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/*
* Copyright © 2009 Keith Packard <keithp@keithp.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "ao.h"
#define SERIAL_FIFO 32
struct ao_fifo {
uint8_t insert;
uint8_t remove;
uint8_t fifo[SERIAL_FIFO];
};
volatile __xdata struct ao_fifo ao_usart1_rx_fifo;
volatile __xdata struct ao_fifo ao_usart1_tx_fifo;
#define ao_fifo_insert(f,c) do { \
(f).fifo[(f).insert] = (c); \
(f).insert = ((f).insert + 1) & (SERIAL_FIFO-1); \
} while(0)
#define ao_fifo_remove(f,c) do {\
c = (f).fifo[(f).remove]; \
(f).remove = ((f).remove + 1) & (SERIAL_FIFO-1); \
} while(0)
#define ao_fifo_full(f) ((((f).insert + 1) & (SERIAL_FIFO-1)) == (f).remove)
#define ao_fifo_empty(f) ((f).insert == (f).remove)
void
ao_serial_rx1_isr(void) interrupt 3
{
if (!ao_fifo_full(ao_usart1_rx_fifo))
ao_fifo_insert(ao_usart1_rx_fifo, U1DBUF);
ao_wakeup(&ao_usart1_rx_fifo);
}
static __xdata uint8_t ao_serial_tx1_started;
static void
ao_serial_tx1_start(void)
{
if (!ao_fifo_empty(ao_usart1_tx_fifo) &&
!ao_serial_tx1_started)
{
ao_serial_tx1_started = 1;
ao_fifo_remove(ao_usart1_tx_fifo, U1DBUF);
}
}
void
ao_serial_tx1_isr(void) interrupt 14
{
UTX1IF = 0;
ao_serial_tx1_started = 0;
ao_serial_tx1_start();
ao_wakeup(&ao_usart1_tx_fifo);
}
uint8_t
ao_serial_getchar(void) __critical
{
uint8_t c;
while (ao_fifo_empty(ao_usart1_rx_fifo))
ao_sleep(&ao_usart1_rx_fifo);
ao_fifo_remove(ao_usart1_rx_fifo, c);
return c;
}
void
ao_serial_putchar(uint8_t c) __critical
{
while (ao_fifo_full(ao_usart1_tx_fifo))
ao_sleep(&ao_usart1_tx_fifo);
ao_fifo_insert(ao_usart1_tx_fifo, c);
ao_serial_tx1_start();
}
void
ao_serial_init(void)
{
/* Set up the USART pin assignment */
PERCFG = (PERCFG & ~PERCFG_U1CFG_ALT_MASK) | PERCFG_U1CFG_ALT_2;
/* ee has already set the P2SEL bits */
/* Make the USART pins be controlled by the USART */
P1SEL |= (1 << 6) | (1 << 7);
/* UART mode with receiver enabled */
U1CSR = (UxCSR_MODE_UART | UxCSR_RE);
/* Pick a 4800 baud rate */
U1BAUD = 163; /* 4800 */
U1GCR = 7 << UxGCR_BAUD_E_SHIFT; /* 4800 */
/* Reasonable serial parameters */
U1UCR = (UxUCR_FLUSH |
UxUCR_FLOW_DISABLE |
UxUCR_D9_ODD_PARITY |
UxUCR_BIT9_8_BITS |
UxUCR_PARITY_DISABLE |
UxUCR_SPB_1_STOP_BIT |
UxUCR_STOP_HIGH |
UxUCR_START_LOW);
IEN0 |= IEN0_URX1IE;
IEN2 |= IEN2_UTX1IE;
}
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