/* 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.
 *
 * @command: called by in-kernel drivers in order to call functions internal
 *         to subdev drivers driver that have a separate callback.
 *
 * @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 (*command)(struct v4l2_subdev *sd, unsigned int cmd, void *arg);
        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_flags - 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;
};

/**
 * enum v4l2_subdev_pre_streamon_flags - Flags for pre_streamon subdev core op
 *
 * @V4L2_SUBDEV_PRE_STREAMON_FL_MANUAL_LP: Set the transmitter to either LP-11
 *      or LP-111 mode before call to s_stream().
 */
enum v4l2_subdev_pre_streamon_flags {
        V4L2_SUBDEV_PRE_STREAMON_FL_MANUAL_LP = BIT(0),
};

/**
 * 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.
 *
 * @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.
 *
 * @pre_streamon: May be called before streaming is actually started, to help
 *      initialising the bus. Current usage is to set a CSI-2 transmitter to
 *      LP-11 or LP-111 mode before streaming. See &enum
 *      v4l2_subdev_pre_streamon_flags.
 *
 *      pre_streamon shall return error if it cannot perform the operation as
 *      indicated by the flags argument. In particular, -EACCES indicates lack
 *      of support for the operation. The caller shall call post_streamoff for
 *      each successful call of pre_streamon.
 *
 * @post_streamoff: Called after streaming is stopped, but if and only if
 *      pre_streamon was called earlier.
 */
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_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);
        int (*pre_streamon)(struct v4l2_subdev *sd, u32 flags);
        int (*post_streamoff)(struct v4l2_subdev *sd);
};

/**
 * 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_state - Used for storing subdev state information.
 *
 * @pads: &struct v4l2_subdev_pad_config array
 *
 * 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_state {
        struct v4l2_subdev_pad_config *pads;
};

/**
 * 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_state *state);
        int (*enum_mbus_code)(struct v4l2_subdev *sd,
                              struct v4l2_subdev_state *state,
                              struct v4l2_subdev_mbus_code_enum *code);
        int (*enum_frame_size)(struct v4l2_subdev *sd,
                               struct v4l2_subdev_state *state,
                               struct v4l2_subdev_frame_size_enum *fse);
        int (*enum_frame_interval)(struct v4l2_subdev *sd,
                                   struct v4l2_subdev_state *state,
                                   struct v4l2_subdev_frame_interval_enum *fie);
        int (*get_fmt)(struct v4l2_subdev *sd,
                       struct v4l2_subdev_state *state,
                       struct v4l2_subdev_format *format);
        int (*set_fmt)(struct v4l2_subdev *sd,
                       struct v4l2_subdev_state *state,
                       struct v4l2_subdev_format *format);
        int (*get_selection)(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *state,
                             struct v4l2_subdev_selection *sel);
        int (*set_selection)(struct v4l2_subdev *sd,
                             struct v4l2_subdev_state *state,
                             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_async_register_subdev_sensor().
 * @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
 * @state: pointer to &struct v4l2_subdev_state
 * @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_state *state;
#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
 * @state: pointer to &struct v4l2_subdev_state
 * @pad: index of the pad in the &struct v4l2_subdev_state->pads array
 */
static inline struct v4l2_mbus_framefmt *
v4l2_subdev_get_try_format(struct v4l2_subdev *sd,
                           struct v4l2_subdev_state *state,
                           unsigned int pad)
{
        if (WARN_ON(pad >= sd->entity.num_pads))
                pad = 0;
        return &state->pads[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
 * @state: pointer to &struct v4l2_subdev_state.
 * @pad: index of the pad in the &struct v4l2_subdev_state->pads array.
 */
static inline struct v4l2_rect *
v4l2_subdev_get_try_crop(struct v4l2_subdev *sd,
                         struct v4l2_subdev_state *state,
                         unsigned int pad)
{
        if (WARN_ON(pad >= sd->entity.num_pads))
                pad = 0;
        return &state->pads[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
 * @state: pointer to &struct v4l2_subdev_state.
 * @pad: index of the pad in the &struct v4l2_subdev_state->pads array.
 */
static inline struct v4l2_rect *
v4l2_subdev_get_try_compose(struct v4l2_subdev *sd,
                            struct v4l2_subdev_state *state,
                            unsigned int pad)
{
        if (WARN_ON(pad >= sd->entity.num_pads))
                pad = 0;
        return &state->pads[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_state - allocate v4l2_subdev_state
 *
 * @sd: pointer to &struct v4l2_subdev for which the state is being allocated.
 *
 * Must call v4l2_subdev_free_state() when state is no longer needed.
 */
struct v4l2_subdev_state *v4l2_subdev_alloc_state(struct v4l2_subdev *sd);

/**
 * v4l2_subdev_free_state - free a v4l2_subdev_state
 *
 * @state: v4l2_subdev_state to be freed.
 */
void v4l2_subdev_free_state(struct v4l2_subdev_state *state);

#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