Re: [RFC 2.6.26-rc9 3/5] pxafb: add shared framebuffer interface

These changes are to make it possible for a secondary driver to share the
pxafb framebuffer. The changes include:
- adding extra_video_mem entry so that a driver can tell pxafb of its
  additional needs.
- adding share_video_mem/unshare_video_mem callbacks to notify the secondary
  driver of the framebuffer address, to allow refcounting, and to cleanup on
  completion.

Signed-off-by: Jaya Kumar <redacted>
---

diff --git a/drivers/video/pxafb.c b/drivers/video/pxafb.c
index bb25143..f799c52 100644
--- a/drivers/video/pxafb.c
+++ b/drivers/video/pxafb.c

@@ -57,6 +57,8 @@
  */
 #define DEBUG_VAR 1
 
+static struct platform_driver pxafb_driver;
+

-static int __devinit pxafb_map_video_memory(struct pxafb_info *fbi)
+static int __devinit pxafb_map_video_memory(struct pxafb_info *fbi,
+						struct pxafb_mach_info *inf)
 {
+	int ret;
 	/*
 	 * We reserve one page for the palette, plus the size
 	 * of the framebuffer.
 	 */
 	fbi->video_offset = PAGE_ALIGN(sizeof(struct pxafb_dma_buff));
-	fbi->map_size = PAGE_ALIGN(fbi->fb.fix.smem_len + fbi->video_offset);
+	fbi->map_size = PAGE_ALIGN(fbi->fb.fix.smem_len + fbi->video_offset +
+					inf->extra_video_mem);
 	fbi->map_cpu = dma_alloc_writecombine(fbi->dev, fbi->map_size,
 					      &fbi->map_dma, GFP_KERNEL);
 

@@ -1340,6 +1346,13 @@ static int __devinit pxafb_map_video_memory(struct pxafb_info *fbi)
 		fbi->smart_cmds = (uint16_t *) fbi->dma_buff->cmd_buff;
 		fbi->n_smart_cmds = 0;
 #endif
+		if (inf->share_video_mem) {
+			ret = inf->share_video_mem(fbi->fb.screen_base,
+				fbi->screen_dma, pxafb_driver.driver.owner,

+				inf->extra_data);
+			if (ret)
+				return ret;
+		}
 	}