[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"

/* parser.c */
SR_PRIV int sr_brymen_parse(const uint8_t *buf, float *floatval,
			    struct sr_datafeed_analog *analog, void *info);

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;

	devc = sdi->priv;

	/* Try to get as much data as the buffer can hold. */
	len = DMM_BUFSIZE - devc->buflen;
	len = serial_read(devc->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;
	int ret;
	int64_t time;

	(void)fd;

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

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

	if (revents == G_IO_IN) {
		/* Serial data arrived. */
		handle_new_data(sdi);
	} else {
		/* Timeout, send another packet request. */
		if ((ret = brymen_packet_request(devc->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 FD %d (timeout = %" PRIu64
	       "ms, baudrate = %d).", serial->fd, 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
c5d6f5cc	22	/* parser.c */
601fb67c AG	23	SR_PRIV int sr_brymen_parse(const uint8_t buf, float floatval,
	24	struct sr_datafeed_analog analog, void info);
	25
601fb67c AG	26	static void handle_packet(const uint8_t buf, struct sr_dev_inst sdi)
	27	{
	28	float floatval;
	29	struct dev_context *devc;
	30	struct sr_datafeed_packet packet;
	31	struct sr_datafeed_analog analog;
	32
	33	devc = sdi->priv;
c5d6f5cc	34
601fb67c AG	35	analog.num_samples = 1;
	36	analog.mq = -1;
	37
	38	sr_brymen_parse(buf, &floatval, &analog, NULL);
	39	analog.data = &floatval;
	40
	41	analog.probes = sdi->probes;
	42
	43	if (analog.mq != -1) {
	44	/* Got a measurement. */
	45	packet.type = SR_DF_ANALOG;
	46	packet.payload = &analog;
	47	sr_session_send(devc->cb_data, &packet);
	48	devc->num_samples++;
	49	}
	50	}
	51
	52	static void handle_new_data(struct sr_dev_inst *sdi)
	53	{
	54	struct dev_context *devc;
	55	int len, status, offset = 0;
	56
	57	devc = sdi->priv;
	58
	59	/* Try to get as much data as the buffer can hold. */
	60	len = DMM_BUFSIZE - devc->buflen;
	61	len = serial_read(devc->serial, devc->buf + devc->buflen, len);
	62	if (len < 1) {
	63	sr_err("Serial port read error: %d.", len);
	64	return;
	65	}
	66	devc->buflen += len;
	67	status = PACKET_INVALID_HEADER;
	68
	69	/* Now look for packets in that data. */
	70	while (status != PACKET_NEED_MORE_DATA) {
c5d6f5cc	71	/* We don't have a header, look for one. */
601fb67c AG	72	if (devc->next_packet_len == 0) {
	73	len = devc->buflen - offset;
	74	status = brymen_packet_length(devc->buf + offset, &len);
	75	if (status == PACKET_HEADER_OK) {
c5d6f5cc	76	/* We know how large the packet will be. */
601fb67c AG	77	devc->next_packet_len = len;
601fb67c AG	78	} else if (status == PACKET_NEED_MORE_DATA) {
c5d6f5cc	79	/* We didn't yet receive the full header. */
601fb67c AG	80	devc->next_packet_len = 0;
	81	break;
	82	} else {
c5d6f5cc	83	/* Invalid header. Move on. */
601fb67c AG	84	devc->next_packet_len = 0;
	85	offset++;
	86	continue;
	87	}
	88	}
	89
	90	/* We know how the packet size, but did we receive all of it? */
	91	if (devc->buflen - offset < devc->next_packet_len)
	92	break;
	93
c5d6f5cc	94	/* We should have a full packet here, so we can check it. */
601fb67c AG	95	if (brymen_packet_is_valid(devc->buf + offset)) {
	96	handle_packet(devc->buf + offset, sdi);
	97	offset += devc->next_packet_len;
	98	} else {
	99	offset++;
	100	}
c5d6f5cc	101
601fb67c AG	102	/* We are done with this packet. Look for a new one. */
	103	devc->next_packet_len = 0;
	104	}
	105
	106	/* If we have any data left, move it to the beginning of our buffer. */
	107	memmove(devc->buf, devc->buf + offset, devc->buflen - offset);
	108	devc->buflen -= offset;
	109	}
	110
20cbc785 AG	111	SR_PRIV int brymen_dmm_receive_data(int fd, int revents, void *cb_data)
20cbc785 AG	112	{
601fb67c	113	struct sr_dev_inst *sdi;
20cbc785	114	struct dev_context *devc;
601fb67c AG	115	int ret;
	116	int64_t time;
	117
	118	(void)fd;
20cbc785 AG	119
	120	if (!(sdi = cb_data))
	121	return TRUE;
	122
	123	if (!(devc = sdi->priv))
	124	return TRUE;
	125
	126	if (revents == G_IO_IN) {
601fb67c AG	127	/* Serial data arrived. */
	128	handle_new_data(sdi);
	129	} else {
	130	/* Timeout, send another packet request. */
c5d6f5cc	131	if ((ret = brymen_packet_request(devc->serial)) < 0) {
601fb67c AG	132	sr_err("Failed to request packet: %d.", ret);
	133	return FALSE;
	134	}
	135	}
	136
	137	if (devc->limit_samples && devc->num_samples >= devc->limit_samples) {
	138	sr_info("Requested number of samples reached, stopping.");
	139	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	140	return TRUE;
	141	}
	142
	143	if (devc->limit_msec) {
	144	time = (g_get_monotonic_time() - devc->starttime) / 1000;
	145	if (time > (int64_t)devc->limit_msec) {
	146	sr_info("Requested time limit reached, stopping.");
	147	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	148	return TRUE;
	149	}
20cbc785 AG	150	}
	151
	152	return TRUE;
	153	}
601fb67c AG	154
	155	/**
	156	* Try to find a valid packet in a serial data stream.
	157	*
	158	* @param serial Previously initialized serial port structure.
	159	* @param buf Buffer containing the bytes to write.
	160	* @param buflen Size of the buffer.
c5d6f5cc	161	* @param get_packet_size Callback that assesses the size of incoming packets.
601fb67c AG	162	* @param is_valid Callback that assesses whether the packet is valid or not.
	163	* @param timeout_ms The timeout after which, if no packet is detected, to
	164	* abort scanning.
	165	* @param baudrate The baudrate of the serial port. This parameter is not
	166	* critical, but it helps fine tune the serial port polling
	167	* delay.
	168	*
	169	* @return SR_OK if a valid packet is found within the given timeout,
	170	* SR_ERR upon failure.
	171	*/
	172	SR_PRIV int brymen_stream_detect(struct sr_serial_dev_inst *serial,
	173	uint8_t buf, size_t buflen,
	174	packet_length_t get_packet_size,
	175	packet_valid_t is_valid,
	176	uint64_t timeout_ms, int baudrate)
	177	{
	178	int64_t start, time, byte_delay_us;
	179	size_t ibuf, i, maxlen;
	180	int status, len, packet_len, stream_len;
	181
	182	maxlen = *buflen;
	183
	184	sr_dbg("Detecting packets on FD %d (timeout = %" PRIu64
c5d6f5cc	185	"ms, baudrate = %d).", serial->fd, timeout_ms, baudrate);
601fb67c AG	186
	187	/* Assume 8n1 transmission. That is 10 bits for every byte. */
	188	byte_delay_us = 10 * (1000000 / baudrate);
	189	start = g_get_monotonic_time();
	190
	191	packet_len = i = ibuf = len = 0;
	192	while (ibuf < maxlen) {
	193	len = serial_read(serial, &buf[ibuf], maxlen - ibuf);
	194	if (len > 0) {
	195	ibuf += len;
c5d6f5cc	196	sr_spew("Read %d bytes.", len);
601fb67c AG	197	}
	198
	199	time = g_get_monotonic_time() - start;
	200	time /= 1000;
	201
	202	stream_len = ibuf - i;
	203	if (stream_len > 0 && packet_len == 0) {
	204	/* How large of a packet are we expecting? */
	205	packet_len = stream_len;
	206	status = get_packet_size(&buf[i], &packet_len);
	207	switch(status) {
	208	case PACKET_HEADER_OK:
c5d6f5cc	209	/* We know how much data we need to wait for. */
601fb67c AG	210	break;
601fb67c AG	211	case PACKET_NEED_MORE_DATA:
c5d6f5cc	212	/* We did not receive the full header. */
601fb67c AG	213	packet_len = 0;
	214	break;
	215	case PACKET_INVALID_HEADER:
	216	default:
	217	/*
	218	* We had enough data, but here was an error in
	219	* parsing the header. Restart parsing from the
c5d6f5cc	220	* next byte.
601fb67c AG	221	*/
	222	packet_len = 0;
	223	i++;
	224	break;
	225	}
	226	}
	227
c5d6f5cc	228	if ((stream_len >= packet_len) && (packet_len != 0)) {
601fb67c AG	229	/* We have at least a packet's worth of data. */
	230	if (is_valid(&buf[i])) {
	231	sr_spew("Found valid %d-byte packet after "
c5d6f5cc	232	"%" PRIu64 "ms.", packet_len, time);
601fb67c AG	233	*buflen = ibuf;
	234	return SR_OK;
	235	} else {
	236	sr_spew("Got %d bytes, but not a valid "
c5d6f5cc	237	"packet.", packet_len);
601fb67c AG	238
601fb67c AG	239	}
c5d6f5cc	240
601fb67c AG	241	/* Not a valid packet. Continue searching. */
	242	i++;
	243	packet_len = 0;
	244	}
c5d6f5cc	245
601fb67c AG	246	if (time >= (int64_t)timeout_ms) {
	247	/* Timeout */
	248	sr_dbg("Detection timed out after %dms.", time);
	249	break;
	250	}
	251	g_usleep(byte_delay_us);
	252	}
	253
	254	*buflen = ibuf;
	255	sr_err("Didn't find a valid packet (read %d bytes).", ibuf);
	256
	257	return SR_ERR;
	258	}