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/*
* Pneumatic pressure controller.
* Remote control.
*
* Copyright (C) 2008 Michael Buesch <mb@bu3sch.de>
*
* 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, either version 3 of the License, or
* (at your option) any later version.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include "remote.h"
#include "util.h"
#include "calibration.h"
#include "main.h"
#include <string.h>
#include <avr/io.h>
#define BAUDRATE 9600
static struct remote_message rx_msg;
static uint8_t rx_msg_count;
static bool rx_msg_valid;
static inline void usart_tx(uint8_t data)
{
while (!(UCSRA & (1 << UDRE)))
;
UDR = data;
}
static void usart_tx_buf(const void *_buf, uint8_t size)
{
const uint8_t *buf = _buf;
while (size) {
usart_tx(*buf);
buf++;
size--;
}
}
#define ERXFE 1 /* USART RX frame error */
#define ERXPE 2 /* USART RX parity error */
#define ERXOV 3 /* USART RX hardware buffer overflow */
#define ENODATA 4 /* No data available */
static inline int8_t usart_rx(uint8_t *data)
{
uint8_t status;
status = UCSRA;
if (!(status & (1 << RXC)))
return -ENODATA;
if (unlikely(status & ((1 << FE) | (1 << PE) | (1 << DOR)))) {
if (status & (1 << FE))
return -ERXFE;
if (status & (1 << PE))
return -ERXPE;
if (status & (1 << DOR))
return -ERXOV;
}
*data = UDR;
return 0;
}
static void send_message(struct remote_message *msg)
{
/* Calculate the CRC. */
msg->crc = crc16_block_update(0xFFFF, msg,
sizeof(*msg) - sizeof(msg->crc));
msg->crc ^= 0xFFFF;
/* And transmit the bits. */
usart_tx_buf(msg, sizeof(*msg));
}
static void send_message_error(uint8_t error_code)
{
struct remote_message msg;
memset(&msg, 0, sizeof(msg));
msg.id = MSG_ERROR;
msg.error.code = error_code;
send_message(&msg);
}
static void handle_received_message(void)
{
struct remote_message reply;
uint16_t calc_crc;
calc_crc = crc16_block_update(0xFFFF, &rx_msg,
sizeof(rx_msg) - sizeof(rx_msg.crc));
calc_crc ^= 0xFFFF;
if (calc_crc != rx_msg.crc) {
/* CRC mismatch. */
send_message_error(MSG_ERR_CHKSUM);
return;
}
memset(&reply, 0, sizeof(reply));
switch (rx_msg.id) {
case MSG_PING:
reply.id = MSG_PONG;
send_message(&reply);
break;
case MSG_GET_CURRENT_PRESSURE: {
struct pressure_state state;
get_pressure_state(&state);
reply.id = MSG_CURRENT_PRESSURE;
reply.pressure.mbar = state.mbar;
send_message(&reply);
break;
}
case MSG_GET_DESIRED_PRESSURE: {
struct pressure_config conf;
get_pressure_config(&conf);
reply.id = MSG_DESIRED_PRESSURE;
reply.pressure.mbar = conf.desired;
send_message(&reply);
break;
}
case MSG_GET_HYSTERESIS: {
struct pressure_config conf;
get_pressure_config(&conf);
reply.id = MSG_HYSTERESIS;
reply.pressure.mbar = conf.hysteresis;
send_message(&reply);
break;
}
case MSG_GET_CONFIG_FLAGS: {
struct pressure_config conf;
get_pressure_config(&conf);
reply.id = MSG_CONFIG_FLAGS;
if (conf.autoadjust_enable)
reply.config.flags |= (1 << CFG_FLAG_AUTOADJUST_ENABLE);
send_message(&reply);
break;
} }
}
/* RX interrupt */
ISR(USART_RXC_vect)
{
uint8_t *rxbuf = (uint8_t *)&rx_msg;
int8_t err;
uint8_t data;
if (rx_msg_valid)
return;
while (1) {
err = usart_rx(&data);
if (err == -ENODATA)
break;
if (unlikely(err)) {
//TODO other error
data = 0;
}
rxbuf[rx_msg_count++] = data;
if (rx_msg_count == sizeof(struct remote_message)) {
rx_msg_count = 0;
mb();
rx_msg_valid = 1;
}
}
}
void print_pgm(const prog_char *str)
{
struct remote_message msg;
uint8_t c, i;
do {
memset(&msg, 0, sizeof(msg));
msg.id = MSG_LOGMESSAGE;
for (i = 0; i < sizeof(msg.logmessage.str); i++) {
c = pgm_read_byte(str);
if (c == '\0')
break;
str++;
msg.logmessage.str[i] = c;
}
send_message(&msg);
} while (c != '\0');
}
/* Maintanance work. Called with IRQs enabled. */
void remote_work(void)
{
if (rx_msg_valid) {
handle_received_message();
mb();
rx_msg_valid = 0;
}
}
static void usart_init(void)
{
uint8_t dummy;
/* Set baud rate */
UBRRL = lo8((CPU_HZ / 16 / BAUDRATE) * 2);
UBRRH = hi8((CPU_HZ / 16 / BAUDRATE) * 2) & ~(1 << URSEL);
UCSRA = (1 << U2X);
/* 8 Data bits, 2 Stop bits, Even parity */
UCSRC = (1 << URSEL) | (1 << UCSZ0) | (1 << UCSZ1) | (1 << UPM1) | (1 << USBS);
/* Enable transceiver and RX IRQs */
UCSRB = (1 << RXEN) | (1 << TXEN) | (1 << RXCIE);
/* Drain the RX buffer */
while (usart_rx(&dummy) != -ENODATA)
mb();
}
void remote_init(void)
{
/* The remote tool depends on the exact size (and layout). */
BUILD_BUG_ON(sizeof(struct remote_message) != 38);
usart_init();
}
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