UVC driver used to have partial no-mmu arch support, but it's removed by
commit c29fcff3daafbf46d64a543c1950bbd206ad8c1c.

This patch added them back and expanded to fully support no-mmu arch, so that
uvc cameras can be used on no-mmu platforms like Blackfin.

Signed-off-by: Bob Liu <lliu...@gmail.com>
---
 drivers/media/video/uvc/uvc_queue.c |   26 +++++++++++++++++++++++++-
 drivers/media/video/uvc/uvc_v4l2.c  |   13 +++++++++++++
 drivers/media/video/uvc/uvcvideo.h  |    6 ++++++
 drivers/media/video/v4l2-dev.c      |   18 ++++++++++++++++++
 include/media/v4l2-dev.h            |    2 ++
 5 files changed, 64 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/uvc/uvc_queue.c 
b/drivers/media/video/uvc/uvc_queue.c
index f14581b..caf8f6f 100644
--- a/drivers/media/video/uvc/uvc_queue.c
+++ b/drivers/media/video/uvc/uvc_queue.c
@@ -424,7 +424,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue, struct 
vm_area_struct *vma)
                        break;
        }
 
-       if (i == queue->count || size != queue->buf_size) {
+       if (i == queue->count || PAGE_ALIGN(size) != queue->buf_size) {
                ret = -EINVAL;
                goto done;
        }
@@ -436,6 +436,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue, struct 
vm_area_struct *vma)
        vma->vm_flags |= VM_IO;
 
        addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+#ifdef CONFIG_MMU
        while (size > 0) {
                page = vmalloc_to_page((void *)addr);
                if ((ret = vm_insert_page(vma, start, page)) < 0)
@@ -445,6 +446,7 @@ int uvc_queue_mmap(struct uvc_video_queue *queue, struct 
vm_area_struct *vma)
                addr += PAGE_SIZE;
                size -= PAGE_SIZE;
        }
+#endif
 
        vma->vm_ops = &uvc_vm_ops;
        vma->vm_private_data = buffer;
@@ -489,6 +491,28 @@ done:
 }
 
 /*
+ * Get unmapped area.
+ *
+ * NO-MMU arch need this function to make mmap() work correctly.
+ */
+unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+               unsigned long addr, unsigned long len, unsigned long pgoff)
+{
+       struct uvc_buffer *buffer;
+       unsigned int i;
+
+       mutex_lock(&queue->mutex);
+       for (i = 0; i < queue->count; ++i) {
+               buffer = &queue->buffer[i];
+               if ((buffer->buf.m.offset >> PAGE_SHIFT) == pgoff)
+                       break;
+       }
+       addr = (unsigned long)queue->mem + buffer->buf.m.offset;
+       mutex_unlock(&queue->mutex);
+       return addr;
+}
+
+/*
  * Enable or disable the video buffers queue.
  *
  * The queue must be enabled before starting video acquisition and must be
diff --git a/drivers/media/video/uvc/uvc_v4l2.c 
b/drivers/media/video/uvc/uvc_v4l2.c
index 9005a8d..9efab61 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -1081,6 +1081,18 @@ static unsigned int uvc_v4l2_poll(struct file *file, 
poll_table *wait)
        return uvc_queue_poll(&stream->queue, file, wait);
 }
 
+static unsigned long uvc_v4l2_get_unmapped_area(struct file *file,
+               unsigned long addr, unsigned long len, unsigned long pgoff,
+               unsigned long flags)
+{
+       struct uvc_fh *handle = file->private_data;
+       struct uvc_streaming *stream = handle->stream;
+
+       uvc_trace(UVC_TRACE_CALLS, "uvc_v4l2_get_unmapped_area\n");
+
+       return uvc_queue_get_unmapped_area(&stream->queue, addr, len, pgoff);
+}
+
 const struct v4l2_file_operations uvc_fops = {
        .owner          = THIS_MODULE,
        .open           = uvc_v4l2_open,
@@ -1089,5 +1101,6 @@ const struct v4l2_file_operations uvc_fops = {
        .read           = uvc_v4l2_read,
        .mmap           = uvc_v4l2_mmap,
        .poll           = uvc_v4l2_poll,
+       .get_unmapped_area = uvc_v4l2_get_unmapped_area,
 };
 
diff --git a/drivers/media/video/uvc/uvcvideo.h 
b/drivers/media/video/uvc/uvcvideo.h
index 45f01e7..48a2378 100644
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -580,6 +580,12 @@ extern int uvc_queue_mmap(struct uvc_video_queue *queue,
                struct vm_area_struct *vma);
 extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
                struct file *file, poll_table *wait);
+#ifdef CONFIG_MMU
+#define uvc_queue_get_unmapped_area NULL
+#else
+extern unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue,
+               unsigned long addr, unsigned long len, unsigned long pgoff);
+#endif
 extern int uvc_queue_allocated(struct uvc_video_queue *queue);
 static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
 {
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c
index 498e674..221e73f 100644
--- a/drivers/media/video/v4l2-dev.c
+++ b/drivers/media/video/v4l2-dev.c
@@ -368,6 +368,23 @@ static int v4l2_mmap(struct file *filp, struct 
vm_area_struct *vm)
        return ret;
 }
 
+#ifdef CONFIG_MMU
+#define v4l2_get_unmapped_area NULL
+#else
+static unsigned long v4l2_get_unmapped_area(struct file *filp,
+               unsigned long addr, unsigned long len, unsigned long pgoff,
+               unsigned long flags)
+{
+       struct video_device *vdev = video_devdata(filp);
+
+       if (!vdev->fops->get_unmapped_area)
+               return -ENOSYS;
+       if (!video_is_registered(vdev))
+               return -ENODEV;
+       return vdev->fops->get_unmapped_area(filp, addr, len, pgoff, flags);
+}
+#endif
+
 /* Override for the open function */
 static int v4l2_open(struct inode *inode, struct file *filp)
 {
@@ -452,6 +469,7 @@ static const struct file_operations v4l2_fops = {
        .write = v4l2_write,
        .open = v4l2_open,
        .mmap = v4l2_mmap,
+       .get_unmapped_area = v4l2_get_unmapped_area,
        .unlocked_ioctl = v4l2_ioctl,
 #ifdef CONFIG_COMPAT
        .compat_ioctl = v4l2_compat_ioctl32,
diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h
index 8266d5a..0616a43 100644
--- a/include/media/v4l2-dev.h
+++ b/include/media/v4l2-dev.h
@@ -63,6 +63,8 @@ struct v4l2_file_operations {
        long (*ioctl) (struct file *, unsigned int, unsigned long);
        long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
        int (*mmap) (struct file *, struct vm_area_struct *);
+       unsigned long (*get_unmapped_area) (struct file *, unsigned long,
+                       unsigned long, unsigned long, unsigned long);
        int (*open) (struct file *);
        int (*release) (struct file *);
 };
-- 
1.6.3.3

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