Low level lcd for avr.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@719 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/hw/hw_lcd.h b/hw/hw_lcd.h
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+/**
+ * \file
+ * <!--
+ * Copyright 2003, 2004, 2005 Develer S.r.l. (http://www.develer.com/)
+ * Copyright 2001 Bernardo Innocenti <bernie@codewiz.org>
+ * This file is part of DevLib - See README.devlib for information.
+ * -->
+ *
+ * \version $Id$
+ *
+ * \author Bernardo Innocenti <bernie@develer.com>
+ * \author Stefano Fedrigo <aleph@develer.com>
+ *
+ * \brief LCD low-level hardware macros
+ */
+
+/*#*
+ *#* $Log$
+ *#* Revision 1.1  2006/09/20 17:39:24  marco
+ *#* Low level lcd for avr.
+ *#*
+ *#*/
+
+#ifndef HW_LCD_H
+#define HW_LCD_H
+
+#include <appconfig.h>
+//#include <hw.h>
+
+#include <cfg/cpu.h>
+#include <cfg/macros.h> /* BV() */
+#include <cfg/debug.h>
+
+#include <avr/io.h>
+#include <stdbool.h>
+#include <inttypes.h>
+
+/**
+ * \name LCD I/O pins/ports
+ * @{
+ */
+#define LCD_RS    BV(PG3)
+#define LCD_RW    BV(PG0)
+#define LCD_E     BV(PG2)
+#define LCD_DB0   BV(PA0)
+#define LCD_DB1   BV(PA1)
+#define LCD_DB2   BV(PA2)
+#define LCD_DB3   BV(PA3)
+#define LCD_DB4   BV(PA4)
+#define LCD_DB5   BV(PA5)
+#define LCD_DB6   BV(PA6)
+#define LCD_DB7   BV(PA7)
+/*@}*/
+
+/**
+ * \name DB high nibble (DB[4-7])
+ * @{
+ */
+#define LCD_PORT     PORTG
+#define LCD_DB_PORT  PORTA
+#define LCD_PIN      PING
+#define LCD_DB_PIN   PINA
+#define LCD_DDR      DDRG
+#define LCD_DB_DDR   DDRA
+
+#if CONFIG_LCD_4BIT
+       #define LCD_MASK    (LCD_DB7 | LCD_DB6 | LCD_DB5 | LCD_DB4)
+       #define LCD_SHIFT   4
+#else
+       #define LCD_MASK (uint8_t)0xff
+       #define LCD_SHIFT 0
+#endif
+/*@}*/
+
+/**
+ * \name LCD bus control macros
+ * @{
+ */
+#define LCD_CLR_RS      (LCD_PORT &= ~LCD_RS)
+#define LCD_SET_RS      (LCD_PORT |=  LCD_RS)
+#define LCD_CLR_RD      (LCD_PORT &= ~LCD_RW)
+#define LCD_SET_RD      (LCD_PORT |=  LCD_RW)
+#define LCD_CLR_E       (LCD_PORT &= ~LCD_E)
+#define LCD_SET_E       (LCD_PORT |=  LCD_E)
+
+#if CONFIG_LCD_4BIT
+       #define LCD_WRITE_H(x)  (LCD_DB_PORT = (LCD_DB_PORT & ~LCD_MASK) | (((x) >> (4 - LCD_SHIFT)) & LCD_MASK))
+       #define LCD_WRITE_L(x)  (LCD_DB_PORT = (LCD_DB_PORT & ~LCD_MASK) | (((x) << LCD_SHIFT) & LCD_MASK))
+       #define LCD_READ_H      ((LCD_DB_PIN & LCD_MASK) >> (4 - LCD_SHIFT))
+       #define LCD_READ_L      ((LCD_DB_PIN & LCD_MASK) >> LCD_SHIFT)
+#else
+       #define LCD_WRITE(x) (LCD_DB_PORT = (x))
+       #define LCD_READ (LCD_DB_PIN)
+#endif
+/*@}*/
+
+/** Set data bus direction to output (write to display) */
+#define LCD_DB_OUT  (LCD_DB_DDR |= LCD_MASK)
+
+/** Set data bus direction to input (read from display) */
+#define LCD_DB_IN   (LCD_DB_DDR &= ~LCD_MASK)
+
+/** Delay for write (Enable pulse width, 220ns) */
+#define LCD_DELAY_WRITE \
+       do { \
+               NOP; \
+               NOP; \
+               NOP; \
+               NOP; \
+               NOP; \
+       } while (0)
+
+/** Delay for read (Data ouput delay time, 120ns) */
+#define LCD_DELAY_READ \
+       do { \
+               NOP; \
+               NOP; \
+               NOP; \
+               NOP; \
+       } while (0)
+
+
+INLINE void lcd_bus_init(void)
+{
+       cpuflags_t flags;
+       IRQ_SAVE_DISABLE(flags);
+
+       LCD_PORT = (LCD_PORT & ~(LCD_E | LCD_RW)) | LCD_RS;
+       LCD_DDR  |= LCD_RS | LCD_RW | LCD_E;
+
+       /*
+        * Data bus is in output state most of the time:
+        * LCD r/w functions assume it is left in output state
+        */
+       LCD_DB_OUT;
+
+
+       IRQ_RESTORE(flags);
+}
+
+#endif /* HW_LCD_H */