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
34static 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
44static 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
66void 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
77void lcd_shiftleft(void)
78{
79	lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_LEFT);
80	udelay(50);
81}
82
83void lcd_shiftright(void)
84{
85	lcd_put_byte(LCD_INSTR_ADDR, LCD_SHIFT_RIGHT);
86	udelay(50);
87}
88
89arch_initcall(lcd_init);
90