/*
 * Memory-to-memory device framework for Video for Linux 2.
 *
 * Helper functions for devices that use memory buffers for both source
 * and destination.
 *
 * Copyright (c) 2009 Samsung Electronics Co., Ltd.
 * Pawel Osciak, <pawel@osciak.com>
 * Marek Szyprowski, <m.szyprowski@samsung.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version
 */

#ifndef _MEDIA_V4L2_MEM2MEM_H
#define _MEDIA_V4L2_MEM2MEM_H

#include <media/videobuf2-core.h>

/**
 * struct v4l2_m2m_ops - mem-to-mem device driver callbacks
 * @device_run: required. Begin the actual job (transaction) inside this
 *              callback.
 *              The job does NOT have to end before this callback returns
 *              (and it will be the usual case). When the job finishes,
 *              v4l2_m2m_job_finish() has to be called.
 * @job_ready:  optional. Should return 0 if the driver does not have a job
 *              fully prepared to run yet (i.e. it will not be able to finish a
 *              transaction without sleeping). If not provided, it will be
 *              assumed that one source and one destination buffer are all
 *              that is required for the driver to perform one full transaction.
 *              This method may not sleep.
 * @job_abort:  required. Informs the driver that it has to abort the currently
 *              running transaction as soon as possible (i.e. as soon as it can
 *              stop the device safely; e.g. in the next interrupt handler),
 *              even if the transaction would not have been finished by then.
 *              After the driver performs the necessary steps, it has to call
 *              v4l2_m2m_job_finish() (as if the transaction ended normally).
 *              This function does not have to (and will usually not) wait
 *              until the device enters a state when it can be stopped.
 */
struct v4l2_m2m_ops {
        void (*device_run)(void *priv);
        int (*job_ready)(void *priv);
        void (*job_abort)(void *priv);
        void (*lock)(void *priv);
        void (*unlock)(void *priv);
};

struct v4l2_m2m_dev;

struct v4l2_m2m_queue_ctx {
/* private: internal use only */
        struct vb2_queue        q;

        /* Queue for buffers ready to be processed as soon as this
         * instance receives access to the device */
        struct list_head        rdy_queue;
        spinlock_t              rdy_spinlock;
        u8                      num_rdy;
};

struct v4l2_m2m_ctx {
/* private: internal use only */
        struct v4l2_m2m_dev             *m2m_dev;

        /* Capture (output to memory) queue context */
        struct v4l2_m2m_queue_ctx       cap_q_ctx;

        /* Output (input from memory) queue context */
        struct v4l2_m2m_queue_ctx       out_q_ctx;

        /* For device job queue */
        struct list_head                queue;
        unsigned long                   job_flags;
        wait_queue_head_t               finished;

        /* Instance private data */
        void                            *priv;
};

struct v4l2_m2m_buffer {
        struct vb2_buffer       vb;
        struct list_head        list;
};

void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);

struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
                                       enum v4l2_buf_type type);

void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
                         struct v4l2_m2m_ctx *m2m_ctx);

static inline void
v4l2_m2m_buf_done(struct vb2_buffer *buf, enum vb2_buffer_state state)
{
        vb2_buffer_done(buf, state);
}

int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                     struct v4l2_requestbuffers *reqbufs);

int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                      struct v4l2_buffer *buf);

int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                  struct v4l2_buffer *buf);
int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                   struct v4l2_buffer *buf);

int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                      enum v4l2_buf_type type);
int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                       enum v4l2_buf_type type);

unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                           struct poll_table_struct *wait);

int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
                  struct vm_area_struct *vma);

struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops);
void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);

struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
                void *drv_priv,
                int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq));

void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);

void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb);

/**
 * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
 * use
 */
static inline
unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
{
        return m2m_ctx->cap_q_ctx.num_rdy;
}

/**
 * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
 * ready for use
 */
static inline
unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
{
        return m2m_ctx->out_q_ctx.num_rdy;
}

void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);

/**
 * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
 * buffers
 */
static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
{
        return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
}

/**
 * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
 * ready buffers
 */
static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
{
        return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
}

/**
 * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers
 */
static inline
struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
{
        return &m2m_ctx->out_q_ctx.q;
}

/**
 * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers
 */
static inline
struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
{
        return &m2m_ctx->cap_q_ctx.q;
}

void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);

/**
 * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
 * buffers and return it
 */
static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
{
        return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
}

/**
 * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
 * ready buffers and return it
 */
static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
{
        return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
}

#endif /* _MEDIA_V4L2_MEM2MEM_H */