90 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			90 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Driver for the LCD display on the Tensilica XTFPGA board family.
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|  * http://www.mytechcorp.com/cfdata/productFile/File1/MOC-16216B-B-A0A04.pdf
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|  *
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|  * This file is subject to the terms and conditions of the GNU General Public
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|  * License.  See the file "COPYING" in the main directory of this archive
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|  * for more details.
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|  *
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|  * Copyright (C) 2001, 2006 Tensilica Inc.
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|  * Copyright (C) 2015 Cadence Design Systems Inc.
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|  */
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| 
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| #include <linux/delay.h>
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| #include <linux/init.h>
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| #include <linux/io.h>
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| 
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| #include <platform/hardware.h>
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| #include <platform/lcd.h>
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| 
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| /* LCD instruction and data addresses. */
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| #define LCD_INSTR_ADDR		((char *)IOADDR(CONFIG_XTFPGA_LCD_BASE_ADDR))
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| #define LCD_DATA_ADDR		(LCD_INSTR_ADDR + 4)
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| 
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| #define LCD_CLEAR		0x1
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| #define LCD_DISPLAY_ON		0xc
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| 
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| /* 8bit and 2 lines display */
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| #define LCD_DISPLAY_MODE8BIT	0x38
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| #define LCD_DISPLAY_MODE4BIT	0x28
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| #define LCD_DISPLAY_POS		0x80
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| #define LCD_SHIFT_LEFT		0x18
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| #define LCD_SHIFT_RIGHT		0x1c
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| 
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| static void lcd_put_byte(u8 *addr, u8 data)
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| {
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| #ifdef CONFIG_XTFPGA_LCD_8BIT_ACCESS
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| 	WRITE_ONCE(*addr, data);
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| #else
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| 	WRITE_ONCE(*addr, data & 0xf0);
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| 	WRITE_ONCE(*addr, (data << 4) & 0xf0);
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| #endif
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| }
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| 
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| static int __init lcd_init(void)
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| {
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| 	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
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| 	mdelay(5);
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| 	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
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| 	udelay(200);
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| 	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
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| 	udelay(50);
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| #ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS
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| 	WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT);
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| 	udelay(50);
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| 	lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT);
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| 	udelay(50);
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| #endif
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| 	lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_ON);
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| 	udelay(50);
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| 	lcd_put_byte(LCD_INSTR_ADDR, LCD_CLEAR);
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| 	mdelay(10);
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| 	lcd_disp_at_pos("XTENSA LINUX", 0);
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| 	return 0;
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| }
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| 
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| void lcd_disp_at_pos(char *str, unsigned char pos)
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| {
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| 	lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_POS | pos);
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| 	udelay(100);
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| 	while (*str != 0) {
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| 		lcd_put_byte(LCD_DATA_ADDR, *str);
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| 		udelay(200);
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| 		str++;
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| 	}
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| }
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| 
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| void lcd_shiftleft(void)
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| {
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| 	lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_LEFT);
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| 	udelay(50);
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| }
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| 
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| void lcd_shiftright(void)
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| {
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| 	lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_RIGHT);
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| 	udelay(50);
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| }
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| 
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| arch_initcall(lcd_init);
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