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, 41 insertions, 15 deletions

diff --git a/include/media/video-buf.h b/include/media/video-buf.h
index d90dec5484ee..fff3fd0fbf94 100644
--- a/include/media/video-buf.h
+++ b/include/media/video-buf.h
@@ -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 as
- * data often must be uncompressed by the drivers).
+ * to touch the video data.
+ *
+ * device specific map/unmap/sync stuff now are mapped as file operations
+ * to allow its usage by USB and virtual devices.
  *
  * (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
@@ -38,6 +43,9 @@ struct scatterlist* videobuf_vmalloc_to_sg(unsigned char *virt, int nr_pages);
 struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages,
                                          int offset);
 
+struct videobuf_buffer;
+struct videobuf_queue;
+
 /* --------------------------------------------------------------------- */
 
 /*
@@ -49,7 +57,7 @@ struct scatterlist* videobuf_pages_to_sg(struct page **pages, int nr_pages,
  *      pointer + length.  The kernel version just wants the size and
  *      does memory allocation too using vmalloc_32().
  *
- * videobuf_dma_pci_*()
+ * videobuf_dma_*()
  *      see Documentation/DMA-mapping.txt, these functions to
  *      basically the same.  The map function does also build a
  *      scatterlist for the buffer (and unmap frees it ...)
@@ -86,12 +94,18 @@ int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
                              int nr_pages);
 int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
                               dma_addr_t addr, int nr_pages);
-int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma);
-int videobuf_dma_pci_sync(struct pci_dev *dev,
-                          struct videobuf_dmabuf *dma);
-int videobuf_dma_pci_unmap(struct pci_dev *dev, struct videobuf_dmabuf *dma);
 int videobuf_dma_free(struct videobuf_dmabuf *dma);
 
+int videobuf_dma_map(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
+int videobuf_dma_sync(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
+int videobuf_dma_unmap(struct videobuf_queue* q,struct videobuf_dmabuf *dma);
+
+        /*FIXME: these variants are used only on *-alsa code, where videobuf is
+         * used without queue
+         */
+int videobuf_pci_dma_map(struct pci_dev *pci,struct videobuf_dmabuf *dma);
+int videobuf_pci_dma_unmap(struct pci_dev *pci,struct videobuf_dmabuf *dma);
+
 /* --------------------------------------------------------------------- */
 
 /*
@@ -115,9 +129,6 @@ int videobuf_dma_free(struct videobuf_dmabuf *dma);
  *
  */
 
-struct videobuf_buffer;
-struct videobuf_queue;
-
 struct videobuf_mapping {
         unsigned int count;
         unsigned long start;
@@ -164,6 +175,10 @@ struct videobuf_buffer {
         struct timeval          ts;
 };
 
+typedef int (vb_map_sg_t)(void *dev,struct scatterlist *sglist,int nr_pages,
+                                        int direction);
+
+
 struct videobuf_queue_ops {
         int (*buf_setup)(struct videobuf_queue *q,
                          unsigned int *count, unsigned int *size);
@@ -174,12 +189,20 @@ struct videobuf_queue_ops {
                           struct videobuf_buffer *vb);
         void (*buf_release)(struct videobuf_queue *q,
                             struct videobuf_buffer *vb);
+
+        /* Helper operations - device dependent.
+         * If null, videobuf_init defaults all to PCI handling
+         */
+
+        vb_map_sg_t     *vb_map_sg;
+        vb_map_sg_t     *vb_dma_sync_sg;
+        vb_map_sg_t     *vb_unmap_sg;
 };
 
 struct videobuf_queue {
         struct mutex               lock;
         spinlock_t                 *irqlock;
-        struct pci_dev             *pci;
+        void                       *dev; /* on pci, points to struct pci_dev */
 
         enum v4l2_buf_type         type;
         unsigned int               inputs; /* for V4L2_BUF_FLAG_INPUT */
@@ -204,12 +227,15 @@ struct videobuf_queue {
 
 void* videobuf_alloc(unsigned int size);
 int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
-int videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
-                    struct v4l2_framebuffer *fbuf);
+int videobuf_iolock(struct videobuf_queue* q, struct videobuf_buffer *vb,
+                struct v4l2_framebuffer *fbuf);
+
+/* Maps fops to PCI stuff */
+void videobuf_queue_pci(struct videobuf_queue* q);
 
 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,