video: ARM CLCD: add special panel hook for Versatiles

This adds a special panel init hook for the ARM reference designs
Integrator (IM-PD1), Versatile and RealView, so we can configure
a DPI panel from device tree and have it working without
boardfiles for these machines.

Basically this is the same code as from the board files, just
moved over to look up the syscon DT node and manipulate the
special CLCD register from their regmap.

Tested on RealView PB11MPcore.

Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/fbdev/Kconfig

@@ -307,6 +307,8 @@ config PLAT_VERSATILE_CLCD
 	def_bool ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS || ARCH_INTEGRATOR
 	depends on ARM
 	depends on FB_ARMCLCD && FB=y
+	select REGMAP
+	select MFD_SYSCON
 
 config FB_ACORN
 	bool "Acorn VIDC support"

drivers/video/fbdev/amba-clcd-versatile.h

+/*
+ * Special local versatile callbacks
+ */
+#include <linux/of.h>
+#include <linux/amba/bus.h>
+#include <linux/platform_data/video-clcd-versatile.h>
+
+#if defined(CONFIG_PLAT_VERSATILE_CLCD) && defined(CONFIG_OF)
+int versatile_clcd_init_panel(struct clcd_fb *fb,
+			      struct device_node *endpoint);
+#else
+static inline int versatile_clcd_init_panel(struct clcd_fb *fb,
+				struct device_node *endpoint)
+{
+	return 0;
+}
+#endif

drivers/video/fbdev/amba-clcd.c

@@ -36,6 +36,7 @@
 #include <video/videomode.h>
 
 #include "amba-clcd-nomadik.h"
+#include "amba-clcd-versatile.h"
 
 #define to_clcd(info)	container_of(info, struct clcd_fb, fb)
 
@@ -1036,7 +1037,8 @@ static int clcdfb_remove(struct amba_device *dev)
 }
 
 static struct clcd_vendor_data vendor_arm = {
-	/* No special business */
+	/* Sets up the versatile board displays */
+	.init_panel = versatile_clcd_init_panel,
 };
 
 static struct clcd_vendor_data vendor_nomadik = {