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042741ecc3
commit 4949009eb8 upstream.
LCD driver is always built for the XTFPGA platform, but its base address
is not configurable, and is wrong for ML605/KC705. Its initialization
locks up KC705 board hardware.
Make the whole driver optional, and its base address and bus width
configurable. Implement 4-bit bus access method.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/io.h>
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#include <platform/hardware.h>
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#include <platform/lcd.h>
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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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#define LCD_CLEAR 0x1
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#define LCD_DISPLAY_ON 0xc
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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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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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ACCESS_ONCE(*addr) = data;
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#else
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ACCESS_ONCE(*addr) = data & 0xf0;
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ACCESS_ONCE(*addr) = (data << 4) & 0xf0;
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#endif
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}
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static int __init lcd_init(void)
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{
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ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT;
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mdelay(5);
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ACCESS_ONCE(*LCD_INSTR_ADDR) = LCD_DISPLAY_MODE8BIT;
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udelay(200);
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ACCESS_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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ACCESS_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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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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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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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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arch_initcall(lcd_init);
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