fbdev: add support for handoff from firmware to hw framebuffers

[sfrench/cifs-2.6.git] / drivers / video / fbmem.c

diff --git a/drivers/video/fbmem.c b/drivers/video/fbmem.c
index d412a1ddc12fabb50df8562af40b5df25351d2bd..f8a09bf8d0cdecb0963116a4fb7a7d3793ed798d 100644 (file)
--- a/drivers/video/fbmem.c
+++ b/drivers/video/fbmem.c
@@ -1462,6 +1462,16 @@ static int fb_check_foreignness(struct fb_info *fi)
        return 0;
 }
 
+static bool fb_do_apertures_overlap(struct fb_info *gen, struct fb_info *hw)
+{
+       /* is the generic aperture base the same as the HW one */
+       if (gen->aperture_base == hw->aperture_base)
+               return true;
+       /* is the generic aperture base inside the hw base->hw base+size */
+       if (gen->aperture_base > hw->aperture_base && gen->aperture_base <= hw->aperture_base + hw->aperture_size)
+               return true;
+       return false;
+}
 /**
  *     register_framebuffer - registers a frame buffer device
  *     @fb_info: frame buffer info structure
@@ -1485,6 +1495,23 @@ register_framebuffer(struct fb_info *fb_info)
        if (fb_check_foreignness(fb_info))
                return -ENOSYS;
 
+       /* check all firmware fbs and kick off if the base addr overlaps */
+       for (i = 0 ; i < FB_MAX; i++) {
+               if (!registered_fb[i])
+                       continue;
+
+               if (registered_fb[i]->flags & FBINFO_MISC_FIRMWARE) {
+                       if (fb_do_apertures_overlap(registered_fb[i], fb_info)) {
+                               printk(KERN_ERR "fb: conflicting fb hw usage "
+                                      "%s vs %s - removing generic driver\n",
+                                      fb_info->fix.id,
+                                      registered_fb[i]->fix.id);
+                               unregister_framebuffer(registered_fb[i]);
+                               break;
+                       }
+               }
+       }
+
        num_registered_fb++;
        for (i = 0 ; i < FB_MAX; i++)
                if (!registered_fb[i])
@@ -1586,6 +1613,10 @@ unregister_framebuffer(struct fb_info *fb_info)
        device_destroy(fb_class, MKDEV(FB_MAJOR, i));
        event.info = fb_info;
        fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
+
+       /* this may free fb info */
+       if (fb_info->fbops->fb_destroy)
+               fb_info->fbops->fb_destroy(fb_info);
 done:
        return ret;
 }