备串联链表struct module *owner; // 属于那个模块，一般指向i2c_lient驱动模块bool owner_v4l2_dev;u32 flags; // 标志位，确定该设备属于那种设备，由V4L2_SUBDEV_FL_IS_XX宏确定// 指向父设备struct v4l2_device *v4l2_dev;// v4l2子设备的操作函数集合const struct v4l2_subdev_ops *ops;// 提供给v4l2框架的操作函数，只有v4l2框架会调用，驱动不使用const struct v4l2_subdev_internal_ops *internal_ops;// subdev控制接口struct v4l2_ctrl_handler *ctrl_handler;// name must be unique// 从设备的名称，必须独一无二char name[V4L2_SUBDEV_NAME_SIZE];// 从设备组的ID，由驱动定义，相似的从设备可以编为一组u32 grp_id;// 从设备私有数据指针，一般指向i2c_client的设备结构体devvoid *dev_priv;// 主设备私有数据指针，一般指向v4l2_device嵌入的结构体void *host_priv;// 指向video设备结构体struct video_device *devnode;// 指向物理设备struct device *dev;struct fwnode_handle *fwnode;// 将所有从设备连接到全局subdev_list链表或notifier->done链表struct list_head async_list;// 指向struct v4l2_async_subdev，用于异步事件struct v4l2_async_subdev *asd;// 指向管理的notifier，用于主设备和从设备的异步关联struct v4l2_async_notifier *notifier;struct v4l2_async_notifier *subdev_notifier;/* common part of subdevice platform data */struct v4l2_subdev_platform_data *pdata;
};
struct v4l2_subdev_ops
//源码：include/media/v4l2-subdev.h
/*** struct v4l2_subdev_ops - Subdev operations** @core: pointer to &struct v4l2_subdev_core_ops. Can be %NULL* @tuner: pointer to &struct v4l2_subdev_tuner_ops. Can be %NULL* @audio: pointer to &struct v4l2_subdev_audio_ops. Can be %NULL* @video: pointer to &struct v4l2_subdev_video_ops. Can be %NULL* @vbi: pointer to &struct v4l2_subdev_vbi_ops. Can be %NULL* @ir: pointer to &struct v4l2_subdev_ir_ops. Can be %NULL* @sensor: pointer to &struct v4l2_subdev_sensor_ops. Can be %NULL* @pad: pointer to &struct v4l2_subdev_pad_ops. Can be %NULL*/
struct v4l2_subdev_ops {//视频设备通用的操作：初始化、加载FW、上电和RESET等const struct v4l2_subdev_core_ops *core;/* 调谐器操作合集 */const struct v4l2_subdev_tuner_ops *tuner;/* 音频操作合集 */const struct v4l2_subdev_audio_ops *audio;//视频设备的特有操作：设置帧率、裁剪图像、开关视频流等const struct v4l2_subdev_video_ops *video; /* 视频操作合集 */const struct v4l2_subdev_vbi_ops *vbi;const struct v4l2_subdev_ir_ops *ir;const struct v4l2_subdev_sensor_ops *sensor;const struct v4l2_subdev_pad_ops *pad;
};
struct v4l2_subdev_core_ops
//源码：include/media/v4l2-subdev.h
/*** struct v4l2_subdev_core_ops - Define core ops callbacks for subdevs** @log_status: callback for VIDIOC_LOG_STATUS() ioctl handler code.** @s_io_pin_config: configure one or more chip I/O pins for chips that* multiplex different internal signal pads out to IO pins. This function* takes a pointer to an array of 'n' pin configuration entries, one for* each pin being configured. This function could be called at times* other than just subdevice initialization.** @init: initialize the sensor registers to some sort of reasonable default* values. Do not use for new drivers and should be removed in existing* drivers.** @load_fw: load firmware.** @reset: generic reset command. The argument selects which subsystems to* reset. Passing 0 will always reset the whole chip. Do not use for new* drivers without discussing this first on the linux-media mailinglist.* There should be no reason normally to reset a device.** @s_gpio: set GPIO pins. Very simple right now, might need to be extended with* a direction argument if needed.** @ioctl: called at the end of ioctl() syscall handler at the V4L2 core.* used to provide support for private ioctls used on the driver.** @compat_ioctl32: called when a 32 bits application uses a 64 bits Kernel,* in order to fix data passed from/to userspace.** @g_register: callback for VIDIOC_DBG_G_REGISTER() ioctl handler code.** @s_register: callback for VIDIOC_DBG_S_REGISTER() ioctl handler code.** @s_power: puts subdevice in power saving mode (on == 0) or normal operation* mode (on == 1).** @interrupt_service_routine: Called by the bridge chip's interrupt service* handler, when an interrupt status has be raised due to this subdev,* so that this subdev can handle the details. It may schedule work to be* performed later. It must not sleep. **Called from an IRQ context**.** @subscribe_event: used by the drivers to request the control framework that* for it to be warned when the value of a control changes.** @unsubscribe_event: remove event subscription from the control framework.*/
struct v4l2_subdev_core_ops {int (*log_status)(struct v4l2_subdev *sd); /* 状态消息 */int (*s_io_pin_config)(struct v4l2_subdev *sd, size_t n,struct v4l2_subdev_io_pin_config *pincfg);int (*init)(struct v4l2_subdev *sd, u32 val); /* 初始化设备 */int (*load_fw)(struct v4l2_subdev *sd); /* 加载firmware */int (*reset)(struct v4l2_subdev *sd, u32 val); /* 重置设备 */int (*s_gpio)(struct v4l2_subdev *sd, u32 val); /* 设置gpio */long (*ioctl)(struct v4l2_subdev *sd, unsigned int cmd, void *arg); /* 处理特殊命令 */
#ifdef CONFIG_COMPATlong (*compat_ioctl32)(struct v4l2_subdev *sd, unsigned int cmd,unsigned long arg);
#endif
#ifdef CONFIG_VIDEO_ADV_DEBUGint (*g_register)(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg); /* 获取寄存器值 */int (*s_register)(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg); /* 设置寄存器值 */
#endifint (*s_power)(struct v4l2_subdev *sd, int on); /* 控制设备上下电 */int (*interrupt_service_routine)(struct v4l2_subdev *sd,u32 status, bool *handled); /* 中断服务函数 */int (*subscribe_event)(struct v4l2_subdev *sd, struct v4l2_fh *fh,struct v4l2_event_subscription *sub);int (*unsubscribe_event)(struct v4l2_subdev *sd, struct v4l2_fh *fh,struct v4l2_event_subscription *sub);
};
struct v4l2_subdev_tuner_ops
//源码：include/media/v4l2-subdev.h
/*** struct v4l2_subdev_tuner_ops - Callbacks used when v4l device was opened* in radio mode.** @standby: puts the tuner in standby mode. It will be woken up* automatically the next time it is used.** @s_radio: callback that switches the tuner to radio mode.* drivers should explicitly call it when a tuner ops should* operate on radio mode, before being able to handle it.* Used on devices that have both AM/FM radio receiver and TV.** @s_frequency: callback for VIDIOC_S_FREQUENCY() ioctl handler code.** @g_frequency: callback for VIDIOC_G_FREQUENCY() ioctl handler code.* freq->type must be filled in. Normally done by video_ioctl2()* or the bridge driver.** @enum_freq_bands: callback for VIDIOC_ENUM_FREQ_BANDS() ioctl handler code.** @g_tuner: callback for VIDIOC_G_TUNER() ioctl handler code.** @s_tuner: callback for VIDIOC_S_TUNER() ioctl handler code. @vt->type must be* filled in. Normally done by video_ioctl2 or the* bridge driver.** @g_modulator: callback for VIDIOC_G_MODULATOR() ioctl handler code.** @s_modulator: callback for VIDIOC_S_MODULATOR() ioctl handler code.** @s_type_addr: sets tuner type and its I2C addr.** @s_config: sets tda9887 specific stuff, like port1, port2 and qss** .. note::** On devices that have both AM/FM and TV, it is up to the driver* to explicitly call s_radio when the tuner should be switched to* radio mode, before handling other &struct v4l2_subdev_tuner_ops* that would require it. An example of such usage is::** static void s_frequency(void *priv, const struct v4l2_frequency *f)* {* ...* if (f.type == V4L2_TUNER_RADIO)* v4l2_device_call_all(v4l2_dev, 0, tuner, s_radio);* ...* v4l2_device_call_all(v4l2_dev, 0, tuner, s_frequency);* }*/
struct v4l2_subdev_tuner_ops {int (*standby)(struct v4l2_subdev *sd); /* 控制standby模式 */int (*s_radio)(struct v4l2_subdev *sd); /* 设置无线设备信息 */int (*s_frequency)(struct v4l2_subdev *sd, const struct v4l2_frequency *freq); /* 设置频率 */int (*g_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq);/* 获取频率 */int (*enum_freq_bands)(struct v4l2_subdev *sd, struct v4l2_frequency_band *band);int (*g_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt); /* 获取调谐器信息 */int (*s_tuner)(struct v4l2_subdev *sd, const struct v4l2_tuner *vt);/* 设置调谐器信息 */int (*g_modulator)(struct v4l2_subdev *sd, struct v4l2_modulator *vm); /* 获取调幅器信息 */int (*s_modulator)(struct v4l2_subdev *sd, const struct v4l2_modulator *vm); /* 设置调幅器信息 */int (*s_type_addr)(struct v4l2_subdev *sd, struct tuner_setup *type); /* 安装调谐器 */int (*s_config)(struct v4l2_subdev *sd, const struct v4l2_priv_tun_config *config); /* 设置配置信息 */
};struct v4l2_subdev_audio_ops
//源码：include/media/v4l2-subdev.h
/*** struct v4l2_subdev_audio_ops - Callbacks used for audio-related settings** @s_clock_freq: set the frequency (in Hz) of the audio clock output.* Used to slave an audio processor to the video decoder, ensuring that* audio and video remain synchronized. Usual values for the frequency* are 48000, 44100 or 32000 Hz. If the frequency is not supported, then* -EINVAL is returned.** @s_i2s_clock_freq: sets I2S speed in bps. This is used to provide a standard* way to select I2S clock used by driving digital audio streams at some* board designs. Usual values for the frequency are 1024000 and 2048000.* If the frequency is not supported, then %-EINVAL is returned.** @s_routing: used to define the input and/or output pins of an audio chip,* and any additional configuration data.* Never attempt to use user-level input IDs (e.g. Composite, S-Video,* Tuner) at this level. An i2c device shouldn't know about whether an* input pin is connected to a Composite connector, become on another* board or platform it might be connected to something else entirely.* The calling driver is responsible for mapping a user-level input to* the right pins on the i2c device.** @s_stream: used to notify the audio code that stream will start or has* stopped.*/
struct v4l2_subdev_audio_ops {int (*s_clock_freq)(struct v4l2_subdev *sd, u32 freq); /* 设置音频设备频率 */int (*s_i2s_clock_freq)(struct v4l2_subdev *sd, u32 freq); /* 设置i2s总线频率 */int (*s_routing)(struct v4l2_subdev *sd, u32 input, u32 output, u32 config); /* 设置音频路由 */int (*s_stream)(struct v4l2_subdev *sd, int enable); /* 控制音频流 */
};struct v4l2_subdev_video_ops
//源码：include/media/v4l2-subdev.h/*** struct v4l2_subdev_video_ops - Callbacks used when v4l device was opened* in video mode.** @s_routing: see s_routing in audio_ops, except this version is for video* devices.** @s_crystal_freq: sets the frequency of the crystal used to generate the* clocks in Hz. An extra flags field allows device specific configuration* regarding clock frequency dividers, etc. If not used, then set flags* to 0. If the frequency is not supported, then -EINVAL is returned.** @g_std: callback for VIDIOC_G_STD() ioctl handler code.** @s_std: callback for VIDIOC_S_STD() ioctl handler code.** @s_std_output: set v4l2_std_id for video OUTPUT devices. This is ignored by* video input devices.** @g_std_output: get current standard for video OUTPUT devices. This is ignored* by video input devices.** @querystd: callback for VIDIOC_QUERYSTD() ioctl handler code.** @g_tvnorms: get &v4l2_std_id with all standards supported by the video* CAPTURE device. This is ignored by video output devices.** @g_tvnorms_output: get v4l2_std_id with all standards supported by the video* OUTPUT device. This is ignored by video capture devices.** @g_input_status: get input status. Same as the status field in the* &struct &v4l2_input** @s_stream: used to notify the driver that a video stream will start or has* stopped.** @g_pixelaspect: callback to return the pixelaspect ratio.** @g_frame_interval: callback for VIDIOC_SUBDEV_G_FRAME_INTERVAL()* ioctl handler code.** @s_frame_interval: callback for VIDIOC_SUBDEV_S_FRAME_INTERVAL()* ioctl handler code.** @s_dv_timings: Set custom dv timings in the sub device. This is used* when sub device is capable of setting detailed timing information* in the hardware to generate/detect the video signal.** @g_dv_timings: Get custom dv timings in the sub device.** @query_dv_timings: callback for VIDIOC_QUERY_DV_TIMINGS() ioctl handler code.** @g_mbus_config: get supported mediabus configurations** @s_mbus_config: set a certain mediabus configuration. This operation is added* for compatibility with soc-camera drivers and should not be used by new* software.** @s_rx_buffer: set a host allocated memory buffer for the subdev. The subdev* can adjust @size to a lower value and must not write more data to the* buffer starting at @data than the original value of @size.*/
struct v4l2_subdev_video_ops {int (*s_routing)(struct v4l2_subdev *sd, u32 input, u32 output, u32 config); /* 设置视频路由 */int (*s_crystal_freq)(struct v4l2_subdev *sd, u32 freq, u32 flags); /* 设置设备频率 */int (*g_std)(struct v4l2_subdev *sd, v4l2_std_id *norm);int (*s_std)(struct v4l2_subdev *sd, v4l2_std_id norm);int (*s_std_output)(struct v4l2_subdev *sd, v4l2_std_id std); /* 设置标准输出 */int (*g_std_output)(struct v4l2_subdev *sd, v4l2_std_id *std); /* 获取标准输出 */int (*querystd)(struct v4l2_subdev *sd, v4l2_std_id *std); /* 查询标准 */int (*g_tvnorms)(struct v4l2_subdev *sd, v4l2_std_id *std);int (*g_tvnorms_output)(struct v4l2_subdev *sd, v4l2_std_id *std);int (*g_input_status)(struct v4l2_subdev *sd, u32 *status); /* 获取输入状态 */int (*s_stream)(struct v4l2_subdev *sd, int enable); /* 设置数据流 */int (*g_pixelaspect)(struct v4l2_subdev *sd, struct v4l2_fract *aspect);// 获取帧间隔参数（帧率）int (*g_frame_interval)(struct v4l2_subdev *sd,struct v4l2_subdev_frame_interval *interval);int (*s_frame_interval)(struct v4l2_subdev *sd,struct v4l2_subdev_frame_interval *interval);int (*s_dv_timings)(struct v4l2_subdev *sd,struct v4l2_dv_timings *timings);int (*g_dv_timings)(struct v4l2_subdev *sd,struct v4l2_dv_timings *timings);int (*query_dv_timings)(struct v4l2_subdev *sd,struct v4l2_dv_timings *timings);// 获取总线配置，对于 MIPI接口，// sensor驱动内若支持不同 lane数配置或者支持 HDR,// 通过这个接口返回当前 sensor 工作模式下的MIPI配置int (*g_mbus_config)(struct v4l2_subdev *sd,struct v4l2_mbus_config *cfg);int (*s_mbus_config)(struct v4l2_subdev *sd,const struct v4l2_mbus_config *cfg);int (*s_rx_buffer)(struct v4l2_subdev *sd, void *buf,unsigned int *size);
};
struct v4l2_subdev_pad_ops
//源码：include/media/v4l2-subdev.h
/*** struct v4l2_subdev_pad_ops - v4l2-subdev pad level operations** @init_cfg: initialize the pad config to default values* @enum_mbus_code: callback for VIDIOC_SUBDEV_ENUM_MBUS_CODE() ioctl handler* code.* @enum_frame_size: callback for VIDIOC_SUBDEV_ENUM_FRAME_SIZE() ioctl handler* code.** @enum_frame_interval: callback for VIDIOC_SUBDEV_ENUM_FRAME_INTERVAL() ioctl* handler code.** @get_fmt: callback for VIDIOC_SUBDEV_G_FMT() ioctl handler code.** @set_fmt: callback for VIDIOC_SUBDEV_S_FMT() ioctl handler code.** @get_selection: callback for VIDIOC_SUBDEV_G_SELECTION() ioctl handler code.** @set_selection: callback for VIDIOC_SUBDEV_S_SELECTION() ioctl handler code.** @get_edid: callback for VIDIOC_SUBDEV_G_EDID() ioctl handler code.** @set_edid: callback for VIDIOC_SUBDEV_S_EDID() ioctl handler code.** @dv_timings_cap: callback for VIDIOC_SUBDEV_DV_TIMINGS_CAP() ioctl handler* code.** @enum_dv_timings: callback for VIDIOC_SUBDEV_ENUM_DV_TIMINGS() ioctl handler* code.** @link_validate: used by the media controller code to check if the links* that belongs to a pipeline can be used for stream.** @get_frame_desc: get the current low level media bus frame parameters.** @set_frame_desc: set the low level media bus frame parameters, @fd array* may be adjusted by the subdev driver to device capabilities.*/
struct v4l2_subdev_pad_ops {int (*init_cfg)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg);// 枚举当前CIS 驱动支持数据格式int (*enum_mbus_code)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_mbus_code_enum *code);// 枚举当前CIS 驱动支持分辨率 int (*enum_frame_size)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_frame_size_enum *fse);// 枚举sensor支持的帧间隔，包含分辨率int (*enum_frame_interval)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_frame_interval_enum *fie);// 枚举当前CIS 驱动支持分辨率 int (*get_fmt)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_format *format);//设置CIS 驱动输出数据格式以及分辨率，务必实现int (*set_fmt)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_format *format);// 配置裁剪参数，isp输入的宽度要求16对齐，高度 8 对齐int (*get_selection)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_selection *sel);int (*set_selection)(struct v4l2_subdev *sd,struct v4l2_subdev_pad_config *cfg,struct v4l2_subdev_selection *sel);int (*get_edid)(struct v4l2_subdev *sd, struct v4l2_edid *edid);int (*set_edid)(struct v4l2_subdev *sd, struct v4l2_edid *edid);int (*dv_timings_cap)(struct v4l2_subdev *sd,struct v4l2_dv_timings_cap *cap);int (*enum_dv_timings)(struct v4l2_subdev *sd,struct v4l2_enum_dv_timings *timings);
#ifdef CONFIG_MEDIA_CONTROLLERint (*link_validate)(struct v4l2_subdev *sd, struct media_link *link,struct v4l2_subdev_format *source_fmt,struct v4l2_subdev_format *sink_fmt);
#endif /* CONFIG_MEDIA_CONTROLLER */int (*get_frame_desc)(struct v4l2_subdev *sd, unsigned int pad,struct v4l2_mbus_frame_desc *fd);int (*set_frame_desc)(struct v4l2_subdev *sd, unsigned int pad,struct v4l2_mbus_frame_desc *fd);
};
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