XON/XOFF corrections, tweaks, formatting, etc.

This commit is contained in:
Scott Lahteine 2017-10-02 00:26:56 -05:00
parent 94caabf89a
commit 4e19ff75b6
6 changed files with 228 additions and 291 deletions

View file

@ -27,15 +27,30 @@
* Modified 23 November 2006 by David A. Mellis
* Modified 28 September 2010 by Mark Sproul
* Modified 14 February 2016 by Andreas Hardtung (added tx buffer)
* Modified 01 October 2017 by Eduardo José Tagle (added XON/XOFF)
*/
#include "MarlinSerial.h"
#include "Marlin.h"
// Disable HardwareSerial.cpp to support chips without a UART (Attiny, etc.)
#include "MarlinConfig.h"
#if !defined(USBCON) && (defined(UBRRH) || defined(UBRR0H) || defined(UBRR1H) || defined(UBRR2H) || defined(UBRR3H))
#include "MarlinSerial.h"
#include "Marlin.h"
struct ring_buffer_r {
unsigned char buffer[RX_BUFFER_SIZE];
volatile ring_buffer_pos_t head, tail;
};
#if TX_BUFFER_SIZE > 0
struct ring_buffer_t {
unsigned char buffer[TX_BUFFER_SIZE];
volatile uint8_t head, tail;
};
#endif
#if UART_PRESENT(SERIAL_PORT)
ring_buffer_r rx_buffer = { { 0 }, 0, 0 };
#if TX_BUFFER_SIZE > 0
@ -45,15 +60,21 @@
#endif
#if ENABLED(SERIAL_XON_XOFF)
uint8_t xon_xoff_state = XON_XOFF_CHAR_SENT | XON_CHAR;
uint8_t xon_xoff_state = XON_XOFF_CHAR_SENT | XON_CHAR;
constexpr uint8_t XON_XOFF_CHAR_SENT = 0x80; // XON / XOFF Character was sent
constexpr uint8_t XON_XOFF_CHAR_MASK = 0x1F; // XON / XOFF character to send
// XON / XOFF character definitions
constexpr uint8_t XON_CHAR = 17;
constexpr uint8_t XOFF_CHAR = 19;
#endif
#if ENABLED(SERIAL_STATS_DROPPED_RX)
uint8_t rx_dropped_bytes = 0;
uint8_t rx_dropped_bytes = 0;
#endif
#if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
ring_buffer_pos_t rx_max_enqueued = 0;
#endif
ring_buffer_pos_t rx_max_enqueued = 0;
#endif
#if ENABLED(EMERGENCY_PARSER)
@ -149,92 +170,76 @@
FORCE_INLINE void store_rxd_char() {
const ring_buffer_pos_t h = rx_buffer.head,
i = (ring_buffer_pos_t)(h + 1) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
i = (ring_buffer_pos_t)(h + 1) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// if we should be storing the received character into the location
// just before the tail (meaning that the head would advance to the
// current location of the tail), we're about to overflow the buffer
// and so we don't write the character or advance the head.
if (i != rx_buffer.tail) {
// If the character is to be stored at the index just before the tail
// (such that the head would advance to the current tail), the buffer is
// critical, so don't write the character or advance the head.
if (i != rx_buffer.tail) {
rx_buffer.buffer[h] = M_UDRx;
rx_buffer.head = i;
rx_buffer.head = i;
}
else {
(void)M_UDRx;
#if ENABLED(SERIAL_STATS_DROPPED_RX)
if (!++rx_dropped_bytes) ++rx_dropped_bytes;
#endif
}
#if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
// calculate count of bytes stored into the RX buffer
ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// Keep track of the maximum count of enqueued bytes
NOLESS(rx_max_enqueued, rx_count);
#endif
#if ENABLED(SERIAL_XON_XOFF)
// for high speed transfers, we can use XON/XOFF protocol to do
// software handshake and avoid overruns.
if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XON_CHAR) {
// calculate count of bytes stored into the RX buffer
ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// if we are above 12.5% of RX buffer capacity, send XOFF before
// we run out of RX buffer space .. We need 325 bytes @ 250kbits/s to
// let the host react and stop sending bytes. This translates to 13mS
// propagation time.
if (rx_count >= (RX_BUFFER_SIZE) / 8) {
// If TX interrupts are disabled and data register is empty,
// just write the byte to the data register and be done. This
// shortcut helps significantly improve the effective datarate
// at high (>500kbit/s) bitrates, where interrupt overhead
// becomes a slowdown.
if (!TEST(M_UCSRxB, M_UDRIEx) && TEST(M_UCSRxA, M_UDREx)) {
// Send an XOFF character
M_UDRx = XOFF_CHAR;
// clear the TXC bit -- "can be cleared by writing a one to its bit
// location". This makes sure flush() won't return until the bytes
// actually got written
SBI(M_UCSRxA, M_TXCx);
// And remember it was sent
xon_xoff_state = XOFF_CHAR | XON_XOFF_CHAR_SENT;
}
else {
// TX interrupts disabled, but buffer still not empty ... or
// TX interrupts enabled. Reenable TX ints and schedule XOFF
// character to be sent
#if TX_BUFFER_SIZE > 0
SBI(M_UCSRxB, M_UDRIEx);
xon_xoff_state = XOFF_CHAR;
#else
// We are not using TX interrupts, we will have to send this manually
while (!TEST(M_UCSRxA, M_UDREx)) {/* nada */}
M_UDRx = XOFF_CHAR;
// And remember we already sent it
xon_xoff_state = XOFF_CHAR | XON_XOFF_CHAR_SENT;
#endif
}
}
}
else {
(void)M_UDRx;
#if ENABLED(SERIAL_STATS_DROPPED_RX)
if (!++rx_dropped_bytes)
++rx_dropped_bytes;
#endif
}
#if ENABLED(SERIAL_STATS_MAX_RX_QUEUED)
{
// calculate count of bytes stored into the RX buffer
ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// Keep track of the maximum count of enqueued bytes
if (rx_max_enqueued < rx_count)
rx_max_enqueued = rx_count;
}
#endif
#if ENABLED(SERIAL_XON_XOFF)
// for high speed transfers, we can use XON/XOFF protocol to do
// software handshake and avoid overruns.
if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XON_CHAR) {
// calculate count of bytes stored into the RX buffer
ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// if we are above 12.5% of RX buffer capacity, send XOFF before
// we run out of RX buffer space .. We need 325 bytes @ 250kbits/s to
// let the host react and stop sending bytes. This translates to 13mS
// propagation time.
if (rx_count >= (RX_BUFFER_SIZE/8)) {
// If TX interrupts are disabled and data register is empty,
// just write the byte to the data register and be done. This
// shortcut helps significantly improve the effective datarate
// at high (>500kbit/s) bitrates, where interrupt overhead
// becomes a slowdown.
if (!TEST(M_UCSRxB, M_UDRIEx) && TEST(M_UCSRxA, M_UDREx)) {
// Send an XOFF character
M_UDRx = XOFF_CHAR;
// clear the TXC bit -- "can be cleared by writing a one to its bit
// location". This makes sure flush() won't return until the bytes
// actually got written
SBI(M_UCSRxA, M_TXCx);
// And remember we already sent it
xon_xoff_state = XOFF_CHAR | XON_XOFF_CHAR_SENT;
} else {
// TX interrupts disabled, but buffer still not empty ... or
// TX interrupts enabled. Reenable TX ints and schedule XOFF
// character to be sent
#if TX_BUFFER_SIZE > 0
SBI(M_UCSRxB, M_UDRIEx);
xon_xoff_state = XOFF_CHAR;
#else
// We are not using TX interrupts, we will have to send this manually
while (!TEST(M_UCSRxA, M_UDREx))
;
M_UDRx = XOFF_CHAR;
// And remember we already sent it
xon_xoff_state = XOFF_CHAR | XON_XOFF_CHAR_SENT;
#endif
}
}
}
#endif
#endif // SERIAL_XON_XOFF
#if ENABLED(EMERGENCY_PARSER)
emergency_parser(c);
@ -247,52 +252,39 @@
// If interrupts are enabled, there must be more data in the output
// buffer.
#if ENABLED(SERIAL_XON_XOFF)
// If we must do a priority insertion of an XON/XOFF char,
// do it now
uint8_t state = xon_xoff_state;
if (!(state & XON_XOFF_CHAR_SENT)) {
M_UDRx = state & XON_XOFF_CHAR_MASK;
xon_xoff_state = state | XON_XOFF_CHAR_SENT;
} else {
#endif
// Send the next byte
const uint8_t t = tx_buffer.tail,
c = tx_buffer.buffer[t];
tx_buffer.tail = (t + 1) & (TX_BUFFER_SIZE - 1);
#if ENABLED(SERIAL_XON_XOFF)
// Do a priority insertion of an XON/XOFF char, if needed.
const uint8_t state = xon_xoff_state;
if (!(state & XON_XOFF_CHAR_SENT)) {
M_UDRx = state & XON_XOFF_CHAR_MASK;
xon_xoff_state = state | XON_XOFF_CHAR_SENT;
}
else
#endif
{ // Send the next byte
const uint8_t t = tx_buffer.tail, c = tx_buffer.buffer[t];
tx_buffer.tail = (t + 1) & (TX_BUFFER_SIZE - 1);
M_UDRx = c;
}
M_UDRx = c;
#if ENABLED(SERIAL_XON_XOFF)
}
#endif
// clear the TXC bit -- "can be cleared by writing a one to its bit
// location". This makes sure flush() won't return until the bytes
// actually got written
SBI(M_UCSRxA, M_TXCx);
if (tx_buffer.head == tx_buffer.tail) {
// Buffer empty, so disable interrupts
// Disable interrupts if the buffer is empty
if (tx_buffer.head == tx_buffer.tail)
CBI(M_UCSRxB, M_UDRIEx);
}
}
#ifdef M_USARTx_UDRE_vect
ISR(M_USARTx_UDRE_vect) {
_tx_udr_empty_irq();
}
ISR(M_USARTx_UDRE_vect) { _tx_udr_empty_irq(); }
#endif
#endif // TX_BUFFER_SIZE
#ifdef M_USARTx_RX_vect
ISR(M_USARTx_RX_vect) {
store_rxd_char();
}
ISR(M_USARTx_RX_vect) { store_rxd_char(); }
#endif
// Public Methods
@ -302,9 +294,9 @@
bool useU2X = true;
#if F_CPU == 16000000UL && SERIAL_PORT == 0
// hard-coded exception for compatibility with the bootloader shipped
// with the Duemilanove and previous boards and the firmware on the 8U2
// on the Uno and Mega 2560.
// Hard-coded exception for compatibility with the bootloader shipped
// with the Duemilanove and previous boards, and the firmware on the
// 8U2 on the Uno and Mega 2560.
if (baud == 57600) useU2X = false;
#endif
@ -339,9 +331,9 @@
void MarlinSerial::checkRx(void) {
if (TEST(M_UCSRxA, M_RXCx)) {
CRITICAL_SECTION_START;
CRITICAL_SECTION_START;
store_rxd_char();
CRITICAL_SECTION_END;
CRITICAL_SECTION_END;
}
}
@ -361,35 +353,21 @@
else {
v = rx_buffer.buffer[t];
rx_buffer.tail = (ring_buffer_pos_t)(t + 1) & (RX_BUFFER_SIZE - 1);
#if ENABLED(SERIAL_XON_XOFF)
// for high speed transfers, we can use XON/XOFF protocol to do
// software handshake and avoid overruns.
if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XOFF_CHAR) {
// calculate count of bytes stored into the RX buffer
ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// if we are below 10% of RX buffer capacity, send XON before
// we run out of RX buffer bytes
if (rx_count < (RX_BUFFER_SIZE/10)) {
// Send an XON character
xon_xoff_state = XON_CHAR | XON_XOFF_CHAR_SENT;
// End critical section
CRITICAL_SECTION_END;
// Transmit the XON character
writeNoHandshake(XON_CHAR);
// Done
return v;
}
}
#endif
#if ENABLED(SERIAL_XON_XOFF)
if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XOFF_CHAR) {
// Get count of bytes in the RX buffer
ring_buffer_pos_t rx_count = (ring_buffer_pos_t)(rx_buffer.head - rx_buffer.tail) & (ring_buffer_pos_t)(RX_BUFFER_SIZE - 1);
// When below 10% of RX buffer capacity, send XON before
// running out of RX buffer bytes
if (rx_count < (RX_BUFFER_SIZE) / 10) {
xon_xoff_state = XON_CHAR | XON_XOFF_CHAR_SENT;
CRITICAL_SECTION_END; // End critical section before returning!
writeNoHandshake(XON_CHAR);
return v;
}
}
#endif
}
CRITICAL_SECTION_END;
return v;
@ -397,68 +375,53 @@
ring_buffer_pos_t MarlinSerial::available(void) {
CRITICAL_SECTION_START;
const ring_buffer_pos_t h = rx_buffer.head,
t = rx_buffer.tail;
const ring_buffer_pos_t h = rx_buffer.head, t = rx_buffer.tail;
CRITICAL_SECTION_END;
return (ring_buffer_pos_t)(RX_BUFFER_SIZE + h - t) & (RX_BUFFER_SIZE - 1);
}
void MarlinSerial::flush(void) {
// RX
// don't reverse this or there may be problems if the RX interrupt
// occurs after reading the value of rx_buffer_head but before writing
// the value to rx_buffer_tail; the previous value of rx_buffer_head
// may be written to rx_buffer_tail, making it appear as if the buffer
// were full, not empty.
// Don't change this order of operations. If the RX interrupt occurs between
// reading rx_buffer_head and updating rx_buffer_tail, the previous rx_buffer_head
// may be written to rx_buffer_tail, making the buffer appear full rather than empty.
CRITICAL_SECTION_START;
rx_buffer.head = rx_buffer.tail;
CRITICAL_SECTION_END;
#if ENABLED(SERIAL_XON_XOFF)
// for high speed transfers, we can use XON/XOFF protocol to do
// software handshake and avoid overruns.
if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XOFF_CHAR) {
// Send an XON character
xon_xoff_state = XON_CHAR | XON_XOFF_CHAR_SENT;
// Transmit the XON character
writeNoHandshake(XON_CHAR);
}
#endif
#if ENABLED(SERIAL_XON_XOFF)
if ((xon_xoff_state & XON_XOFF_CHAR_MASK) == XOFF_CHAR) {
xon_xoff_state = XON_CHAR | XON_XOFF_CHAR_SENT;
writeNoHandshake(XON_CHAR);
}
#endif
}
#if TX_BUFFER_SIZE > 0
uint8_t MarlinSerial::availableForWrite(void) {
CRITICAL_SECTION_START;
const uint8_t h = tx_buffer.head,
t = tx_buffer.tail;
const uint8_t h = tx_buffer.head, t = tx_buffer.tail;
CRITICAL_SECTION_END;
return (uint8_t)(TX_BUFFER_SIZE + h - t) & (TX_BUFFER_SIZE - 1);
}
void MarlinSerial::write(const uint8_t c) {
#if ENABLED(SERIAL_XON_XOFF)
uint8_t state = xon_xoff_state;
if (!(state & XON_XOFF_CHAR_SENT)) {
// 2 characters to send: The XON/XOFF character and the user
// specified char.
writeNoHandshake(state & XON_XOFF_CHAR_MASK);
xon_xoff_state = state | XON_XOFF_CHAR_SENT;
}
#endif
writeNoHandshake(c);
#if ENABLED(SERIAL_XON_XOFF)
const uint8_t state = xon_xoff_state;
if (!(state & XON_XOFF_CHAR_SENT)) {
// Send 2 chars: XON/XOFF, then a user-specified char
writeNoHandshake(state & XON_XOFF_CHAR_MASK);
xon_xoff_state = state | XON_XOFF_CHAR_SENT;
}
#endif
writeNoHandshake(c);
}
void MarlinSerial::writeNoHandshake(uint8_t c) {
void MarlinSerial::writeNoHandshake(const uint8_t c) {
_written = true;
CRITICAL_SECTION_START;
bool emty = (tx_buffer.head == tx_buffer.tail);
CRITICAL_SECTION_END;
// If the buffer and the data register is empty, just write the byte
// to the data register and be done. This shortcut helps
// significantly improve the effective datarate at high (>
@ -497,7 +460,6 @@
return;
}
void MarlinSerial::flushTX(void) {
// TX
// If we have never written a byte, no need to flush. This special
@ -516,35 +478,32 @@
}
// If we get here, nothing is queued anymore (DRIE is disabled) and
// the hardware finished tranmission (TXC is set).
}
#else
void MarlinSerial::write(uint8_t c) {
#if ENABLED(SERIAL_XON_XOFF)
// If we must do a priority insertion of an XON/XOFF char, do it now
uint8_t state = xon_xoff_state;
if (!(state & XON_XOFF_CHAR_SENT)) {
writeNoHandshake(state & XON_XOFF_CHAR_MASK);
xon_xoff_state = state | XON_XOFF_CHAR_SENT;
}
#endif
writeNoHandshake(c);
}
#else // TX_BUFFER_SIZE == 0
void MarlinSerial::write(const uint8_t c) {
#if ENABLED(SERIAL_XON_XOFF)
// Do a priority insertion of an XON/XOFF char, if needed.
const uint8_t state = xon_xoff_state;
if (!(state & XON_XOFF_CHAR_SENT)) {
writeNoHandshake(state & XON_XOFF_CHAR_MASK);
xon_xoff_state = state | XON_XOFF_CHAR_SENT;
}
#endif
writeNoHandshake(c);
}
void MarlinSerial::writeNoHandshake(uint8_t c) {
while (!TEST(M_UCSRxA, M_UDREx))
;
while (!TEST(M_UCSRxA, M_UDREx)) {/* nada */}
M_UDRx = c;
}
#endif
// end NEW
/// imports from print.h
#endif // TX_BUFFER_SIZE == 0
/**
* Imports from print.h
*/
void MarlinSerial::print(char c, int base) {
print((long)c, base);