video1394: add poll file operation support

This patch adds support for the poll file operation to the video1394
driver.

Signed-off-by: David Moore <dcm@acm.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

1 files changed, 37 insertions, 1 deletions

diff --git a/drivers/ieee1394/video1394.c b/drivers/ieee1394/video1394.c
index 6b5353d81ae2..af78b840dc26 100644
--- a/drivers/ieee1394/video1394.c
+++ b/drivers/ieee1394/video1394.c
@@ -1181,7 +1181,8 @@ static int video1394_mmap(struct file *file, struct vm_area_struct *vma)
 
         lock_kernel();
         if (ctx->current_ctx == NULL) {
-                PRINT(KERN_ERR, ctx->ohci->host->id, "Current iso context not set");
+                PRINT(KERN_ERR, ctx->ohci->host->id,
+                                "Current iso context not set");
         } else
                 res = dma_region_mmap(&ctx->current_ctx->dma, file, vma);
         unlock_kernel();
@@ -1189,6 +1190,40 @@ static int video1394_mmap(struct file *file, struct vm_area_struct *vma)
         return res;
 }
 
+static unsigned int video1394_poll(struct file *file, poll_table *pt)
+{
+        struct file_ctx *ctx;
+        unsigned int mask = 0;
+        unsigned long flags;
+        struct dma_iso_ctx *d;
+        int i;
+
+        lock_kernel();
+        ctx = file->private_data;
+        d = ctx->current_ctx;
+        if (d == NULL) {
+                PRINT(KERN_ERR, ctx->ohci->host->id,
+                                "Current iso context not set");
+                mask = POLLERR;
+                goto done;
+        }
+
+        poll_wait(file, &d->waitq, pt);
+
+        spin_lock_irqsave(&d->lock, flags);
+        for (i = 0; i < d->num_desc; i++) {
+                if (d->buffer_status[i] == VIDEO1394_BUFFER_READY) {
+                        mask |= POLLIN | POLLRDNORM;
+                        break;
+                }
+        }
+        spin_unlock_irqrestore(&d->lock, flags);
+done:
+        unlock_kernel();
+
+        return mask;
+}
+
 static int video1394_open(struct inode *inode, struct file *file)
 {
         int i = ieee1394_file_to_instance(file);
@@ -1257,6 +1292,7 @@ static struct file_operations video1394_fops=
 #ifdef CONFIG_COMPAT
         .compat_ioctl = video1394_compat_ioctl,
 #endif
+        .poll =         video1394_poll,
         .mmap =         video1394_mmap,
         .open =         video1394_open,
         .release =      video1394_release