fb: add support for drivers not needing VT switch at suspend/resume time

Use the new PM routines to indicate whether we need to VT switch at suspend
and resume time.  When a new driver is bound, set its flag accordingly,
and when unbound, remove it from the PM's console tracking list.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/video/fbmem.c

@@ -1645,6 +1645,11 @@ static int do_register_framebuffer(struct fb_info *fb_info)
 	if (!fb_info->modelist.prev || !fb_info->modelist.next)
 		INIT_LIST_HEAD(&fb_info->modelist);
 
+	if (fb_info->skip_vt_switch)
+		pm_vt_switch_required(fb_info->dev, false);
+	else
+		pm_vt_switch_required(fb_info->dev, true);
+
 	fb_var_to_videomode(&mode, &fb_info->var);
 	fb_add_videomode(&mode, &fb_info->modelist);
 	registered_fb[i] = fb_info;
@@ -1679,6 +1684,8 @@ static int do_unregister_framebuffer(struct fb_info *fb_info)
 	if (ret)
 		return -EINVAL;
 
+	pm_vt_switch_unregister(fb_info->dev);
+
 	unlink_framebuffer(fb_info);
 	if (fb_info->pixmap.addr &&
 	    (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT))

include/linux/fb.h

@@ -501,6 +501,8 @@ struct fb_info {
 			resource_size_t size;
 		} ranges[0];
 	} *apertures;
+
+	bool skip_vt_switch; /* no VT switch on suspend/resume required */
 };
 
 static inline struct apertures_struct *alloc_apertures(unsigned int max_num) {