/* SPDX-License-Identifier: GPL-2.0-only */

  /*
   * generic helper functions for handling video4linux capture buffers
   *

   * (c) 2007 Mauro Carvalho Chehab, <mchehab@kernel.org>

   *
   * Highly based on video-buf written originally by:
   * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>

   * (c) 2006 Mauro Carvalho Chehab, <mchehab@kernel.org>

   * (c) 2006 Ted Walther and John Sokol

   */

  #ifndef _VIDEOBUF_CORE_H
  #define _VIDEOBUF_CORE_H

  #include <linux/poll.h>

  #include <linux/videodev2.h>
  
  #define UNSET (-1U)
  
  
  struct videobuf_buffer;
  struct videobuf_queue;
  
  /* --------------------------------------------------------------------- */
  
  /*
   * A small set of helper functions to manage video4linux buffers.
   *
   * struct videobuf_buffer holds the data structures used by the helper
   * functions, additionally some commonly used fields for v4l buffers
   * (width, height, lists, waitqueue) are in there.  That struct should
   * be used as first element in the drivers buffer struct.
   *
   * about the mmap helpers (videobuf_mmap_*):
   *

   * The mmaper function allows to map any subset of contiguous buffers.

   * This includes one mmap() call for all buffers (which the original
   * video4linux API uses) as well as one mmap() for every single buffer
   * (which v4l2 uses).
   *
   * If there is a valid mapping for a buffer, buffer->baddr/bsize holds

   * userspace address + size which can be fed into the

   * videobuf_dma_init_user function listed above.
   *
   */
  
  struct videobuf_mapping {
  	unsigned int count;

  	struct videobuf_queue *q;
  };
  
  enum videobuf_state {

  	VIDEOBUF_NEEDS_INIT = 0,
  	VIDEOBUF_PREPARED   = 1,
  	VIDEOBUF_QUEUED     = 2,
  	VIDEOBUF_ACTIVE     = 3,
  	VIDEOBUF_DONE       = 4,
  	VIDEOBUF_ERROR      = 5,
  	VIDEOBUF_IDLE       = 6,

  };
  
  struct videobuf_buffer {
  	unsigned int            i;
  	u32                     magic;
  
  	/* info about the buffer */
  	unsigned int            width;
  	unsigned int            height;
  	unsigned int            bytesperline; /* use only if != 0 */
  	unsigned long           size;

  	enum v4l2_field         field;
  	enum videobuf_state     state;
  	struct list_head        stream;  /* QBUF/DQBUF list */
  
  	/* touched by irq handler */
  	struct list_head        queue;
  	wait_queue_head_t       done;
  	unsigned int            field_count;

  	u64			ts;

  
  	/* Memory type */
  	enum v4l2_memory        memory;
  
  	/* buffer size */
  	size_t                  bsize;
  
  	/* buffer offset (mmap + overlay) */
  	size_t                  boff;
  
  	/* buffer addr (userland ptr!) */
  	unsigned long           baddr;

  	/* for mmap'ed buffers */
  	struct videobuf_mapping *map;

  	/* Private pointer to allow specific methods to store their data */
  	int			privsize;
  	void                    *priv;
  };
  
  struct videobuf_queue_ops {
  	int (*buf_setup)(struct videobuf_queue *q,
  			 unsigned int *count, unsigned int *size);
  	int (*buf_prepare)(struct videobuf_queue *q,
  			   struct videobuf_buffer *vb,
  			   enum v4l2_field field);
  	void (*buf_queue)(struct videobuf_queue *q,
  			  struct videobuf_buffer *vb);
  	void (*buf_release)(struct videobuf_queue *q,
  			    struct videobuf_buffer *vb);
  };
  
  #define MAGIC_QTYPE_OPS	0x12261003
  
  /* Helper operations - device type dependent */
  struct videobuf_qtype_ops {
  	u32                     magic;

  	struct videobuf_buffer *(*alloc_vb)(size_t size);

  	void *(*vaddr)		(struct videobuf_buffer *buf);

  	int (*iolock)		(struct videobuf_queue *q,

  				 struct videobuf_buffer *vb,
  				 struct v4l2_framebuffer *fbuf);

  	int (*sync)		(struct videobuf_queue *q,

  				 struct videobuf_buffer *buf);

  	int (*mmap_mapper)	(struct videobuf_queue *q,

  				 struct videobuf_buffer *buf,
  				 struct vm_area_struct *vma);

  };
  
  struct videobuf_queue {

  	struct mutex               vb_lock;

  	struct mutex               *ext_lock;

  	spinlock_t                 *irqlock;

  	struct device		   *dev;

  	wait_queue_head_t	   wait; /* wait if queue is empty */

  	enum v4l2_buf_type         type;

  	unsigned int               msize;
  	enum v4l2_field            field;
  	enum v4l2_field            last;   /* for field=V4L2_FIELD_ALTERNATE */
  	struct videobuf_buffer     *bufs[VIDEO_MAX_FRAME];

  	const struct videobuf_queue_ops  *ops;

  	struct videobuf_qtype_ops  *int_ops;

  	unsigned int               streaming:1;
  	unsigned int               reading:1;

  	/* capture via mmap() + ioctl(QBUF/DQBUF) */

  	struct list_head           stream;
  
  	/* capture via read() */

  	unsigned int               read_off;
  	struct videobuf_buffer     *read_buf;
  
  	/* driver private data */
  	void                       *priv_data;

  };

  static inline void videobuf_queue_lock(struct videobuf_queue *q)
  {
  	if (!q->ext_lock)
  		mutex_lock(&q->vb_lock);
  }
  
  static inline void videobuf_queue_unlock(struct videobuf_queue *q)
  {
  	if (!q->ext_lock)
  		mutex_unlock(&q->vb_lock);
  }

  int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
  		int non_blocking, int intr);

  int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,

  		struct v4l2_framebuffer *fbuf);

  struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q);

  /* Used on videobuf-dvb */

  void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
  			      struct videobuf_buffer *buf);

  void videobuf_queue_core_init(struct videobuf_queue *q,

  			 const struct videobuf_queue_ops *ops,

  			 struct device *dev,

  			 spinlock_t *irqlock,
  			 enum v4l2_buf_type type,
  			 enum v4l2_field field,
  			 unsigned int msize,

  			 void *priv,

  			 struct videobuf_qtype_ops *int_ops,
  			 struct mutex *ext_lock);

  int  videobuf_queue_is_busy(struct videobuf_queue *q);
  void videobuf_queue_cancel(struct videobuf_queue *q);
  
  enum v4l2_field videobuf_next_field(struct videobuf_queue *q);
  int videobuf_reqbufs(struct videobuf_queue *q,
  		     struct v4l2_requestbuffers *req);
  int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b);
  int videobuf_qbuf(struct videobuf_queue *q,
  		  struct v4l2_buffer *b);
  int videobuf_dqbuf(struct videobuf_queue *q,
  		   struct v4l2_buffer *b, int nonblocking);

  int videobuf_streamon(struct videobuf_queue *q);
  int videobuf_streamoff(struct videobuf_queue *q);

  void videobuf_stop(struct videobuf_queue *q);

  int videobuf_read_start(struct videobuf_queue *q);
  void videobuf_read_stop(struct videobuf_queue *q);
  ssize_t videobuf_read_stream(struct videobuf_queue *q,
  			     char __user *data, size_t count, loff_t *ppos,
  			     int vbihack, int nonblocking);
  ssize_t videobuf_read_one(struct videobuf_queue *q,
  			  char __user *data, size_t count, loff_t *ppos,
  			  int nonblocking);

  __poll_t videobuf_poll_stream(struct file *file,

  				  struct videobuf_queue *q,
  				  poll_table *wait);
  
  int videobuf_mmap_setup(struct videobuf_queue *q,
  			unsigned int bcount, unsigned int bsize,
  			enum v4l2_memory memory);

  int __videobuf_mmap_setup(struct videobuf_queue *q,
  			unsigned int bcount, unsigned int bsize,
  			enum v4l2_memory memory);

  int videobuf_mmap_free(struct videobuf_queue *q);
  int videobuf_mmap_mapper(struct videobuf_queue *q,
  			 struct vm_area_struct *vma);

  #endif