/************************************************************************************
* configs/scp16c26/src/up_lcd.c
*
* Copyright (C) 2009 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name Gregory Nutt nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
************************************************************************************/
/************************************************************************************
* Included Files
************************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdbool.h>
#include <ctype.h>
#include "up_arch.h"
#include "up_internal.h"
#include "chip.h"
#ifdef CONFIG_ARCH_LCD
/************************************************************************************
* Definitions
************************************************************************************/
/* LCD dimensions *******************************************************************/
#define LCD_NLINES 2 /* Two lines */
#define LCD_NCHARS 8 /* Eight characters per line */
/* LCD commands *********************************************************************/
#define LCD_CLEAR 0x01 /* Clear LCD display and home cursor */
#define CURSOR_MODE_DEC 0x04 /* Cursor auto decrement after R/W */
#define CURSOR_MODE_INC 0x06 /* Cursor auto increment after R/W */
#define LCD_CURSOR_ON 0x0e /* Display ON with Cursor */
#define LCD_CURSOR_OFF 0x0c /* Display ON with Cursor off */
#define LCD_CURSOR_BLINK 0x0d /* Display on with blinking cursor */
#define LCD_CURSOR_LEFT 0x10 /* Move Cursor Left One Position */
#define LCD_CURSOR_RIGHT 0x14 /* Move Cursor Right One Position */
#define FUNCTION_SET 0x28 /* Setup, 4 bits,2 lines, 5X7 */
#define LCD_CGRAM 0x40 /* Map characters to CG RAM */
#define LCD_POS_L1(p) (0x80 | p) /* Move cursor to line 1, character p+1 */
#define LCD_POS_L2(p) (0xc0 | p) /* Move cursor to line 2, character p+1 */
#define LCD_HOME_L1 0x80 /* Move cursor to line 1 */
#define LCD_HOME_L2 0xc0 /* Move cursor to line 2 */
/************************************************************************************
* Private Data
************************************************************************************/
static uint8_t g_nchars; /* Number of characters in lines 2 */
static uint8_t g_line[LCD_NCHARS]; /* The content of lines 2 */
/************************************************************************************
* Private Functions
************************************************************************************/
/************************************************************************************
* Name: up_lcddelay
************************************************************************************/
static void up_lcddelay(uint16_t count)
{
uint32_t counter = (uint16_t)count << 8;
while(counter--)
{
asm("\tnop\n\tnop\n\tnop\n" : :); /* 3 NOPs */
}
}
/************************************************************************************
* Name: up_setrs
************************************************************************************/
static inline void up_setrs(bool data)
{
/* Set/clear bit 1 of port 6 */
register uint8_t regval = getreg8(M16C_P6);
if (data)
{
regval |= (1 << 0); /* High = data */
}
else
{
regval &= ~(1 << 0); /* Low = control */
}
putreg8(regval, M16C_P6);
}
/************************************************************************************
* Name: up_seten
************************************************************************************/
static inline void up_seten(void)
{
/* Set bit 1 of port 6 */
register uint8_t regval = getreg8(M16C_P6);
regval = (1 << 1);
putreg8(regval, M16C_P6);
}
/************************************************************************************
* Name: up_clren
************************************************************************************/
static inline void up_clren(void)
{
/* Clear bit 1 of port 6 */
register uint8_t regval = getreg8(M16C_P6);
regval &= ~(1 << 1);
putreg8(regval, M16C_P6);
}
/************************************************************************************
* Name: up_enpluse
************************************************************************************/
static inline void up_enpulse(bool data)
{
up_seten(); /* EN enable chip (HIGH) */
up_lcddelay(0); /* Short delay */
up_clren(); /* Latch data by setting EN low */
up_lcddelay(0); /* Short delay for data writes */
if (!data) up_lcddelay(0); /* Longer delay for control writes */
}
/************************************************************************************
* Name: up_lcdwrite
************************************************************************************/
void up_lcdwrite(bool data, uint8_t ch)
{
up_setrs(data); /* Set RS appropriately */
/* Write upper nibble first. Only the lower 4 bits of P9 are valid. The upper four
* bits are reserved and must be zero.
*/
putreg8(ch >> 4, M16C_P9);
up_enpulse(data);
/* Write lower nibble second */
putreg8(ch & 0x0f, M16C_P9);
up_enpulse(data);
}
/************************************************************************************
* Name: up_scroll
************************************************************************************/
static void up_scroll(void)
{
int i;
/* Clear the display and position the cursor at the beginning of line 1 */
up_lcdwrite(false, LCD_CLEAR);
up_lcdwrite(false, LCD_HOME_L1);
/* Copy line 2 to line 1 */
for (i = 0; i < g_nchars; i++)
{
up_lcdwrite(true, g_line[i]);
}
/* Position the cursor at the beginning of line 2 */
up_lcdwrite(false, LCD_HOME_L2);
g_nchars = 0;
}
/************************************************************************************
* Public Functions
************************************************************************************/
/************************************************************************************
* Name: up_lcdinit
************************************************************************************/
void up_lcdinit(void)
{
uint8_t regval;
/* Enable writing to PD9 by selecting bit 2 in the protection register */
regval = getreg8(M16C_PRCR);
regval |= (1 << 2);
putreg8(regval, M16C_PRCR);
/* We can't read PD9, so we can't OR the values in */
putreg8(0x0f, M16C_PD9);
/* Set EN (port 6 bit 1) and Set RS (port 6 bit 0) as outputs */
regval = getreg8(M16C_P6);
regval |= (1 << 1) | (1 << 0);
putreg8(regval, M16C_P6);
regval = getreg8(M16C_PD6);
regval |= (1 << 1) | (1 << 0);
putreg8(regval, M16C_PD6);
/* Set EN low */
up_clren();
/* Write the reset sequence */
up_lcdwrite(false, 0x33);
up_lcddelay(20);
up_lcdwrite(false, 0x32);
up_lcddelay(20);
up_lcdwrite(false, FUNCTION_SET); /* reset sequence */
up_lcdwrite(false, FUNCTION_SET);
up_lcdwrite(false, LCD_CURSOR_OFF);
up_lcdwrite(false, LCD_CLEAR);
up_lcdwrite(false, LCD_HOME_L1);
}
/************************************************************************************
* Name: up_lcdputc
************************************************************************************/
void up_lcdputc(char ch)
{
/* Check for new line */
if (ch == '\n')
{
up_scroll();
}
/* Should we wrap to truncate at the end of line??? Let's truncate. In either
* case, let's ignore all other non-printable characters.
*/
else if (g_nchars < LCD_NCHARS && isprint(ch))
{
up_lcdwrite(true, ch);
g_line[g_nchars] = ch;
g_nchars++;
}
}
#endif /* CONFIG_ARCH_LCD */
