Blame view

kernel/linux-rt-4.4.41/arch/xtensa/platforms/xtfpga/lcd.c 2.1 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
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
  	ACCESS_ONCE(*addr) = data;
  #else
  	ACCESS_ONCE(*addr) = data & 0xf0;
  	ACCESS_ONCE(*addr) = (data << 4) & 0xf0;
  #endif
  }
  
  static int __init lcd_init(void)
  {
  	ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT;
  	mdelay(5);
  	ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT;
  	udelay(200);
  	ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT;
  	udelay(50);
  #ifndef CONFIG_XTFPGA_LCD_8BIT_ACCESS
  	ACCESS_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);