[libsigrok.git] / hardware / brymen-dmm / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
 *
 * 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 "protocol.h"

static void handle_packet(const uint8_t *buf, struct sr_dev_inst *sdi)
{
	float floatval;
	struct dev_context *devc;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_analog analog;

	devc = sdi->priv;

	analog.num_samples = 1;
	analog.mq = -1;

	sr_brymen_parse(buf, &floatval, &analog, NULL);
	analog.data = &floatval;

	analog.probes = sdi->probes;

	if (analog.mq != -1) {
		/* Got a measurement. */
		packet.type = SR_DF_ANALOG;
		packet.payload = &analog;
		sr_session_send(devc->cb_data, &packet);
		devc->num_samples++;
	}
}

static void handle_new_data(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	int len, status, offset = 0;
	struct sr_serial_dev_inst *serial;

	devc = sdi->priv;
	serial = sdi->conn;

	/* Try to get as much data as the buffer can hold. */
	len = DMM_BUFSIZE - devc->buflen;
	len = serial_read(serial, devc->buf + devc->buflen, len);
	if (len < 1) {
		sr_err("Serial port read error: %d.", len);
		return;
	}
	devc->buflen += len;
	status = PACKET_INVALID_HEADER;

	/* Now look for packets in that data. */
	while (status != PACKET_NEED_MORE_DATA) {
		/* We don't have a header, look for one. */
		if (devc->next_packet_len == 0) {
			len = devc->buflen - offset;
			status = brymen_packet_length(devc->buf + offset, &len);
			if (status == PACKET_HEADER_OK) {
				/* We know how large the packet will be. */
				devc->next_packet_len = len;
			} else if (status == PACKET_NEED_MORE_DATA) {
				/* We didn't yet receive the full header. */
				devc->next_packet_len = 0;
				break;
			} else {
				/* Invalid header. Move on. */
				devc->next_packet_len = 0;
				offset++;
				continue;
			}
		}

		/* We know how the packet size, but did we receive all of it? */
		if (devc->buflen - offset < devc->next_packet_len)
			break;

		/* We should have a full packet here, so we can check it. */
		if (brymen_packet_is_valid(devc->buf + offset)) {
			handle_packet(devc->buf + offset, sdi);
			offset += devc->next_packet_len;
		} else {
			offset++;
		}

		/* We are done with this packet. Look for a new one. */
		devc->next_packet_len = 0;
	}

	/* If we have any data left, move it to the beginning of our buffer. */
	memmove(devc->buf, devc->buf + offset, devc->buflen - offset);
	devc->buflen -= offset;
}

SR_PRIV int brymen_dmm_receive_data(int fd, int revents, void *cb_data)
{
	struct sr_dev_inst *sdi;
	struct dev_context *devc;
	struct sr_serial_dev_inst *serial;
	int ret;
	int64_t time;

	(void)fd;

	if (!(sdi = cb_data))
		return TRUE;

	if (!(devc = sdi->priv))
		return TRUE;

	serial = sdi->conn;

	if (revents == G_IO_IN) {
		/* Serial data arrived. */
		handle_new_data(sdi);
	} else {
		/* Timeout, send another packet request. */
		if ((ret = brymen_packet_request(serial)) < 0) {
			sr_err("Failed to request packet: %d.", ret);
			return FALSE;
		}
	}

	if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
		sr_info("Requested number of samples reached, stopping.");
		sdi->driver->dev_acquisition_stop(sdi, cb_data);
		return TRUE;
	}

	if (devc->limit_msec) {
		time = (g_get_monotonic_time() - devc->starttime) / 1000;
		if (time > (int64_t)devc->limit_msec) {
			sr_info("Requested time limit reached, stopping.");
			sdi->driver->dev_acquisition_stop(sdi, cb_data);
			return TRUE;
		}
	}

	return TRUE;
}

/**
 * Try to find a valid packet in a serial data stream.
 *
 * @param serial Previously initialized serial port structure.
 * @param buf Buffer containing the bytes to write.
 * @param buflen Size of the buffer.
 * @param get_packet_size Callback that assesses the size of incoming packets.
 * @param is_valid Callback that assesses whether the packet is valid or not.
 * @param timeout_ms The timeout after which, if no packet is detected, to
 *                   abort scanning.
 * @param baudrate The baudrate of the serial port. This parameter is not
 *                 critical, but it helps fine tune the serial port polling
 *                 delay.
 *
 * @return SR_OK if a valid packet is found within the given timeout,
 *         SR_ERR upon failure.
 */
SR_PRIV int brymen_stream_detect(struct sr_serial_dev_inst *serial,
				uint8_t *buf, size_t *buflen,
				packet_length_t get_packet_size,
				packet_valid_t is_valid,
				uint64_t timeout_ms, int baudrate)
{
	int64_t start, time, byte_delay_us;
	size_t ibuf, i, maxlen;
	int status, len, packet_len, stream_len;

	maxlen = *buflen;

	sr_dbg("Detecting packets on %s (timeout = %" PRIu64
	       "ms, baudrate = %d).", serial->port, timeout_ms, baudrate);

	/* Assume 8n1 transmission. That is 10 bits for every byte. */
	byte_delay_us = 10 * (1000000 / baudrate);
	start = g_get_monotonic_time();

	packet_len = i = ibuf = len = 0;
	while (ibuf < maxlen) {
		len = serial_read(serial, &buf[ibuf], maxlen - ibuf);
		if (len > 0) {
			ibuf += len;
			sr_spew("Read %d bytes.", len);
		}

		time = g_get_monotonic_time() - start;
		time /= 1000;

		stream_len = ibuf - i;
		if (stream_len > 0 && packet_len == 0) {
			/* How large of a packet are we expecting? */
			packet_len = stream_len;
			status = get_packet_size(&buf[i], &packet_len);
			switch(status) {
			case PACKET_HEADER_OK:
				/* We know how much data we need to wait for. */
				break;
			case PACKET_NEED_MORE_DATA:
				/* We did not receive the full header. */
				packet_len = 0;
				break;
			case PACKET_INVALID_HEADER:
			default:
				/*
				 * We had enough data, but here was an error in
				 * parsing the header. Restart parsing from the
				 * next byte.
				 */
				packet_len = 0;
				i++;
				break;
			}
		}

		if ((stream_len >= packet_len) && (packet_len != 0)) {
			/* We have at least a packet's worth of data. */
			if (is_valid(&buf[i])) {
				sr_spew("Found valid %d-byte packet after "
					"%" PRIu64 "ms.", packet_len, time);
				*buflen = ibuf;
				return SR_OK;
			} else {
				sr_spew("Got %d bytes, but not a valid "
					"packet.", packet_len);

			}

			/* Not a valid packet. Continue searching. */
			i++;
			packet_len = 0;
		}

		if (time >= (int64_t)timeout_ms) {
			/* Timeout */
			sr_dbg("Detection timed out after %dms.", time);
			break;
		}
		g_usleep(byte_delay_us);
	}

	*buflen = ibuf;
	sr_err("Didn't find a valid packet (read %d bytes).", ibuf);

	return SR_ERR;
}
Commit	Line	Data
20cbc785 AG	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
	5	*
	6	* This program is free software: you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation, either version 3 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU General Public License
	17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	18	*/
	19
20cbc785 AG	20	#include "protocol.h"
20cbc785 AG	21
601fb67c AG	22	static void handle_packet(const uint8_t buf, struct sr_dev_inst sdi)
	23	{
	24	float floatval;
	25	struct dev_context *devc;
	26	struct sr_datafeed_packet packet;
	27	struct sr_datafeed_analog analog;
	28
	29	devc = sdi->priv;
c5d6f5cc	30
601fb67c AG	31	analog.num_samples = 1;
	32	analog.mq = -1;
	33
	34	sr_brymen_parse(buf, &floatval, &analog, NULL);
	35	analog.data = &floatval;
	36
	37	analog.probes = sdi->probes;
	38
	39	if (analog.mq != -1) {
	40	/* Got a measurement. */
	41	packet.type = SR_DF_ANALOG;
	42	packet.payload = &analog;
	43	sr_session_send(devc->cb_data, &packet);
	44	devc->num_samples++;
	45	}
	46	}
	47
	48	static void handle_new_data(struct sr_dev_inst *sdi)
	49	{
	50	struct dev_context *devc;
	51	int len, status, offset = 0;
d9a7c349	52	struct sr_serial_dev_inst *serial;
601fb67c AG	53
601fb67c AG	54	devc = sdi->priv;
d9a7c349	55	serial = sdi->conn;
601fb67c AG	56
	57	/* Try to get as much data as the buffer can hold. */
	58	len = DMM_BUFSIZE - devc->buflen;
d9a7c349	59	len = serial_read(serial, devc->buf + devc->buflen, len);
601fb67c AG	60	if (len < 1) {
	61	sr_err("Serial port read error: %d.", len);
	62	return;
	63	}
	64	devc->buflen += len;
	65	status = PACKET_INVALID_HEADER;
	66
	67	/* Now look for packets in that data. */
	68	while (status != PACKET_NEED_MORE_DATA) {
c5d6f5cc	69	/* We don't have a header, look for one. */
601fb67c AG	70	if (devc->next_packet_len == 0) {
	71	len = devc->buflen - offset;
	72	status = brymen_packet_length(devc->buf + offset, &len);
	73	if (status == PACKET_HEADER_OK) {
c5d6f5cc	74	/* We know how large the packet will be. */
601fb67c AG	75	devc->next_packet_len = len;
601fb67c AG	76	} else if (status == PACKET_NEED_MORE_DATA) {
c5d6f5cc	77	/* We didn't yet receive the full header. */
601fb67c AG	78	devc->next_packet_len = 0;
	79	break;
	80	} else {
c5d6f5cc	81	/* Invalid header. Move on. */
601fb67c AG	82	devc->next_packet_len = 0;
	83	offset++;
	84	continue;
	85	}
	86	}
	87
	88	/* We know how the packet size, but did we receive all of it? */
	89	if (devc->buflen - offset < devc->next_packet_len)
	90	break;
	91
c5d6f5cc	92	/* We should have a full packet here, so we can check it. */
601fb67c AG	93	if (brymen_packet_is_valid(devc->buf + offset)) {
	94	handle_packet(devc->buf + offset, sdi);
	95	offset += devc->next_packet_len;
	96	} else {
	97	offset++;
	98	}
c5d6f5cc	99
601fb67c AG	100	/* We are done with this packet. Look for a new one. */
	101	devc->next_packet_len = 0;
	102	}
	103
	104	/* If we have any data left, move it to the beginning of our buffer. */
	105	memmove(devc->buf, devc->buf + offset, devc->buflen - offset);
	106	devc->buflen -= offset;
	107	}
	108
20cbc785 AG	109	SR_PRIV int brymen_dmm_receive_data(int fd, int revents, void *cb_data)
20cbc785 AG	110	{
601fb67c	111	struct sr_dev_inst *sdi;
20cbc785	112	struct dev_context *devc;
d9a7c349	113	struct sr_serial_dev_inst *serial;
601fb67c AG	114	int ret;
	115	int64_t time;
	116
	117	(void)fd;
20cbc785 AG	118
	119	if (!(sdi = cb_data))
	120	return TRUE;
	121
	122	if (!(devc = sdi->priv))
	123	return TRUE;
	124
d9a7c349 UH	125	serial = sdi->conn;
d9a7c349 UH	126
20cbc785	127	if (revents == G_IO_IN) {
601fb67c AG	128	/* Serial data arrived. */
	129	handle_new_data(sdi);
	130	} else {
	131	/* Timeout, send another packet request. */
d9a7c349	132	if ((ret = brymen_packet_request(serial)) < 0) {
601fb67c AG	133	sr_err("Failed to request packet: %d.", ret);
	134	return FALSE;
	135	}
	136	}
	137
	138	if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
	139	sr_info("Requested number of samples reached, stopping.");
	140	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	141	return TRUE;
	142	}
	143
	144	if (devc->limit_msec) {
	145	time = (g_get_monotonic_time() - devc->starttime) / 1000;
	146	if (time > (int64_t)devc->limit_msec) {
	147	sr_info("Requested time limit reached, stopping.");
	148	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	149	return TRUE;
	150	}
20cbc785 AG	151	}
	152
	153	return TRUE;
	154	}
601fb67c AG	155
	156	/**
	157	* Try to find a valid packet in a serial data stream.
	158	*
	159	* @param serial Previously initialized serial port structure.
	160	* @param buf Buffer containing the bytes to write.
	161	* @param buflen Size of the buffer.
c5d6f5cc	162	* @param get_packet_size Callback that assesses the size of incoming packets.
601fb67c AG	163	* @param is_valid Callback that assesses whether the packet is valid or not.
	164	* @param timeout_ms The timeout after which, if no packet is detected, to
	165	* abort scanning.
	166	* @param baudrate The baudrate of the serial port. This parameter is not
	167	* critical, but it helps fine tune the serial port polling
	168	* delay.
	169	*
	170	* @return SR_OK if a valid packet is found within the given timeout,
	171	* SR_ERR upon failure.
	172	*/
	173	SR_PRIV int brymen_stream_detect(struct sr_serial_dev_inst *serial,
	174	uint8_t buf, size_t buflen,
	175	packet_length_t get_packet_size,
	176	packet_valid_t is_valid,
	177	uint64_t timeout_ms, int baudrate)
	178	{
	179	int64_t start, time, byte_delay_us;
	180	size_t ibuf, i, maxlen;
	181	int status, len, packet_len, stream_len;
	182
	183	maxlen = *buflen;
	184
af473e0e ML	185	sr_dbg("Detecting packets on %s (timeout = %" PRIu64
af473e0e ML	186	"ms, baudrate = %d).", serial->port, timeout_ms, baudrate);
601fb67c AG	187
	188	/* Assume 8n1 transmission. That is 10 bits for every byte. */
	189	byte_delay_us = 10 * (1000000 / baudrate);
	190	start = g_get_monotonic_time();
	191
	192	packet_len = i = ibuf = len = 0;
	193	while (ibuf < maxlen) {
	194	len = serial_read(serial, &buf[ibuf], maxlen - ibuf);
	195	if (len > 0) {
	196	ibuf += len;
c5d6f5cc	197	sr_spew("Read %d bytes.", len);
601fb67c AG	198	}
	199
	200	time = g_get_monotonic_time() - start;
	201	time /= 1000;
	202
	203	stream_len = ibuf - i;
	204	if (stream_len > 0 && packet_len == 0) {
	205	/* How large of a packet are we expecting? */
	206	packet_len = stream_len;
	207	status = get_packet_size(&buf[i], &packet_len);
	208	switch(status) {
	209	case PACKET_HEADER_OK:
c5d6f5cc	210	/* We know how much data we need to wait for. */
601fb67c AG	211	break;
601fb67c AG	212	case PACKET_NEED_MORE_DATA:
c5d6f5cc	213	/* We did not receive the full header. */
601fb67c AG	214	packet_len = 0;
	215	break;
	216	case PACKET_INVALID_HEADER:
	217	default:
	218	/*
	219	* We had enough data, but here was an error in
	220	* parsing the header. Restart parsing from the
c5d6f5cc	221	* next byte.
601fb67c AG	222	*/
	223	packet_len = 0;
	224	i++;
	225	break;
	226	}
	227	}
	228
c5d6f5cc	229	if ((stream_len >= packet_len) && (packet_len != 0)) {
601fb67c AG	230	/* We have at least a packet's worth of data. */
	231	if (is_valid(&buf[i])) {
	232	sr_spew("Found valid %d-byte packet after "
c5d6f5cc	233	"%" PRIu64 "ms.", packet_len, time);
601fb67c AG	234	*buflen = ibuf;
	235	return SR_OK;
	236	} else {
	237	sr_spew("Got %d bytes, but not a valid "
c5d6f5cc	238	"packet.", packet_len);
601fb67c AG	239
601fb67c AG	240	}
c5d6f5cc	241
601fb67c AG	242	/* Not a valid packet. Continue searching. */
	243	i++;
	244	packet_len = 0;
	245	}
c5d6f5cc	246
601fb67c AG	247	if (time >= (int64_t)timeout_ms) {
	248	/* Timeout */
	249	sr_dbg("Detection timed out after %dms.", time);
	250	break;
	251	}
	252	g_usleep(byte_delay_us);
	253	}
	254
	255	*buflen = ibuf;
	256	sr_err("Didn't find a valid packet (read %d bytes).", ibuf);
	257
	258	return SR_ERR;
	259	}