V4L/DVB (3516): Make video_buf more generic

Video_buf were concerned to allow PCI devices to be used as
video capture devices. This patch extends video_buf features
by virtualizing pci-dependent functions and allowing other
type of devices to use it.
It is still DMA centric, although it may be used also by
devices that emulates scatter/gather behavior or a DMA device

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 187 insertions, 63 deletions

diff --git a/drivers/media/video/video-buf.c b/drivers/media/video/video-buf.c
index 87e937581d5a..d2ca0f08d0df 100644
--- a/drivers/media/video/video-buf.c
+++ b/drivers/media/video/video-buf.c
@@ -1,15 +1,20 @@
 /*
  *
  * generic helper functions for video4linux capture buffers, to handle
- * memory management and PCI DMA.  Right now bttv + saa7134 use it.
+ * memory management and PCI DMA.
+ * Right now, bttv, saa7134, saa7146 and cx88 use it.
  *
  * The functions expect the hardware being able to scatter gatter
  * (i.e. the buffers are not linear in physical memory, but fragmented
  * into PAGE_SIZE chunks).  They also assume the driver does not need
- * to touch the video data (thus it is probably not useful for USB 1.1
- * as data often must be uncompressed by the drivers).
+ * to touch the video data.
+ *
+ * device specific map/unmap/sync stuff now are mapped as operations
+ * to allow its usage by USB and virtual devices.
  *
  * (c) 2001-2004 Gerd Knorr <kraxel@bytesex.org> [SUSE Labs]
+ * (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
@@ -167,6 +172,9 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
                 dprintk(1,"vmalloc_32(%d pages) failed\n",nr_pages);
                 return -ENOMEM;
         }
+        dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
+                                (unsigned long)dma->vmalloc,
+                                nr_pages << PAGE_SHIFT);
         memset(dma->vmalloc,0,nr_pages << PAGE_SHIFT);
         dma->nr_pages = nr_pages;
         return 0;
@@ -186,8 +194,10 @@ int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
         return 0;
 }
 
-int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
+int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 {
+        void                   *dev=q->dev;
+
         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
         BUG_ON(0 == dma->nr_pages);
 
@@ -197,7 +207,7 @@ int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
         }
         if (dma->vmalloc) {
                 dma->sglist = videobuf_vmalloc_to_sg
-                        (dma->vmalloc,dma->nr_pages);
+                                                (dma->vmalloc,dma->nr_pages);
         }
         if (dma->bus_addr) {
                 dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
@@ -212,13 +222,14 @@ int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
                 dprintk(1,"scatterlist is NULL\n");
                 return -ENOMEM;
         }
-
         if (!dma->bus_addr) {
-                dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
-                                        dma->direction);
+                if (q->ops->vb_map_sg) {
+                        dma->sglen = q->ops->vb_map_sg(dev,dma->sglist,
+                                        dma->nr_pages, dma->direction);
+                }
                 if (0 == dma->sglen) {
                         printk(KERN_WARNING
-                               "%s: pci_map_sg failed\n",__FUNCTION__);
+                               "%s: videobuf_map_sg failed\n",__FUNCTION__);
                         kfree(dma->sglist);
                         dma->sglist = NULL;
                         dma->sglen = 0;
@@ -228,24 +239,31 @@ int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
         return 0;
 }
 
-int videobuf_dma_pci_sync(struct pci_dev *dev, struct videobuf_dmabuf *dma)
+int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 {
+        void                   *dev=q->dev;
+
         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
         BUG_ON(!dma->sglen);
 
-        if (!dma->bus_addr)
-                pci_dma_sync_sg_for_cpu(dev,dma->sglist,dma->nr_pages,dma->direction);
+        if (!dma->bus_addr && q->ops->vb_dma_sync_sg)
+                q->ops->vb_dma_sync_sg(dev,dma->sglist,dma->nr_pages,
+                                                        dma->direction);
+
         return 0;
 }
 
-int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma)
+int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma)
 {
+        void                   *dev=q->dev;
+
         MAGIC_CHECK(dma->magic,MAGIC_DMABUF);
         if (!dma->sglen)
                 return 0;
 
-        if (!dma->bus_addr)
-                pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
+        if (!dma->bus_addr && q->ops->vb_unmap_sg)
+                        q->ops->vb_unmap_sg(dev,dma->sglist,dma->nr_pages,
+                                                        dma->direction);
         kfree(dma->sglist);
         dma->sglist = NULL;
         dma->sglen = 0;
@@ -318,7 +336,7 @@ int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr)
 }
 
 int
-videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
+videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
                 struct v4l2_framebuffer *fbuf)
 {
         int err,pages;
@@ -357,7 +375,7 @@ videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
         default:
                 BUG();
         }
-        err = videobuf_dma_pci_map(pci,&vb->dma);
+        err = videobuf_dma_map(q,&vb->dma);
         if (0 != err)
                 return err;
 
@@ -366,9 +384,41 @@ videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
 
 /* --------------------------------------------------------------------- */
 
+void videobuf_queue_pci(struct videobuf_queue* q)
+{
+        /* If not specified, defaults to PCI map sg */
+        if (!q->ops->vb_map_sg)
+                q->ops->vb_map_sg=(vb_map_sg_t *)pci_map_sg;
+
+        if (!q->ops->vb_dma_sync_sg)
+                q->ops->vb_dma_sync_sg=(vb_map_sg_t *)pci_dma_sync_sg_for_cpu;
+        if (!q->ops->vb_unmap_sg)
+                q->ops->vb_unmap_sg=(vb_map_sg_t *)pci_unmap_sg;
+}
+
+int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma)
+{
+        struct videobuf_queue q;
+
+        q.dev=pci;
+        q.ops->vb_map_sg=(vb_map_sg_t *)pci_unmap_sg;
+
+        return (videobuf_dma_unmap(&q,dma));
+}
+
+int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma)
+{
+        struct videobuf_queue q;
+
+        q.dev=pci;
+        q.ops->vb_map_sg=(vb_map_sg_t *)pci_unmap_sg;
+
+        return (videobuf_dma_unmap(&q,dma));
+}
+
 void videobuf_queue_init(struct videobuf_queue* q,
                          struct videobuf_queue_ops *ops,
-                         struct pci_dev *pci,
+                         void *dev,
                          spinlock_t *irqlock,
                          enum v4l2_buf_type type,
                          enum v4l2_field field,
@@ -377,13 +427,15 @@ void videobuf_queue_init(struct videobuf_queue* q,
 {
         memset(q,0,sizeof(*q));
         q->irqlock = irqlock;
-        q->pci     = pci;
+        q->dev     = dev;
         q->type    = type;
         q->field   = field;
         q->msize   = msize;
         q->ops     = ops;
         q->priv_data = priv;
 
+        videobuf_queue_pci(q);
+
         mutex_init(&q->lock);
         INIT_LIST_HEAD(&q->stream);
 }
@@ -431,7 +483,8 @@ videobuf_queue_cancel(struct videobuf_queue *q)
         int i;
 
         /* remove queued buffers from list */
-        spin_lock_irqsave(q->irqlock,flags);
+        if (q->irqlock)
+                spin_lock_irqsave(q->irqlock,flags);
         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
                 if (NULL == q->bufs[i])
                         continue;
@@ -440,7 +493,8 @@ videobuf_queue_cancel(struct videobuf_queue *q)
                         q->bufs[i]->state = STATE_ERROR;
                 }
         }
-        spin_unlock_irqrestore(q->irqlock,flags);
+        if (q->irqlock)
+                spin_unlock_irqrestore(q->irqlock,flags);
 
         /* free all buffers + clear queue */
         for (i = 0; i < VIDEO_MAX_FRAME; i++) {
@@ -534,19 +588,29 @@ videobuf_reqbufs(struct videobuf_queue *q,
         unsigned int size,count;
         int retval;
 
-        if (req->type != q->type)
+        if (req->type != q->type) {
+                dprintk(1,"reqbufs: queue type invalid\n");
                 return -EINVAL;
-        if (req->count < 1)
+        }
+        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)
+            req->memory != V4L2_MEMORY_OVERLAY) {
+                dprintk(1,"reqbufs: memory type invalid\n");
                 return -EINVAL;
+        }
 
-        if (q->streaming)
+        if (q->streaming) {
+                dprintk(1,"reqbufs: streaming already exists\n");
                 return -EBUSY;
-        if (!list_empty(&q->stream))
+        }
+        if (!list_empty(&q->stream)) {
+                dprintk(1,"reqbufs: stream running\n");
                 return -EBUSY;
+        }
 
         mutex_lock(&q->lock);
         count = req->count;
@@ -559,8 +623,10 @@ videobuf_reqbufs(struct videobuf_queue *q,
                 count, size, (count*size)>>PAGE_SHIFT);
 
         retval = videobuf_mmap_setup(q,count,size,req->memory);
-        if (retval < 0)
+        if (retval < 0) {
+                dprintk(1,"reqbufs: mmap setup returned %d\n",retval);
                 goto done;
+        }
 
         req->count = count;
 
@@ -572,12 +638,18 @@ videobuf_reqbufs(struct videobuf_queue *q,
 int
 videobuf_querybuf(struct videobuf_queue *q, struct v4l2_buffer *b)
 {
-        if (unlikely(b->type != q->type))
+        if (unlikely(b->type != q->type)) {
+                dprintk(1,"querybuf: Wrong type.\n");
                 return -EINVAL;
-        if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME))
+        }
+        if (unlikely(b->index < 0 || b->index >= VIDEO_MAX_FRAME)) {
+                dprintk(1,"querybuf: index out of range.\n");
                 return -EINVAL;
-        if (unlikely(NULL == q->bufs[b->index]))
+        }
+        if (unlikely(NULL == q->bufs[b->index])) {
+                dprintk(1,"querybuf: buffer is null.\n");
                 return -EINVAL;
+        }
         videobuf_status(b,q->bufs[b->index],q->type);
         return 0;
 }
@@ -593,26 +665,40 @@ videobuf_qbuf(struct videobuf_queue *q,
 
         mutex_lock(&q->lock);
         retval = -EBUSY;
-        if (q->reading)
+        if (q->reading) {
+                dprintk(1,"qbuf: Reading running...\n");
                 goto done;
+        }
         retval = -EINVAL;
-        if (b->type != q->type)
+        if (b->type != q->type) {
+                dprintk(1,"qbuf: Wrong type.\n");
                 goto done;
-        if (b->index < 0 || b->index >= VIDEO_MAX_FRAME)
+        }
+        if (b->index < 0 || b->index >= VIDEO_MAX_FRAME) {
+                dprintk(1,"qbuf: index out of range.\n");
                 goto done;
+        }
         buf = q->bufs[b->index];
-        if (NULL == buf)
+        if (NULL == buf) {
+                dprintk(1,"qbuf: buffer is null.\n");
                 goto done;
+        }
         MAGIC_CHECK(buf->magic,MAGIC_BUFFER);
-        if (buf->memory != b->memory)
+        if (buf->memory != b->memory) {
+                dprintk(1,"qbuf: memory type is wrong.\n");
                 goto done;
+        }
         if (buf->state == STATE_QUEUED ||
-            buf->state == STATE_ACTIVE)
+            buf->state == STATE_ACTIVE) {
+                dprintk(1,"qbuf: buffer is already queued or active.\n");
                 goto done;
+        }
 
         if (b->flags & V4L2_BUF_FLAG_INPUT) {
-                if (b->input >= q->inputs)
+                if (b->input >= q->inputs) {
+                        dprintk(1,"qbuf: wrong input.\n");
                         goto done;
+                }
                 buf->input = b->input;
         } else {
                 buf->input = UNSET;
@@ -620,12 +706,16 @@ videobuf_qbuf(struct videobuf_queue *q,
 
         switch (b->memory) {
         case V4L2_MEMORY_MMAP:
-                if (0 == buf->baddr)
+                if (0 == buf->baddr) {
+                        dprintk(1,"qbuf: mmap requested but buffer addr is zero!\n");
                         goto done;
+                }
                 break;
         case V4L2_MEMORY_USERPTR:
-                if (b->length < buf->bsize)
+                if (b->length < buf->bsize) {
+                        dprintk(1,"qbuf: buffer length is not enough\n");
                         goto done;
+                }
                 if (STATE_NEEDS_INIT != buf->state && buf->baddr != b->m.userptr)
                         q->ops->buf_release(q,buf);
                 buf->baddr = b->m.userptr;
@@ -634,20 +724,27 @@ videobuf_qbuf(struct videobuf_queue *q,
                 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)
+        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);
+                if (q->irqlock)
+                        spin_lock_irqsave(q->irqlock,flags);
                 q->ops->buf_queue(q,buf);
-                spin_unlock_irqrestore(q->irqlock,flags);
+                if (q->irqlock)
+                        spin_unlock_irqrestore(q->irqlock,flags);
         }
+        dprintk(1,"qbuf: succeded\n");
         retval = 0;
 
  done:
@@ -664,26 +761,39 @@ videobuf_dqbuf(struct videobuf_queue *q,
 
         mutex_lock(&q->lock);
         retval = -EBUSY;
-        if (q->reading)
+        if (q->reading) {
+                dprintk(1,"dqbuf: Reading running...\n");
                 goto done;
+        }
         retval = -EINVAL;
-        if (b->type != q->type)
+        if (b->type != q->type) {
+                dprintk(1,"dqbuf: Wrong type.\n");
                 goto done;
-        if (list_empty(&q->stream))
+        }
+        if (list_empty(&q->stream)) {
+                dprintk(1,"dqbuf: stream running\n");
                 goto done;
+        }
         buf = list_entry(q->stream.next, struct videobuf_buffer, stream);
         retval = videobuf_waiton(buf, nonblocking, 1);
-        if (retval < 0)
+        if (retval < 0) {
+                dprintk(1,"dqbuf: waiton returned %d\n",retval);
                 goto done;
+        }
         switch (buf->state) {
         case STATE_ERROR:
+                dprintk(1,"dqbuf: state is error\n");
                 retval = -EIO;
-                /* fall through */
+                videobuf_dma_sync(q,&buf->dma);
+                buf->state = STATE_IDLE;
+                break;
         case STATE_DONE:
-                videobuf_dma_pci_sync(q->pci,&buf->dma);
+                dprintk(1,"dqbuf: state is done\n");
+                videobuf_dma_sync(q,&buf->dma);
                 buf->state = STATE_IDLE;
                 break;
         default:
+                dprintk(1,"dqbuf: state invalid\n");
                 retval = -EINVAL;
                 goto done;
         }
@@ -711,13 +821,15 @@ int videobuf_streamon(struct videobuf_queue *q)
         if (q->streaming)
                 goto done;
         q->streaming = 1;
-        spin_lock_irqsave(q->irqlock,flags);
+        if (q->irqlock)
+                spin_lock_irqsave(q->irqlock,flags);
         list_for_each(list,&q->stream) {
                 buf = list_entry(list, struct videobuf_buffer, stream);
                 if (buf->state == STATE_PREPARED)
                         q->ops->buf_queue(q,buf);
         }
-        spin_unlock_irqrestore(q->irqlock,flags);
+        if (q->irqlock)
+                spin_unlock_irqrestore(q->irqlock,flags);
 
  done:
         mutex_unlock(&q->lock);
@@ -762,12 +874,14 @@ videobuf_read_zerocopy(struct videobuf_queue *q, char __user *data,
                 goto done;
 
         /* start capture & wait */
-        spin_lock_irqsave(q->irqlock,flags);
+        if (q->irqlock)
+                spin_lock_irqsave(q->irqlock,flags);
         q->ops->buf_queue(q,q->read_buf);
-        spin_unlock_irqrestore(q->irqlock,flags);
+        if (q->irqlock)
+                spin_unlock_irqrestore(q->irqlock,flags);
         retval = videobuf_waiton(q->read_buf,0,0);
         if (0 == retval) {
-                videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
+                videobuf_dma_sync(q,&q->read_buf->dma);
                 if (STATE_ERROR == q->read_buf->state)
                         retval = -EIO;
                 else
@@ -809,6 +923,7 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
                 /* need to capture a new frame */
                 retval = -ENOMEM;
                 q->read_buf = videobuf_alloc(q->msize);
+                dprintk(1,"video alloc=0x%08x\n",(unsigned int) q->read_buf);
                 if (NULL == q->read_buf)
                         goto done;
                 q->read_buf->memory = V4L2_MEMORY_USERPTR;
@@ -820,9 +935,11 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
                         q->read_buf = NULL;
                         goto done;
                 }
-                spin_lock_irqsave(q->irqlock,flags);
+                if (q->irqlock)
+                        spin_lock_irqsave(q->irqlock,flags);
                 q->ops->buf_queue(q,q->read_buf);
-                spin_unlock_irqrestore(q->irqlock,flags);
+                if (q->irqlock)
+                        spin_unlock_irqrestore(q->irqlock,flags);
                 q->read_off = 0;
         }
 
@@ -830,7 +947,7 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
         retval = videobuf_waiton(q->read_buf, nonblocking, 1);
         if (0 != retval)
                 goto done;
-        videobuf_dma_pci_sync(q->pci,&q->read_buf->dma);
+        videobuf_dma_sync(q,&q->read_buf->dma);
 
         if (STATE_ERROR == q->read_buf->state) {
                 /* catch I/O errors */
@@ -887,10 +1004,12 @@ int videobuf_read_start(struct videobuf_queue *q)
                         return err;
                 list_add_tail(&q->bufs[i]->stream, &q->stream);
         }
-        spin_lock_irqsave(q->irqlock,flags);
+        if (q->irqlock)
+                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);
+        if (q->irqlock)
+                spin_unlock_irqrestore(q->irqlock,flags);
         q->reading = 1;
         return 0;
 }
@@ -985,9 +1104,11 @@ ssize_t videobuf_read_stream(struct videobuf_queue *q,
                 if (q->read_off == q->read_buf->size) {
                         list_add_tail(&q->read_buf->stream,
                                       &q->stream);
-                        spin_lock_irqsave(q->irqlock,flags);
+                        if (q->irqlock)
+                                spin_lock_irqsave(q->irqlock,flags);
                         q->ops->buf_queue(q,q->read_buf);
-                        spin_unlock_irqrestore(q->irqlock,flags);
+                        if (q->irqlock)
+                                spin_unlock_irqrestore(q->irqlock,flags);
                         q->read_buf = NULL;
                 }
                 if (retval < 0)
@@ -1249,11 +1370,14 @@ EXPORT_SYMBOL_GPL(videobuf_dma_init);
 EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
 EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
 EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
-EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
-EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
-EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
+EXPORT_SYMBOL_GPL(videobuf_dma_map);
+EXPORT_SYMBOL_GPL(videobuf_dma_sync);
+EXPORT_SYMBOL_GPL(videobuf_dma_unmap);
 EXPORT_SYMBOL_GPL(videobuf_dma_free);
 
+EXPORT_SYMBOL_GPL(videobuf_pci_dma_map);
+EXPORT_SYMBOL_GPL(videobuf_pci_dma_unmap);
+
 EXPORT_SYMBOL_GPL(videobuf_alloc);
 EXPORT_SYMBOL_GPL(videobuf_waiton);
 EXPORT_SYMBOL_GPL(videobuf_iolock);