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path: root/drivers/media/v4l2-core/videobuf-core.c
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Diffstat (limited to 'drivers/media/v4l2-core/videobuf-core.c')
-rw-r--r--drivers/media/v4l2-core/videobuf-core.c1189
1 files changed, 1189 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf-core.c b/drivers/media/v4l2-core/videobuf-core.c
new file mode 100644
index 000000000000..bf7a326b1cdc
--- /dev/null
+++ b/drivers/media/v4l2-core/videobuf-core.c
@@ -0,0 +1,1189 @@
+/*
+ * generic helper functions for handling video4linux capture buffers
+ *
+ * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
+ *
+ * Highly based on video-buf written originally by:
+ * (c) 2001,02 Gerd Knorr <kraxel@bytesex.org>
+ * (c) 2006 Mauro Carvalho Chehab, <mchehab@infradead.org>
+ * (c) 2006 Ted Walther and John Sokol
+ *
+ * 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
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+
+#include <media/videobuf-core.h>
+
+#define MAGIC_BUFFER 0x20070728
+#define MAGIC_CHECK(is, should) \
+ do { \
+ if (unlikely((is) != (should))) { \
+ printk(KERN_ERR \
+ "magic mismatch: %x (expected %x)\n", \
+ is, should); \
+ BUG(); \
+ } \
+ } while (0)
+
+static int debug;
+module_param(debug, int, 0644);
+
+MODULE_DESCRIPTION("helper module to manage video4linux buffers");
+MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
+MODULE_LICENSE("GPL");
+
+#define dprintk(level, fmt, arg...) \
+ do { \
+ if (debug >= level) \
+ printk(KERN_DEBUG "vbuf: " fmt, ## arg); \
+ } while (0)
+
+/* --------------------------------------------------------------------- */
+
+#define CALL(q, f, arg...) \
+ ((q->int_ops->f) ? q->int_ops->f(arg) : 0)
+
+struct videobuf_buffer *videobuf_alloc_vb(struct videobuf_queue *q)
+{
+ struct videobuf_buffer *vb;
+
+ BUG_ON(q->msize < sizeof(*vb));
+
+ if (!q->int_ops || !q->int_ops->alloc_vb) {
+ printk(KERN_ERR "No specific ops defined!\n");
+ BUG();
+ }
+
+ vb = q->int_ops->alloc_vb(q->msize);
+ if (NULL != vb) {
+ init_waitqueue_head(&vb->done);
+ vb->magic = MAGIC_BUFFER;
+ }
+
+ return vb;
+}
+EXPORT_SYMBOL_GPL(videobuf_alloc_vb);
+
+static int is_state_active_or_queued(struct videobuf_queue *q, struct videobuf_buffer *vb)
+{
+ unsigned long flags;
+ bool rc;
+
+ spin_lock_irqsave(q->irqlock, flags);
+ rc = vb->state != VIDEOBUF_ACTIVE && vb->state != VIDEOBUF_QUEUED;
+ spin_unlock_irqrestore(q->irqlock, flags);
+ return rc;
+};
+
+int videobuf_waiton(struct videobuf_queue *q, struct videobuf_buffer *vb,
+ int non_blocking, int intr)
+{
+ bool is_ext_locked;
+ int ret = 0;
+
+ MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
+
+ if (non_blocking) {
+ if (is_state_active_or_queued(q, vb))
+ return 0;
+ return -EAGAIN;
+ }
+
+ is_ext_locked = q->ext_lock && mutex_is_locked(q->ext_lock);
+
+ /* Release vdev lock to prevent this wait from blocking outside access to
+ the device. */
+ if (is_ext_locked)
+ mutex_unlock(q->ext_lock);
+ if (intr)
+ ret = wait_event_interruptible(vb->done, is_state_active_or_queued(q, vb));
+ else
+ wait_event(vb->done, is_state_active_or_queued(q, vb));
+ /* Relock */
+ if (is_ext_locked)
+ mutex_lock(q->ext_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(videobuf_waiton);
+
+int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
+ struct v4l2_framebuffer *fbuf)
+{
+ MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ return CALL(q, iolock, q, vb, fbuf);
+}
+EXPORT_SYMBOL_GPL(videobuf_iolock);
+
+void *videobuf_queue_to_vaddr(struct videobuf_queue *q,
+ struct videobuf_buffer *buf)
+{
+ if (q->int_ops->vaddr)
+ return q->int_ops->vaddr(buf);
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(videobuf_queue_to_vaddr);
+
+/* --------------------------------------------------------------------- */
+
+
+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)
+{
+ BUG_ON(!q);
+ memset(q, 0, sizeof(*q));
+ q->irqlock = irqlock;
+ q->ext_lock = ext_lock;
+ q->dev = dev;
+ q->type = type;
+ q->field = field;
+ q->msize = msize;
+ q->ops = ops;
+ q->priv_data = priv;
+ q->int_ops = int_ops;
+
+ /* All buffer operations are mandatory */
+ BUG_ON(!q->ops->buf_setup);
+ BUG_ON(!q->ops->buf_prepare);
+ BUG_ON(!q->ops->buf_queue);
+ BUG_ON(!q->ops->buf_release);
+
+ /* Lock is mandatory for queue_cancel to work */
+ BUG_ON(!irqlock);
+
+ /* Having implementations for abstract methods are mandatory */
+ BUG_ON(!q->int_ops);
+
+ mutex_init(&q->vb_lock);
+ init_waitqueue_head(&q->wait);
+ INIT_LIST_HEAD(&q->stream);
+}
+EXPORT_SYMBOL_GPL(videobuf_queue_core_init);
+
+/* Locking: Only usage in bttv unsafe find way to remove */
+int videobuf_queue_is_busy(struct videobuf_queue *q)
+{
+ int i;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ if (q->streaming) {
+ dprintk(1, "busy: streaming active\n");
+ return 1;
+ }
+ if (q->reading) {
+ dprintk(1, "busy: pending read #1\n");
+ return 1;
+ }
+ if (q->read_buf) {
+ dprintk(1, "busy: pending read #2\n");
+ return 1;
+ }
+ for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+ if (NULL == q->bufs[i])
+ continue;
+ if (q->bufs[i]->map) {
+ dprintk(1, "busy: buffer #%d mapped\n", i);
+ return 1;
+ }
+ if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
+ dprintk(1, "busy: buffer #%d queued\n", i);
+ return 1;
+ }
+ if (q->bufs[i]->state == VIDEOBUF_ACTIVE) {
+ dprintk(1, "busy: buffer #%d avtive\n", i);
+ return 1;
+ }
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(videobuf_queue_is_busy);
+
+/**
+ * __videobuf_free() - free all the buffers and their control structures
+ *
+ * This function can only be called if streaming/reading is off, i.e. no buffers
+ * are under control of the driver.
+ */
+/* Locking: Caller holds q->vb_lock */
+static int __videobuf_free(struct videobuf_queue *q)
+{
+ int i;
+
+ dprintk(1, "%s\n", __func__);
+ if (!q)
+ return 0;
+
+ if (q->streaming || q->reading) {
+ dprintk(1, "Cannot free buffers when streaming or reading\n");
+ return -EBUSY;
+ }
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ for (i = 0; i < VIDEO_MAX_FRAME; i++)
+ if (q->bufs[i] && q->bufs[i]->map) {
+ dprintk(1, "Cannot free mmapped buffers\n");
+ return -EBUSY;
+ }
+
+ for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+ if (NULL == q->bufs[i])
+ continue;
+ q->ops->buf_release(q, q->bufs[i]);
+ kfree(q->bufs[i]);
+ q->bufs[i] = NULL;
+ }
+
+ return 0;
+}
+
+/* Locking: Caller holds q->vb_lock */
+void videobuf_queue_cancel(struct videobuf_queue *q)
+{
+ unsigned long flags = 0;
+ int i;
+
+ q->streaming = 0;
+ q->reading = 0;
+ wake_up_interruptible_sync(&q->wait);
+
+ /* remove queued buffers from list */
+ spin_lock_irqsave(q->irqlock, flags);
+ for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+ if (NULL == q->bufs[i])
+ continue;
+ if (q->bufs[i]->state == VIDEOBUF_QUEUED) {
+ list_del(&q->bufs[i]->queue);
+ q->bufs[i]->state = VIDEOBUF_ERROR;
+ wake_up_all(&q->bufs[i]->done);
+ }
+ }
+ spin_unlock_irqrestore(q->irqlock, flags);
+
+ /* free all buffers + clear queue */
+ for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+ if (NULL == q->bufs[i])
+ continue;
+ q->ops->buf_release(q, q->bufs[i]);
+ }
+ INIT_LIST_HEAD(&q->stream);
+}
+EXPORT_SYMBOL_GPL(videobuf_queue_cancel);
+
+/* --------------------------------------------------------------------- */
+
+/* Locking: Caller holds q->vb_lock */
+enum v4l2_field videobuf_next_field(struct videobuf_queue *q)
+{
+ enum v4l2_field field = q->field;
+
+ BUG_ON(V4L2_FIELD_ANY == field);
+
+ if (V4L2_FIELD_ALTERNATE == field) {
+ if (V4L2_FIELD_TOP == q->last) {
+ field = V4L2_FIELD_BOTTOM;
+ q->last = V4L2_FIELD_BOTTOM;
+ } else {
+ field = V4L2_FIELD_TOP;
+ q->last = V4L2_FIELD_TOP;
+ }
+ }
+ return field;
+}
+EXPORT_SYMBOL_GPL(videobuf_next_field);
+
+/* Locking: Caller holds q->vb_lock */
+static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b,
+ struct videobuf_buffer *vb, enum v4l2_buf_type type)
+{
+ MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ b->index = vb->i;
+ b->type = type;
+
+ b->memory = vb->memory;
+ switch (b->memory) {
+ case V4L2_MEMORY_MMAP:
+ b->m.offset = vb->boff;
+ b->length = vb->bsize;
+ break;
+ case V4L2_MEMORY_USERPTR:
+ b->m.userptr = vb->baddr;
+ b->length = vb->bsize;
+ break;
+ case V4L2_MEMORY_OVERLAY:
+ b->m.offset = vb->boff;
+ break;
+ }
+
+ b->flags = 0;
+ if (vb->map)
+ b->flags |= V4L2_BUF_FLAG_MAPPED;
+
+ switch (vb->state) {
+ case VIDEOBUF_PREPARED:
+ case VIDEOBUF_QUEUED:
+ case VIDEOBUF_ACTIVE:
+ b->flags |= V4L2_BUF_FLAG_QUEUED;
+ break;
+ case VIDEOBUF_ERROR:
+ b->flags |= V4L2_BUF_FLAG_ERROR;
+ /* fall through */
+ case VIDEOBUF_DONE:
+ b->flags |= V4L2_BUF_FLAG_DONE;
+ break;
+ case VIDEOBUF_NEEDS_INIT:
+ case VIDEOBUF_IDLE:
+ /* nothing */
+ break;
+ }
+
+ b->field = vb->field;
+ b->timestamp = vb->ts;
+ b->bytesused = vb->size;
+ b->sequence = vb->field_count >> 1;
+}
+
+int videobuf_mmap_free(struct videobuf_queue *q)
+{
+ int ret;
+ videobuf_queue_lock(q);
+ ret = __videobuf_free(q);
+ videobuf_queue_unlock(q);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(videobuf_mmap_free);
+
+/* Locking: Caller holds q->vb_lock */
+int __videobuf_mmap_setup(struct videobuf_queue *q,
+ unsigned int bcount, unsigned int bsize,
+ enum v4l2_memory memory)
+{
+ unsigned int i;
+ int err;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ err = __videobuf_free(q);
+ if (0 != err)
+ return err;
+
+ /* Allocate and initialize buffers */
+ for (i = 0; i < bcount; i++) {
+ q->bufs[i] = videobuf_alloc_vb(q);
+
+ if (NULL == q->bufs[i])
+ break;
+
+ q->bufs[i]->i = i;
+ q->bufs[i]->memory = memory;
+ q->bufs[i]->bsize = bsize;
+ switch (memory) {
+ case V4L2_MEMORY_MMAP:
+ q->bufs[i]->boff = PAGE_ALIGN(bsize) * i;
+ break;
+ case V4L2_MEMORY_USERPTR:
+ case V4L2_MEMORY_OVERLAY:
+ /* nothing */
+ break;
+ }
+ }
+
+ if (!i)
+ return -ENOMEM;
+
+ dprintk(1, "mmap setup: %d buffers, %d bytes each\n", i, bsize);
+
+ return i;
+}
+EXPORT_SYMBOL_GPL(__videobuf_mmap_setup);
+
+int videobuf_mmap_setup(struct videobuf_queue *q,
+ unsigned int bcount, unsigned int bsize,
+ enum v4l2_memory memory)
+{
+ int ret;
+ videobuf_queue_lock(q);
+ ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
+ videobuf_queue_unlock(q);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(videobuf_mmap_setup);
+
+int videobuf_reqbufs(struct videobuf_queue *q,
+ struct v4l2_requestbuffers *req)
+{
+ unsigned int size, count;
+ int retval;
+
+ if (req->count < 1) {
+ dprintk(1, "reqbufs: count invalid (%d)\n", req->count);
+ return -EINVAL;
+ }
+
+ if (req->memory != V4L2_MEMORY_MMAP &&
+ req->memory != V4L2_MEMORY_USERPTR &&
+ req->memory != V4L2_MEMORY_OVERLAY) {
+ dprintk(1, "reqbufs: memory type invalid\n");
+ return -EINVAL;
+ }
+
+ videobuf_queue_lock(q);
+ if (req->type != q->type) {
+ dprintk(1, "reqbufs: queue type invalid\n");
+ retval = -EINVAL;
+ goto done;
+ }
+
+ if (q->streaming) {
+ dprintk(1, "reqbufs: streaming already exists\n");
+ retval = -EBUSY;
+ goto done;
+ }
+ if (!list_empty(&q->stream)) {
+ dprintk(1, "reqbufs: stream running\n");
+ retval = -EBUSY;
+ goto done;
+ }
+
+ count = req->count;
+ if (count > VIDEO_MAX_FRAME)
+ count = VIDEO_MAX_FRAME;
+ size = 0;
+ q->ops->buf_setup(q, &count, &size);
+ dprintk(1, "reqbufs: bufs=%d, size=0x%x [%u pages total]\n",
+ count, size,
+ (unsigned int)((count * PAGE_ALIGN(size)) >> PAGE_SHIFT));
+
+ retval = __videobuf_mmap_setup(q, count, size, req->memory);
+ if (retval < 0) {
+ dprintk(1, "reqbufs: mmap setup returned %d\n", retval);
+ goto done;
+ }
+
+ req->count = retval;
+ retval = 0;
+
+ done:
+ videobuf_queue_unlock(q);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_reqbufs);
+
+int videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
+{
+ int ret = -EINVAL;
+
+ videobuf_queue_lock(q);
+ if (unlikely(b->type != q->type)) {
+ dprintk(1, "querybuf: Wrong type.\n");
+ goto done;
+ }
+ if (unlikely(b->index >= VIDEO_MAX_FRAME)) {
+ dprintk(1, "querybuf: index out of range.\n");
+ goto done;
+ }
+ if (unlikely(NULL == q->bufs[b->index])) {
+ dprintk(1, "querybuf: buffer is null.\n");
+ goto done;
+ }
+
+ videobuf_status(q, b, q->bufs[b->index], q->type);
+
+ ret = 0;
+done:
+ videobuf_queue_unlock(q);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(videobuf_querybuf);
+
+int videobuf_qbuf(struct videobuf_queue *q, struct v4l2_buffer *b)
+{
+ struct videobuf_buffer *buf;
+ enum v4l2_field field;
+ unsigned long flags = 0;
+ int retval;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ if (b->memory == V4L2_MEMORY_MMAP)
+ down_read(&current->mm->mmap_sem);
+
+ videobuf_queue_lock(q);
+ retval = -EBUSY;
+ if (q->reading) {
+ dprintk(1, "qbuf: Reading running...\n");
+ goto done;
+ }
+ retval = -EINVAL;
+ if (b->type != q->type) {
+ dprintk(1, "qbuf: Wrong type.\n");
+ goto done;
+ }
+ if (b->index >= VIDEO_MAX_FRAME) {
+ dprintk(1, "qbuf: index out of range.\n");
+ goto done;
+ }
+ buf = q->bufs[b->index];
+ if (NULL == buf) {
+ dprintk(1, "qbuf: buffer is null.\n");
+ goto done;
+ }
+ MAGIC_CHECK(buf->magic, MAGIC_BUFFER);
+ if (buf->memory != b->memory) {
+ dprintk(1, "qbuf: memory type is wrong.\n");
+ goto done;
+ }
+ if (buf->state != VIDEOBUF_NEEDS_INIT && buf->state != VIDEOBUF_IDLE) {
+ dprintk(1, "qbuf: buffer is already queued or active.\n");
+ goto done;
+ }
+
+ switch (b->memory) {
+ case V4L2_MEMORY_MMAP:
+ if (0 == buf->baddr) {
+ dprintk(1, "qbuf: mmap requested "
+ "but buffer addr is zero!\n");
+ goto done;
+ }
+ if (q->type == V4L2_BUF_TYPE_VIDEO_OUTPUT
+ || q->type == V4L2_BUF_TYPE_VBI_OUTPUT
+ || q->type == V4L2_BUF_TYPE_SLICED_VBI_OUTPUT) {
+ buf->size = b->bytesused;
+ buf->field = b->field;
+ buf->ts = b->timestamp;
+ }
+ break;
+ case V4L2_MEMORY_USERPTR:
+ if (b->length < buf->bsize) {
+ dprintk(1, "qbuf: buffer length is not enough\n");
+ goto done;
+ }
+ if (VIDEOBUF_NEEDS_INIT != buf->state &&
+ buf->baddr != b->m.userptr)
+ q->ops->buf_release(q, buf);
+ buf->baddr = b->m.userptr;
+ break;
+ case V4L2_MEMORY_OVERLAY:
+ buf->boff = b->m.offset;
+ break;
+ default:
+ dprintk(1, "qbuf: wrong memory type\n");
+ goto done;
+ }
+
+ dprintk(1, "qbuf: requesting next field\n");
+ field = videobuf_next_field(q);
+ retval = q->ops->buf_prepare(q, buf, field);
+ if (0 != retval) {
+ dprintk(1, "qbuf: buffer_prepare returned %d\n", retval);
+ goto done;
+ }
+
+ list_add_tail(&buf->stream, &q->stream);
+ if (q->streaming) {
+ spin_lock_irqsave(q->irqlock, flags);
+ q->ops->buf_queue(q, buf);
+ spin_unlock_irqrestore(q->irqlock, flags);
+ }
+ dprintk(1, "qbuf: succeeded\n");
+ retval = 0;
+ wake_up_interruptible_sync(&q->wait);
+
+done:
+ videobuf_queue_unlock(q);
+
+ if (b->memory == V4L2_MEMORY_MMAP)
+ up_read(&current->mm->mmap_sem);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_qbuf);
+
+/* Locking: Caller holds q->vb_lock */
+static int stream_next_buffer_check_queue(struct videobuf_queue *q, int noblock)
+{
+ int retval;
+
+checks:
+ if (!q->streaming) {
+ dprintk(1, "next_buffer: Not streaming\n");
+ retval = -EINVAL;
+ goto done;
+ }
+
+ if (list_empty(&q->stream)) {
+ if (noblock) {
+ retval = -EAGAIN;
+ dprintk(2, "next_buffer: no buffers to dequeue\n");
+ goto done;
+ } else {
+ dprintk(2, "next_buffer: waiting on buffer\n");
+
+ /* Drop lock to avoid deadlock with qbuf */
+ videobuf_queue_unlock(q);
+
+ /* Checking list_empty and streaming is safe without
+ * locks because we goto checks to validate while
+ * holding locks before proceeding */
+ retval = wait_event_interruptible(q->wait,
+ !list_empty(&q->stream) || !q->streaming);
+ videobuf_queue_lock(q);
+
+ if (retval)
+ goto done;
+
+ goto checks;
+ }
+ }
+
+ retval = 0;
+
+done:
+ return retval;
+}
+
+/* Locking: Caller holds q->vb_lock */
+static int stream_next_buffer(struct videobuf_queue *q,
+ struct videobuf_buffer **vb, int nonblocking)
+{
+ int retval;
+ struct videobuf_buffer *buf = NULL;
+
+ retval = stream_next_buffer_check_queue(q, nonblocking);
+ if (retval)
+ goto done;
+
+ buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
+ retval = videobuf_waiton(q, buf, nonblocking, 1);
+ if (retval < 0)
+ goto done;
+
+ *vb = buf;
+done:
+ return retval;
+}
+
+int videobuf_dqbuf(struct videobuf_queue *q,
+ struct v4l2_buffer *b, int nonblocking)
+{
+ struct videobuf_buffer *buf = NULL;
+ int retval;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ memset(b, 0, sizeof(*b));
+ videobuf_queue_lock(q);
+
+ retval = stream_next_buffer(q, &buf, nonblocking);
+ if (retval < 0) {
+ dprintk(1, "dqbuf: next_buffer error: %i\n", retval);
+ goto done;
+ }
+
+ switch (buf->state) {
+ case VIDEOBUF_ERROR:
+ dprintk(1, "dqbuf: state is error\n");
+ break;
+ case VIDEOBUF_DONE:
+ dprintk(1, "dqbuf: state is done\n");
+ break;
+ default:
+ dprintk(1, "dqbuf: state invalid\n");
+ retval = -EINVAL;
+ goto done;
+ }
+ CALL(q, sync, q, buf);
+ videobuf_status(q, b, buf, q->type);
+ list_del(&buf->stream);
+ buf->state = VIDEOBUF_IDLE;
+ b->flags &= ~V4L2_BUF_FLAG_DONE;
+done:
+ videobuf_queue_unlock(q);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_dqbuf);
+
+int videobuf_streamon(struct videobuf_queue *q)
+{
+ struct videobuf_buffer *buf;
+ unsigned long flags = 0;
+ int retval;
+
+ videobuf_queue_lock(q);
+ retval = -EBUSY;
+ if (q->reading)
+ goto done;
+ retval = 0;
+ if (q->streaming)
+ goto done;
+ q->streaming = 1;
+ spin_lock_irqsave(q->irqlock, flags);
+ list_for_each_entry(buf, &q->stream, stream)
+ if (buf->state == VIDEOBUF_PREPARED)
+ q->ops->buf_queue(q, buf);
+ spin_unlock_irqrestore(q->irqlock, flags);
+
+ wake_up_interruptible_sync(&q->wait);
+done:
+ videobuf_queue_unlock(q);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_streamon);
+
+/* Locking: Caller holds q->vb_lock */
+static int __videobuf_streamoff(struct videobuf_queue *q)
+{
+ if (!q->streaming)
+ return -EINVAL;
+
+ videobuf_queue_cancel(q);
+
+ return 0;
+}
+
+int videobuf_streamoff(struct videobuf_queue *q)
+{
+ int retval;
+
+ videobuf_queue_lock(q);
+ retval = __videobuf_streamoff(q);
+ videobuf_queue_unlock(q);
+
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_streamoff);
+
+/* Locking: Caller holds q->vb_lock */
+static ssize_t videobuf_read_zerocopy(struct videobuf_queue *q,
+ char __user *data,
+ size_t count, loff_t *ppos)
+{
+ enum v4l2_field field;
+ unsigned long flags = 0;
+ int retval;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ /* setup stuff */
+ q->read_buf = videobuf_alloc_vb(q);
+ if (NULL == q->read_buf)
+ return -ENOMEM;
+
+ q->read_buf->memory = V4L2_MEMORY_USERPTR;
+ q->read_buf->baddr = (unsigned long)data;
+ q->read_buf->bsize = count;
+
+ field = videobuf_next_field(q);
+ retval = q->ops->buf_prepare(q, q->read_buf, field);
+ if (0 != retval)
+ goto done;
+
+ /* start capture & wait */
+ spin_lock_irqsave(q->irqlock, flags);
+ q->ops->buf_queue(q, q->read_buf);
+ spin_unlock_irqrestore(q->irqlock, flags);
+ retval = videobuf_waiton(q, q->read_buf, 0, 0);
+ if (0 == retval) {
+ CALL(q, sync, q, q->read_buf);
+ if (VIDEOBUF_ERROR == q->read_buf->state)
+ retval = -EIO;
+ else
+ retval = q->read_buf->size;
+ }
+
+done:
+ /* cleanup */
+ q->ops->buf_release(q, q->read_buf);
+ kfree(q->read_buf);
+ q->read_buf = NULL;
+ return retval;
+}
+
+static int __videobuf_copy_to_user(struct videobuf_queue *q,
+ struct videobuf_buffer *buf,
+ char __user *data, size_t count,
+ int nonblocking)
+{
+ void *vaddr = CALL(q, vaddr, buf);
+
+ /* copy to userspace */
+ if (count > buf->size - q->read_off)
+ count = buf->size - q->read_off;
+
+ if (copy_to_user(data, vaddr + q->read_off, count))
+ return -EFAULT;
+
+ return count;
+}
+
+static int __videobuf_copy_stream(struct videobuf_queue *q,
+ struct videobuf_buffer *buf,
+ char __user *data, size_t count, size_t pos,
+ int vbihack, int nonblocking)
+{
+ unsigned int *fc = CALL(q, vaddr, buf);
+
+ if (vbihack) {
+ /* dirty, undocumented hack -- pass the frame counter
+ * within the last four bytes of each vbi data block.
+ * We need that one to maintain backward compatibility
+ * to all vbi decoding software out there ... */
+ fc += (buf->size >> 2) - 1;
+ *fc = buf->field_count >> 1;
+ dprintk(1, "vbihack: %d\n", *fc);
+ }
+
+ /* copy stuff using the common method */
+ count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
+
+ if ((count == -EFAULT) && (pos == 0))
+ return -EFAULT;
+
+ return count;
+}
+
+ssize_t videobuf_read_one(struct videobuf_queue *q,
+ char __user *data, size_t count, loff_t *ppos,
+ int nonblocking)
+{
+ enum v4l2_field field;
+ unsigned long flags = 0;
+ unsigned size = 0, nbufs = 1;
+ int retval;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ videobuf_queue_lock(q);
+
+ q->ops->buf_setup(q, &nbufs, &size);
+
+ if (NULL == q->read_buf &&
+ count >= size &&
+ !nonblocking) {
+ retval = videobuf_read_zerocopy(q, data, count, ppos);
+ if (retval >= 0 || retval == -EIO)
+ /* ok, all done */
+ goto done;
+ /* fallback to kernel bounce buffer on failures */
+ }
+
+ if (NULL == q->read_buf) {
+ /* need to capture a new frame */
+ retval = -ENOMEM;
+ q->read_buf = videobuf_alloc_vb(q);
+
+ dprintk(1, "video alloc=0x%p\n", q->read_buf);
+ if (NULL == q->read_buf)
+ goto done;
+ q->read_buf->memory = V4L2_MEMORY_USERPTR;
+ q->read_buf->bsize = count; /* preferred size */
+ field = videobuf_next_field(q);
+ retval = q->ops->buf_prepare(q, q->read_buf, field);
+
+ if (0 != retval) {
+ kfree(q->read_buf);
+ q->read_buf = NULL;
+ goto done;
+ }
+
+ spin_lock_irqsave(q->irqlock, flags);
+ q->ops->buf_queue(q, q->read_buf);
+ spin_unlock_irqrestore(q->irqlock, flags);
+
+ q->read_off = 0;
+ }
+
+ /* wait until capture is done */
+ retval = videobuf_waiton(q, q->read_buf, nonblocking, 1);
+ if (0 != retval)
+ goto done;
+
+ CALL(q, sync, q, q->read_buf);
+
+ if (VIDEOBUF_ERROR == q->read_buf->state) {
+ /* catch I/O errors */
+ q->ops->buf_release(q, q->read_buf);
+ kfree(q->read_buf);
+ q->read_buf = NULL;
+ retval = -EIO;
+ goto done;
+ }
+
+ /* Copy to userspace */
+ retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
+ if (retval < 0)
+ goto done;
+
+ q->read_off += retval;
+ if (q->read_off == q->read_buf->size) {
+ /* all data copied, cleanup */
+ q->ops->buf_release(q, q->read_buf);
+ kfree(q->read_buf);
+ q->read_buf = NULL;
+ }
+
+done:
+ videobuf_queue_unlock(q);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_read_one);
+
+/* Locking: Caller holds q->vb_lock */
+static int __videobuf_read_start(struct videobuf_queue *q)
+{
+ enum v4l2_field field;
+ unsigned long flags = 0;
+ unsigned int count = 0, size = 0;
+ int err, i;
+
+ q->ops->buf_setup(q, &count, &size);
+ if (count < 2)
+ count = 2;
+ if (count > VIDEO_MAX_FRAME)
+ count = VIDEO_MAX_FRAME;
+ size = PAGE_ALIGN(size);
+
+ err = __videobuf_mmap_setup(q, count, size, V4L2_MEMORY_USERPTR);
+ if (err < 0)
+ return err;
+
+ count = err;
+
+ for (i = 0; i < count; i++) {
+ field = videobuf_next_field(q);
+ err = q->ops->buf_prepare(q, q->bufs[i], field);
+ if (err)
+ return err;
+ list_add_tail(&q->bufs[i]->stream, &q->stream);
+ }
+ spin_lock_irqsave(q->irqlock, flags);
+ for (i = 0; i < count; i++)
+ q->ops->buf_queue(q, q->bufs[i]);
+ spin_unlock_irqrestore(q->irqlock, flags);
+ q->reading = 1;
+ return 0;
+}
+
+static void __videobuf_read_stop(struct videobuf_queue *q)
+{
+ int i;
+
+ videobuf_queue_cancel(q);
+ __videobuf_free(q);
+ INIT_LIST_HEAD(&q->stream);
+ for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+ if (NULL == q->bufs[i])
+ continue;
+ kfree(q->bufs[i]);
+ q->bufs[i] = NULL;
+ }
+ q->read_buf = NULL;
+}
+
+int videobuf_read_start(struct videobuf_queue *q)
+{
+ int rc;
+
+ videobuf_queue_lock(q);
+ rc = __videobuf_read_start(q);
+ videobuf_queue_unlock(q);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(videobuf_read_start);
+
+void videobuf_read_stop(struct videobuf_queue *q)
+{
+ videobuf_queue_lock(q);
+ __videobuf_read_stop(q);
+ videobuf_queue_unlock(q);
+}
+EXPORT_SYMBOL_GPL(videobuf_read_stop);
+
+void videobuf_stop(struct videobuf_queue *q)
+{
+ videobuf_queue_lock(q);
+
+ if (q->streaming)
+ __videobuf_streamoff(q);
+
+ if (q->reading)
+ __videobuf_read_stop(q);
+
+ videobuf_queue_unlock(q);
+}
+EXPORT_SYMBOL_GPL(videobuf_stop);
+
+ssize_t videobuf_read_stream(struct videobuf_queue *q,
+ char __user *data, size_t count, loff_t *ppos,
+ int vbihack, int nonblocking)
+{
+ int rc, retval;
+ unsigned long flags = 0;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ dprintk(2, "%s\n", __func__);
+ videobuf_queue_lock(q);
+ retval = -EBUSY;
+ if (q->streaming)
+ goto done;
+ if (!q->reading) {
+ retval = __videobuf_read_start(q);
+ if (retval < 0)
+ goto done;
+ }
+
+ retval = 0;
+ while (count > 0) {
+ /* get / wait for data */
+ if (NULL == q->read_buf) {
+ q->read_buf = list_entry(q->stream.next,
+ struct videobuf_buffer,
+ stream);
+ list_del(&q->read_buf->stream);
+ q->read_off = 0;
+ }
+ rc = videobuf_waiton(q, q->read_buf, nonblocking, 1);
+ if (rc < 0) {
+ if (0 == retval)
+ retval = rc;
+ break;
+ }
+
+ if (q->read_buf->state == VIDEOBUF_DONE) {
+ rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
+ retval, vbihack, nonblocking);
+ if (rc < 0) {
+ retval = rc;
+ break;
+ }
+ retval += rc;
+ count -= rc;
+ q->read_off += rc;
+ } else {
+ /* some error */
+ q->read_off = q->read_buf->size;
+ if (0 == retval)
+ retval = -EIO;
+ }
+
+ /* requeue buffer when done with copying */
+ if (q->read_off == q->read_buf->size) {
+ list_add_tail(&q->read_buf->stream,
+ &q->stream);
+ spin_lock_irqsave(q->irqlock, flags);
+ q->ops->buf_queue(q, q->read_buf);
+ spin_unlock_irqrestore(q->irqlock, flags);
+ q->read_buf = NULL;
+ }
+ if (retval < 0)
+ break;
+ }
+
+done:
+ videobuf_queue_unlock(q);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(videobuf_read_stream);
+
+unsigned int videobuf_poll_stream(struct file *file,
+ struct videobuf_queue *q,
+ poll_table *wait)
+{
+ unsigned long req_events = poll_requested_events(wait);
+ struct videobuf_buffer *buf = NULL;
+ unsigned int rc = 0;
+
+ videobuf_queue_lock(q);
+ if (q->streaming) {
+ if (!list_empty(&q->stream))
+ buf = list_entry(q->stream.next,
+ struct videobuf_buffer, stream);
+ } else if (req_events & (POLLIN | POLLRDNORM)) {
+ if (!q->reading)
+ __videobuf_read_start(q);
+ if (!q->reading) {
+ rc = POLLERR;
+ } else if (NULL == q->read_buf) {
+ q->read_buf = list_entry(q->stream.next,
+ struct videobuf_buffer,
+ stream);
+ list_del(&q->read_buf->stream);
+ q->read_off = 0;
+ }
+ buf = q->read_buf;
+ }
+ if (!buf)
+ rc = POLLERR;
+
+ if (0 == rc) {
+ poll_wait(file, &buf->done, wait);
+ if (buf->state == VIDEOBUF_DONE ||
+ buf->state == VIDEOBUF_ERROR) {
+ switch (q->type) {
+ case V4L2_BUF_TYPE_VIDEO_OUTPUT:
+ case V4L2_BUF_TYPE_VBI_OUTPUT:
+ case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT:
+ rc = POLLOUT | POLLWRNORM;
+ break;
+ default:
+ rc = POLLIN | POLLRDNORM;
+ break;
+ }
+ }
+ }
+ videobuf_queue_unlock(q);
+ return rc;
+}
+EXPORT_SYMBOL_GPL(videobuf_poll_stream);
+
+int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
+{
+ int rc = -EINVAL;
+ int i;
+
+ MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
+
+ if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
+ dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
+ return -EINVAL;
+ }
+
+ videobuf_queue_lock(q);
+ for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+ struct videobuf_buffer *buf = q->bufs[i];
+
+ if (buf && buf->memory == V4L2_MEMORY_MMAP &&
+ buf->boff == (vma->vm_pgoff << PAGE_SHIFT)) {
+ rc = CALL(q, mmap_mapper, q, buf, vma);
+ break;
+ }
+ }
+ videobuf_queue_unlock(q);
+
+ return rc;
+}
+EXPORT_SYMBOL_GPL(videobuf_mmap_mapper);

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