parisc/stifb: Implement fb_is_primary_device()

Implement fb_is_primary_device() function, so that fbcon detects if this
framebuffer belongs to the default graphics card which was used to start
the system.

Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org   # v5.10+

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/video/console/sticore.c b/drivers/video/console/sticore.c
index f869b723494f..62005064911b 100644
--- a/drivers/video/console/sticore.c
+++ b/drivers/video/console/sticore.c
@@ -30,6 +30,7 @@
 #include <asm/pdc.h>
 #include <asm/cacheflush.h>
 #include <asm/grfioctl.h>
+#include <asm/fb.h>
 
 #include "../fbdev/sticore.h"
 
@@ -1127,6 +1128,22 @@ int sti_call(const struct sti_struct *sti, unsigned long func,
 	return ret;
 }
 
+/* check if given fb_info is the primary device */
+int fb_is_primary_device(struct fb_info *info)
+{
+	struct sti_struct *sti;
+
+	sti = sti_get_rom(0);
+
+	/* if no built-in graphics card found, allow any fb driver as default */
+	if (!sti)
+		return true;
+
+	/* return true if it's the default built-in framebuffer driver */
+	return (sti->info == info);
+}
+EXPORT_SYMBOL(fb_is_primary_device);
+
 MODULE_AUTHOR("Philipp Rumpf, Helge Deller, Thomas Bogendoerfer");
 MODULE_DESCRIPTION("Core STI driver for HP's NGLE series graphics cards in HP PARISC machines");
 MODULE_LICENSE("GPL v2");