different from existing drivers that use memory buffers for only one
of those at once.
In terms of V4L2 such a device would be both of OUTPUT and CAPTURE type.
Although no such devices are present in the V4L2 framework, a demand for such
a model exists, e.g. for 'resizer devices'.
Signed-off-by: Pawel Osciak <p.osciak@samsung.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Kyungmin Park <kyungmin.park@samsung.com>
---
drivers/media/video/Kconfig | 4 +
drivers/media/video/Makefile | 2 +
drivers/media/video/v4l2-mem2mem.c | 671 ++++++++++++++++++++++++++++++++++++
include/media/v4l2-mem2mem.h | 152 ++++++++
4 files changed, 829 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/v4l2-mem2mem.c
create mode 100644 include/media/v4l2-mem2mem.h
@@ -49,6 +49,10 @@ config VIDEO_TUNER
tristate
depends on MEDIA_TUNER
+config V4L2_MEM2MEM_DEV
+ tristate
+ depends on VIDEOBUF_GEN
+
#
# Multimedia Video device configuration
#
@@ -112,6 +112,8 @@ 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
new file mode 100644
@@ -0,0 +1,671 @@
+/*
+ * 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
+ */
+
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <media/videobuf-core.h>
+#include <media/v4l2-mem2mem.h>
+
+MODULE_DESCRIPTION("Mem to mem device framework for V4L2");
+MODULE_AUTHOR("Pawel Osciak, <p.osciak@samsung.com>");
+MODULE_LICENSE("GPL");
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(fmt, arg...) do {\
+ if (debug >= 1)\
+ printk(KERN_DEBUG "%s: " fmt, __func__, ## arg); } while (0)
+
+
+/* The instance is already queued on the jobqueue */
+#define TRANS_QUEUED (1 << 0)
+/* The 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 (TASK_SIZE / 2)
+
+
+struct v4l2_m2m_dev {
+ /* Currently running instance */
+ struct v4l2_m2m_ctx *curr_ctx;
+ /* Instances queued to run */
+ struct list_head jobqueue;
+ spinlock_t job_spinlock;
+
+ struct v4l2_m2m_ops *m2m_ops;
+};
+
+static inline
+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_get_src_vq() - return videobuf_queue for source buffers
+ */
+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);
+}
+EXPORT_SYMBOL(v4l2_m2m_get_src_vq);
+
+/**
+ * v4l2_m2m_get_dst_vq() - return videobuf_queue for destination buffers
+ */
+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);
+}
+EXPORT_SYMBOL(v4l2_m2m_get_dst_vq);
+
+/**
+ * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
+ */
+static 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;
+
+ q_ctx = get_queue_ctx(m2m_ctx, type);
+
+ vb = list_entry(q_ctx->rdy_queue.next, struct videobuf_buffer, queue);
+ vb->state = VIDEOBUF_ACTIVE;
+
+ return vb;
+}
+
+/**
+ * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
+ * buffers
+ */
+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);
+}
+EXPORT_SYMBOL(v4l2_m2m_next_src_buf);
+
+/**
+ * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
+ * ready buffers
+ */
+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);
+}
+EXPORT_SYMBOL(v4l2_m2m_next_dst_buf);
+
+/**
+ * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
+ * return it
+ */
+static 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 = 0;
+
+ q_ctx = get_queue_ctx(m2m_ctx, type);
+
+ spin_lock_irqsave(q_ctx->q.irqlock, flags);
+ 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;
+}
+
+/**
+ * v4l2_m2m_src_buf_remove() - take off a srouce buffer from the list of ready
+ * buffers and return it
+ */
+void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
+{
+ return v4l2_m2m_buf_remove(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
+}
+EXPORT_SYMBOL(v4l2_m2m_src_buf_remove);
+
+/**
+ * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
+ * ready buffers and return it
+ */
+void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
+{
+ return v4l2_m2m_buf_remove(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
+
+}
+EXPORT_SYMBOL(v4l2_m2m_dst_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)
+{
+ if (!m2m_dev->curr_ctx)
+ return NULL;
+ else
+ return m2m_dev->curr_ctx->priv;
+}
+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 = 0;
+
+ 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->jobqueue)) {
+ spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+ dprintk("No job pending\n");
+ return;
+ }
+
+ m2m_dev->curr_ctx = list_entry(m2m_dev->jobqueue.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);
+
+ return;
+}
+
+/**
+ * v4l2_m2m_schedule() - add an instance to the pending job queue
+ * @m2m_ctx: The instance to be added to the pending job queue
+ *
+ * Called when an instance is fully prepared to run a transaction, i.e. the
+ * instance will not sleep before finishing the transaction when run.
+ * If an instance is already on the queue, it will not be added for the second
+ * time and it is the responsibility of the instance to retry this at a later
+ * time.
+ */
+static void v4l2_m2m_schedule(struct v4l2_m2m_ctx *m2m_ctx)
+{
+ struct v4l2_m2m_dev *dev = m2m_ctx->m2m_dev;
+ unsigned long flags = 0;
+
+ spin_lock_irqsave(&dev->job_spinlock, flags);
+ if (!(m2m_ctx->job_flags & TRANS_QUEUED)) {
+ list_add_tail(&m2m_ctx->queue, &dev->jobqueue);
+ m2m_ctx->job_flags |= TRANS_QUEUED;
+ }
+ spin_unlock_irqrestore(&dev->job_spinlock, flags);
+
+ v4l2_m2m_try_run(dev);
+}
+
+/**
+ * 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 can also be additional, custom requirements. In such case the driver
+ * should supply a custom method (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 = 0;
+
+ m2m_dev = m2m_ctx->m2m_dev;
+ dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
+
+ spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
+ if (m2m_ctx->job_flags & TRANS_QUEUED) {
+ spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+ dprintk("On job queue already\n");
+ return;
+ }
+ spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
+
+ /* Checking only one queue is enough, we always turn on both */
+ if (!m2m_ctx->out_q_ctx.q.streaming) {
+ dprintk("Streaming not on, will not schedule\n");
+ return;
+ }
+
+ if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
+ dprintk("No input buffers available\n");
+ return;
+ }
+ if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
+ dprintk("No output buffers available\n");
+ return;
+ }
+
+ if (m2m_dev->m2m_ops->job_ready
+ && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
+ dprintk("Driver not ready\n");
+ return;
+ }
+
+ dprintk("Instance ready to be scheduled\n");
+ v4l2_m2m_schedule(m2m_ctx);
+}
+
+/**
+ * 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.
+ *
+ * TODO: An instance that fails to give back the device before a predefined
+ * amount of time may have its device ownership taken away forcibly.
+ */
+void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
+ struct v4l2_m2m_ctx *m2m_ctx)
+{
+ unsigned long flags = 0;
+
+ 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;
+ }
+
+ /*mutex_lock(&m2m_dev->dev_mutex);*/
+ 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);
+
+ 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 = 0;
+
+ 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;
+
+ vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
+ return videobuf_qbuf(vq, buf);
+}
+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() - start streaming
+ */
+int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+ enum v4l2_buf_type type)
+{
+ int ret = 0;
+
+ /* These can fail only if the queues are in use,
+ * but they shouldn't be as we are managing instances manually */
+ ret = videobuf_streamon(&m2m_ctx->out_q_ctx.q);
+ if (ret) {
+ printk(KERN_ERR "Streamon on output queue failed\n");
+ return ret;
+ }
+
+ ret = videobuf_streamon(&m2m_ctx->cap_q_ctx.q);
+ if (ret) {
+ printk(KERN_ERR "Streamon on capture queue failed\n");
+ return ret;
+ }
+
+ v4l2_m2m_try_schedule(m2m_ctx);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
+
+/**
+ * v4l2_m2m_streamoff() - stop streaming
+ */
+int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+ enum v4l2_buf_type type)
+{
+ /* streamoff() fails only when we are not streaming */
+ if (videobuf_streamoff(&m2m_ctx->out_q_ctx.q)
+ || videobuf_streamoff(&m2m_ctx->cap_q_ctx.q))
+ return -EINVAL;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
+
+/**
+ * v4l2_m2m_poll() - poll replacement, for destination buffers only
+ *
+ * Call from driver's poll() function. Will poll the destination queue only.
+ */
+unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
+ struct poll_table_struct *wait)
+{
+ struct videobuf_queue *dst_q = NULL;
+ struct videobuf_buffer *vb = NULL;
+ unsigned int rc = 0;
+
+ dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
+
+ mutex_lock(&dst_q->vb_lock);
+
+ if (dst_q->streaming) {
+ if (!list_empty(&dst_q->stream))
+ vb = list_entry(dst_q->stream.next,
+ struct videobuf_buffer, stream);
+ }
+
+ if (!vb)
+ rc = POLLERR;
+
+ if (0 == rc) {
+ poll_wait(file, &vb->done, wait);
+ if (vb->state == VIDEOBUF_DONE || vb->state == VIDEOBUF_ERROR)
+ rc = POLLOUT | POLLRDNORM;
+ }
+
+ mutex_unlock(&dst_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 differentation 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->job_ready);*/
+ 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->jobqueue);
+ 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;
+ struct v4l2_m2m_queue_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);
+
+ /*spin_lock_init(&m2m_ctx->queue_lock);*/
+ 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 = m2m_ctx;
+
+ 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 = 0;
+
+ 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 withing buf_queue() videobuf_queue_ops callback.
+ */
+/* Locking: Caller holds q->irqlock */
+void v4l2_m2m_buf_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
+{
+ struct v4l2_m2m_ctx *m2m_ctx = vq->priv_data;
+ 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;
+
+ v4l2_m2m_try_schedule(m2m_ctx);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
+
new file mode 100644
@@ -0,0 +1,152 @@
+/*
+ * 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
+ * transactio 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.
+ * @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;
+
+ /* Base value for offsets of mmaped buffers on this queue */
+ unsigned long offset_base;
+
+ /* 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_src_vq(struct v4l2_m2m_ctx *m2m_ctx);
+struct videobuf_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx);
+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);
+
+void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx);
+void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx);
+
+void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx);
+void *v4l2_m2m_dst_buf_remove(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 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;
+}
+
+#endif /* _MEDIA_V4L2_MEM2MEM_H */
+