[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 "libsigrok.h"
#include "libsigrok-internal.h"
#include "protocol.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <errno.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_driver_info;
static struct sr_dev_driver *di = &tekpower_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;
	}

	di->priv = drvc;

	return SR_OK;
}

static int serial_readline(int fd, char **buf, size_t *buflen,
			   uint64_t timeout_ms)
{
	uint64_t start;
	int maxlen, len;

	timeout_ms *= 1000;
	start = g_get_monotonic_time();

	maxlen = *buflen;
	*buflen = len = 0;
	while(1) {
		len = maxlen - *buflen - 1;
		if (len < 1)
			break;
		len = serial_read(fd, *buf + *buflen, 1);
		if (len > 0) {
			*buflen += len;
			*(*buf + *buflen) = '\0';
			if (*buflen > 0 && *(*buf + *buflen - 1) == '\r') {
				/* Strip LF and terminate. */
				*(*buf + --*buflen) = '\0';
				break;
			}
		}
		if (g_get_monotonic_time() - start > timeout_ms)
			/* Timeout */
			break;
		g_usleep(2000);
	}

	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;
	GSList *devices;
	int fd, retry;
	size_t len;
	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 (serial_set_paramstr(fd, serialcomm) != SR_OK) {
		sr_err("unable to set serial parameters");
		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)
	{
		size_t i;
		size_t good_packets = 0;
		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 < LCD14_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 - LCD14_PACKET_SIZE + 1;
		    /* don't increment i here */ )
		{
			const lcd14_packet *packet = (void *)(&buf[i]);
			if( !lcd14_is_packet_valid(packet, NULL) ){
				i++;
				continue;
			}
			good_packets++;
			i += LCD14_PACKET_SIZE;
		}

		/* If we dropped more than two packets worth of data, something
		 * is wrong */
		size_t dropped = len - (good_packets * LCD14_PACKET_SIZE);
		if(dropped > 2 * LCD14_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_dbg("failed to malloc devc");
			return NULL;
		}

		/* devc->profile = RADIOSHACK_22_812; */
		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 {
		/* Then 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)
{
	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;
	}
	if (serial_set_paramstr(devc->serial->fd, devc->serialcomm) != SR_OK) {
		sr_err("unable to set serial parameters");
		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; /* Does nothing. prevents "unused parameter" warning */

	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 aquiring 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 100ms, or whenever some data comes in. */
	sr_source_add(devc->serial->fd, G_IO_IN, 50,
		      lcd14_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_driver_info = {
	.name = "tekpower-dmm",
	.longname = "TekPower/Digitek 4000ZC",
	.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>
	22	#include "libsigrok.h"
	23	#include "libsigrok-internal.h"
	24	#include "protocol.h"
	25	#include <sys/types.h>
	26	#include <sys/stat.h>
	27	#include <fcntl.h>
	28	#include <string.h>
	29	#include <errno.h>
	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
	49	SR_PRIV struct sr_dev_driver tekpower_driver_info;
	50	static struct sr_dev_driver *di = &tekpower_driver_info;
	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)))) {
83	sr_err("driver context malloc failed.");
84	return SR_ERR;
85	}
86
87	di->priv = drvc;
88
89	return SR_OK;
90	}
91
92	static int serial_readline(int fd, char *buf, size_t buflen,
93	uint64_t timeout_ms)
94	{
95	uint64_t start;
96	int maxlen, len;
97
98	timeout_ms *= 1000;
99	start = g_get_monotonic_time();
100
101	maxlen = *buflen;
102	*buflen = len = 0;
103	while(1) {
104	len = maxlen - *buflen - 1;
105	if (len < 1)
106	break;
107	len = serial_read(fd, buf + buflen, 1);
108	if (len > 0) {
109	*buflen += len;
110	(buf + *buflen) = '\0';
111	if (buflen > 0 && (buf + buflen - 1) == '\r') {
112	/* Strip LF and terminate. */
113	(buf + --*buflen) = '\0';
114	break;
115	}
116	}
117	if (g_get_monotonic_time() - start > timeout_ms)
118	/* Timeout */
119	break;
120	g_usleep(2000);
121	}
122
123	return SR_OK;
124	}
125
126	static GSList lcd14_scan(const char conn, const char *serialcomm)
127	{
128	struct sr_dev_inst *sdi;
129	struct drv_context *drvc;
130	struct dev_context *devc;
131	struct sr_probe *probe;
132	GSList *devices;
133	int fd, retry;
134	size_t len;
135	char buf[128], *b;
136
137	if ((fd = serial_open(conn, O_RDONLY\|O_NONBLOCK)) == -1) {
138	sr_err("unable to open %s: %s",
139	conn, strerror(errno));
140	return NULL;
141	}
142	if (serial_set_paramstr(fd, serialcomm) != SR_OK) {
143	sr_err("unable to set serial parameters");
144	return NULL;
145	}
146
147	sr_info("probing port %s readonly", conn);
148
149	drvc = di->priv;
150	b = buf;
151	retry = 0;
152	devices = NULL;
153	serial_flush(fd);
154	/* There's no way to get an ID from the multimeter. It just sends data
155	* periodically, so the best we can do is check if the packets match the
156	* expected format. */
157	while (!devices && retry < 3)
158	{
159	size_t i;
160	size_t good_packets = 0;
161	retry++;
162
163	/* Let's get a bit of data and see if we can find a packet */
164	len = sizeof(buf);
165	serial_readline(fd, &b, &len, 500);
166	if( (len == 0) \|\| (len < LCD14_PACKET_SIZE) ) {
167	/* Not enough data received, is the DMM connected ? */
168	continue;
169	}
170
171	/* Let's treat our buffer like a stream, and find any
172	* valid packets */
173	for( i = 0; i < len - LCD14_PACKET_SIZE + 1;
174	/* don't increment i here */ )
175	{
176	const lcd14_packet packet = (void )(&buf[i]);
177	if( !lcd14_is_packet_valid(packet, NULL) ){
178	i++;
179	continue;
180	}
181	good_packets++;
182	i += LCD14_PACKET_SIZE;
183	}
184
185	/* If we dropped more than two packets worth of data, something
186	* is wrong */
187	size_t dropped = len - (good_packets * LCD14_PACKET_SIZE);
188	if(dropped > 2 * LCD14_PACKET_SIZE)
189	continue;
190
191	/* Let's see if we have anything good */
192	if (good_packets == 0)
193	continue;
194
195	sr_info("found device on port %s", conn);
196
197	if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "TekPower",
198	"TP4000ZC", "")))
199	return NULL;
200	if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
201	sr_dbg("failed to malloc devc");
202	return NULL;
203	}
204
205	/* devc->profile = RADIOSHACK_22_812; */
206	devc->serial = sr_serial_dev_inst_new(conn, -1);
207	devc->serialcomm = g_strdup(serialcomm);
208
209	sdi->priv = devc;
210	sdi->driver = di;
211	if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, "P1")))
212	return NULL;
213	sdi->probes = g_slist_append(sdi->probes, probe);
214	drvc->instances = g_slist_append(drvc->instances, sdi);
215	devices = g_slist_append(devices, sdi);
216	break;
217	}
218
219	serial_close(fd);
220	return devices;
221	}
222
223	static GSList hw_scan(GSList options)
224	{
225	struct sr_hwopt *opt;
226	GSList l, devices;
227	const char conn, serialcomm;
228
229	conn = serialcomm = NULL;
230	for (l = options; l; l = l->next) {
231	opt = l->data;
232	switch (opt->hwopt) {
233	case SR_HWOPT_CONN:
234	conn = opt->value;
235	break;
236	case SR_HWOPT_SERIALCOMM:
237	serialcomm = opt->value;
238	break;
239	}
240	}
241	if (!conn)
242	return NULL;
243
244	if (serialcomm) {
245	/* Use the provided comm specs. */
246	devices = lcd14_scan(conn, serialcomm);
247	} else {
248	/* Then try the default 2400 8n1 */
249	devices = lcd14_scan(conn, "2400/8n1");
250	}
251
252	return devices;
253	}
254
255	static GSList *hw_dev_list(void)
256	{
257	struct drv_context *drvc;
258
259	drvc = di->priv;
260
261	return drvc->instances;
262	}
263
264	static int hw_dev_open(struct sr_dev_inst *sdi)
265	{
266	struct dev_context *devc;
267
268	if (!(devc = sdi->priv)) {
269	sr_err("sdi->priv was NULL.");
270	return SR_ERR_BUG;
271	}
272
273	devc->serial->fd = serial_open(devc->serial->port, O_RDONLY);
274	if (devc->serial->fd == -1) {
275	sr_err("Couldn't open serial port '%s'.",
276	devc->serial->port);
277	return SR_ERR;
278	}
279	if (serial_set_paramstr(devc->serial->fd, devc->serialcomm) != SR_OK) {
280	sr_err("unable to set serial parameters");
281	return SR_ERR;
282	}
283	sdi->status = SR_ST_ACTIVE;
284
285	return SR_OK;
286	}
287
288	static int hw_dev_close(struct sr_dev_inst *sdi)
289	{
290	struct dev_context *devc;
291
292	if (!(devc = sdi->priv)) {
293	sr_err("sdi->priv was NULL.");
294	return SR_ERR_BUG;
295	}
296
297	if (devc->serial && devc->serial->fd != -1) {
298	serial_close(devc->serial->fd);
299	devc->serial->fd = -1;
300	sdi->status = SR_ST_INACTIVE;
301	}
302
303	return SR_OK;
304	}
305
306	static int hw_cleanup(void)
307	{
308	clear_instances();
309
310	return SR_OK;
311	}
312
313	static int hw_info_get(int info_id, const void **data,
314	const struct sr_dev_inst *sdi)
315	{
316	(void)sdi; /* Does nothing. prevents "unused parameter" warning */
317
318	switch (info_id) {
319	case SR_DI_HWOPTS:
320	*data = hwopts;
321	break;
322	case SR_DI_HWCAPS:
323	*data = hwcaps;
324	break;
325	case SR_DI_NUM_PROBES:
326	*data = GINT_TO_POINTER(1);
327	break;
328	case SR_DI_PROBE_NAMES:
329	*data = probe_names;
330	break;
331	default:
332	return SR_ERR_ARG;
333	}
334
335	return SR_OK;
336	}
337
338	static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
339	const void *value)
340	{
341	struct dev_context *devc;
342
343	if (sdi->status != SR_ST_ACTIVE)
344	return SR_ERR;
345
346	if (!(devc = sdi->priv)) {
347	sr_err("sdi->priv was NULL.");
348	return SR_ERR_BUG;
349	}
350
351	switch (hwcap) {
352	case SR_HWCAP_LIMIT_SAMPLES:
353	devc->limit_samples = (const uint64_t )value;
354	sr_dbg("Setting sample limit to %" PRIu64 ".",
355	devc->limit_samples);
356	break;
357	default:
358	sr_err("Unknown capability: %d.", hwcap);
359	return SR_ERR;
360	break;
361	}
362
363	return SR_OK;
364	}
365
366	static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
367	void *cb_data)
368	{
369	struct sr_datafeed_packet packet;
370	struct sr_datafeed_header header;
371	struct sr_datafeed_meta_analog meta;
372	struct dev_context *devc;
373
374	if (!(devc = sdi->priv)) {
375	sr_err("sdi->priv was NULL.");
376	return SR_ERR_BUG;
377	}
378
379	sr_dbg("Starting acquisition.");
380
381	devc->cb_data = cb_data;
382
383	/* Reset the number of samples to take. If we've already collected our
384	* quota, but we start a new session, and don't reset this, we'll just
385	* quit without aquiring any new samples */
386	devc->num_samples = 0;
387
388	/* Send header packet to the session bus. */
389	sr_dbg("Sending SR_DF_HEADER.");
390	packet.type = SR_DF_HEADER;
391	packet.payload = (uint8_t *)&header;
392	header.feed_version = 1;
393	gettimeofday(&header.starttime, NULL);
394	sr_session_send(devc->cb_data, &packet);
395
396	/* Send metadata about the SR_DF_ANALOG packets to come. */
397	sr_dbg("Sending SR_DF_META_ANALOG.");
398	packet.type = SR_DF_META_ANALOG;
399	packet.payload = &meta;
400	meta.num_probes = 1;
401	sr_session_send(devc->cb_data, &packet);
402
403	/* Poll every 100ms, or whenever some data comes in. */
404	sr_source_add(devc->serial->fd, G_IO_IN, 50,
405	lcd14_receive_data, (void *)sdi );
406
407	return SR_OK;
408	}
409
410	static int hw_dev_acquisition_stop(const struct sr_dev_inst *sdi,
411	void *cb_data)
412	{
413	struct sr_datafeed_packet packet;
414	struct dev_context *devc;
415
416	if (sdi->status != SR_ST_ACTIVE)
417	return SR_ERR;
418
419	if (!(devc = sdi->priv)) {
420	sr_err("sdi->priv was NULL.");
421	return SR_ERR_BUG;
422	}
423
424	sr_dbg("Stopping acquisition.");
425
426	sr_source_remove(devc->serial->fd);
427	hw_dev_close((struct sr_dev_inst *)sdi);
428
429	/* Send end packet to the session bus. */
430	sr_dbg("Sending SR_DF_END.");
431	packet.type = SR_DF_END;
432	sr_session_send(cb_data, &packet);
433
434	return SR_OK;
435	}
436
437	SR_PRIV struct sr_dev_driver tekpower_driver_info = {
438	.name = "tekpower-dmm",
439	.longname = "TekPower/Digitek 4000ZC",
440	.api_version = 1,
441	.init = hw_init,
442	.cleanup = hw_cleanup,
443	.scan = hw_scan,
444	.dev_list = hw_dev_list,
445	.dev_clear = clear_instances,
446	.dev_open = hw_dev_open,
447	.dev_close = hw_dev_close,
448	.info_get = hw_info_get,
449	.dev_config_set = hw_dev_config_set,
450	.dev_acquisition_start = hw_dev_acquisition_start,
451	.dev_acquisition_stop = hw_dev_acquisition_stop,
452	.priv = NULL,
453	};