MIPS: malta: Use img-ascii-lcd driver for LCD display

Remove the Malta display platform code in favour of probing the
img-ascii-lcd driver via device tree. This reduces the amount of
platform code & the img-ascii-lcd driver offers us advantages in terms
of code sharing with other boards & functionality such as changing the
displayed message via sysfs. Defconfigs are untouched because the driver
already defaults y on when CONFIG_MIPS_MALTA=y.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21182/
Cc: linux-mips@linux-mips.org

arch/mips/boot/dts/mti/malta.dts

@@ -87,6 +87,11 @@ fpga_regs: system-controller@1f000000 {
 		reg = <0x1f000000 0x1000>;
 		native-endian;
 
+		lcd@410 {
+			compatible = "mti,malta-lcd";
+			offset = <0x410>;
+		};
+
 		reboot {
 			compatible = "syscon-reboot";
 			regmap = <&fpga_regs>;

arch/mips/mti-malta/Makefile

@@ -6,7 +6,6 @@
 # Copyright (C) 2008 Wind River Systems, Inc.
 #   written by Ralf Baechle <ralf@linux-mips.org>
 #
-obj-y				+= malta-display.o
 obj-y				+= malta-dt.o
 obj-y				+= malta-dtshim.o
 obj-y				+= malta-init.o

arch/mips/mti-malta/malta-display.c

-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Display routines for display messages in MIPS boards ascii display.
- *
- * Copyright (C) 1999,2000,2012  MIPS Technologies, Inc.
- * All rights reserved.
- * Authors: Carsten Langgaard <carstenl@mips.com>
- *          Steven J. Hill <sjhill@mips.com>
- */
-#include <linux/compiler.h>
-#include <linux/timer.h>
-#include <linux/io.h>
-
-#include <asm/mips-boards/generic.h>
-
-extern const char display_string[];
-static unsigned int display_count;
-static unsigned int max_display_count;
-
-void mips_display_message(const char *str)
-{
-	static unsigned int __iomem *display = NULL;
-	int i;
-
-	if (unlikely(display == NULL))
-		display = ioremap(ASCII_DISPLAY_POS_BASE, 16*sizeof(int));
-
-	for (i = 0; i <= 14; i += 2) {
-		if (*str)
-			__raw_writel(*str++, display + i);
-		else
-			__raw_writel(' ', display + i);
-	}
-}
-
-static void scroll_display_message(struct timer_list *unused);
-static DEFINE_TIMER(mips_scroll_timer, scroll_display_message);
-
-static void scroll_display_message(struct timer_list *unused)
-{
-	mips_display_message(&display_string[display_count++]);
-	if (display_count == max_display_count)
-		display_count = 0;
-
-	mod_timer(&mips_scroll_timer, jiffies + HZ);
-}
-
-void mips_scroll_message(void)
-{
-	del_timer_sync(&mips_scroll_timer);
-	max_display_count = strlen(display_string) + 1 - 8;
-	mod_timer(&mips_scroll_timer, jiffies + 1);
-}

arch/mips/mti-malta/malta-init.c

@@ -118,8 +118,6 @@ phys_addr_t mips_cpc_default_phys_base(void)
 
 void __init prom_init(void)
 {
-	mips_display_message("LINUX");
-
 	/*
 	 * early setup of _pcictrl_bonito so that we can determine
 	 * the system controller on a CORE_EMUL board
@@ -277,7 +275,6 @@ void __init prom_init(void)
 
 	default:
 		/* Unknown system controller */
-		mips_display_message("SC Error");
 		while (1);	/* We die here... */
 	}
 	board_nmi_handler_setup = mips_nmi_setup;

arch/mips/mti-malta/malta-setup.c

@@ -81,8 +81,6 @@ const char *get_system_type(void)
 	return "MIPS Malta";
 }
 
-const char display_string[] = "	       LINUX ON MALTA	    ";
-
 #ifdef CONFIG_BLK_DEV_FD
 static void __init fd_activate(void)
 {

arch/mips/mti-malta/malta-time.c

@@ -251,8 +251,6 @@ void __init plat_time_init(void)
 	printk("CPU frequency %d.%02d MHz\n", freq/1000000,
 	       (freq%1000000)*100/1000000);
 
-	mips_scroll_message();
-
 #ifdef CONFIG_I8253
 	/* Only Malta has a PIT. */
 	setup_pit_timer();