1 files changed, 89 insertions, 0 deletions
diff --git a/arch/xtensa/platforms/xtfpga/lcd.c b/arch/xtensa/platforms/xtfpga/lcd.c
new file mode 100644
index 000000000..2f7eb66c2
--- /dev/null
+++ b/arch/xtensa/platforms/xtfpga/lcd.c
@@ -0,0 +1,89 @@
+/*
+ * Driver for the LCD display on the Tensilica XTFPGA board family.
+ * http://www.mytechcorp.com/cfdata/productFile/File1/MOC-16216B-B-A0A04.pdf
+ *
+ * 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.
+ *
+ * Copyright (C) 2001, 2006 Tensilica Inc.
+ * Copyright (C) 2015 Cadence Design Systems Inc.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+
+#include <platform/hardware.h>
+#include <platform/lcd.h>
+
+/* LCD instruction and data addresses. */
+#define LCD_INSTR_ADDR		((char *)IOADDR(CONFIG_XTFPGA_LCD_BASE_ADDR))
+#define LCD_DATA_ADDR		(LCD_INSTR_ADDR + 4)
+
+#define LCD_CLEAR		0x1
+#define LCD_DISPLAY_ON		0xc
+
+/* 8bit and 2 lines display */
+#define LCD_DISPLAY_MODE8BIT	0x38
+#define LCD_DISPLAY_MODE4BIT	0x28
+#define LCD_DISPLAY_POS		0x80
+#define LCD_SHIFT_LEFT		0x18
+#define LCD_SHIFT_RIGHT		0x1c
+
+static void lcd_put_byte(u8 *addr, u8 data)
+{
+#ifdef CONFIG_XTFPGA_LCD_8BIT_ACCESS
+	WRITE_ONCE(*addr, data);
+#else
+	WRITE_ONCE(*addr, data & 0xf0);
+	WRITE_ONCE(*addr, (data << 4) & 0xf0);
+#endif
+}
+
+static int __init lcd_init(void)
+{
+	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
+	mdelay(5);
+	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
+	udelay(200);
+	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
+	udelay(50);
+#ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS
+	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT);
+	udelay(50);
+	lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT);
+	udelay(50);
+#endif
+	lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_ON);
+	udelay(50);
+	lcd_put_byte(LCD_INSTR_ADDR, LCD_CLEAR);
+	mdelay(10);
+	lcd_disp_at_pos("XTENSA LINUX", 0);
+	return 0;
+}
+
+void lcd_disp_at_pos(char *str, unsigned char pos)
+{
+	lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_POS | pos);
+	udelay(100);
+	while (*str != 0) {
+		lcd_put_byte(LCD_DATA_ADDR, *str);
+		udelay(200);
+		str++;
+	}
+}
+
+void lcd_shiftleft(void)
+{
+	lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_LEFT);
+	udelay(50);
+}
+
+void lcd_shiftright(void)
+{
+	lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_RIGHT);
+	udelay(50);
+}
+
+arch_initcall(lcd_init);