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 WRITE_ONCE(*addr, data);
38 #else
39 WRITE_ONCE(*addr, data & 0xf0);
40 WRITE_ONCE(*addr, (data << 4) & 0xf0);
41 #endif
42 }
43
44 static int __init lcd_init(void)
45 {
46 WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
47 mdelay(5);
48 WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
49 udelay(200);
50 WRITE_ONCE(*LCD_INSTR_ADDR, LCD_DISPLAY_MODE8BIT);
51 udelay(50);
52 #ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS
53 WRITE_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
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