[libsigrok.git] / hardware / tekpower-dmm / api.c

/*
 * This file is part of the sigrok project.
 *
 * Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
 * 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 <glib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
#include "protocol.h"

static const int hwopts[] = {
	SR_HWOPT_CONN,
	SR_HWOPT_SERIALCOMM,
	0,
};

static const int hwcaps[] = {
	SR_HWCAP_MULTIMETER,
	SR_HWCAP_LIMIT_SAMPLES,
	SR_HWCAP_CONTINUOUS,
	0,
};

static const char *probe_names[] = {
	"Probe",
	NULL,
};

SR_PRIV struct sr_dev_driver tekpower_dmm_driver_info;
static struct sr_dev_driver *di = &tekpower_dmm_driver_info;

/* Properly close and free all devices. */
static int clear_instances(void)
{
	struct sr_dev_inst *sdi;
	struct drv_context *drvc;
	struct dev_context *devc;
	GSList *l;

	if (!(drvc = di->priv))
		return SR_OK;

	drvc = di->priv;
	for (l = drvc->instances; l; l = l->next) {
		if (!(sdi = l->data))
			continue;
		if (!(devc = sdi->priv))
			continue;
		sr_serial_dev_inst_free(devc->serial);
		sr_dev_inst_free(sdi);
	}
	g_slist_free(drvc->instances);
	drvc->instances = NULL;

	return SR_OK;
}

static int hw_init(void)
{
	struct drv_context *drvc;

	if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
		sr_err("Driver context malloc failed.");
		return SR_ERR_MALLOC;
	}

	di->priv = drvc;

	return SR_OK;
}

static GSList *lcd14_scan(const char *conn, const char *serialcomm)
{
	struct sr_dev_inst *sdi;
	struct drv_context *drvc;
	struct dev_context *devc;
	struct sr_probe *probe;
	struct fs9721_packet *packet;
	GSList *devices;
	int i, len, fd, retry, good_packets = 0, dropped, ret;
	char buf[128], *b;

	if ((fd = serial_open(conn, O_RDONLY | O_NONBLOCK)) == -1) {
		sr_err("Unable to open %s: %s.", conn, strerror(errno));
		return NULL;
	}
	if ((ret = serial_set_paramstr(fd, serialcomm)) != SR_OK) {
		sr_err("Unable to set serial parameters: %d", ret);
		return NULL;
	}

	sr_info("Probing port %s readonly.", conn);

	drvc = di->priv;
	b = buf;
	retry = 0;
	devices = NULL;
	serial_flush(fd);

	/*
	 * There's no way to get an ID from the multimeter. It just sends data
	 * periodically, so the best we can do is check if the packets match
	 * the expected format.
	 */
	while (!devices && retry < 3) {
		retry++;

		/* Let's get a bit of data and see if we can find a packet. */
		len = sizeof(buf);
		serial_readline(fd, &b, &len, 500);
		if ((len == 0) || (len < FS9721_PACKET_SIZE)) {
			/* Not enough data received, is the DMM connected? */
			continue;
		}

		/* Let's treat our buffer like a stream, and find any
		 * valid packets */
		for (i = 0; i < len - FS9721_PACKET_SIZE + 1;) {
			packet = (void *)(&buf[i]);
			if (!fs9721_is_packet_valid(packet, NULL)) {
				i++;
				continue;
			}
			good_packets++;
			i += FS9721_PACKET_SIZE;
		}

		/*
		 * If we dropped more than two packets worth of data,
		 * something is wrong.
		 */
		dropped = len - (good_packets * FS9721_PACKET_SIZE);
		if (dropped > 2 * FS9721_PACKET_SIZE)
			continue;

		/* Let's see if we have anything good. */
		if (good_packets == 0)
			continue;

		sr_info("Found device on port %s.", conn);

		if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
					    "TP4000ZC", "")))
			return NULL;
		if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
			sr_err("Device context malloc failed.");
			return NULL;
		}

		devc->serial = sr_serial_dev_inst_new(conn, -1);
		devc->serialcomm = g_strdup(serialcomm);

		sdi->priv = devc;
		sdi->driver = di;
		if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
			return NULL;
		sdi->probes = g_slist_append(sdi->probes, probe);
		drvc->instances = g_slist_append(drvc->instances, sdi);
		devices = g_slist_append(devices, sdi);
		break;
	}

	serial_close(fd);
	return devices;
}

static GSList *hw_scan(GSList *options)
{
	struct sr_hwopt *opt;
	GSList *l, *devices;
	const char *conn, *serialcomm;

	conn = serialcomm = NULL;
	for (l = options; l; l = l->next) {
		opt = l->data;
		switch (opt->hwopt) {
		case SR_HWOPT_CONN:
			conn = opt->value;
			break;
		case SR_HWOPT_SERIALCOMM:
			serialcomm = opt->value;
			break;
		}
	}
	if (!conn)
		return NULL;

	if (serialcomm) {
		/* Use the provided comm specs. */
		devices = lcd14_scan(conn, serialcomm);
	} else {
		/* Try the default 2400/8n1. */
		devices = lcd14_scan(conn, "2400/8n1");
	}

	return devices;
}

static GSList *hw_dev_list(void)
{
	struct drv_context *drvc;

	drvc = di->priv;

	return drvc->instances;
}

static int hw_dev_open(struct sr_dev_inst *sdi)
{
	int ret;
	struct dev_context *devc;

	if (!(devc = sdi->priv)) {
		sr_err("sdi->priv was NULL.");
		return SR_ERR_BUG;
	}

	devc->serial->fd = serial_open(devc->serial->port, O_RDONLY);
	if (devc->serial->fd == -1) {
		sr_err("Couldn't open serial port '%s'.", devc->serial->port);
		return SR_ERR;
	}

	ret = serial_set_paramstr(devc->serial->fd, devc->serialcomm);
	if (ret != SR_OK) {
		sr_err("Unable to set serial parameters: %d.", ret);
		return SR_ERR;
	}
	sdi->status = SR_ST_ACTIVE;

	return SR_OK;
}

static int hw_dev_close(struct sr_dev_inst *sdi)
{
	struct dev_context *devc;

	if (!(devc = sdi->priv)) {
		sr_err("sdi->priv was NULL.");
		return SR_ERR_BUG;
	}

	if (devc->serial && devc->serial->fd != -1) {
		serial_close(devc->serial->fd);
		devc->serial->fd = -1;
		sdi->status = SR_ST_INACTIVE;
	}

	return SR_OK;
}

static int hw_cleanup(void)
{
	clear_instances();

	return SR_OK;
}

static int hw_info_get(int info_id, const void **data,
		       const struct sr_dev_inst *sdi)
{
	(void)sdi;

	switch (info_id) {
	case SR_DI_HWOPTS:
		*data = hwopts;
		break;
	case SR_DI_HWCAPS:
		*data = hwcaps;
		break;
	case SR_DI_NUM_PROBES:
		*data = GINT_TO_POINTER(1);
		break;
	case SR_DI_PROBE_NAMES:
		*data = probe_names;
		break;
	default:
		return SR_ERR_ARG;
	}

	return SR_OK;
}

static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
			     const void *value)
{
	struct dev_context *devc;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR;

	if (!(devc = sdi->priv)) {
		sr_err("sdi->priv was NULL.");
		return SR_ERR_BUG;
	}

	switch (hwcap) {
	case SR_HWCAP_LIMIT_SAMPLES:
		devc->limit_samples = *(const uint64_t *)value;
		sr_dbg("Setting sample limit to %" PRIu64 ".",
		       devc->limit_samples);
		break;
	default:
		sr_err("Unknown capability: %d.", hwcap);
		return SR_ERR;
		break;
	}

	return SR_OK;
}

static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
				    void *cb_data)
{
	struct sr_datafeed_packet packet;
	struct sr_datafeed_header header;
	struct sr_datafeed_meta_analog meta;
	struct dev_context *devc;

	if (!(devc = sdi->priv)) {
		sr_err("sdi->priv was NULL.");
		return SR_ERR_BUG;
	}

	sr_dbg("Starting acquisition.");

	devc->cb_data = cb_data;

	/*
	 * Reset the number of samples to take. If we've already collected our
	 * quota, but we start a new session, and don't reset this, we'll just
	 * quit without acquiring any new samples.
	 */
	devc->num_samples = 0;

	/* Send header packet to the session bus. */
	sr_dbg("Sending SR_DF_HEADER.");
	packet.type = SR_DF_HEADER;
	packet.payload = (uint8_t *)&header;
	header.feed_version = 1;
	gettimeofday(&header.starttime, NULL);
	sr_session_send(devc->cb_data, &packet);

	/* Send metadata about the SR_DF_ANALOG packets to come. */
	sr_dbg("Sending SR_DF_META_ANALOG.");
	packet.type = SR_DF_META_ANALOG;
	packet.payload = &meta;
	meta.num_probes = 1;
	sr_session_send(devc->cb_data, &packet);

	/* Poll every 50ms, or whenever some data comes in. */
	sr_source_add(devc->serial->fd, G_IO_IN, 50,
		      tekpower_dmm_receive_data, (void *)sdi);

	return SR_OK;
}

static int hw_dev_acquisition_stop(const struct sr_dev_inst *sdi,
				   void *cb_data)
{
	struct sr_datafeed_packet packet;
	struct dev_context *devc;

	if (sdi->status != SR_ST_ACTIVE)
		return SR_ERR;

	if (!(devc = sdi->priv)) {
		sr_err("sdi->priv was NULL.");
		return SR_ERR_BUG;
	}

	sr_dbg("Stopping acquisition.");

	sr_source_remove(devc->serial->fd);
	hw_dev_close((struct sr_dev_inst *)sdi);

	/* Send end packet to the session bus. */
	sr_dbg("Sending SR_DF_END.");
	packet.type = SR_DF_END;
	sr_session_send(cb_data, &packet);

	return SR_OK;
}

SR_PRIV struct sr_dev_driver tekpower_dmm_driver_info = {
	.name = "tekpower-dmm",
	.longname = "TekPower/Digitek TP4000ZC/DT4000ZC DMM",
	.api_version = 1,
	.init = hw_init,
	.cleanup = hw_cleanup,
	.scan = hw_scan,
	.dev_list = hw_dev_list,
	.dev_clear = clear_instances,
	.dev_open = hw_dev_open,
	.dev_close = hw_dev_close,
	.info_get = hw_info_get,
	.dev_config_set = hw_dev_config_set,
	.dev_acquisition_start = hw_dev_acquisition_start,
	.dev_acquisition_stop = hw_dev_acquisition_stop,
	.priv = NULL,
};
Commit	Line	Data
7dc55d93 AG	1	/*
	2	* This file is part of the sigrok project.
	3	*
	4	* Copyright (C) 2012 Bert Vermeulen <bert@biot.com>
	5	* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
	6	*
	7	* This program is free software: you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation, either version 3 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	19	*/
	20
	21	#include <glib.h>
7dc55d93 AG	22	#include <sys/types.h>
	23	#include <sys/stat.h>
	24	#include <fcntl.h>
	25	#include <string.h>
	26	#include <errno.h>
bbabddbd UH	27	#include "libsigrok.h"
	28	#include "libsigrok-internal.h"
	29	#include "protocol.h"
7dc55d93 AG	30
	31	static const int hwopts[] = {
	32	SR_HWOPT_CONN,
	33	SR_HWOPT_SERIALCOMM,
	34	0,
	35	};
	36
	37	static const int hwcaps[] = {
	38	SR_HWCAP_MULTIMETER,
	39	SR_HWCAP_LIMIT_SAMPLES,
	40	SR_HWCAP_CONTINUOUS,
	41	0,
	42	};
	43
	44	static const char *probe_names[] = {
	45	"Probe",
	46	NULL,
	47	};
	48
bbabddbd UH	49	SR_PRIV struct sr_dev_driver tekpower_dmm_driver_info;
bbabddbd UH	50	static struct sr_dev_driver *di = &tekpower_dmm_driver_info;
7dc55d93 AG	51
	52	/* Properly close and free all devices. */
	53	static int clear_instances(void)
	54	{
	55	struct sr_dev_inst *sdi;
	56	struct drv_context *drvc;
	57	struct dev_context *devc;
	58	GSList *l;
	59
	60	if (!(drvc = di->priv))
	61	return SR_OK;
	62
	63	drvc = di->priv;
	64	for (l = drvc->instances; l; l = l->next) {
	65	if (!(sdi = l->data))
	66	continue;
	67	if (!(devc = sdi->priv))
	68	continue;
	69	sr_serial_dev_inst_free(devc->serial);
	70	sr_dev_inst_free(sdi);
	71	}
	72	g_slist_free(drvc->instances);
	73	drvc->instances = NULL;
	74
	75	return SR_OK;
	76	}
	77
	78	static int hw_init(void)
	79	{
	80	struct drv_context *drvc;
	81
	82	if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
bbabddbd UH	83	sr_err("Driver context malloc failed.");
bbabddbd UH	84	return SR_ERR_MALLOC;
7dc55d93 AG	85	}
	86
	87	di->priv = drvc;
	88
	89	return SR_OK;
	90	}
	91
7dc55d93 AG	92	static GSList lcd14_scan(const char conn, const char *serialcomm)
	93	{
	94	struct sr_dev_inst *sdi;
	95	struct drv_context *drvc;
	96	struct dev_context *devc;
	97	struct sr_probe *probe;
be5c1d3b	98	struct fs9721_packet *packet;
7dc55d93	99	GSList *devices;
bbabddbd	100	int i, len, fd, retry, good_packets = 0, dropped, ret;
7dc55d93 AG	101	char buf[128], *b;
7dc55d93 AG	102
bbabddbd UH	103	if ((fd = serial_open(conn, O_RDONLY \| O_NONBLOCK)) == -1) {
bbabddbd UH	104	sr_err("Unable to open %s: %s.", conn, strerror(errno));
7dc55d93 AG	105	return NULL;
7dc55d93 AG	106	}
bbabddbd UH	107	if ((ret = serial_set_paramstr(fd, serialcomm)) != SR_OK) {
bbabddbd UH	108	sr_err("Unable to set serial parameters: %d", ret);
7dc55d93 AG	109	return NULL;
	110	}
	111
bbabddbd	112	sr_info("Probing port %s readonly.", conn);
7dc55d93 AG	113
	114	drvc = di->priv;
	115	b = buf;
	116	retry = 0;
	117	devices = NULL;
	118	serial_flush(fd);
bbabddbd UH	119
	120	/*
	121	* There's no way to get an ID from the multimeter. It just sends data
	122	* periodically, so the best we can do is check if the packets match
	123	* the expected format.
	124	*/
	125	while (!devices && retry < 3) {
7dc55d93 AG	126	retry++;
7dc55d93 AG	127
bbabddbd	128	/* Let's get a bit of data and see if we can find a packet. */
7dc55d93 AG	129	len = sizeof(buf);
7dc55d93 AG	130	serial_readline(fd, &b, &len, 500);
be5c1d3b	131	if ((len == 0) \|\| (len < FS9721_PACKET_SIZE)) {
bbabddbd	132	/* Not enough data received, is the DMM connected? */
7dc55d93 AG	133	continue;
	134	}
	135
	136	/* Let's treat our buffer like a stream, and find any
	137	* valid packets */
be5c1d3b	138	for (i = 0; i < len - FS9721_PACKET_SIZE + 1;) {
bbabddbd	139	packet = (void *)(&buf[i]);
be5c1d3b	140	if (!fs9721_is_packet_valid(packet, NULL)) {
7dc55d93 AG	141	i++;
	142	continue;
	143	}
	144	good_packets++;
be5c1d3b	145	i += FS9721_PACKET_SIZE;
7dc55d93 AG	146	}
7dc55d93 AG	147
bbabddbd UH	148	/*
	149	* If we dropped more than two packets worth of data,
	150	* something is wrong.
	151	*/
be5c1d3b AG	152	dropped = len - (good_packets * FS9721_PACKET_SIZE);
be5c1d3b AG	153	if (dropped > 2 * FS9721_PACKET_SIZE)
7dc55d93 AG	154	continue;
7dc55d93 AG	155
bbabddbd	156	/* Let's see if we have anything good. */
7dc55d93 AG	157	if (good_packets == 0)
	158	continue;
	159
bbabddbd	160	sr_info("Found device on port %s.", conn);
7dc55d93 AG	161
	162	if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
	163	"TP4000ZC", "")))
	164	return NULL;
	165	if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
bbabddbd	166	sr_err("Device context malloc failed.");
7dc55d93 AG	167	return NULL;
	168	}
	169
7dc55d93 AG	170	devc->serial = sr_serial_dev_inst_new(conn, -1);
	171	devc->serialcomm = g_strdup(serialcomm);
	172
	173	sdi->priv = devc;
	174	sdi->driver = di;
	175	if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
	176	return NULL;
	177	sdi->probes = g_slist_append(sdi->probes, probe);
	178	drvc->instances = g_slist_append(drvc->instances, sdi);
	179	devices = g_slist_append(devices, sdi);
	180	break;
	181	}
	182
	183	serial_close(fd);
	184	return devices;
	185	}
	186
	187	static GSList hw_scan(GSList options)
	188	{
	189	struct sr_hwopt *opt;
	190	GSList l, devices;
	191	const char conn, serialcomm;
	192
	193	conn = serialcomm = NULL;
	194	for (l = options; l; l = l->next) {
	195	opt = l->data;
	196	switch (opt->hwopt) {
	197	case SR_HWOPT_CONN:
	198	conn = opt->value;
	199	break;
	200	case SR_HWOPT_SERIALCOMM:
	201	serialcomm = opt->value;
	202	break;
	203	}
	204	}
	205	if (!conn)
	206	return NULL;
	207
	208	if (serialcomm) {
	209	/* Use the provided comm specs. */
	210	devices = lcd14_scan(conn, serialcomm);
	211	} else {
bbabddbd	212	/* Try the default 2400/8n1. */
7dc55d93 AG	213	devices = lcd14_scan(conn, "2400/8n1");
	214	}
	215
	216	return devices;
	217	}
	218
	219	static GSList *hw_dev_list(void)
	220	{
	221	struct drv_context *drvc;
	222
	223	drvc = di->priv;
	224
	225	return drvc->instances;
	226	}
	227
	228	static int hw_dev_open(struct sr_dev_inst *sdi)
	229	{
bbabddbd	230	int ret;
7dc55d93 AG	231	struct dev_context *devc;
	232
	233	if (!(devc = sdi->priv)) {
	234	sr_err("sdi->priv was NULL.");
	235	return SR_ERR_BUG;
	236	}
	237
	238	devc->serial->fd = serial_open(devc->serial->port, O_RDONLY);
	239	if (devc->serial->fd == -1) {
bbabddbd	240	sr_err("Couldn't open serial port '%s'.", devc->serial->port);
7dc55d93 AG	241	return SR_ERR;
7dc55d93 AG	242	}
bbabddbd UH	243
	244	ret = serial_set_paramstr(devc->serial->fd, devc->serialcomm);
	245	if (ret != SR_OK) {
	246	sr_err("Unable to set serial parameters: %d.", ret);
7dc55d93 AG	247	return SR_ERR;
	248	}
	249	sdi->status = SR_ST_ACTIVE;
	250
	251	return SR_OK;
	252	}
	253
	254	static int hw_dev_close(struct sr_dev_inst *sdi)
	255	{
	256	struct dev_context *devc;
	257
	258	if (!(devc = sdi->priv)) {
	259	sr_err("sdi->priv was NULL.");
	260	return SR_ERR_BUG;
	261	}
	262
	263	if (devc->serial && devc->serial->fd != -1) {
	264	serial_close(devc->serial->fd);
	265	devc->serial->fd = -1;
	266	sdi->status = SR_ST_INACTIVE;
	267	}
	268
	269	return SR_OK;
	270	}
	271
	272	static int hw_cleanup(void)
	273	{
	274	clear_instances();
	275
	276	return SR_OK;
	277	}
	278
	279	static int hw_info_get(int info_id, const void **data,
bbabddbd	280	const struct sr_dev_inst *sdi)
7dc55d93	281	{
bbabddbd	282	(void)sdi;
7dc55d93 AG	283
	284	switch (info_id) {
	285	case SR_DI_HWOPTS:
	286	*data = hwopts;
	287	break;
	288	case SR_DI_HWCAPS:
	289	*data = hwcaps;
	290	break;
	291	case SR_DI_NUM_PROBES:
	292	*data = GINT_TO_POINTER(1);
	293	break;
	294	case SR_DI_PROBE_NAMES:
	295	*data = probe_names;
	296	break;
	297	default:
	298	return SR_ERR_ARG;
	299	}
	300
	301	return SR_OK;
	302	}
	303
	304	static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
bbabddbd	305	const void *value)
7dc55d93 AG	306	{
	307	struct dev_context *devc;
	308
	309	if (sdi->status != SR_ST_ACTIVE)
	310	return SR_ERR;
	311
	312	if (!(devc = sdi->priv)) {
	313	sr_err("sdi->priv was NULL.");
	314	return SR_ERR_BUG;
	315	}
	316
	317	switch (hwcap) {
	318	case SR_HWCAP_LIMIT_SAMPLES:
	319	devc->limit_samples = (const uint64_t )value;
	320	sr_dbg("Setting sample limit to %" PRIu64 ".",
	321	devc->limit_samples);
	322	break;
	323	default:
	324	sr_err("Unknown capability: %d.", hwcap);
	325	return SR_ERR;
	326	break;
	327	}
	328
	329	return SR_OK;
	330	}
	331
	332	static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
bbabddbd	333	void *cb_data)
7dc55d93 AG	334	{
	335	struct sr_datafeed_packet packet;
	336	struct sr_datafeed_header header;
	337	struct sr_datafeed_meta_analog meta;
	338	struct dev_context *devc;
	339
	340	if (!(devc = sdi->priv)) {
	341	sr_err("sdi->priv was NULL.");
	342	return SR_ERR_BUG;
	343	}
	344
	345	sr_dbg("Starting acquisition.");
	346
	347	devc->cb_data = cb_data;
	348
bbabddbd UH	349	/*
bbabddbd UH	350	* Reset the number of samples to take. If we've already collected our
7dc55d93	351	* quota, but we start a new session, and don't reset this, we'll just
bbabddbd UH	352	* quit without acquiring any new samples.
bbabddbd UH	353	*/
7dc55d93 AG	354	devc->num_samples = 0;
	355
	356	/* Send header packet to the session bus. */
	357	sr_dbg("Sending SR_DF_HEADER.");
	358	packet.type = SR_DF_HEADER;
	359	packet.payload = (uint8_t *)&header;
	360	header.feed_version = 1;
	361	gettimeofday(&header.starttime, NULL);
	362	sr_session_send(devc->cb_data, &packet);
	363
	364	/* Send metadata about the SR_DF_ANALOG packets to come. */
	365	sr_dbg("Sending SR_DF_META_ANALOG.");
	366	packet.type = SR_DF_META_ANALOG;
	367	packet.payload = &meta;
	368	meta.num_probes = 1;
	369	sr_session_send(devc->cb_data, &packet);
	370
bbabddbd	371	/* Poll every 50ms, or whenever some data comes in. */
7dc55d93	372	sr_source_add(devc->serial->fd, G_IO_IN, 50,
bbabddbd	373	tekpower_dmm_receive_data, (void *)sdi);
7dc55d93 AG	374
	375	return SR_OK;
	376	}
	377
	378	static int hw_dev_acquisition_stop(const struct sr_dev_inst *sdi,
bbabddbd	379	void *cb_data)
7dc55d93 AG	380	{
	381	struct sr_datafeed_packet packet;
	382	struct dev_context *devc;
	383
	384	if (sdi->status != SR_ST_ACTIVE)
	385	return SR_ERR;
	386
	387	if (!(devc = sdi->priv)) {
	388	sr_err("sdi->priv was NULL.");
	389	return SR_ERR_BUG;
	390	}
	391
	392	sr_dbg("Stopping acquisition.");
	393
	394	sr_source_remove(devc->serial->fd);
	395	hw_dev_close((struct sr_dev_inst *)sdi);
	396
	397	/* Send end packet to the session bus. */
	398	sr_dbg("Sending SR_DF_END.");
	399	packet.type = SR_DF_END;
	400	sr_session_send(cb_data, &packet);
	401
	402	return SR_OK;
	403	}
	404
bbabddbd	405	SR_PRIV struct sr_dev_driver tekpower_dmm_driver_info = {
7dc55d93	406	.name = "tekpower-dmm",
bbabddbd	407	.longname = "TekPower/Digitek TP4000ZC/DT4000ZC DMM",
7dc55d93 AG	408	.api_version = 1,
	409	.init = hw_init,
	410	.cleanup = hw_cleanup,
	411	.scan = hw_scan,
	412	.dev_list = hw_dev_list,
	413	.dev_clear = clear_instances,
	414	.dev_open = hw_dev_open,
	415	.dev_close = hw_dev_close,
	416	.info_get = hw_info_get,
	417	.dev_config_set = hw_dev_config_set,
	418	.dev_acquisition_start = hw_dev_acquisition_start,
	419	.dev_acquisition_stop = hw_dev_acquisition_stop,
	420	.priv = NULL,
	421	};