4 files changed, 850 insertions, 0 deletions

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 747f106e7b53..f8cbd4adebfd 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -45,6 +45,10 @@ config VIDEO_TUNER
         tristate
         depends on MEDIA_TUNER
 
+config V4L2_MEM2MEM_DEV
+        tristate
+        depends on VIDEOBUF_GEN
+
 #
 # Multimedia Video device configuration
 #
@@ -1121,3 +1125,13 @@ config USB_S2255
 
 endif # V4L_USB_DRIVERS
 endif # VIDEO_CAPTURE_DRIVERS
+
+menuconfig V4L_MEM2MEM_DRIVERS
+        bool "Memory-to-memory multimedia devices"
+        depends on VIDEO_V4L2
+        default n
+        ---help---
+          Say Y here to enable selecting drivers for V4L devices that
+          use system memory for both source and destination buffers, as opposed
+          to capture and output drivers, which use memory buffers for just
+          one of those.
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 4555f5f31ff0..b57be2f542e8 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -117,6 +117,8 @@ obj-$(CONFIG_VIDEOBUF_VMALLOC) += videobuf-vmalloc.o
 obj-$(CONFIG_VIDEOBUF_DVB) += videobuf-dvb.o
 obj-$(CONFIG_VIDEO_BTCX)  += btcx-risc.o
 
+obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
+
 obj-$(CONFIG_VIDEO_M32R_AR_M64278) += arv.o
 
 obj-$(CONFIG_VIDEO_CX2341X) += cx2341x.o
diff --git a/drivers/media/video/v4l2-mem2mem.c b/drivers/media/video/v4l2-mem2mem.c
new file mode 100644
index 000000000000..f45f9405ea39
--- /dev/null
+++ b/drivers/media/video/v4l2-mem2mem.c
@@ -0,0 +1,633 @@
+/*
+ * Memory-to-memory device framework for Video for Linux 2 and videobuf.
+ *
+ * Helper functions for devices that use videobuf buffers for both their
+ * source and destination.
+ *
+ * Copyright (c) 2009-2010 Samsung Electronics Co., Ltd.
+ * Pawel Osciak, <p.osciak@samsung.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.
+ */
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <media/videobuf-core.h>
+#include <media/v4l2-mem2mem.h>
+
+MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
+MODULE_AUTHOR("Pawel Osciak, <p.osciak@samsung.com>");
+MODULE_LICENSE("GPL");
+
+static bool debug;
+module_param(debug, bool, 0644);
+
+#define dprintk(fmt, arg...)                                            \
+        do {                                                            \
+                if (debug)                                              \
+                        printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
+        } while (0)
+
+
+/* Instance is already queued on the job_queue */
+#define TRANS_QUEUED            (1 << 0)
+/* Instance is currently running in hardware */
+#define TRANS_RUNNING           (1 << 1)
+
+
+/* Offset base for buffers on the destination queue - used to distinguish
+ * between source and destination buffers when mmapping - they receive the same
+ * offsets but for different queues */
+#define DST_QUEUE_OFF_BASE      (1 << 30)
+
+
+/**
+ * struct v4l2_m2m_dev - per-device context
+ * @curr_ctx:           currently running instance
+ * @job_queue:          instances queued to run
+ * @job_spinlock:       protects job_queue
+ * @m2m_ops:            driver callbacks
+ */
+struct v4l2_m2m_dev {
+        struct v4l2_m2m_ctx     *curr_ctx;
+
+        struct list_head        job_queue;
+        spinlock_t              job_spinlock;
+
+        struct v4l2_m2m_ops     *m2m_ops;
+};
+
+static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
+                                                enum v4l2_buf_type type)
+{
+        switch (type) {
+        case V4L2_BUF_TYPE_VIDEO_CAPTURE:
+                return &m2m_ctx->cap_q_ctx;
+        case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+                return &m2m_ctx->out_q_ctx;
+        default:
+                printk(KERN_ERR "Invalid buffer type\n");
+                return NULL;
+        }
+}
+
+/**
+ * v4l2_m2m_get_vq() - return videobuf_queue for the given type
+ */
+struct videobuf_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
+                                       enum v4l2_buf_type type)
+{
+        struct v4l2_m2m_queue_ctx *q_ctx;
+
+        q_ctx = get_queue_ctx(m2m_ctx, type);
+        if (!q_ctx)
+                return NULL;
+
+        return &q_ctx->q;
+}
+EXPORT_SYMBOL(v4l2_m2m_get_vq);
+
+/**
+ * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
+ */
+void *v4l2_m2m_next_buf(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type)
+{
+        struct v4l2_m2m_queue_ctx *q_ctx;
+        struct videobuf_buffer *vb = NULL;
+        unsigned long flags;
+
+        q_ctx = get_queue_ctx(m2m_ctx, type);
+        if (!q_ctx)
+                return NULL;
+
+        spin_lock_irqsave(q_ctx->q.irqlock, flags);
+
+        if (list_empty(&q_ctx->rdy_queue))
+                goto end;
+
+        vb = list_entry(q_ctx->rdy_queue.next, struct videobuf_buffer, queue);
+        vb->state = VIDEOBUF_ACTIVE;
+
+end:
+        spin_unlock_irqrestore(q_ctx->q.irqlock, flags);
+        return vb;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
+
+/**
+ * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
+ * return it
+ */
+void *v4l2_m2m_buf_remove(struct v4l2_m2m_ctx *m2m_ctx, enum v4l2_buf_type type)
+{
+        struct v4l2_m2m_queue_ctx *q_ctx;
+        struct videobuf_buffer *vb = NULL;
+        unsigned long flags;
+
+        q_ctx = get_queue_ctx(m2m_ctx, type);
+        if (!q_ctx)
+                return NULL;
+
+        spin_lock_irqsave(q_ctx->q.irqlock, flags);
+        if (!list_empty(&q_ctx->rdy_queue)) {
+                vb = list_entry(q_ctx->rdy_queue.next, struct videobuf_buffer,
+                                queue);
+                list_del(&vb->queue);
+                q_ctx->num_rdy--;
+        }
+        spin_unlock_irqrestore(q_ctx->q.irqlock, flags);
+
+        return vb;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
+
+/*
+ * Scheduling handlers
+ */
+
+/**
+ * v4l2_m2m_get_curr_priv() - return driver private data for the currently
+ * running instance or NULL if no instance is running
+ */
+void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
+{
+        unsigned long flags;
+        void *ret = NULL;
+
+        spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+        if (m2m_dev->curr_ctx)
+                ret = m2m_dev->curr_ctx->priv;
+        spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+
+        return ret;
+}
+EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
+
+/**
+ * v4l2_m2m_try_run() - select next job to perform and run it if possible
+ *
+ * Get next transaction (if present) from the waiting jobs list and run it.
+ */
+static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+        if (NULL != m2m_dev->curr_ctx) {
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+                dprintk("Another instance is running, won't run now\n");
+                return;
+        }
+
+        if (list_empty(&m2m_dev->job_queue)) {
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+                dprintk("No job pending\n");
+                return;
+        }
+
+        m2m_dev->curr_ctx = list_entry(m2m_dev->job_queue.next,
+                                   struct v4l2_m2m_ctx, queue);
+        m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
+        spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+
+        m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
+}
+
+/**
+ * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
+ * the pending job queue and add it if so.
+ * @m2m_ctx:    m2m context assigned to the instance to be checked
+ *
+ * There are three basic requirements an instance has to meet to be able to run:
+ * 1) at least one source buffer has to be queued,
+ * 2) at least one destination buffer has to be queued,
+ * 3) streaming has to be on.
+ *
+ * There may also be additional, custom requirements. In such case the driver
+ * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
+ * return 1 if the instance is ready.
+ * An example of the above could be an instance that requires more than one
+ * src/dst buffer per transaction.
+ */
+static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
+{
+        struct v4l2_m2m_dev *m2m_dev;
+        unsigned long flags_job, flags;
+
+        m2m_dev = m2m_ctx->m2m_dev;
+        dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
+
+        if (!m2m_ctx->out_q_ctx.q.streaming
+            || !m2m_ctx->cap_q_ctx.q.streaming) {
+                dprintk("Streaming needs to be on for both queues\n");
+                return;
+        }
+
+        spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
+        if (m2m_ctx->job_flags & TRANS_QUEUED) {
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
+                dprintk("On job queue already\n");
+                return;
+        }
+
+        spin_lock_irqsave(m2m_ctx->out_q_ctx.q.irqlock, flags);
+        if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
+                spin_unlock_irqrestore(m2m_ctx->out_q_ctx.q.irqlock, flags);
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
+                dprintk("No input buffers available\n");
+                return;
+        }
+        if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
+                spin_unlock_irqrestore(m2m_ctx->out_q_ctx.q.irqlock, flags);
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
+                dprintk("No output buffers available\n");
+                return;
+        }
+        spin_unlock_irqrestore(m2m_ctx->out_q_ctx.q.irqlock, flags);
+
+        if (m2m_dev->m2m_ops->job_ready
+                && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
+                dprintk("Driver not ready\n");
+                return;
+        }
+
+        list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
+        m2m_ctx->job_flags |= TRANS_QUEUED;
+
+        spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
+
+        v4l2_m2m_try_run(m2m_dev);
+}
+
+/**
+ * v4l2_m2m_job_finish() - inform the framework that a job has been finished
+ * and have it clean up
+ *
+ * Called by a driver to yield back the device after it has finished with it.
+ * Should be called as soon as possible after reaching a state which allows
+ * other instances to take control of the device.
+ *
+ * This function has to be called only after device_run() callback has been
+ * called on the driver. To prevent recursion, it should not be called directly
+ * from the device_run() callback though.
+ */
+void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
+                         struct v4l2_m2m_ctx *m2m_ctx)
+{
+        unsigned long flags;
+
+        spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+        if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+                dprintk("Called by an instance not currently running\n");
+                return;
+        }
+
+        list_del(&m2m_dev->curr_ctx->queue);
+        m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
+        m2m_dev->curr_ctx = NULL;
+
+        spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+
+        /* This instance might have more buffers ready, but since we do not
+         * allow more than one job on the job_queue per instance, each has
+         * to be scheduled separately after the previous one finishes. */
+        v4l2_m2m_try_schedule(m2m_ctx);
+        v4l2_m2m_try_run(m2m_dev);
+}
+EXPORT_SYMBOL(v4l2_m2m_job_finish);
+
+/**
+ * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
+ */
+int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                     struct v4l2_requestbuffers *reqbufs)
+{
+        struct videobuf_queue *vq;
+
+        vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
+        return videobuf_reqbufs(vq, reqbufs);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
+
+/**
+ * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
+ *
+ * See v4l2_m2m_mmap() documentation for details.
+ */
+int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                      struct v4l2_buffer *buf)
+{
+        struct videobuf_queue *vq;
+        int ret;
+
+        vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
+        ret = videobuf_querybuf(vq, buf);
+
+        if (buf->memory == V4L2_MEMORY_MMAP
+            && vq->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
+                buf->m.offset += DST_QUEUE_OFF_BASE;
+        }
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
+
+/**
+ * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
+ * the type
+ */
+int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                  struct v4l2_buffer *buf)
+{
+        struct videobuf_queue *vq;
+        int ret;
+
+        vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
+        ret = videobuf_qbuf(vq, buf);
+        if (!ret)
+                v4l2_m2m_try_schedule(m2m_ctx);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
+
+/**
+ * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
+ * the type
+ */
+int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                   struct v4l2_buffer *buf)
+{
+        struct videobuf_queue *vq;
+
+        vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
+        return videobuf_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
+
+/**
+ * v4l2_m2m_streamon() - turn on streaming for a video queue
+ */
+int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                      enum v4l2_buf_type type)
+{
+        struct videobuf_queue *vq;
+        int ret;
+
+        vq = v4l2_m2m_get_vq(m2m_ctx, type);
+        ret = videobuf_streamon(vq);
+        if (!ret)
+                v4l2_m2m_try_schedule(m2m_ctx);
+
+        return ret;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
+
+/**
+ * v4l2_m2m_streamoff() - turn off streaming for a video queue
+ */
+int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                       enum v4l2_buf_type type)
+{
+        struct videobuf_queue *vq;
+
+        vq = v4l2_m2m_get_vq(m2m_ctx, type);
+        return videobuf_streamoff(vq);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
+
+/**
+ * v4l2_m2m_poll() - poll replacement, for destination buffers only
+ *
+ * Call from the driver's poll() function. Will poll both queues. If a buffer
+ * is available to dequeue (with dqbuf) from the source queue, this will
+ * indicate that a non-blocking write can be performed, while read will be
+ * returned in case of the destination queue.
+ */
+unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                           struct poll_table_struct *wait)
+{
+        struct videobuf_queue *src_q, *dst_q;
+        struct videobuf_buffer *src_vb = NULL, *dst_vb = NULL;
+        unsigned int rc = 0;
+
+        src_q = v4l2_m2m_get_src_vq(m2m_ctx);
+        dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
+
+        mutex_lock(&src_q->vb_lock);
+        mutex_lock(&dst_q->vb_lock);
+
+        if (src_q->streaming && !list_empty(&src_q->stream))
+                src_vb = list_first_entry(&src_q->stream,
+                                          struct videobuf_buffer, stream);
+        if (dst_q->streaming && !list_empty(&dst_q->stream))
+                dst_vb = list_first_entry(&dst_q->stream,
+                                          struct videobuf_buffer, stream);
+
+        if (!src_vb && !dst_vb) {
+                rc = POLLERR;
+                goto end;
+        }
+
+        if (src_vb) {
+                poll_wait(file, &src_vb->done, wait);
+                if (src_vb->state == VIDEOBUF_DONE
+                    || src_vb->state == VIDEOBUF_ERROR)
+                        rc |= POLLOUT | POLLWRNORM;
+        }
+        if (dst_vb) {
+                poll_wait(file, &dst_vb->done, wait);
+                if (dst_vb->state == VIDEOBUF_DONE
+                    || dst_vb->state == VIDEOBUF_ERROR)
+                        rc |= POLLIN | POLLRDNORM;
+        }
+
+end:
+        mutex_unlock(&dst_q->vb_lock);
+        mutex_unlock(&src_q->vb_lock);
+        return rc;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
+
+/**
+ * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
+ *
+ * Call from driver's mmap() function. Will handle mmap() for both queues
+ * seamlessly for videobuffer, which will receive normal per-queue offsets and
+ * proper videobuf queue pointers. The differentiation is made outside videobuf
+ * by adding a predefined offset to buffers from one of the queues and
+ * subtracting it before passing it back to videobuf. Only drivers (and
+ * thus applications) receive modified offsets.
+ */
+int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+                         struct vm_area_struct *vma)
+{
+        unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+        struct videobuf_queue *vq;
+
+        if (offset < DST_QUEUE_OFF_BASE) {
+                vq = v4l2_m2m_get_src_vq(m2m_ctx);
+        } else {
+                vq = v4l2_m2m_get_dst_vq(m2m_ctx);
+                vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
+        }
+
+        return videobuf_mmap_mapper(vq, vma);
+}
+EXPORT_SYMBOL(v4l2_m2m_mmap);
+
+/**
+ * v4l2_m2m_init() - initialize per-driver m2m data
+ *
+ * Usually called from driver's probe() function.
+ */
+struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops)
+{
+        struct v4l2_m2m_dev *m2m_dev;
+
+        if (!m2m_ops)
+                return ERR_PTR(-EINVAL);
+
+        BUG_ON(!m2m_ops->device_run);
+        BUG_ON(!m2m_ops->job_abort);
+
+        m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
+        if (!m2m_dev)
+                return ERR_PTR(-ENOMEM);
+
+        m2m_dev->curr_ctx = NULL;
+        m2m_dev->m2m_ops = m2m_ops;
+        INIT_LIST_HEAD(&m2m_dev->job_queue);
+        spin_lock_init(&m2m_dev->job_spinlock);
+
+        return m2m_dev;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_init);
+
+/**
+ * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
+ *
+ * Usually called from driver's remove() function.
+ */
+void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
+{
+        kfree(m2m_dev);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_release);
+
+/**
+ * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
+ * @priv - driver's instance private data
+ * @m2m_dev - a previously initialized m2m_dev struct
+ * @vq_init - a callback for queue type-specific initialization function to be
+ * used for initializing videobuf_queues
+ *
+ * Usually called from driver's open() function.
+ */
+struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(void *priv, struct v4l2_m2m_dev *m2m_dev,
+                        void (*vq_init)(void *priv, struct videobuf_queue *,
+                                        enum v4l2_buf_type))
+{
+        struct v4l2_m2m_ctx *m2m_ctx;
+        struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
+
+        if (!vq_init)
+                return ERR_PTR(-EINVAL);
+
+        m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
+        if (!m2m_ctx)
+                return ERR_PTR(-ENOMEM);
+
+        m2m_ctx->priv = priv;
+        m2m_ctx->m2m_dev = m2m_dev;
+
+        out_q_ctx = get_queue_ctx(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+        cap_q_ctx = get_queue_ctx(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+
+        INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
+        INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
+
+        INIT_LIST_HEAD(&m2m_ctx->queue);
+
+        vq_init(priv, &out_q_ctx->q, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+        vq_init(priv, &cap_q_ctx->q, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+        out_q_ctx->q.priv_data = cap_q_ctx->q.priv_data = priv;
+
+        return m2m_ctx;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
+
+/**
+ * v4l2_m2m_ctx_release() - release m2m context
+ *
+ * Usually called from driver's release() function.
+ */
+void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
+{
+        struct v4l2_m2m_dev *m2m_dev;
+        struct videobuf_buffer *vb;
+        unsigned long flags;
+
+        m2m_dev = m2m_ctx->m2m_dev;
+
+        spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+        if (m2m_ctx->job_flags & TRANS_RUNNING) {
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+                m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
+                dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
+                vb = v4l2_m2m_next_dst_buf(m2m_ctx);
+                BUG_ON(NULL == vb);
+                wait_event(vb->done, vb->state != VIDEOBUF_ACTIVE
+                                     && vb->state != VIDEOBUF_QUEUED);
+        } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
+                list_del(&m2m_ctx->queue);
+                m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+                dprintk("m2m_ctx: %p had been on queue and was removed\n",
+                        m2m_ctx);
+        } else {
+                /* Do nothing, was not on queue/running */
+                spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+        }
+
+        videobuf_stop(&m2m_ctx->cap_q_ctx.q);
+        videobuf_stop(&m2m_ctx->out_q_ctx.q);
+
+        videobuf_mmap_free(&m2m_ctx->cap_q_ctx.q);
+        videobuf_mmap_free(&m2m_ctx->out_q_ctx.q);
+
+        kfree(m2m_ctx);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
+
+/**
+ * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
+ *
+ * Call from buf_queue(), videobuf_queue_ops callback.
+ *
+ * Locking: Caller holds q->irqlock (taken by videobuf before calling buf_queue
+ * callback in the driver).
+ */
+void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct videobuf_queue *vq,
+                        struct videobuf_buffer *vb)
+{
+        struct v4l2_m2m_queue_ctx *q_ctx;
+
+        q_ctx = get_queue_ctx(m2m_ctx, vq->type);
+        if (!q_ctx)
+                return;
+
+        list_add_tail(&vb->queue, &q_ctx->rdy_queue);
+        q_ctx->num_rdy++;
+
+        vb->state = VIDEOBUF_QUEUED;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
+
diff --git a/include/media/v4l2-mem2mem.h b/include/media/v4l2-mem2mem.h
new file mode 100644
index 000000000000..8d149f1c58d0
--- /dev/null
+++ b/include/media/v4l2-mem2mem.h
@@ -0,0 +1,201 @@
+/*
+ * 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, <p.osciak@samsung.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/videobuf-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);
+};
+
+struct v4l2_m2m_dev;
+
+struct v4l2_m2m_queue_ctx {
+/* private: internal use only */
+        struct videobuf_queue   q;
+
+        /* Queue for buffers ready to be processed as soon as this
+         * instance receives access to the device */
+        struct list_head        rdy_queue;
+        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;
+
+        /* Instance private data */
+        void                            *priv;
+};
+
+void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
+
+struct videobuf_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);
+
+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(void *priv, struct v4l2_m2m_dev *m2m_dev,
+                        void (*vq_init)(void *priv, struct videobuf_queue *,
+                                        enum v4l2_buf_type));
+void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
+
+void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct videobuf_queue *vq,
+                        struct videobuf_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_ctx *m2m_ctx, enum v4l2_buf_type type);
+
+/**
+ * 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, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+
+/**
+ * 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, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+}
+
+/**
+ * v4l2_m2m_get_src_vq() - return videobuf_queue for source buffers
+ */
+static inline
+struct videobuf_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
+{
+        return v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+
+/**
+ * v4l2_m2m_get_dst_vq() - return videobuf_queue for destination buffers
+ */
+static inline
+struct videobuf_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
+{
+        return v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+}
+
+void *v4l2_m2m_buf_remove(struct v4l2_m2m_ctx *m2m_ctx,
+                          enum v4l2_buf_type type);
+
+/**
+ * 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, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+
+/**
+ * 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, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+}
+
+#endif /* _MEDIA_V4L2_MEM2MEM_H */
+