1 /* 2 * Driver for the LCD display on the Tensilica XTFPGA board family. 3 * http://www.mytechcorp.com/cfdata/productFile/File1/MOC-16216B-B-A0A04.pdf 4 * 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 * 9 * Copyright (C) 2001, 2006 Tensilica Inc. 10 * Copyright (C) 2015 Cadence Design Systems Inc. 11 */ 12 13 #include <linux/delay.h> 14 #include <linux/init.h> 15 #include <linux/io.h> 16 17 #include <platform/hardware.h> 18 #include <platform/lcd.h> 19 20 /* LCD instruction and data addresses. */ 21 #define LCD_INSTR_ADDR ((char *)IOADDR(CONFIG_XTFPGA_LCD_BASE_ADDR)) 22 #define LCD_DATA_ADDR (LCD_INSTR_ADDR + 4) 23 24 #define LCD_CLEAR 0x1 25 #define LCD_DISPLAY_ON 0xc 26 27 /* 8bit and 2 lines display */ 28 #define LCD_DISPLAY_MODE8BIT 0x38 29 #define LCD_DISPLAY_MODE4BIT 0x28 30 #define LCD_DISPLAY_POS 0x80 31 #define LCD_SHIFT_LEFT 0x18 32 #define LCD_SHIFT_RIGHT 0x1c 33 34 static void lcd_put_byte(u8 *addr, u8 data) 35 { 36 #ifdef CONFIG_XTFPGA_LCD_8BIT_ACCESS 37 ACCESS_ONCE(*addr) = data; 38 #else 39 ACCESS_ONCE(*addr) = data & 0xf0; 40 ACCESS_ONCE(*addr) = (data << 4) & 0xf0; 41 #endif 42 } 43 44 static int __init lcd_init(void) 45 { 46 ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT; 47 mdelay(5); 48 ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT; 49 udelay(200); 50 ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT; 51 udelay(50); 52 #ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS 53 ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE4BIT; 54 udelay(50); 55 lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_MODE4BIT); 56 udelay(50); 57 #endif 58 lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_ON); 59 udelay(50); 60 lcd_put_byte(LCD_INSTR_ADDR, LCD_CLEAR); 61 mdelay(10); 62 lcd_disp_at_pos("XTENSA LINUX", 0); 63 return 0; 64 } 65 66 void lcd_disp_at_pos(char *str, unsigned char pos) 67 { 68 lcd_put_byte(LCD_INSTR_ADDR, LCD_DISPLAY_POS | pos); 69 udelay(100); 70 while (*str != 0) { 71 lcd_put_byte(LCD_DATA_ADDR, *str); 72 udelay(200); 73 str++; 74 } 75 } 76 77 void lcd_shiftleft(void) 78 { 79 lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_LEFT); 80 udelay(50); 81 } 82 83 void lcd_shiftright(void) 84 { 85 lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_RIGHT); 86 udelay(50); 87 } 88 89 arch_initcall(lcd_init); 90