[media] marvell-cam: convert to videobuf2

This is a basic, naive conversion to the videobuf2 infrastructure, removing
a lot of code in the process.  For now, we're using vmalloc, which is
suboptimal, but it does match what the cafe driver did before.  In the cafe
case, it may have to stay that way just because memory is too tight to do
direct streaming; mmp-camera will be able to do better.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/marvell-ccic/Kconfig

@@ -2,6 +2,7 @@ config VIDEO_CAFE_CCIC
 	tristate "Marvell 88ALP01 (Cafe) CMOS Camera Controller support"
 	depends on PCI && I2C && VIDEO_V4L2
 	select VIDEO_OV7670
+	select VIDEOBUF2_VMALLOC
 	---help---
 	  This is a video4linux2 driver for the Marvell 88ALP01 integrated
 	  CMOS camera controller.  This is the controller found on first-
@@ -12,6 +13,7 @@ config VIDEO_MMP_CAMERA
 	depends on ARCH_MMP && I2C && VIDEO_V4L2
 	select VIDEO_OV7670
 	select I2C_GPIO
+	select VIDEOBUF2_VMALLOC
 	---help---
 	  This is a Video4Linux2 driver for the integrated camera
 	  controller found on Marvell Armada 610 application

drivers/media/video/marvell-ccic/mcam-core.c

@@ -17,6 +17,7 @@
 #include <media/v4l2-ioctl.h>
 #include <media/v4l2-chip-ident.h>
 #include <media/ov7670.h>
+#include <media/videobuf2-vmalloc.h>
 #include <linux/device.h>
 #include <linux/wait.h>
 #include <linux/list.h>
@@ -149,7 +150,6 @@ static void mcam_reset_buffers(struct mcam_camera *cam)
 	cam->next_buf = -1;
 	for (i = 0; i < cam->nbufs; i++)
 		clear_bit(i, &cam->flags);
-	cam->specframes = 0;
 }
 
 static inline int mcam_needs_config(struct mcam_camera *cam)
@@ -165,6 +165,21 @@ static void mcam_set_config_needed(struct mcam_camera *cam, int needed)
 		clear_bit(CF_CONFIG_NEEDED, &cam->flags);
 }
 
+/*
+ * Our buffer type for working with videobuf2.  Note that the vb2
+ * developers have decreed that struct vb2_buffer must be at the
+ * beginning of this structure.
+ */
+struct mcam_vb_buffer {
+	struct vb2_buffer vb_buf;
+	struct list_head queue;
+};
+
+static inline struct mcam_vb_buffer *vb_to_mvb(struct vb2_buffer *vb)
+{
+	return container_of(vb, struct mcam_vb_buffer, vb_buf);
+}
+
 
 /*
  * Debugging and related.
@@ -339,9 +354,7 @@ static void mcam_ctlr_stop_dma(struct mcam_camera *cam)
 	spin_lock_irqsave(&cam->dev_lock, flags);
 	mcam_ctlr_stop(cam);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
-	mdelay(1);
-	wait_event_timeout(cam->iowait,
-			!test_bit(CF_DMA_ACTIVE, &cam->flags), HZ);
+	msleep(10);
 	if (test_bit(CF_DMA_ACTIVE, &cam->flags))
 		cam_err(cam, "Timeout waiting for DMA to end\n");
 		/* This would be bad news - what now? */
@@ -524,44 +537,11 @@ static void mcam_free_dma_bufs(struct mcam_camera *cam)
 
 
 
-
-
 /* ----------------------------------------------------------------------- */
 /*
  * Here starts the V4L2 interface code.
  */
 
-/*
- * Read an image from the device.
- */
-static ssize_t mcam_deliver_buffer(struct mcam_camera *cam,
-		char __user *buffer, size_t len, loff_t *pos)
-{
-	int bufno;
-	unsigned long flags;
-
-	spin_lock_irqsave(&cam->dev_lock, flags);
-	if (cam->next_buf < 0) {
-		cam_err(cam, "deliver_buffer: No next buffer\n");
-		spin_unlock_irqrestore(&cam->dev_lock, flags);
-		return -EIO;
-	}
-	bufno = cam->next_buf;
-	clear_bit(bufno, &cam->flags);
-	if (++(cam->next_buf) >= cam->nbufs)
-		cam->next_buf = 0;
-	if (!test_bit(cam->next_buf, &cam->flags))
-		cam->next_buf = -1;
-	cam->specframes = 0;
-	spin_unlock_irqrestore(&cam->dev_lock, flags);
-
-	if (len > cam->pix_format.sizeimage)
-		len = cam->pix_format.sizeimage;
-	if (copy_to_user(buffer, cam->dma_bufs[bufno], len))
-		return -EFAULT;
-	(*pos) += len;
-	return len;
-}
 
 /*
  * Get everything ready, and start grabbing frames.
@@ -598,75 +578,138 @@ static int mcam_read_setup(struct mcam_camera *cam, enum mcam_state state)
 	return 0;
 }
 
+/* ----------------------------------------------------------------------- */
+/*
+ * Videobuf2 interface code.
+ */
 
-static ssize_t mcam_v4l_read(struct file *filp,
-		char __user *buffer, size_t len, loff_t *pos)
+static int mcam_vb_queue_setup(struct vb2_queue *vq, unsigned int *nbufs,
+		unsigned int *num_planes, unsigned long sizes[],
+		void *alloc_ctxs[])
 {
-	struct mcam_camera *cam = filp->private_data;
-	int ret = 0;
+	struct mcam_camera *cam = vb2_get_drv_priv(vq);
+
+	sizes[0] = cam->pix_format.sizeimage;
+	*num_planes = 1; /* Someday we have to support planar formats... */
+	if (*nbufs < 2 || *nbufs > 32)
+		*nbufs = 6;  /* semi-arbitrary numbers */
+	return 0;
+}
+
+static int mcam_vb_buf_init(struct vb2_buffer *vb)
+{
+	struct mcam_vb_buffer *mvb = vb_to_mvb(vb);
+
+	INIT_LIST_HEAD(&mvb->queue);
+	return 0;
+}
+
+static void mcam_vb_buf_queue(struct vb2_buffer *vb)
+{
+	struct mcam_vb_buffer *mvb = vb_to_mvb(vb);
+	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
+	unsigned long flags;
+
+	spin_lock_irqsave(&cam->dev_lock, flags);
+	list_add(&cam->buffers, &mvb->queue);
+	spin_unlock_irqrestore(&cam->dev_lock, flags);
+}
+
+/*
+ * vb2 uses these to release the mutex when waiting in dqbuf.  I'm
+ * not actually sure we need to do this (I'm not sure that vb2_dqbuf() needs
+ * to be called with the mutex held), but better safe than sorry.
+ */
+static void mcam_vb_wait_prepare(struct vb2_queue *vq)
+{
+	struct mcam_camera *cam = vb2_get_drv_priv(vq);
+
+	mutex_unlock(&cam->s_mutex);
+}
+
+static void mcam_vb_wait_finish(struct vb2_queue *vq)
+{
+	struct mcam_camera *cam = vb2_get_drv_priv(vq);
 
-	/*
-	 * Perhaps we're in speculative read mode and already
-	 * have data?
-	 */
 	mutex_lock(&cam->s_mutex);
-	if (cam->state == S_SPECREAD) {
-		if (cam->next_buf >= 0) {
-			ret = mcam_deliver_buffer(cam, buffer, len, pos);
-			if (ret != 0)
-				goto out_unlock;
-		}
-	} else if (cam->state == S_FLAKED || cam->state == S_NOTREADY) {
-		ret = -EIO;
-		goto out_unlock;
-	} else if (cam->state != S_IDLE) {
-		ret = -EBUSY;
-		goto out_unlock;
-	}
+}
 
-	/*
-	 * v4l2: multiple processes can open the device, but only
-	 * one gets to grab data from it.
-	 */
-	if (cam->owner && cam->owner != filp) {
-		ret = -EBUSY;
-		goto out_unlock;
-	}
-	cam->owner = filp;
+/*
+ * These need to be called with the mutex held from vb2
+ */
+static int mcam_vb_start_streaming(struct vb2_queue *vq)
+{
+	struct mcam_camera *cam = vb2_get_drv_priv(vq);
+	int ret = -EINVAL;
 
-	/*
-	 * Do setup if need be.
-	 */
-	if (cam->state != S_SPECREAD) {
-		ret = mcam_read_setup(cam, S_SINGLEREAD);
-		if (ret)
-			goto out_unlock;
-	}
-	/*
-	 * Wait for something to happen.  This should probably
-	 * be interruptible (FIXME).
-	 */
-	wait_event_timeout(cam->iowait, cam->next_buf >= 0, HZ);
-	if (cam->next_buf < 0) {
-		cam_err(cam, "read() operation timed out\n");
-		mcam_ctlr_stop_dma(cam);
-		ret = -EIO;
-		goto out_unlock;
+	if (cam->state == S_IDLE) {
+		cam->sequence = 0;
+		ret = mcam_read_setup(cam, S_STREAMING);
 	}
+	return ret;
+}
+
+static int mcam_vb_stop_streaming(struct vb2_queue *vq)
+{
+	struct mcam_camera *cam = vb2_get_drv_priv(vq);
+	unsigned long flags;
+
+	if (cam->state != S_STREAMING)
+		return -EINVAL;
+	mcam_ctlr_stop_dma(cam);
 	/*
-	 * Give them their data and we should be done.
+	 * VB2 reclaims the buffers, so we need to forget
+	 * about them.
 	 */
-	ret = mcam_deliver_buffer(cam, buffer, len, pos);
-
-out_unlock:
-	mutex_unlock(&cam->s_mutex);
-	return ret;
+	spin_lock_irqsave(&cam->dev_lock, flags);
+	INIT_LIST_HEAD(&cam->buffers);
+	spin_unlock_irqrestore(&cam->dev_lock, flags);
+	return 0;
 }
 
 
+static const struct vb2_ops mcam_vb2_ops = {
+	.queue_setup		= mcam_vb_queue_setup,
+	.buf_init		= mcam_vb_buf_init,
+	.buf_queue		= mcam_vb_buf_queue,
+	.start_streaming	= mcam_vb_start_streaming,
+	.stop_streaming		= mcam_vb_stop_streaming,
+	.wait_prepare		= mcam_vb_wait_prepare,
+	.wait_finish		= mcam_vb_wait_finish,
+};
 
+static int mcam_setup_vb2(struct mcam_camera *cam)
+{
+	struct vb2_queue *vq = &cam->vb_queue;
 
+	memset(vq, 0, sizeof(*vq));
+	vq->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+	vq->io_modes = VB2_MMAP;  /* Add userptr */
+	vq->drv_priv = cam;
+	vq->ops = &mcam_vb2_ops;
+	vq->mem_ops = &vb2_vmalloc_memops;
+	vq->buf_struct_size = sizeof(struct mcam_vb_buffer);
 
+	return vb2_queue_init(vq);
+}
+
+static void mcam_cleanup_vb2(struct mcam_camera *cam)
+{
+	vb2_queue_release(&cam->vb_queue);
+}
+
+static ssize_t mcam_v4l_read(struct file *filp,
+		char __user *buffer, size_t len, loff_t *pos)
+{
+	struct mcam_camera *cam = filp->private_data;
+	int ret;
+
+	mutex_lock(&cam->s_mutex);
+	ret = vb2_read(&cam->vb_queue, buffer, len, pos,
+			filp->f_flags & O_NONBLOCK);
+	mutex_unlock(&cam->s_mutex);
+	return ret;
+}
 
 
 
@@ -674,26 +717,15 @@ out_unlock:
  * Streaming I/O support.
  */
 
-
-
 static int mcam_vidioc_streamon(struct file *filp, void *priv,
 		enum v4l2_buf_type type)
 {
 	struct mcam_camera *cam = filp->private_data;
-	int ret = -EINVAL;
+	int ret;
 
-	if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
-		goto out;
 	mutex_lock(&cam->s_mutex);
-	if (cam->state != S_IDLE || cam->n_sbufs == 0)
-		goto out_unlock;
-
-	cam->sequence = 0;
-	ret = mcam_read_setup(cam, S_STREAMING);
-
-out_unlock:
+	ret = vb2_streamon(&cam->vb_queue, type);
 	mutex_unlock(&cam->s_mutex);
-out:
 	return ret;
 }
 
@@ -702,137 +734,23 @@ static int mcam_vidioc_streamoff(struct file *filp, void *priv,
 		enum v4l2_buf_type type)
 {
 	struct mcam_camera *cam = filp->private_data;
-	int ret = -EINVAL;
+	int ret;
 
-	if (type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
-		goto out;
 	mutex_lock(&cam->s_mutex);
-	if (cam->state != S_STREAMING)
-		goto out_unlock;
-
-	mcam_ctlr_stop_dma(cam);
-	ret = 0;
-
-out_unlock:
+	ret = vb2_streamoff(&cam->vb_queue, type);
 	mutex_unlock(&cam->s_mutex);
-out:
 	return ret;
 }
 
 
-
-static int mcam_setup_siobuf(struct mcam_camera *cam, int index)
-{
-	struct mcam_sio_buffer *buf = cam->sb_bufs + index;
-
-	INIT_LIST_HEAD(&buf->list);
-	buf->v4lbuf.length = PAGE_ALIGN(cam->pix_format.sizeimage);
-	buf->buffer = vmalloc_user(buf->v4lbuf.length);
-	if (buf->buffer == NULL)
-		return -ENOMEM;
-	buf->mapcount = 0;
-	buf->cam = cam;
-
-	buf->v4lbuf.index = index;
-	buf->v4lbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
-	buf->v4lbuf.field = V4L2_FIELD_NONE;
-	buf->v4lbuf.memory = V4L2_MEMORY_MMAP;
-	/*
-	 * Offset: must be 32-bit even on a 64-bit system.  videobuf-dma-sg
-	 * just uses the length times the index, but the spec warns
-	 * against doing just that - vma merging problems.  So we
-	 * leave a gap between each pair of buffers.
-	 */
-	buf->v4lbuf.m.offset = 2*index*buf->v4lbuf.length;
-	return 0;
-}
-
-static int mcam_free_sio_buffers(struct mcam_camera *cam)
-{
-	int i;
-
-	/*
-	 * If any buffers are mapped, we cannot free them at all.
-	 */
-	for (i = 0; i < cam->n_sbufs; i++)
-		if (cam->sb_bufs[i].mapcount > 0)
-			return -EBUSY;
-	/*
-	 * OK, let's do it.
-	 */
-	for (i = 0; i < cam->n_sbufs; i++)
-		vfree(cam->sb_bufs[i].buffer);
-	cam->n_sbufs = 0;
-	kfree(cam->sb_bufs);
-	cam->sb_bufs = NULL;
-	INIT_LIST_HEAD(&cam->sb_avail);
-	INIT_LIST_HEAD(&cam->sb_full);
-	return 0;
-}
-
-
-
 static int mcam_vidioc_reqbufs(struct file *filp, void *priv,
 		struct v4l2_requestbuffers *req)
 {
 	struct mcam_camera *cam = filp->private_data;
-	int ret = 0;  /* Silence warning */
+	int ret;
 
-	/*
-	 * Make sure it's something we can do.  User pointers could be
-	 * implemented without great pain, but that's not been done yet.
-	 */
-	if (req->memory != V4L2_MEMORY_MMAP)
-		return -EINVAL;
-	/*
-	 * If they ask for zero buffers, they really want us to stop streaming
-	 * (if it's happening) and free everything.  Should we check owner?
-	 */
 	mutex_lock(&cam->s_mutex);
-	if (req->count == 0) {
-		if (cam->state == S_STREAMING)
-			mcam_ctlr_stop_dma(cam);
-		ret = mcam_free_sio_buffers(cam);
-		goto out;
-	}
-	/*
-	 * Device needs to be idle and working.  We *could* try to do the
-	 * right thing in S_SPECREAD by shutting things down, but it
-	 * probably doesn't matter.
-	 */
-	if (cam->state != S_IDLE || (cam->owner && cam->owner != filp)) {
-		ret = -EBUSY;
-		goto out;
-	}
-	cam->owner = filp;
-
-	if (req->count < min_buffers)
-		req->count = min_buffers;
-	else if (req->count > max_buffers)
-		req->count = max_buffers;
-	if (cam->n_sbufs > 0) {
-		ret = mcam_free_sio_buffers(cam);
-		if (ret)
-			goto out;
-	}
-
-	cam->sb_bufs = kzalloc(req->count*sizeof(struct mcam_sio_buffer),
-			GFP_KERNEL);
-	if (cam->sb_bufs == NULL) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	for (cam->n_sbufs = 0; cam->n_sbufs < req->count; (cam->n_sbufs++)) {
-		ret = mcam_setup_siobuf(cam, cam->n_sbufs);
-		if (ret)
-			break;
-	}
-
-	if (cam->n_sbufs == 0)  /* no luck at all - ret already set */
-		kfree(cam->sb_bufs);
-	req->count = cam->n_sbufs;  /* In case of partial success */
-
-out:
+	ret = vb2_reqbufs(&cam->vb_queue, req);
 	mutex_unlock(&cam->s_mutex);
 	return ret;
 }
@@ -842,14 +760,10 @@ static int mcam_vidioc_querybuf(struct file *filp, void *priv,
 		struct v4l2_buffer *buf)
 {
 	struct mcam_camera *cam = filp->private_data;
-	int ret = -EINVAL;
+	int ret;
 
 	mutex_lock(&cam->s_mutex);
-	if (buf->index >= cam->n_sbufs)
-		goto out;
-	*buf = cam->sb_bufs[buf->index].v4lbuf;
-	ret = 0;
-out:
+	ret = vb2_querybuf(&cam->vb_queue, buf);
 	mutex_unlock(&cam->s_mutex);
 	return ret;
 }
@@ -858,29 +772,10 @@ static int mcam_vidioc_qbuf(struct file *filp, void *priv,
 		struct v4l2_buffer *buf)
 {
 	struct mcam_camera *cam = filp->private_data;
-	struct mcam_sio_buffer *sbuf;
-	int ret = -EINVAL;
-	unsigned long flags;
+	int ret;
 
 	mutex_lock(&cam->s_mutex);
-	if (buf->index >= cam->n_sbufs)
-		goto out;
-	sbuf = cam->sb_bufs + buf->index;
-	if (sbuf->v4lbuf.flags & V4L2_BUF_FLAG_QUEUED) {
-		ret = 0; /* Already queued?? */
-		goto out;
-	}
-	if (sbuf->v4lbuf.flags & V4L2_BUF_FLAG_DONE) {
-		/* Spec doesn't say anything, seems appropriate tho */
-		ret = -EBUSY;
-		goto out;
-	}
-	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_QUEUED;
-	spin_lock_irqsave(&cam->dev_lock, flags);
-	list_add(&sbuf->list, &cam->sb_avail);
-	spin_unlock_irqrestore(&cam->dev_lock, flags);
-	ret = 0;
-out:
+	ret = vb2_qbuf(&cam->vb_queue, buf);
 	mutex_unlock(&cam->s_mutex);
 	return ret;
 }
@@ -889,111 +784,22 @@ static int mcam_vidioc_dqbuf(struct file *filp, void *priv,
 		struct v4l2_buffer *buf)
 {
 	struct mcam_camera *cam = filp->private_data;
-	struct mcam_sio_buffer *sbuf;
-	int ret = -EINVAL;
-	unsigned long flags;
+	int ret;
 
 	mutex_lock(&cam->s_mutex);
-	if (cam->state != S_STREAMING)
-		goto out_unlock;
-	if (list_empty(&cam->sb_full) && filp->f_flags & O_NONBLOCK) {
-		ret = -EAGAIN;
-		goto out_unlock;
-	}
-
-	while (list_empty(&cam->sb_full) && cam->state == S_STREAMING) {
-		mutex_unlock(&cam->s_mutex);
-		if (wait_event_interruptible(cam->iowait,
-						!list_empty(&cam->sb_full))) {
-			ret = -ERESTARTSYS;
-			goto out;
-		}
-		mutex_lock(&cam->s_mutex);
-	}
-
-	if (cam->state != S_STREAMING)
-		ret = -EINTR;
-	else {
-		spin_lock_irqsave(&cam->dev_lock, flags);
-		/* Should probably recheck !list_empty() here */
-		sbuf = list_entry(cam->sb_full.next,
-				struct mcam_sio_buffer, list);
-		list_del_init(&sbuf->list);
-		spin_unlock_irqrestore(&cam->dev_lock, flags);
-		sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_DONE;
-		*buf = sbuf->v4lbuf;
-		ret = 0;
-	}
-
-out_unlock:
+	ret = vb2_dqbuf(&cam->vb_queue, buf, filp->f_flags & O_NONBLOCK);
 	mutex_unlock(&cam->s_mutex);
-out:
 	return ret;
 }
 
 
-
-static void mcam_v4l_vm_open(struct vm_area_struct *vma)
-{
-	struct mcam_sio_buffer *sbuf = vma->vm_private_data;
-	/*
-	 * Locking: done under mmap_sem, so we don't need to
-	 * go back to the camera lock here.
-	 */
-	sbuf->mapcount++;
-}
-
-
-static void mcam_v4l_vm_close(struct vm_area_struct *vma)
-{
-	struct mcam_sio_buffer *sbuf = vma->vm_private_data;
-
-	mutex_lock(&sbuf->cam->s_mutex);
-	sbuf->mapcount--;
-	/* Docs say we should stop I/O too... */
-	if (sbuf->mapcount == 0)
-		sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_MAPPED;
-	mutex_unlock(&sbuf->cam->s_mutex);
-}
-
-static const struct vm_operations_struct mcam_v4l_vm_ops = {
-	.open = mcam_v4l_vm_open,
-	.close = mcam_v4l_vm_close
-};
-
-
 static int mcam_v4l_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	struct mcam_camera *cam = filp->private_data;
-	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
-	int ret = -EINVAL;
-	int i;
-	struct mcam_sio_buffer *sbuf = NULL;
+	int ret;
 
-	if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
-		return -EINVAL;
-	/*
-	 * Find the buffer they are looking for.
-	 */
 	mutex_lock(&cam->s_mutex);
-	for (i = 0; i < cam->n_sbufs; i++)
-		if (cam->sb_bufs[i].v4lbuf.m.offset == offset) {
-			sbuf = cam->sb_bufs + i;
-			break;
-		}
-	if (sbuf == NULL)
-		goto out;
-
-	ret = remap_vmalloc_range(vma, sbuf->buffer, 0);
-	if (ret)
-		goto out;
-	vma->vm_flags |= VM_DONTEXPAND;
-	vma->vm_private_data = sbuf;
-	vma->vm_ops = &mcam_v4l_vm_ops;
-	sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_MAPPED;
-	mcam_v4l_vm_open(vma);
-	ret = 0;
-out:
+	ret = vb2_mmap(&cam->vb_queue, vma);
 	mutex_unlock(&cam->s_mutex);
 	return ret;
 }
@@ -1003,19 +809,23 @@ out:
 static int mcam_v4l_open(struct file *filp)
 {
 	struct mcam_camera *cam = video_drvdata(filp);
+	int ret = 0;
 
 	filp->private_data = cam;
 
 	mutex_lock(&cam->s_mutex);
 	if (cam->users == 0) {
+		ret = mcam_setup_vb2(cam);
+		if (ret)
+			goto out;
 		mcam_ctlr_power_up(cam);
 		__mcam_cam_reset(cam);
 		mcam_set_config_needed(cam, 1);
-	/* FIXME make sure this is complete */
 	}
 	(cam->users)++;
+out:
 	mutex_unlock(&cam->s_mutex);
-	return 0;
+	return ret;
 }
 
 
@@ -1027,10 +837,10 @@ static int mcam_v4l_release(struct file *filp)
 	(cam->users)--;
 	if (filp == cam->owner) {
 		mcam_ctlr_stop_dma(cam);
-		mcam_free_sio_buffers(cam);
 		cam->owner = NULL;
 	}
 	if (cam->users == 0) {
+		mcam_cleanup_vb2(cam);
 		mcam_ctlr_power_down(cam);
 		if (alloc_bufs_at_read)
 			mcam_free_dma_bufs(cam);
@@ -1045,11 +855,12 @@ static unsigned int mcam_v4l_poll(struct file *filp,
 		struct poll_table_struct *pt)
 {
 	struct mcam_camera *cam = filp->private_data;
+	int ret;
 
-	poll_wait(filp, &cam->iowait, pt);
-	if (cam->next_buf >= 0)
-		return POLLIN | POLLRDNORM;
-	return 0;
+	mutex_lock(&cam->s_mutex);
+	ret = vb2_poll(&cam->vb_queue, filp, pt);
+	mutex_unlock(&cam->s_mutex);
+	return ret;
 }
 
 
@@ -1093,9 +904,6 @@ static int mcam_vidioc_s_ctrl(struct file *filp, void *priv,
 }
 
 
-
-
-
 static int mcam_vidioc_querycap(struct file *file, void *priv,
 		struct v4l2_capability *cap)
 {
@@ -1166,7 +974,7 @@ static int mcam_vidioc_s_fmt_vid_cap(struct file *filp, void *priv,
 	 * Can't do anything if the device is not idle
 	 * Also can't if there are streaming buffers in place.
 	 */
-	if (cam->state != S_IDLE || cam->n_sbufs > 0)
+	if (cam->state != S_IDLE || cam->vb_queue.num_buffers > 0)
 		return -EBUSY;
 
 	f = mcam_find_format(fmt->fmt.pix.pixelformat);
@@ -1416,39 +1224,39 @@ static void mcam_frame_tasklet(unsigned long data)
 	struct mcam_camera *cam = (struct mcam_camera *) data;
 	int i;
 	unsigned long flags;
-	struct mcam_sio_buffer *sbuf;
+	struct mcam_vb_buffer *buf;
 
 	spin_lock_irqsave(&cam->dev_lock, flags);
 	for (i = 0; i < cam->nbufs; i++) {
 		int bufno = cam->next_buf;
-		if (bufno < 0) {  /* "will never happen" */
-			cam_err(cam, "No valid bufs in tasklet!\n");
-			break;
-		}
+
+		if (cam->state != S_STREAMING || bufno < 0)
+			break;  /* I/O got stopped */
 		if (++(cam->next_buf) >= cam->nbufs)
 			cam->next_buf = 0;
 		if (!test_bit(bufno, &cam->flags))
 			continue;
-		if (list_empty(&cam->sb_avail))
+		if (list_empty(&cam->buffers))
 			break;  /* Leave it valid, hope for better later */
 		clear_bit(bufno, &cam->flags);
-		sbuf = list_entry(cam->sb_avail.next,
-				struct mcam_sio_buffer, list);
+		buf = list_first_entry(&cam->buffers, struct mcam_vb_buffer,
+				queue);
+		list_del_init(&buf->queue);
 		/*
 		 * Drop the lock during the big copy.  This *should* be safe...
 		 */
 		spin_unlock_irqrestore(&cam->dev_lock, flags);
-		memcpy(sbuf->buffer, cam->dma_bufs[bufno],
+		memcpy(vb2_plane_vaddr(&buf->vb_buf, 0), cam->dma_bufs[bufno],
 				cam->pix_format.sizeimage);
-		sbuf->v4lbuf.bytesused = cam->pix_format.sizeimage;
-		sbuf->v4lbuf.sequence = cam->buf_seq[bufno];
-		sbuf->v4lbuf.flags &= ~V4L2_BUF_FLAG_QUEUED;
-		sbuf->v4lbuf.flags |= V4L2_BUF_FLAG_DONE;
+		buf->vb_buf.v4l2_buf.bytesused = cam->pix_format.sizeimage;
+		buf->vb_buf.v4l2_buf.sequence = cam->buf_seq[bufno];
+		buf->vb_buf.v4l2_buf.flags &= ~V4L2_BUF_FLAG_QUEUED;
+		buf->vb_buf.v4l2_buf.flags |= V4L2_BUF_FLAG_DONE;
+		vb2_set_plane_payload(&buf->vb_buf, 0,
+				cam->pix_format.sizeimage);
+		vb2_buffer_done(&buf->vb_buf, VB2_BUF_STATE_DONE);
 		spin_lock_irqsave(&cam->dev_lock, flags);
-		list_move_tail(&sbuf->list, &cam->sb_full);
 	}
-	if (!list_empty(&cam->sb_full))
-		wake_up(&cam->iowait);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
 }
 
@@ -1468,27 +1276,6 @@ static void mcam_frame_complete(struct mcam_camera *cam, int frame)
 	cam->buf_seq[frame] = ++(cam->sequence);
 
 	switch (cam->state) {
-	/*
-	 * If in single read mode, try going speculative.
-	 */
-	case S_SINGLEREAD:
-		cam->state = S_SPECREAD;
-		cam->specframes = 0;
-		wake_up(&cam->iowait);
-		break;
-
-	/*
-	 * If we are already doing speculative reads, and nobody is
-	 * reading them, just stop.
-	 */
-	case S_SPECREAD:
-		if (++(cam->specframes) >= cam->nbufs) {
-			mcam_ctlr_stop(cam);
-			mcam_ctlr_irq_disable(cam);
-			cam->state = S_IDLE;
-		}
-		wake_up(&cam->iowait);
-		break;
 	/*
 	 * For the streaming case, we defer the real work to the
 	 * camera tasklet.
@@ -1570,12 +1357,10 @@ int mccic_register(struct mcam_camera *cam)
 	mutex_init(&cam->s_mutex);
 	cam->state = S_NOTREADY;
 	mcam_set_config_needed(cam, 1);
-	init_waitqueue_head(&cam->iowait);
 	cam->pix_format = mcam_def_pix_format;
 	cam->mbus_code = mcam_def_mbus_code;
 	INIT_LIST_HEAD(&cam->dev_list);
-	INIT_LIST_HEAD(&cam->sb_avail);
-	INIT_LIST_HEAD(&cam->sb_full);
+	INIT_LIST_HEAD(&cam->buffers);
 	tasklet_init(&cam->s_tasklet, mcam_frame_tasklet, (unsigned long) cam);
 
 	mcam_ctlr_init(cam);
@@ -1638,10 +1423,8 @@ void mccic_shutdown(struct mcam_camera *cam)
 		cam_warn(cam, "Removing a device with users!\n");
 		mcam_ctlr_power_down(cam);
 	}
+	vb2_queue_release(&cam->vb_queue);
 	mcam_free_dma_bufs(cam);
-	if (cam->n_sbufs > 0)
-		/* What if they are still mapped?  Shouldn't be, but... */
-		mcam_free_sio_buffers(cam);
 	video_unregister_device(&cam->vdev);
 	v4l2_device_unregister(&cam->v4l2_dev);
 }
@@ -1674,9 +1457,7 @@ int mccic_resume(struct mcam_camera *cam)
 	mutex_unlock(&cam->s_mutex);
 
 	set_bit(CF_CONFIG_NEEDED, &cam->flags);
-	if (cam->state == S_SPECREAD)
-		cam->state = S_IDLE;  /* Don't bother restarting */
-	else if (cam->state == S_SINGLEREAD || cam->state == S_STREAMING)
+	if (cam->state == S_STREAMING)
 		ret = mcam_read_setup(cam, cam->state);
 	return ret;
 }

drivers/media/video/marvell-ccic/mcam-core.h

@@ -3,6 +3,13 @@
  *
  * Copyright 2011 Jonathan Corbet corbet@lwn.net
  */
+#ifndef _MCAM_CORE_H
+#define _MCAM_CORE_H
+
+#include <linux/list.h>
+#include <media/v4l2-common.h>
+#include <media/v4l2-dev.h>
+#include <media/videobuf2-core.h>
 
 /*
  * Tracking of streaming I/O buffers.
@@ -20,8 +27,6 @@ enum mcam_state {
 	S_NOTREADY,	/* Not yet initialized */
 	S_IDLE,		/* Just hanging around */
 	S_FLAKED,	/* Some sort of problem */
-	S_SINGLEREAD,	/* In read() */
-	S_SPECREAD,	/* Speculative read (for future read()) */
 	S_STREAMING	/* Streaming data */
 };
 #define MAX_DMA_BUFS 3
@@ -70,21 +75,19 @@ struct mcam_camera {
 
 	struct list_head dev_list;	/* link to other devices */
 
+	/* Videobuf2 stuff */
+	struct vb2_queue vb_queue;
+	struct list_head buffers;	/* Available frames */
+
 	/* DMA buffers */
 	unsigned int nbufs;		/* How many are alloc'd */
 	int next_buf;			/* Next to consume (dev_lock) */
 	unsigned int dma_buf_size;	/* allocated size */
 	void *dma_bufs[MAX_DMA_BUFS];	/* Internal buffer addresses */
 	dma_addr_t dma_handles[MAX_DMA_BUFS]; /* Buffer bus addresses */
-	unsigned int specframes;	/* Unconsumed spec frames (dev_lock) */
 	unsigned int sequence;		/* Frame sequence number */
-	unsigned int buf_seq[MAX_DMA_BUFS]; /* Sequence for individual buffers */
+	unsigned int buf_seq[MAX_DMA_BUFS]; /* Sequence for individual bufs */
 
-	/* Streaming buffers */
-	unsigned int n_sbufs;		/* How many we have */
-	struct mcam_sio_buffer *sb_bufs; /* The array of housekeeping structs */
-	struct list_head sb_avail;	/* Available for data (we own) (dev_lock) */
-	struct list_head sb_full;	/* With data (user space owns) (dev_lock) */
 	struct tasklet_struct s_tasklet;
 
 	/* Current operating parameters */
@@ -94,9 +97,6 @@ struct mcam_camera {
 
 	/* Locks */
 	struct mutex s_mutex; /* Access to this structure */
-
-	/* Misc */
-	wait_queue_head_t iowait;	/* Waiting on frame data */
 };
 
 
@@ -257,3 +257,5 @@ int mccic_resume(struct mcam_camera *cam);
  */
 #define VGA_WIDTH	640
 #define VGA_HEIGHT	480
+
+#endif /* _MCAM_CORE_H */