klipper/src/generic/serial_irq.c

123 lines
3.4 KiB
C

// Generic interrupt based serial uart helper code
//
// Copyright (C) 2016-2018 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU GPLv3 license.
#include <string.h> // memmove
#include "autoconf.h" // CONFIG_SERIAL_BAUD
#include "board/io.h" // readb
#include "board/irq.h" // irq_save
#include "board/misc.h" // console_sendf
#include "board/pgm.h" // READP
#include "command.h" // DECL_CONSTANT
#include "sched.h" // sched_wake_tasks
#include "serial_irq.h" // serial_enable_tx_irq
#define RX_BUFFER_SIZE 192
static uint8_t receive_buf[RX_BUFFER_SIZE], receive_pos;
static uint8_t transmit_buf[96], transmit_pos, transmit_max;
DECL_CONSTANT(SERIAL_BAUD, CONFIG_SERIAL_BAUD);
DECL_CONSTANT(RECEIVE_WINDOW, RX_BUFFER_SIZE);
// Rx interrupt - store read data
void
serial_rx_byte(uint_fast8_t data)
{
if (data == MESSAGE_SYNC)
sched_wake_tasks();
if (receive_pos >= sizeof(receive_buf))
// Serial overflow - ignore it as crc error will force retransmit
return;
receive_buf[receive_pos++] = data;
}
// Tx interrupt - get next byte to transmit
int
serial_get_tx_byte(uint8_t *pdata)
{
if (transmit_pos >= transmit_max)
return -1;
*pdata = transmit_buf[transmit_pos++];
return 0;
}
// Remove from the receive buffer the given number of bytes
static void
console_pop_input(uint_fast8_t len)
{
uint_fast8_t copied = 0;
for (;;) {
uint_fast8_t rpos = readb(&receive_pos);
uint_fast8_t needcopy = rpos - len;
if (needcopy) {
memmove(&receive_buf[copied], &receive_buf[copied + len]
, needcopy - copied);
copied = needcopy;
sched_wake_tasks();
}
irqstatus_t flag = irq_save();
if (rpos != readb(&receive_pos)) {
// Raced with irq handler - retry
irq_restore(flag);
continue;
}
receive_pos = needcopy;
irq_restore(flag);
break;
}
}
// Process any incoming commands
void
console_task(void)
{
uint_fast8_t rpos = readb(&receive_pos), pop_count;
int_fast8_t ret = command_find_block(receive_buf, rpos, &pop_count);
if (ret > 0)
command_dispatch(receive_buf, pop_count);
if (ret) {
console_pop_input(pop_count);
if (ret > 0)
command_send_ack();
}
}
DECL_TASK(console_task);
// Encode and transmit a "response" message
void
console_sendf(const struct command_encoder *ce, va_list args)
{
// Verify space for message
uint_fast8_t tpos = readb(&transmit_pos), tmax = readb(&transmit_max);
if (tpos >= tmax) {
tpos = tmax = 0;
writeb(&transmit_max, 0);
writeb(&transmit_pos, 0);
}
uint_fast8_t max_size = READP(ce->max_size);
if (tmax + max_size > sizeof(transmit_buf)) {
if (tmax + max_size - tpos > sizeof(transmit_buf))
// Not enough space for message
return;
// Disable TX irq and move buffer
writeb(&transmit_max, 0);
tpos = readb(&transmit_pos);
tmax -= tpos;
memmove(&transmit_buf[0], &transmit_buf[tpos], tmax);
writeb(&transmit_pos, 0);
writeb(&transmit_max, tmax);
serial_enable_tx_irq();
}
// Generate message
uint8_t *buf = &transmit_buf[tmax];
uint_fast8_t msglen = command_encode_and_frame(buf, ce, args);
// Start message transmit
writeb(&transmit_max, tmax + msglen);
serial_enable_tx_irq();
}