cores/usb_serial/usb_api.cpp
2014-05-29 06:00:23 -07:00

454 lines
12 KiB
C++

/* USB API for Teensy USB Development Board
* http://www.pjrc.com/teensy/teensyduino.html
* Copyright (c) 2008 PJRC.COM, LLC
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <avr/io.h>
#include <stdint.h>
#include "usb_common.h"
#include "usb_private.h"
#include "usb_api.h"
#include "wiring.h"
// Public Methods //////////////////////////////////////////////////////////////
void usb_serial_class::begin(long speed)
{
// make sure USB is initialized
peek_buf = -1;
usb_init();
uint16_t begin_wait = (uint16_t)millis();
while (1) {
// wait for the host to finish enumeration
if (usb_configuration) {
delay(200); // a little time for host to load a driver
return;
}
// or for suspend mode (powered without USB)
if (usb_suspended) {
uint16_t begin_suspend = (uint16_t)millis();
while (usb_suspended) {
// must remain suspended for a while, because
// normal USB enumeration causes brief suspend
// states, typically under 0.1 second
if ((uint16_t)millis() - begin_suspend > 250) {
return;
}
}
}
// ... or a timout (powered by a USB power adaptor that
// wiggles the data lines to keep a USB device charging)
if ((uint16_t)millis() - begin_wait > 2500) return;
}
}
void usb_serial_class::end()
{
usb_shutdown();
delay(25);
}
// number of bytes available in the receive buffer
int usb_serial_class::available()
{
uint8_t n=0, i, intr_state;
intr_state = SREG;
cli();
if (usb_configuration) {
UENUM = CDC_RX_ENDPOINT;
n = UEBCLX;
if (!n) {
i = UEINTX;
if (i & (1<<RXOUTI) && !(i & (1<<RWAL))) UEINTX = 0x6B;
}
}
SREG = intr_state;
if (peek_buf >= 0 && n < 255) n++;
return n;
}
int usb_serial_class::peek()
{
if (peek_buf < 0) peek_buf = read();
return peek_buf;
}
// get the next character, or -1 if nothing received
int usb_serial_class::read(void)
{
uint8_t c, intr_state;
if (peek_buf >= 0) {
c = peek_buf;
peek_buf = -1;
return c;
}
// interrupts are disabled so these functions can be
// used from the main program or interrupt context,
// even both in the same program!
intr_state = SREG;
cli();
if (!usb_configuration) {
SREG = intr_state;
return -1;
}
UENUM = CDC_RX_ENDPOINT;
retry:
c = UEINTX;
if (!(c & (1<<RWAL))) {
// no data in buffer
if (c & (1<<RXOUTI)) {
UEINTX = 0x6B;
goto retry;
}
SREG = intr_state;
return -1;
}
// take one byte out of the buffer
c = UEDATX;
// if this drained the buffer, release it
if (!(UEINTX & (1<<RWAL))) UEINTX = 0x6B;
SREG = intr_state;
return c;
}
#if ARDUINO >= 100
size_t usb_serial_class::readBytes(char *buffer, size_t length)
{
size_t count=0;
unsigned long startMillis;
uint8_t num, intr_state;
startMillis = millis();
if (length <= 0) return 0;
if (peek_buf >= 0) {
*buffer++ = peek_buf;
peek_buf = -1;
length--;
if (length == 0) return 1;
count = 1;
}
do {
intr_state = SREG;
cli();
if (!usb_configuration) {
SREG = intr_state;
break;
}
UENUM = CDC_RX_ENDPOINT;
if (!(UEINTX & (1<<RXOUTI))) {
SREG = intr_state;
break;
}
num = UEBCLX;
if (num > length) num = length;
for (uint8_t i=0; i < num; i++) {
*buffer++ = UEDATX; // TODO: unroll loop for speed
}
if (!(UEINTX & (1<<RWAL))) UEINTX = 0x6B;
SREG = intr_state;
count += num;
length -= num;
if (length == 0) return count;
} while(millis() - startMillis < _timeout);
setReadError();
return count;
}
#endif
#if ARDUINO >= 100
void usb_serial_class::flush()
{
send_now();
}
#else
// discard any buffered input
void usb_serial_class::flush()
{
uint8_t intr_state;
if (usb_configuration) {
intr_state = SREG;
cli();
UENUM = CDC_RX_ENDPOINT;
while ((UEINTX & (1<<RWAL))) {
UEINTX = 0x6B;
}
SREG = intr_state;
}
peek_buf = -1;
}
#endif
#if 0
// transmit a character.
void usb_serial_class::write(uint8_t c)
{
uint8_t timeout, intr_state;
// if we're not online (enumerated and configured), error
if (!usb_configuration) return;
// interrupts are disabled so these functions can be
// used from the main program or interrupt context,
// even both in the same program!
intr_state = SREG;
cli();
UENUM = CDC_TX_ENDPOINT;
// if we gave up due to timeout before, don't wait again
if (transmit_previous_timeout) {
if (!(UEINTX & (1<<RWAL))) {
SREG = intr_state;
return;
}
transmit_previous_timeout = 0;
}
// wait for the FIFO to be ready to accept data
timeout = UDFNUML + TRANSMIT_TIMEOUT;
while (1) {
// are we ready to transmit?
if (UEINTX & (1<<RWAL)) break;
SREG = intr_state;
// have we waited too long? This happens if the user
// is not running an application that is listening
if (UDFNUML == timeout) {
transmit_previous_timeout = 1;
return;
}
// has the USB gone offline?
if (!usb_configuration) return;
// get ready to try checking again
intr_state = SREG;
cli();
UENUM = CDC_TX_ENDPOINT;
}
// actually write the byte into the FIFO
UEDATX = c;
// if this completed a packet, transmit it now!
if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
SREG = intr_state;
}
#endif
// transmit a block of data
#if ARDUINO >= 100
size_t usb_serial_class::write(const uint8_t *buffer, uint16_t size)
#else
#define setWriteError()
void usb_serial_class::write(const uint8_t *buffer, uint16_t size)
#endif
{
uint8_t timeout, intr_state, write_size;
#if ARDUINO >= 100
size_t count=0;
#endif
// if we're not online (enumerated and configured), error
if (!usb_configuration) {
setWriteError();
goto end;
}
// interrupts are disabled so these functions can be
// used from the main program or interrupt context,
// even both in the same program!
intr_state = SREG;
cli();
UENUM = CDC_TX_ENDPOINT;
// if we gave up due to timeout before, don't wait again
if (transmit_previous_timeout) {
if (!(UEINTX & (1<<RWAL))) {
SREG = intr_state;
setWriteError();
goto end;
}
transmit_previous_timeout = 0;
}
// each iteration of this loop transmits a packet
while (size) {
// wait for the FIFO to be ready to accept data
timeout = UDFNUML + TRANSMIT_TIMEOUT;
while (1) {
// are we ready to transmit?
if (UEINTX & (1<<RWAL)) break;
SREG = intr_state;
// have we waited too long? This happens if the user
// is not running an application that is listening
if (UDFNUML == timeout) {
transmit_previous_timeout = 1;
setWriteError();
goto end;
}
// has the USB gone offline?
if (!usb_configuration) {
setWriteError();
goto end;
}
// get ready to try checking again
intr_state = SREG;
cli();
UENUM = CDC_TX_ENDPOINT;
}
// compute how many bytes will fit into the next packet
write_size = CDC_TX_SIZE - UEBCLX;
if (write_size > size) write_size = size;
size -= write_size;
#if ARDUINO >= 100
count += write_size;
#endif
#define ASM_COPY1(src, dest, tmp) "ld " tmp ", " src "\n\t" "st " dest ", " tmp "\n\t"
#define ASM_COPY2(src, dest, tmp) ASM_COPY1(src, dest, tmp) ASM_COPY1(src, dest, tmp)
#define ASM_COPY4(src, dest, tmp) ASM_COPY2(src, dest, tmp) ASM_COPY2(src, dest, tmp)
#define ASM_COPY8(src, dest, tmp) ASM_COPY4(src, dest, tmp) ASM_COPY4(src, dest, tmp)
#if 1
// write the packet
do {
uint8_t tmp;
asm volatile(
"L%=begin:" "\n\t"
"ldi r30, %4" "\n\t"
"sub r30, %3" "\n\t"
"cpi r30, %4" "\n\t"
"brsh L%=err" "\n\t"
"lsl r30" "\n\t"
"clr r31" "\n\t"
"subi r30, lo8(-(pm(L%=table)))" "\n\t"
"sbci r31, hi8(-(pm(L%=table)))" "\n\t"
"ijmp" "\n\t"
"L%=err:" "\n\t"
"rjmp L%=end" "\n\t"
"L%=table:" "\n\t"
#if (CDC_TX_SIZE == 64)
ASM_COPY8("Y+", "X", "%1")
ASM_COPY8("Y+", "X", "%1")
ASM_COPY8("Y+", "X", "%1")
ASM_COPY8("Y+", "X", "%1")
#endif
#if (CDC_TX_SIZE >= 32)
ASM_COPY8("Y+", "X", "%1")
ASM_COPY8("Y+", "X", "%1")
#endif
#if (CDC_TX_SIZE >= 16)
ASM_COPY8("Y+", "X", "%1")
#endif
ASM_COPY8("Y+", "X", "%1")
"L%=end:" "\n\t"
: "+y" (buffer), "=r" (tmp)
: "x" (&UEDATX), "r" (write_size), "M" (CDC_TX_SIZE)
: "r30", "r31"
);
} while (0);
#endif
// if this completed a packet, transmit it now!
if (!(UEINTX & (1<<RWAL))) UEINTX = 0x3A;
transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
}
SREG = intr_state;
end:
#if ARDUINO >= 100
return count;
#else
return;
#endif
}
// transmit a string
/*
void usb_serial_class::write(const char *str)
{
uint16_t size=0;
const char *p=str;
while (*p++) size++;
if (size) write((const uint8_t *)str, size);
}
*/
// These are Teensy-specific extensions to the Serial object
// immediately transmit any buffered output.
// This doesn't actually transmit the data - that is impossible!
// USB devices only transmit when the host allows, so the best
// we can do is release the FIFO buffer for when the host wants it
void usb_serial_class::send_now(void)
{
uint8_t intr_state;
intr_state = SREG;
cli();
if (usb_configuration && transmit_flush_timer) {
UENUM = CDC_TX_ENDPOINT;
UEINTX = 0x3A;
transmit_flush_timer = 0;
}
SREG = intr_state;
}
uint32_t usb_serial_class::baud(void)
{
return *(uint32_t *)cdc_line_coding;
}
uint8_t usb_serial_class::stopbits(void)
{
return cdc_line_coding[4];
}
uint8_t usb_serial_class::paritytype(void)
{
return cdc_line_coding[5];
}
uint8_t usb_serial_class::numbits(void)
{
return cdc_line_coding[6];
}
uint8_t usb_serial_class::dtr(void)
{
return (cdc_line_rtsdtr & USB_SERIAL_DTR) ? 1 : 0;
}
uint8_t usb_serial_class::rts(void)
{
return (cdc_line_rtsdtr & USB_SERIAL_RTS) ? 1 : 0;
}
usb_serial_class::operator bool()
{
if (usb_configuration &&
(cdc_line_rtsdtr & (USB_SERIAL_DTR | USB_SERIAL_RTS))) {
return true;
}
return false;
}
// Preinstantiate Objects //////////////////////////////////////////////////////
usb_serial_class Serial = usb_serial_class();