/* SPDX-License-Identifier: GPL-2.0-or-later */

  /*

   *  V4L2 sub-device support header.
   *
   *  Copyright (C) 2008  Hans Verkuil <hverkuil@xs4all.nl>

   */
  
  #ifndef _V4L2_SUBDEV_H
  #define _V4L2_SUBDEV_H

  #include <linux/types.h>

  #include <linux/v4l2-subdev.h>

  #include <media/media-entity.h>

  #include <media/v4l2-async.h>

  #include <media/v4l2-common.h>

  #include <media/v4l2-dev.h>

  #include <media/v4l2-fh.h>

  #include <media/v4l2-mediabus.h>

  /* generic v4l2_device notify callback notification values */
  #define V4L2_SUBDEV_IR_RX_NOTIFY		_IOW('v', 0, u32)
  #define V4L2_SUBDEV_IR_RX_FIFO_SERVICE_REQ	0x00000001
  #define V4L2_SUBDEV_IR_RX_END_OF_RX_DETECTED	0x00000002
  #define V4L2_SUBDEV_IR_RX_HW_FIFO_OVERRUN	0x00000004
  #define V4L2_SUBDEV_IR_RX_SW_FIFO_OVERRUN	0x00000008
  
  #define V4L2_SUBDEV_IR_TX_NOTIFY		_IOW('v', 1, u32)
  #define V4L2_SUBDEV_IR_TX_FIFO_SERVICE_REQ	0x00000001

  #define	V4L2_DEVICE_NOTIFY_EVENT		_IOW('v', 2, struct v4l2_event)

  struct v4l2_device;

  struct v4l2_ctrl_handler;

  struct v4l2_event;

  struct v4l2_event_subscription;
  struct v4l2_fh;

  struct v4l2_subdev;

  struct v4l2_subdev_fh;

  struct tuner_setup;

  struct v4l2_mbus_frame_desc;

  /**
   * struct v4l2_decode_vbi_line - used to decode_vbi_line
   *
   * @is_second_field: Set to 0 for the first (odd) field;
   *	set to 1 for the second (even) field.
   * @p: Pointer to the sliced VBI data from the decoder. On exit, points to
   *	the start of the payload.
   * @line: Line number of the sliced VBI data (1-23)
   * @type: VBI service type (V4L2_SLICED_*). 0 if no service found
   */

  struct v4l2_decode_vbi_line {

  	u32 is_second_field;
  	u8 *p;
  	u32 line;
  	u32 type;

  };

  /*
   * Sub-devices are devices that are connected somehow to the main bridge
   * device. These devices are usually audio/video muxers/encoders/decoders or
   * sensors and webcam controllers.
   *

   * Usually these devices are controlled through an i2c bus, but other buses

   * may also be used.
   *
   * The v4l2_subdev struct provides a way of accessing these devices in a
   * generic manner. Most operations that these sub-devices support fall in
   * a few categories: core ops, audio ops, video ops and tuner ops.
   *
   * More categories can be added if needed, although this should remain a
   * limited set (no more than approx. 8 categories).
   *
   * Each category has its own set of ops that subdev drivers can implement.
   *
   * A subdev driver can leave the pointer to the category ops NULL if
   * it does not implement them (e.g. an audio subdev will generally not
   * implement the video category ops). The exception is the core category:
   * this must always be present.
   *
   * These ops are all used internally so it is no problem to change, remove
   * or add ops or move ops from one to another category. Currently these
   * ops are based on the original ioctls, but since ops are not limited to
   * one argument there is room for improvement here once all i2c subdev
   * drivers are converted to use these ops.

   */

  /*
   * Core ops: it is highly recommended to implement at least these ops:
   *
   * log_status
   * g_register
   * s_register
   *
   * This provides basic debugging support.
   *
   * The ioctl ops is meant for generic ioctl-like commands. Depending on
   * the use-case it might be better to use subdev-specific ops (currently
   * not yet implemented) since ops provide proper type-checking.

   */

  /**
   * enum v4l2_subdev_io_pin_bits - Subdevice external IO pin configuration
   *	bits
   *
   * @V4L2_SUBDEV_IO_PIN_DISABLE: disables a pin config. ENABLE assumed.
   * @V4L2_SUBDEV_IO_PIN_OUTPUT: set it if pin is an output.
   * @V4L2_SUBDEV_IO_PIN_INPUT: set it if pin is an input.
   * @V4L2_SUBDEV_IO_PIN_SET_VALUE: to set the output value via

   *				  &struct v4l2_subdev_io_pin_config->value.

   * @V4L2_SUBDEV_IO_PIN_ACTIVE_LOW: pin active is bit 0.
   *				   Otherwise, ACTIVE HIGH is assumed.
   */
  enum v4l2_subdev_io_pin_bits {
  	V4L2_SUBDEV_IO_PIN_DISABLE	= 0,
  	V4L2_SUBDEV_IO_PIN_OUTPUT	= 1,
  	V4L2_SUBDEV_IO_PIN_INPUT	= 2,
  	V4L2_SUBDEV_IO_PIN_SET_VALUE	= 3,
  	V4L2_SUBDEV_IO_PIN_ACTIVE_LOW	= 4,
  };

  /**
   * struct v4l2_subdev_io_pin_config - Subdevice external IO pin configuration
   *

   * @flags: bitmask with flags for this pin's config, whose bits are defined by
   *	   &enum v4l2_subdev_io_pin_bits.

   * @pin: Chip external IO pin to configure
   * @function: Internal signal pad/function to route to IO pin
   * @value: Initial value for pin - e.g. GPIO output value
   * @strength: Pin drive strength
   */

  struct v4l2_subdev_io_pin_config {

  	u32 flags;
  	u8 pin;
  	u8 function;
  	u8 value;
  	u8 strength;

  };

  /**

   * 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);

  	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);

  	int (*load_fw)(struct v4l2_subdev *sd);

  	int (*reset)(struct v4l2_subdev *sd, u32 val);
  	int (*s_gpio)(struct v4l2_subdev *sd, u32 val);

  	long (*ioctl)(struct v4l2_subdev *sd, unsigned int cmd, void *arg);

  #ifdef CONFIG_COMPAT
  	long (*compat_ioctl32)(struct v4l2_subdev *sd, unsigned int cmd,
  			       unsigned long arg);
  #endif

  #ifdef CONFIG_VIDEO_ADV_DEBUG

  	int (*g_register)(struct v4l2_subdev *sd, struct v4l2_dbg_register *reg);

  	int (*s_register)(struct v4l2_subdev *sd, const struct v4l2_dbg_register *reg);

  #endif

  	int (*s_power)(struct v4l2_subdev *sd, int on);

  	int (*interrupt_service_routine)(struct v4l2_subdev *sd,
  						u32 status, bool *handled);

  	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 - 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);

  	int (*s_radio)(struct v4l2_subdev *sd);

  	int (*s_frequency)(struct v4l2_subdev *sd, const struct v4l2_frequency *freq);

  	int (*g_frequency)(struct v4l2_subdev *sd, struct v4l2_frequency *freq);

  	int (*enum_freq_bands)(struct v4l2_subdev *sd, struct v4l2_frequency_band *band);

  	int (*g_tuner)(struct v4l2_subdev *sd, struct v4l2_tuner *vt);

  	int (*s_tuner)(struct v4l2_subdev *sd, const struct v4l2_tuner *vt);

  	int (*g_modulator)(struct v4l2_subdev *sd, struct v4l2_modulator *vm);

  	int (*s_modulator)(struct v4l2_subdev *sd, const struct v4l2_modulator *vm);

  	int (*s_type_addr)(struct v4l2_subdev *sd, struct tuner_setup *type);
  	int (*s_config)(struct v4l2_subdev *sd, const struct v4l2_priv_tun_config *config);
  };

  /**
   * 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);
  	int (*s_i2s_clock_freq)(struct v4l2_subdev *sd, u32 freq);

  	int (*s_routing)(struct v4l2_subdev *sd, u32 input, u32 output, u32 config);

  	int (*s_stream)(struct v4l2_subdev *sd, int enable);

  };

  /**
   * enum v4l2_mbus_frame_desc_entry - media bus frame description flags
   *
   * @V4L2_MBUS_FRAME_DESC_FL_LEN_MAX:
   *	Indicates that &struct v4l2_mbus_frame_desc_entry->length field
   *	specifies maximum data length.
   * @V4L2_MBUS_FRAME_DESC_FL_BLOB:
   *	Indicates that the format does not have line offsets, i.e.
   *	the receiver should use 1D DMA.

   */

  enum v4l2_mbus_frame_desc_flags {
  	V4L2_MBUS_FRAME_DESC_FL_LEN_MAX	= BIT(0),
  	V4L2_MBUS_FRAME_DESC_FL_BLOB	= BIT(1),
  };

  
  /**
   * struct v4l2_mbus_frame_desc_entry - media bus frame description structure

   *

   * @flags:	bitmask flags, as defined by &enum v4l2_mbus_frame_desc_flags.
   * @pixelcode:	media bus pixel code, valid if @flags

   *		%FRAME_DESC_FL_BLOB is not set.

   * @length:	number of octets per frame, valid if @flags
   *		%V4L2_MBUS_FRAME_DESC_FL_LEN_MAX is set.

   */
  struct v4l2_mbus_frame_desc_entry {

  	enum v4l2_mbus_frame_desc_flags flags;

  	u32 pixelcode;
  	u32 length;
  };
  
  #define V4L2_FRAME_DESC_ENTRY_MAX	4
  
  /**
   * struct v4l2_mbus_frame_desc - media bus data frame description
   * @entry: frame descriptors array
   * @num_entries: number of entries in @entry array
   */
  struct v4l2_mbus_frame_desc {
  	struct v4l2_mbus_frame_desc_entry entry[V4L2_FRAME_DESC_ENTRY_MAX];
  	unsigned short num_entries;
  };

  /**
   * 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_parm: callback for VIDIOC_G_PARM() ioctl handler code.
   *
   * @s_parm: callback for VIDIOC_S_PARM() ioctl handler code.
   *

   * @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.

   *

   * @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);

  	int (*s_crystal_freq)(struct v4l2_subdev *sd, u32 freq, u32 flags);

  	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);

  	int (*g_std_output)(struct v4l2_subdev *sd, v4l2_std_id *std);

  	int (*querystd)(struct v4l2_subdev *sd, v4l2_std_id *std);

  	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);

  	int (*s_stream)(struct v4l2_subdev *sd, int enable);

  	int (*g_pixelaspect)(struct v4l2_subdev *sd, struct v4l2_fract *aspect);

  	int (*g_parm)(struct v4l2_subdev *sd, struct v4l2_streamparm *param);
  	int (*s_parm)(struct v4l2_subdev *sd, struct v4l2_streamparm *param);

  	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);

  	int (*s_rx_buffer)(struct v4l2_subdev *sd, void *buf,
  			   unsigned int *size);

  };

  /**
   * struct v4l2_subdev_vbi_ops - Callbacks used when v4l device was opened

   *				  in video mode via the vbi device node.

   *
   *  @decode_vbi_line: video decoders that support sliced VBI need to implement

   *	this ioctl. Field p of the &struct v4l2_decode_vbi_line is set to the

   *	start of the VBI data that was generated by the decoder. The driver
   *	then parses the sliced VBI data and sets the other fields in the
   *	struct accordingly. The pointer p is updated to point to the start of
   *	the payload which can be copied verbatim into the data field of the

   *	&struct v4l2_sliced_vbi_data. If no valid VBI data was found, then the

   *	type field is set to 0 on return.
   *
   * @s_vbi_data: used to generate VBI signals on a video signal.

   *	&struct v4l2_sliced_vbi_data is filled with the data packets that
   *	should be output. Note that if you set the line field to 0, then that
   *	VBI signal is disabled. If no valid VBI data was found, then the type
   *	field is set to 0 on return.

   *
   * @g_vbi_data: used to obtain the sliced VBI packet from a readback register.
   *	Not all video decoders support this. If no data is available because

   *	the readback register contains invalid or erroneous data %-EIO is

   *	returned. Note that you must fill in the 'id' member and the 'field'
   *	member (to determine whether CC data from the first or second field
   *	should be obtained).
   *

   * @g_sliced_vbi_cap: callback for VIDIOC_G_SLICED_VBI_CAP() ioctl handler
   *		      code.

   *

   * @s_raw_fmt: setup the video encoder/decoder for raw VBI.
   *
   * @g_sliced_fmt: retrieve the current sliced VBI settings.
   *
   * @s_sliced_fmt: setup the sliced VBI settings.

   */
  struct v4l2_subdev_vbi_ops {
  	int (*decode_vbi_line)(struct v4l2_subdev *sd, struct v4l2_decode_vbi_line *vbi_line);
  	int (*s_vbi_data)(struct v4l2_subdev *sd, const struct v4l2_sliced_vbi_data *vbi_data);
  	int (*g_vbi_data)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_data *vbi_data);
  	int (*g_sliced_vbi_cap)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_cap *cap);

  	int (*s_raw_fmt)(struct v4l2_subdev *sd, struct v4l2_vbi_format *fmt);
  	int (*g_sliced_fmt)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_format *fmt);
  	int (*s_sliced_fmt)(struct v4l2_subdev *sd, struct v4l2_sliced_vbi_format *fmt);

  };

  /**
   * struct v4l2_subdev_sensor_ops - v4l2-subdev sensor operations
   * @g_skip_top_lines: number of lines at the top of the image to be skipped.
   *		      This is needed for some sensors, which always corrupt
   *		      several top lines of the output image, or which send their
   *		      metadata in them.

   * @g_skip_frames: number of frames to skip at stream start. This is needed for
   *		   buggy sensors that generate faulty frames when they are
   *		   turned on.

   */
  struct v4l2_subdev_sensor_ops {
  	int (*g_skip_top_lines)(struct v4l2_subdev *sd, u32 *lines);

  	int (*g_skip_frames)(struct v4l2_subdev *sd, u32 *frames);

  };

  /**
   * enum v4l2_subdev_ir_mode- describes the type of IR supported
   *
   * @V4L2_SUBDEV_IR_MODE_PULSE_WIDTH: IR uses struct ir_raw_event records

   */

  enum v4l2_subdev_ir_mode {

  	V4L2_SUBDEV_IR_MODE_PULSE_WIDTH,

  };

  /**
   * struct v4l2_subdev_ir_parameters - Parameters for IR TX or TX
   *
   * @bytes_per_data_element: bytes per data element of data in read or
   *	write call.
   * @mode: IR mode as defined by &enum v4l2_subdev_ir_mode.
   * @enable: device is active if true
   * @interrupt_enable: IR interrupts are enabled if true
   * @shutdown: if true: set hardware to low/no power, false: normal mode
   *
   * @modulation: if true, it uses carrier, if false: baseband
   * @max_pulse_width:  maximum pulse width in ns, valid only for baseband signal
   * @carrier_freq: carrier frequency in Hz, valid only for modulated signal
   * @duty_cycle: duty cycle percentage, valid only for modulated signal
   * @invert_level: invert signal level
   *
   * @invert_carrier_sense: Send 0/space as a carrier burst. used only in TX.
   *
   * @noise_filter_min_width: min time of a valid pulse, in ns. Used only for RX.
   * @carrier_range_lower: Lower carrier range, in Hz, valid only for modulated
   *	signal. Used only for RX.
   * @carrier_range_upper: Upper carrier range, in Hz, valid only for modulated
   *	signal. Used only for RX.
   * @resolution: The receive resolution, in ns . Used only for RX.
   */

  struct v4l2_subdev_ir_parameters {

  	unsigned int bytes_per_data_element;

  	enum v4l2_subdev_ir_mode mode;
  
  	bool enable;
  	bool interrupt_enable;

  	bool shutdown;

  	bool modulation;
  	u32 max_pulse_width;
  	unsigned int carrier_freq;
  	unsigned int duty_cycle;
  	bool invert_level;

  
  	/* Tx only */

  	bool invert_carrier_sense;

  
  	/* Rx only */

  	u32 noise_filter_min_width;
  	unsigned int carrier_range_lower;
  	unsigned int carrier_range_upper;
  	u32 resolution;

  };

  /**
   * struct v4l2_subdev_ir_ops - operations for IR subdevices
   *
   * @rx_read: Reads received codes or pulse width data.
   *	The semantics are similar to a non-blocking read() call.

   * @rx_g_parameters: Get the current operating parameters and state of

   *	the IR receiver.

   * @rx_s_parameters: Set the current operating parameters and state of

   *	the IR receiver.  It is recommended to call
   *	[rt]x_g_parameters first to fill out the current state, and only change
   *	the fields that need to be changed.  Upon return, the actual device
   *	operating parameters and state will be returned.  Note that hardware
   *	limitations may prevent the actual settings from matching the requested
   *	settings - e.g. an actual carrier setting of 35,904 Hz when 36,000 Hz
   *	was requested.  An exception is when the shutdown parameter is true.
   *	The last used operational parameters will be returned, but the actual
   *	state of the hardware be different to minimize power consumption and
   *	processing when shutdown is true.
   *
   * @tx_write: Writes codes or pulse width data for transmission.
   *	The semantics are similar to a non-blocking write() call.

   * @tx_g_parameters: Get the current operating parameters and state of

   *	the IR transmitter.

   * @tx_s_parameters: Set the current operating parameters and state of

   *	the IR transmitter.  It is recommended to call
   *	[rt]x_g_parameters first to fill out the current state, and only change
   *	the fields that need to be changed.  Upon return, the actual device
   *	operating parameters and state will be returned.  Note that hardware
   *	limitations may prevent the actual settings from matching the requested
   *	settings - e.g. an actual carrier setting of 35,904 Hz when 36,000 Hz
   *	was requested.  An exception is when the shutdown parameter is true.
   *	The last used operational parameters will be returned, but the actual
   *	state of the hardware be different to minimize power consumption and
   *	processing when shutdown is true.
   */

  struct v4l2_subdev_ir_ops {

  	/* Receiver */
  	int (*rx_read)(struct v4l2_subdev *sd, u8 *buf, size_t count,
  				ssize_t *num);
  
  	int (*rx_g_parameters)(struct v4l2_subdev *sd,
  				struct v4l2_subdev_ir_parameters *params);
  	int (*rx_s_parameters)(struct v4l2_subdev *sd,
  				struct v4l2_subdev_ir_parameters *params);
  
  	/* Transmitter */
  	int (*tx_write)(struct v4l2_subdev *sd, u8 *buf, size_t count,
  				ssize_t *num);
  
  	int (*tx_g_parameters)(struct v4l2_subdev *sd,
  				struct v4l2_subdev_ir_parameters *params);
  	int (*tx_s_parameters)(struct v4l2_subdev *sd,
  				struct v4l2_subdev_ir_parameters *params);
  };

  /**
   * struct v4l2_subdev_pad_config - Used for storing subdev pad information.
   *

   * @try_fmt: &struct v4l2_mbus_framefmt
   * @try_crop: &struct v4l2_rect to be used for crop
   * @try_compose: &struct v4l2_rect to be used for compose

   *
   * This structure only needs to be passed to the pad op if the 'which' field
   * of the main argument is set to %V4L2_SUBDEV_FORMAT_TRY. For
   * %V4L2_SUBDEV_FORMAT_ACTIVE it is safe to pass %NULL.

   */
  struct v4l2_subdev_pad_config {
  	struct v4l2_mbus_framefmt try_fmt;
  	struct v4l2_rect try_crop;
  	struct v4l2_rect try_compose;
  };

  /**
   * 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.

   *
   * @get_mbus_config: get the media bus configuration of a remote sub-device.
   *		     The media bus configuration is usually retrieved from the
   *		     firmware interface at sub-device probe time, immediately
   *		     applied to the hardware and eventually adjusted by the
   *		     driver. Remote sub-devices (usually video receivers) shall
   *		     use this operation to query the transmitting end bus
   *		     configuration in order to adjust their own one accordingly.
   *		     Callers should make sure they get the most up-to-date as
   *		     possible configuration from the remote end, likely calling
   *		     this operation as close as possible to stream on time. The
   *		     operation shall fail if the pad index it has been called on
   *		     is not valid or in case of unrecoverable failures.
   *
   * @set_mbus_config: set the media bus configuration of a remote sub-device.
   *		     This operations is intended to allow, in combination with
   *		     the get_mbus_config operation, the negotiation of media bus
   *		     configuration parameters between media sub-devices. The
   *		     operation shall not fail if the requested configuration is
   *		     not supported, but the driver shall update the content of
   *		     the %config argument to reflect what has been actually
   *		     applied to the hardware. The operation shall fail if the
   *		     pad index it has been called on is not valid or in case of
   *		     unrecoverable failures.

   */

  struct v4l2_subdev_pad_ops {

  	int (*init_cfg)(struct v4l2_subdev *sd,
  			struct v4l2_subdev_pad_config *cfg);

  	int (*enum_mbus_code)(struct v4l2_subdev *sd,
  			      struct v4l2_subdev_pad_config *cfg,

  			      struct v4l2_subdev_mbus_code_enum *code);
  	int (*enum_frame_size)(struct v4l2_subdev *sd,

  			       struct v4l2_subdev_pad_config *cfg,

  			       struct v4l2_subdev_frame_size_enum *fse);

  	int (*enum_frame_interval)(struct v4l2_subdev *sd,

  				   struct v4l2_subdev_pad_config *cfg,

  				   struct v4l2_subdev_frame_interval_enum *fie);

  	int (*get_fmt)(struct v4l2_subdev *sd,
  		       struct v4l2_subdev_pad_config *cfg,

  		       struct v4l2_subdev_format *format);

  	int (*set_fmt)(struct v4l2_subdev *sd,
  		       struct v4l2_subdev_pad_config *cfg,

  		       struct v4l2_subdev_format *format);

  	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_CONTROLLER
  	int (*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);

  	int (*get_mbus_config)(struct v4l2_subdev *sd, unsigned int pad,
  			       struct v4l2_mbus_config *config);
  	int (*set_mbus_config)(struct v4l2_subdev *sd, unsigned int pad,
  			       struct v4l2_mbus_config *config);

  };

  /**
   * 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 {

  	const struct v4l2_subdev_core_ops	*core;
  	const struct v4l2_subdev_tuner_ops	*tuner;
  	const struct v4l2_subdev_audio_ops	*audio;
  	const struct v4l2_subdev_video_ops	*video;

  	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_internal_ops - V4L2 subdev internal ops

   *

   * @registered: called when this subdev is registered. When called the v4l2_dev

   *	field is set to the correct v4l2_device.
   *

   * @unregistered: called when this subdev is unregistered. When called the

   *	v4l2_dev field is still set to the correct v4l2_device.

   *

   * @open: called when the subdev device node is opened by an application.

   *

   * @close: called when the subdev device node is closed. Please note that
   *	it is possible for @close to be called after @unregistered!
   *
   * @release: called when the last user of the subdev device is gone. This
   *	happens after the @unregistered callback and when the last open
   *	filehandle to the v4l-subdevX device node was closed. If no device
   *	node was created for this sub-device, then the @release callback
   *	is called right after the @unregistered callback.
   *	The @release callback is typically used to free the memory containing
   *	the v4l2_subdev structure. It is almost certainly required for any
   *	sub-device that sets the V4L2_SUBDEV_FL_HAS_DEVNODE flag.

   *
   * .. note::
   *	Never call this from drivers, only the v4l2 framework can call
   *	these ops.

   */
  struct v4l2_subdev_internal_ops {
  	int (*registered)(struct v4l2_subdev *sd);
  	void (*unregistered)(struct v4l2_subdev *sd);

  	int (*open)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh);
  	int (*close)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh);

  	void (*release)(struct v4l2_subdev *sd);

  };

  #define V4L2_SUBDEV_NAME_SIZE 32

  /* Set this flag if this subdev is a i2c device. */

  #define V4L2_SUBDEV_FL_IS_I2C			(1U << 0)

  /* Set this flag if this subdev is a spi device. */

  #define V4L2_SUBDEV_FL_IS_SPI			(1U << 1)
  /* Set this flag if this subdev needs a device node. */
  #define V4L2_SUBDEV_FL_HAS_DEVNODE		(1U << 2)

  /*
   * 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)

  struct regulator_bulk_data;

  /**
   * struct v4l2_subdev_platform_data - regulators config struct
   *
   * @regulators: Optional regulators used to power on/off the subdevice
   * @num_regulators: Number of regululators
   * @host_priv: Per-subdevice data, specific for a certain video host device
   */

  struct v4l2_subdev_platform_data {

  	struct regulator_bulk_data *regulators;
  	int num_regulators;

  	void *host_priv;
  };

  /**
   * 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;
  #endif

  	struct list_head list;
  	struct module *owner;

  	bool owner_v4l2_dev;

  	u32 flags;

  	struct v4l2_device *v4l2_dev;

  	const struct v4l2_subdev_ops *ops;

  	const struct v4l2_subdev_internal_ops *internal_ops;

  	struct v4l2_ctrl_handler *ctrl_handler;

  	char name[V4L2_SUBDEV_NAME_SIZE];

  	u32 grp_id;

  	void *dev_priv;
  	void *host_priv;

  	struct video_device *devnode;

  	struct device *dev;

  	struct fwnode_handle *fwnode;

  	struct list_head async_list;

  	struct v4l2_async_subdev *asd;

  	struct v4l2_async_notifier *notifier;

  	struct v4l2_async_notifier *subdev_notifier;

  	struct v4l2_subdev_platform_data *pdata;

  };

  
  /**
   * media_entity_to_v4l2_subdev - Returns a &struct v4l2_subdev from
   *    the &struct media_entity embedded in it.
   *
   * @ent: pointer to &struct media_entity.
   */

  #define media_entity_to_v4l2_subdev(ent)				\
  ({									\
  	typeof(ent) __me_sd_ent = (ent);				\
  									\
  	__me_sd_ent ?							\
  		container_of(__me_sd_ent, struct v4l2_subdev, entity) :	\
  		NULL;							\
  })

  /**
   * vdev_to_v4l2_subdev - Returns a &struct v4l2_subdev from
   *	the &struct video_device embedded on it.
   *
   * @vdev: pointer to &struct video_device
   */

  #define vdev_to_v4l2_subdev(vdev) \

  	((struct v4l2_subdev *)video_get_drvdata(vdev))

  /**
   * struct v4l2_subdev_fh - Used for storing subdev information per file handle
   *

   * @vfh: pointer to &struct v4l2_fh
   * @pad: pointer to &struct v4l2_subdev_pad_config

   * @owner: module pointer to the owner of this file handle

   */
  struct v4l2_subdev_fh {
  	struct v4l2_fh vfh;

  	struct module *owner;

  #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)

  	struct v4l2_subdev_pad_config *pad;

  #endif
  };

  /**
   * to_v4l2_subdev_fh - Returns a &struct v4l2_subdev_fh from
   *	the &struct v4l2_fh embedded on it.
   *
   * @fh: pointer to &struct v4l2_fh
   */

  #define to_v4l2_subdev_fh(fh)	\
  	container_of(fh, struct v4l2_subdev_fh, vfh)
  
  #if defined(CONFIG_VIDEO_V4L2_SUBDEV_API)

  
  /**
   * v4l2_subdev_get_try_format - ancillary routine to call
   *	&struct v4l2_subdev_pad_config->try_fmt
   *
   * @sd: pointer to &struct v4l2_subdev
   * @cfg: pointer to &struct v4l2_subdev_pad_config array.
   * @pad: index of the pad in the @cfg array.
   */

  static inline struct v4l2_mbus_framefmt *
  v4l2_subdev_get_try_format(struct v4l2_subdev *sd,
  			   struct v4l2_subdev_pad_config *cfg,
  			   unsigned int pad)

  {
  	if (WARN_ON(pad >= sd->entity.num_pads))
  		pad = 0;
  	return &cfg[pad].try_fmt;
  }

  /**
   * v4l2_subdev_get_try_crop - ancillary routine to call
   *	&struct v4l2_subdev_pad_config->try_crop
   *
   * @sd: pointer to &struct v4l2_subdev
   * @cfg: pointer to &struct v4l2_subdev_pad_config array.
   * @pad: index of the pad in the @cfg array.
   */

  static inline struct v4l2_rect *
  v4l2_subdev_get_try_crop(struct v4l2_subdev *sd,
  			 struct v4l2_subdev_pad_config *cfg,
  			 unsigned int pad)

  {
  	if (WARN_ON(pad >= sd->entity.num_pads))
  		pad = 0;
  	return &cfg[pad].try_crop;
  }

  /**

   * v4l2_subdev_get_try_compose - ancillary routine to call

   *	&struct v4l2_subdev_pad_config->try_compose
   *
   * @sd: pointer to &struct v4l2_subdev
   * @cfg: pointer to &struct v4l2_subdev_pad_config array.
   * @pad: index of the pad in the @cfg array.
   */

  static inline struct v4l2_rect *
  v4l2_subdev_get_try_compose(struct v4l2_subdev *sd,
  			    struct v4l2_subdev_pad_config *cfg,
  			    unsigned int pad)

  {
  	if (WARN_ON(pad >= sd->entity.num_pads))
  		pad = 0;
  	return &cfg[pad].try_compose;
  }

  #endif

  extern const struct v4l2_file_operations v4l2_subdev_fops;

  /**
   * v4l2_set_subdevdata - Sets V4L2 dev private device data
   *
   * @sd: pointer to &struct v4l2_subdev
   * @p: pointer to the private device data to be stored.
   */

  static inline void v4l2_set_subdevdata(struct v4l2_subdev *sd, void *p)
  {

  	sd->dev_priv = p;

  }

  /**
   * v4l2_get_subdevdata - Gets V4L2 dev private device data
   *
   * @sd: pointer to &struct v4l2_subdev
   *
   * Returns the pointer to the private device data to be stored.
   */

  static inline void *v4l2_get_subdevdata(const struct v4l2_subdev *sd)
  {

  	return sd->dev_priv;
  }

  /**

   * v4l2_set_subdev_hostdata - Sets V4L2 dev private host data

   *
   * @sd: pointer to &struct v4l2_subdev
   * @p: pointer to the private data to be stored.
   */

  static inline void v4l2_set_subdev_hostdata(struct v4l2_subdev *sd, void *p)
  {
  	sd->host_priv = p;
  }

  /**

   * v4l2_get_subdev_hostdata - Gets V4L2 dev private data

   *
   * @sd: pointer to &struct v4l2_subdev
   *
   * Returns the pointer to the private host data to be stored.
   */

  static inline void *v4l2_get_subdev_hostdata(const struct v4l2_subdev *sd)
  {
  	return sd->host_priv;

  }

  #ifdef CONFIG_MEDIA_CONTROLLER

  
  /**

   * v4l2_subdev_get_fwnode_pad_1_to_1 - Get pad number from a subdev fwnode
   *                                     endpoint, assuming 1:1 port:pad
   *

   * @entity: Pointer to the subdev entity
   * @endpoint: Pointer to a parsed fwnode endpoint

   *
   * This function can be used as the .get_fwnode_pad operation for
   * subdevices that map port numbers and pad indexes 1:1. If the endpoint
   * is owned by the subdevice, the function returns the endpoint port
   * number.
   *
   * Returns the endpoint port number on success or a negative error code.
   */
  int v4l2_subdev_get_fwnode_pad_1_to_1(struct media_entity *entity,
  				      struct fwnode_endpoint *endpoint);
  
  /**

   * v4l2_subdev_link_validate_default - validates a media link
   *
   * @sd: pointer to &struct v4l2_subdev
   * @link: pointer to &struct media_link
   * @source_fmt: pointer to &struct v4l2_subdev_format
   * @sink_fmt: pointer to &struct v4l2_subdev_format
   *
   * This function ensures that width, height and the media bus pixel
   * code are equal on both source and sink of the link.
   */

  int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd,
  				      struct media_link *link,
  				      struct v4l2_subdev_format *source_fmt,
  				      struct v4l2_subdev_format *sink_fmt);

  
  /**
   * v4l2_subdev_link_validate - validates a media link
   *
   * @link: pointer to &struct media_link
   *
   * This function calls the subdev's link_validate ops to validate
   * if a media link is valid for streaming. It also internally
   * calls v4l2_subdev_link_validate_default() to ensure that
   * width, height and the media bus pixel code are equal on both
   * source and sink of the link.
   */

  int v4l2_subdev_link_validate(struct media_link *link);

  /**
   * v4l2_subdev_alloc_pad_config - Allocates memory for pad config
   *
   * @sd: pointer to struct v4l2_subdev
   */
  struct
  v4l2_subdev_pad_config *v4l2_subdev_alloc_pad_config(struct v4l2_subdev *sd);
  
  /**
   * v4l2_subdev_free_pad_config - Frees memory allocated by
   *	v4l2_subdev_alloc_pad_config().
   *
   * @cfg: pointer to &struct v4l2_subdev_pad_config
   */

  void v4l2_subdev_free_pad_config(struct v4l2_subdev_pad_config *cfg);

  #endif /* CONFIG_MEDIA_CONTROLLER */

  /**
   * v4l2_subdev_init - initializes the sub-device struct
   *
   * @sd: pointer to the &struct v4l2_subdev to be initialized
   * @ops: pointer to &struct v4l2_subdev_ops.
   */

  void v4l2_subdev_init(struct v4l2_subdev *sd,
  		      const struct v4l2_subdev_ops *ops);

  extern const struct v4l2_subdev_ops v4l2_subdev_call_wrappers;

  /**
   * v4l2_subdev_call - call an operation of a v4l2_subdev.
   *
   * @sd: pointer to the &struct v4l2_subdev
   * @o: name of the element at &struct v4l2_subdev_ops that contains @f.
   *     Each element there groups a set of callbacks functions.

   * @f: callback function to be called.

   *     The callback functions are defined in groups, according to
   *     each element at &struct v4l2_subdev_ops.

   * @args: arguments for @f.

   *
   * Example: err = v4l2_subdev_call(sd, video, s_std, norm);

   */
  #define v4l2_subdev_call(sd, o, f, args...)				\

  	({								\

  		struct v4l2_subdev *__sd = (sd);			\

  		int __result;						\

  		if (!__sd)						\

  			__result = -ENODEV;				\

  		else if (!(__sd->ops->o && __sd->ops->o->f))		\

  			__result = -ENOIOCTLCMD;			\

  		else if (v4l2_subdev_call_wrappers.o &&			\
  			 v4l2_subdev_call_wrappers.o->f)		\
  			__result = v4l2_subdev_call_wrappers.o->f(	\
  							__sd, ##args);	\

  		else							\

  			__result = __sd->ops->o->f(__sd, ##args);	\

  		__result;						\
  	})

  /**
   * v4l2_subdev_has_op - Checks if a subdev defines a certain operation.
   *
   * @sd: pointer to the &struct v4l2_subdev
   * @o: The group of callback functions in &struct v4l2_subdev_ops
   * which @f is a part of.
   * @f: callback function to be checked for its existence.
   */

  #define v4l2_subdev_has_op(sd, o, f) \
  	((sd)->ops->o && (sd)->ops->o->f)

  /**
   * v4l2_subdev_notify_event() - Delivers event notification for subdevice
   * @sd: The subdev for which to deliver the event
   * @ev: The event to deliver
   *
   * Will deliver the specified event to all userspace event listeners which are
   * subscribed to the v42l subdev event queue as well as to the bridge driver
   * using the notify callback. The notification type for the notify callback
   * will be %V4L2_DEVICE_NOTIFY_EVENT.
   */

  void v4l2_subdev_notify_event(struct v4l2_subdev *sd,
  			      const struct v4l2_event *ev);

  #endif