[megadrive.git] / teensy3 / usb_seremu.c

/* Teensyduino Core Library
 * http://www.pjrc.com/teensy/
 * Copyright (c) 2013 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:
 *
 * 1. The above copyright notice and this permission notice shall be 
 * included in all copies or substantial portions of the Software.
 *
 * 2. If the Software is incorporated into a build system that allows 
 * selection among a list of target devices, then similar target
 * devices manufactured by PJRC.COM must be included in the list of
 * target devices and selectable in the same manner.
 *
 * 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 "mk20dx128.h"
#include "usb_dev.h"
#include "usb_seremu.h"
#include "core_pins.h" // for yield()
//#include "HardwareSerial.h"

#ifdef SEREMU_INTERFACE // defined by usb_dev.h -> usb_desc.h

volatile uint8_t usb_seremu_transmit_flush_timer=0;

static usb_packet_t *rx_packet=NULL;
static usb_packet_t *tx_packet=NULL;
static volatile uint8_t tx_noautoflush=0;

#define TRANSMIT_FLUSH_TIMEOUT	5   /* in milliseconds */


// get the next character, or -1 if nothing received
int usb_seremu_getchar(void)
{
	unsigned int i;
	int c;

	while (1) {
		if (!usb_configuration) return -1;
		if (!rx_packet) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
		if (!rx_packet) return -1;
		i = rx_packet->index;
		c = rx_packet->buf[i++];
		if (c) {
			if (i >= rx_packet->len) {
				usb_free(rx_packet);
				rx_packet = NULL;
			} else {
				rx_packet->index = i;
			}
			return c;
		}
		usb_free(rx_packet);
		rx_packet = NULL;
	}
}

// peek at the next character, or -1 if nothing received
int usb_seremu_peekchar(void)
{
	int c;

	while (1) {
		if (!usb_configuration) return -1;
		if (!rx_packet) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
		if (!rx_packet) return -1;
		c = rx_packet->buf[rx_packet->index];
		if (c) return c;
		usb_free(rx_packet);
		rx_packet = NULL;
	}
}

// number of bytes available in the receive buffer
int usb_seremu_available(void)
{
	int i, len, count;

	if (!rx_packet) {
		if (usb_configuration) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
		if (!rx_packet) return 0;
	}
	len = rx_packet->len;
	i = rx_packet->index;
	count = 0;
	for (i = rx_packet->index; i < len; i++) {
		if (rx_packet->buf[i] == 0) break;
		count++;
	}
	if (count == 0) {
		usb_free(rx_packet);
		rx_packet = NULL;
	}
	return count;
}


// discard any buffered input
void usb_seremu_flush_input(void)
{
	usb_packet_t *rx;

	if (!usb_configuration) return;
	if (rx_packet) {
		usb_free(rx_packet);
		rx_packet = NULL;
	}
	while (1) {
		rx = usb_rx(SEREMU_RX_ENDPOINT);
		if (!rx) break;
		usb_free(rx);
	}
}


// Maximum number of transmit packets to queue so we don't starve other endpoints for memory
#define TX_PACKET_LIMIT 6

// When the PC isn't listening, how long do we wait before discarding data?  If this is
// too short, we risk losing data during the stalls that are common with ordinary desktop
// software.  If it's too long, we stall the user's program when no software is running.
#define TX_TIMEOUT_MSEC 30

#if F_CPU == 96000000
  #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
#elif F_CPU == 48000000
  #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
#elif F_CPU == 24000000
  #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
#endif

// When we've suffered the transmit timeout, don't wait again until the computer
// begins accepting data.  If no software is running to receive, we'll just discard
// data as rapidly as Serial.print() can generate it, until there's something to
// actually receive it.
static uint8_t transmit_previous_timeout=0;


// transmit a character.  0 returned on success, -1 on error
int usb_seremu_putchar(uint8_t c)
{
	return usb_seremu_write(&c, 1);
}


int usb_seremu_write(const void *buffer, uint32_t size)
{
#if 1
	uint32_t len;
	uint32_t wait_count;
	const uint8_t *src = (const uint8_t *)buffer;
	uint8_t *dest;

	tx_noautoflush = 1;
	while (size > 0) {
		if (!tx_packet) {
			wait_count = 0;
			while (1) {
				if (!usb_configuration) {
					tx_noautoflush = 0;
					return -1;
				}
				if (usb_tx_packet_count(SEREMU_TX_ENDPOINT) < TX_PACKET_LIMIT) {
					tx_noautoflush = 1;
					tx_packet = usb_malloc();
					if (tx_packet) break;
				}
				if (++wait_count > TX_TIMEOUT || transmit_previous_timeout) {
					transmit_previous_timeout = 1;
					tx_noautoflush = 0;
					return -1;
				}
				tx_noautoflush = 0;
				yield();
				tx_noautoflush = 1;
			}
		}
		transmit_previous_timeout = 0;
		len = SEREMU_TX_SIZE - tx_packet->index;
		if (len > size) len = size;
		dest = tx_packet->buf + tx_packet->index;
		tx_packet->index += len;
		size -= len;
		while (len-- > 0) *dest++ = *src++;
		if (tx_packet->index < SEREMU_TX_SIZE) {
			usb_seremu_transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
		} else {
			tx_packet->len = SEREMU_TX_SIZE;
			usb_seremu_transmit_flush_timer = 0;
			usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
			tx_packet = NULL;
		}
	}
	tx_noautoflush = 0;
	return 0;
#endif
}

void usb_seremu_flush_output(void)
{
	int i;

	if (!usb_configuration) return;
	//serial_print("usb_serial_flush_output\n");
	if (tx_packet && tx_packet->index > 0) {
		usb_seremu_transmit_flush_timer = 0;
		for (i = tx_packet->index; i < SEREMU_TX_SIZE; i++) {
			tx_packet->buf[i] = 0;
		}
		tx_packet->len = SEREMU_TX_SIZE;
		usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
		tx_packet = NULL;
	}
	// while (usb_tx_byte_count(SEREMU_TX_ENDPOINT) > 0) ; // wait
}

void usb_seremu_flush_callback(void)
{
	int i;
	//serial_print("C");
	if (tx_noautoflush) return;
	//serial_print("usb_flush_callback \n");
	for (i = tx_packet->index; i < SEREMU_TX_SIZE; i++) {
		tx_packet->buf[i] = 0;
	}
	tx_packet->len = SEREMU_TX_SIZE;
	usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
	tx_packet = NULL;
	//serial_print("usb_flush_callback end\n");
}

#endif // SEREMU_INTERFACE
Commit	Line	Data
	1	/* Teensyduino Core Library
	2	* http://www.pjrc.com/teensy/
	3	* Copyright (c) 2013 PJRC.COM, LLC.
	4	*
	5	* Permission is hereby granted, free of charge, to any person obtaining
	6	* a copy of this software and associated documentation files (the
	7	* "Software"), to deal in the Software without restriction, including
	8	* without limitation the rights to use, copy, modify, merge, publish,
	9	* distribute, sublicense, and/or sell copies of the Software, and to
	10	* permit persons to whom the Software is furnished to do so, subject to
	11	* the following conditions:
	12	*
	13	* 1. The above copyright notice and this permission notice shall be
	14	* included in all copies or substantial portions of the Software.
	15	*
	16	* 2. If the Software is incorporated into a build system that allows
	17	* selection among a list of target devices, then similar target
	18	* devices manufactured by PJRC.COM must be included in the list of
	19	* target devices and selectable in the same manner.
	20	*
	21	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
	22	* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
	23	* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
	24	* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
	25	* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
	26	* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	27	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	28	* SOFTWARE.
	29	*/
	30
	31	//#include "mk20dx128.h"
	32	#include "usb_dev.h"
	33	#include "usb_seremu.h"
	34	#include "core_pins.h" // for yield()
	35	//#include "HardwareSerial.h"
	36
	37	#ifdef SEREMU_INTERFACE // defined by usb_dev.h -> usb_desc.h
	38
	39	volatile uint8_t usb_seremu_transmit_flush_timer=0;
	40
	41	static usb_packet_t *rx_packet=NULL;
	42	static usb_packet_t *tx_packet=NULL;
	43	static volatile uint8_t tx_noautoflush=0;
	44
	45	#define TRANSMIT_FLUSH_TIMEOUT 5 /* in milliseconds */
	46
	47
	48	// get the next character, or -1 if nothing received
	49	int usb_seremu_getchar(void)
	50	{
	51	unsigned int i;
	52	int c;
	53
	54	while (1) {
	55	if (!usb_configuration) return -1;
	56	if (!rx_packet) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
	57	if (!rx_packet) return -1;
	58	i = rx_packet->index;
	59	c = rx_packet->buf[i++];
	60	if (c) {
	61	if (i >= rx_packet->len) {
	62	usb_free(rx_packet);
	63	rx_packet = NULL;
	64	} else {
	65	rx_packet->index = i;
	66	}
	67	return c;
	68	}
	69	usb_free(rx_packet);
	70	rx_packet = NULL;
	71	}
	72	}
	73
	74	// peek at the next character, or -1 if nothing received
	75	int usb_seremu_peekchar(void)
	76	{
	77	int c;
	78
	79	while (1) {
	80	if (!usb_configuration) return -1;
	81	if (!rx_packet) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
	82	if (!rx_packet) return -1;
	83	c = rx_packet->buf[rx_packet->index];
	84	if (c) return c;
	85	usb_free(rx_packet);
	86	rx_packet = NULL;
	87	}
	88	}
	89
	90	// number of bytes available in the receive buffer
	91	int usb_seremu_available(void)
	92	{
	93	int i, len, count;
	94
	95	if (!rx_packet) {
	96	if (usb_configuration) rx_packet = usb_rx(SEREMU_RX_ENDPOINT);
	97	if (!rx_packet) return 0;
	98	}
	99	len = rx_packet->len;
	100	i = rx_packet->index;
	101	count = 0;
	102	for (i = rx_packet->index; i < len; i++) {
	103	if (rx_packet->buf[i] == 0) break;
	104	count++;
	105	}
	106	if (count == 0) {
	107	usb_free(rx_packet);
	108	rx_packet = NULL;
	109	}
	110	return count;
	111	}
	112
	113
	114	// discard any buffered input
	115	void usb_seremu_flush_input(void)
	116	{
	117	usb_packet_t *rx;
	118
	119	if (!usb_configuration) return;
	120	if (rx_packet) {
	121	usb_free(rx_packet);
	122	rx_packet = NULL;
	123	}
	124	while (1) {
	125	rx = usb_rx(SEREMU_RX_ENDPOINT);
	126	if (!rx) break;
	127	usb_free(rx);
	128	}
	129	}
	130
	131
	132
	133	// Maximum number of transmit packets to queue so we don't starve other endpoints for memory
	134	#define TX_PACKET_LIMIT 6
	135
	136	// When the PC isn't listening, how long do we wait before discarding data? If this is
	137	// too short, we risk losing data during the stalls that are common with ordinary desktop
	138	// software. If it's too long, we stall the user's program when no software is running.
	139	#define TX_TIMEOUT_MSEC 30
	140
	141	#if F_CPU == 96000000
	142	#define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
	143	#elif F_CPU == 48000000
	144	#define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
	145	#elif F_CPU == 24000000
	146	#define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
	147	#endif
	148
	149	// When we've suffered the transmit timeout, don't wait again until the computer
	150	// begins accepting data. If no software is running to receive, we'll just discard
	151	// data as rapidly as Serial.print() can generate it, until there's something to
	152	// actually receive it.
	153	static uint8_t transmit_previous_timeout=0;
	154
	155
	156	// transmit a character. 0 returned on success, -1 on error
	157	int usb_seremu_putchar(uint8_t c)
	158	{
	159	return usb_seremu_write(&c, 1);
	160	}
	161
	162
	163	int usb_seremu_write(const void *buffer, uint32_t size)
	164	{
	165	#if 1
	166	uint32_t len;
	167	uint32_t wait_count;
	168	const uint8_t src = (const uint8_t )buffer;
	169	uint8_t *dest;
	170
	171	tx_noautoflush = 1;
	172	while (size > 0) {
	173	if (!tx_packet) {
	174	wait_count = 0;
	175	while (1) {
	176	if (!usb_configuration) {
	177	tx_noautoflush = 0;
	178	return -1;
	179	}
	180	if (usb_tx_packet_count(SEREMU_TX_ENDPOINT) < TX_PACKET_LIMIT) {
	181	tx_noautoflush = 1;
	182	tx_packet = usb_malloc();
	183	if (tx_packet) break;
	184	}
	185	if (++wait_count > TX_TIMEOUT \|\| transmit_previous_timeout) {
	186	transmit_previous_timeout = 1;
	187	tx_noautoflush = 0;
	188	return -1;
	189	}
	190	tx_noautoflush = 0;
	191	yield();
	192	tx_noautoflush = 1;
	193	}
	194	}
	195	transmit_previous_timeout = 0;
	196	len = SEREMU_TX_SIZE - tx_packet->index;
	197	if (len > size) len = size;
	198	dest = tx_packet->buf + tx_packet->index;
	199	tx_packet->index += len;
	200	size -= len;
	201	while (len-- > 0) dest++ = src++;
	202	if (tx_packet->index < SEREMU_TX_SIZE) {
	203	usb_seremu_transmit_flush_timer = TRANSMIT_FLUSH_TIMEOUT;
	204	} else {
	205	tx_packet->len = SEREMU_TX_SIZE;
	206	usb_seremu_transmit_flush_timer = 0;
	207	usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
	208	tx_packet = NULL;
	209	}
	210	}
	211	tx_noautoflush = 0;
	212	return 0;
	213	#endif
	214	}
	215
	216	void usb_seremu_flush_output(void)
	217	{
	218	int i;
	219
	220	if (!usb_configuration) return;
	221	//serial_print("usb_serial_flush_output\n");
	222	if (tx_packet && tx_packet->index > 0) {
	223	usb_seremu_transmit_flush_timer = 0;
	224	for (i = tx_packet->index; i < SEREMU_TX_SIZE; i++) {
	225	tx_packet->buf[i] = 0;
	226	}
	227	tx_packet->len = SEREMU_TX_SIZE;
	228	usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
	229	tx_packet = NULL;
	230	}
	231	// while (usb_tx_byte_count(SEREMU_TX_ENDPOINT) > 0) ; // wait
	232	}
	233
	234	void usb_seremu_flush_callback(void)
	235	{
	236	int i;
	237	//serial_print("C");
	238	if (tx_noautoflush) return;
	239	//serial_print("usb_flush_callback \n");
	240	for (i = tx_packet->index; i < SEREMU_TX_SIZE; i++) {
	241	tx_packet->buf[i] = 0;
	242	}
	243	tx_packet->len = SEREMU_TX_SIZE;
	244	usb_tx(SEREMU_TX_ENDPOINT, tx_packet);
	245	tx_packet = NULL;
	246	//serial_print("usb_flush_callback end\n");
	247	}
	248
	249	#endif // SEREMU_INTERFACE