[libsigrok.git] / src / hardware / baylibre-acme / protocol.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2015 Bartosz Golaszewski <bgolaszewski@baylibre.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 <string.h>
#include <stdlib.h> /* strtol() */
#include <errno.h>
#include <fcntl.h> /* open(), etc... */
#include "protocol.h"

struct channel_group_priv {
	int hwmon_num;
};

struct channel_priv {
	int ch_type;
	struct channel_group_priv *probe;
};

static const uint8_t enrg_i2c_addrs[] = {
	0x40, 0x41, 0x44, 0x45, 0x42, 0x43, 0x46, 0x47,
};

static const uint8_t temp_i2c_addrs[] = {
	0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
};

SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
{
	return enrg_i2c_addrs[index];
}

SR_PRIV uint8_t bl_acme_get_temp_addr(int index)
{
	return temp_i2c_addrs[index];
}

SR_PRIV gboolean bl_acme_is_sane(void)
{
	gboolean status;

	/*
	 * We expect sysfs to be present and mounted at /sys, ina226 and
	 * tmp435 sensors detected by the system and their appropriate
	 * drivers loaded and functional.
	 */
	status = g_file_test("/sys", G_FILE_TEST_IS_DIR);
	if (!status) {
		sr_err("/sys/ directory not found - sysfs not mounted?");
		return FALSE;
	}

	return TRUE;
}

static void probe_name_path(unsigned int addr, GString *path)
{
	g_string_printf(path,
			"/sys/class/i2c-adapter/i2c-1/1-00%02x/name", addr);
}

/*
 * For given address fill buf with the path to appropriate hwmon entry.
 */
static void probe_hwmon_path(unsigned int addr, GString *path)
{
	g_string_printf(path,
			"/sys/class/i2c-adapter/i2c-1/1-00%02x/hwmon", addr);
}

SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
				      int prb_num, const char *prb_name)
{
	gboolean ret = FALSE, status;
	char *buf = NULL;
	GString *path = g_string_sized_new(64);
	GError *err = NULL;
	gsize size;

	probe_name_path(addr, path);
	status = g_file_get_contents(path->str, &buf, &size, &err);
	if (!status) {
		sr_dbg("Name for probe %d can't be read: %s",
		       prb_num, err->message);
		g_string_free(path, TRUE);
		return ret;

	}

	if (strncmp(buf, prb_name, strlen(prb_name)) == 0) {
		/*
		 * Correct driver registered on this address - but is
		 * there an actual probe connected?
		 */
		probe_hwmon_path(addr, path);
		status = g_file_test(path->str, G_FILE_TEST_IS_DIR);
		if (status) {
			/* We have found an ACME probe. */
			ret = TRUE;
		}
	}

	g_free(buf);
	g_string_free(path, TRUE);

	return ret;
}

static int get_hwmon_index(unsigned int addr)
{
	int status, hwmon;
	GString *path = g_string_sized_new(64);
	GError *err = NULL;
	GDir *dir;

	probe_hwmon_path(addr, path);
	dir = g_dir_open(path->str, 0, &err);
	if (dir == NULL) {
		sr_err("Error opening %s: %s", path->str, err->message);
		g_string_free(path, TRUE);
		return -1;
	}

	g_string_free(path, TRUE);

	/*
	 * The directory should contain a single file named hwmonX where X
	 * is the hwmon index.
	 */
	status = sscanf(g_dir_read_name(dir), "hwmon%d", &hwmon);
	g_dir_close(dir);
	if (status != 1) {
		sr_err("Unable to determine the hwmon entry");
		return -1;
	}

	return hwmon;
}

static void append_channel(struct sr_dev_inst *sdi,
			   struct sr_channel_group *cg,
			   int index, int type)
{
	struct channel_priv *cp;
	struct dev_context *devc;
	struct sr_channel *ch;
	char *name;

	devc = sdi->priv;

	switch (type) {
	case ENRG_PWR:
		name = g_strdup_printf("P%d_ENRG_PWR", index);
		break;
	case ENRG_CURR:
		name = g_strdup_printf("P%d_ENRG_CURR", index);
		break;
	case ENRG_VOL:
		name = g_strdup_printf("P%d_ENRG_VOL", index);
		break;
	case TEMP_IN:
		name = g_strdup_printf("P%d_TEMP_IN", index);
		break;
	case TEMP_OUT:
		name = g_strdup_printf("P%d_TEMP_OUT", index);
		break;
	default:
		sr_err("Bug in the code: invalid channel type!");
		return;
	}

	cp = g_malloc0(sizeof(struct channel_priv));
	cp->ch_type = type;
	cp->probe = cg->priv;

	ch = sr_channel_new(devc->num_channels++,
			    SR_CHANNEL_ANALOG, TRUE, name);
	g_free(name);

	ch->priv = cp;
	cg->channels = g_slist_append(cg->channels, ch);
	sdi->channels = g_slist_append(sdi->channels, ch);
}

SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
					unsigned int addr, int prb_num)
{
	struct sr_channel_group *cg;
	struct channel_group_priv *cgp;
	int hwmon;

	/* Obtain the hwmon index. */
	hwmon = get_hwmon_index(addr);
	if (hwmon < 0)
		return FALSE;

	cg = g_malloc0(sizeof(struct sr_channel_group));
	cgp = g_malloc0(sizeof(struct channel_group_priv));
	cgp->hwmon_num = hwmon;
	cg->name = g_strdup_printf("Probe_%d", prb_num);
	cg->priv = cgp;

	if (type == PROBE_ENRG) {
		append_channel(sdi, cg, prb_num, ENRG_PWR);
		append_channel(sdi, cg, prb_num, ENRG_CURR);
		append_channel(sdi, cg, prb_num, ENRG_VOL);
	} else if (type == PROBE_TEMP) {
		append_channel(sdi, cg, prb_num, TEMP_IN);
		append_channel(sdi, cg, prb_num, TEMP_OUT);
	} else {
		sr_err("Bug in the code: invalid probe type!");
	}

	sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);

	return TRUE;
}

static int channel_to_mq(struct sr_channel *ch)
{
	struct channel_priv *chp;

	chp = ch->priv;

	switch (chp->ch_type) {
	case ENRG_PWR:
		return SR_MQ_POWER;
	case ENRG_CURR:
		return SR_MQ_CURRENT;
	case ENRG_VOL:
		return SR_MQ_VOLTAGE;
	case TEMP_IN:
	case TEMP_OUT:
		return SR_MQ_TEMPERATURE;
	default:
		return -1;
	}
}

static int channel_to_unit(struct sr_channel *ch)
{
	struct channel_priv *chp;

	chp = ch->priv;

	switch (chp->ch_type) {
	case ENRG_PWR:
		return SR_UNIT_WATT;
	case ENRG_CURR:
		return SR_UNIT_AMPERE;
	case ENRG_VOL:
		return SR_UNIT_VOLT;
	case TEMP_IN:
	case TEMP_OUT:
		return SR_UNIT_CELSIUS;
	default:
		return -1;
	}
}

/* We need to scale measurements down from the units used by the drivers. */
static float adjust_data(int val, int type)
{
	switch (type) {
	case ENRG_PWR:
		return ((float)val) / 1000000.0;
	case ENRG_CURR:
	case ENRG_VOL:
	case TEMP_IN:
	case TEMP_OUT:
		return ((float)val) / 1000.0;
	default:
		return 0.0;
	}
}

static float read_sample(struct sr_channel *ch)
{
	struct channel_priv *chp;
	char path[64], *file, buf[16];
	ssize_t len;
	int fd;

	chp = ch->priv;

	switch (chp->ch_type) {
	case ENRG_PWR:	file = "power1_input";	break;
	case ENRG_CURR:	file = "curr1_input";	break;
	case ENRG_VOL:	file = "in1_input";	break;
	case TEMP_IN:	file = "temp1_input";	break;
	case TEMP_OUT:	file = "temp2_input";	break;
	default:
		sr_err("Bug in the code: invalid channel type!");
		return -1.0;
	}

	snprintf(path, sizeof(path),
		 "/sys/class/hwmon/hwmon%d/%s",
		 chp->probe->hwmon_num, file);
	fd = open(path, O_RDONLY);
	if (fd < 0) {
		sr_err("Error opening %s: %s", path, strerror(errno));
		ch->enabled = FALSE;
		return -1.0;
	}

	len = read(fd, buf, sizeof(buf));
	close(fd);
	if (len < 0) {
		sr_err("error reading from %s: %s", path, strerror(errno));
		ch->enabled = FALSE;
		return -1.0;
	}

	return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
}

SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
{
	uint32_t cur_time, elapsed_time, diff_time;
	int64_t time_to_sleep;
	struct sr_datafeed_packet packet, framep;
	struct sr_datafeed_analog analog;
	struct sr_dev_inst *sdi;
	struct sr_channel *ch;
	struct dev_context *devc;
	GSList *chl, chonly;
	float valf;

	(void)fd;
	(void)revents;

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

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

	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;
	memset(&analog, 0, sizeof(analog));
	analog.data = &valf;

	/*
	 * Reading from sysfs takes some time - try to
	 * keep up with samplerate.
	 */
	if (devc->samples_read) {
		cur_time = g_get_monotonic_time();
		diff_time = cur_time - devc->last_sample_fin;
		time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time;
		if (time_to_sleep > 0)
			g_usleep(time_to_sleep);
	}

	framep.type = SR_DF_FRAME_BEGIN;
	sr_session_send(cb_data, &framep);

	/*
	 * Due to different units used in each channel we're sending
	 * samples one-by-one.
	 */
	for (chl = sdi->channels; chl; chl = chl->next) {
		ch = chl->data;
		if (!ch->enabled)
			continue;
		chonly.next = NULL;
		chonly.data = ch;
		analog.channels = &chonly;
		analog.num_samples = 1;
		analog.mq = channel_to_mq(chl->data);
		analog.unit = channel_to_unit(ch);

		valf = read_sample(ch);

		sr_session_send(cb_data, &packet);
	}

	framep.type = SR_DF_FRAME_END;
	sr_session_send(cb_data, &framep);

	devc->samples_read++;
	if (devc->limit_samples > 0 &&
	    devc->samples_read >= devc->limit_samples) {
		sr_info("Requested number of samples reached.");
		sdi->driver->dev_acquisition_stop(sdi, cb_data);
		devc->last_sample_fin = g_get_monotonic_time();
		return TRUE;
	} else if (devc->limit_msec > 0) {
		cur_time = g_get_monotonic_time();
		elapsed_time = cur_time - devc->start_time;

		if (elapsed_time >= devc->limit_msec) {
			sr_info("Sampling time limit reached.");
			sdi->driver->dev_acquisition_stop(sdi, cb_data);
			devc->last_sample_fin = g_get_monotonic_time();
			return TRUE;
		}
	}

	devc->last_sample_fin = g_get_monotonic_time();
	return TRUE;
}
Commit	Line	Data
dfaee1de BG	1	/*
	2	* This file is part of the libsigrok project.
	3	*
	4	* Copyright (C) 2015 Bartosz Golaszewski <bgolaszewski@baylibre.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
6b80b80d BG	20	#include <string.h>
	21	#include <stdlib.h> /* strtol() */
	22	#include <errno.h>
	23	#include <fcntl.h> /* open(), etc... */
dfaee1de BG	24	#include "protocol.h"
dfaee1de BG	25
6b80b80d BG	26	struct channel_group_priv {
	27	int hwmon_num;
	28	};
	29
	30	struct channel_priv {
	31	int ch_type;
	32	struct channel_group_priv *probe;
	33	};
	34
	35	static const uint8_t enrg_i2c_addrs[] = {
	36	0x40, 0x41, 0x44, 0x45, 0x42, 0x43, 0x46, 0x47,
	37	};
	38
	39	static const uint8_t temp_i2c_addrs[] = {
	40	0x0, 0x0, 0x0, 0x0, 0x4c, 0x49, 0x4f, 0x4b,
	41	};
	42
	43	SR_PRIV uint8_t bl_acme_get_enrg_addr(int index)
	44	{
	45	return enrg_i2c_addrs[index];
	46	}
	47
	48	SR_PRIV uint8_t bl_acme_get_temp_addr(int index)
	49	{
	50	return temp_i2c_addrs[index];
	51	}
	52
	53	SR_PRIV gboolean bl_acme_is_sane(void)
	54	{
	55	gboolean status;
	56
	57	/*
	58	* We expect sysfs to be present and mounted at /sys, ina226 and
	59	* tmp435 sensors detected by the system and their appropriate
	60	* drivers loaded and functional.
	61	*/
	62	status = g_file_test("/sys", G_FILE_TEST_IS_DIR);
	63	if (!status) {
	64	sr_err("/sys/ directory not found - sysfs not mounted?");
	65	return FALSE;
	66	}
	67
	68	return TRUE;
	69	}
	70
	71	static void probe_name_path(unsigned int addr, GString *path)
	72	{
	73	g_string_printf(path,
	74	"/sys/class/i2c-adapter/i2c-1/1-00%02x/name", addr);
	75	}
	76
	77	/*
	78	* For given address fill buf with the path to appropriate hwmon entry.
	79	*/
	80	static void probe_hwmon_path(unsigned int addr, GString *path)
	81	{
	82	g_string_printf(path,
	83	"/sys/class/i2c-adapter/i2c-1/1-00%02x/hwmon", addr);
	84	}
	85
	86	SR_PRIV gboolean bl_acme_detect_probe(unsigned int addr,
	87	int prb_num, const char *prb_name)
	88	{
	89	gboolean ret = FALSE, status;
90	char *buf = NULL;
91	GString *path = g_string_sized_new(64);
92	GError *err = NULL;
93	gsize size;
94
95	probe_name_path(addr, path);
96	status = g_file_get_contents(path->str, &buf, &size, &err);
97	if (!status) {
98	sr_dbg("Name for probe %d can't be read: %s",
99	prb_num, err->message);
100	g_string_free(path, TRUE);
101	return ret;
102
103	}
104
105	if (strncmp(buf, prb_name, strlen(prb_name)) == 0) {
106	/*
107	* Correct driver registered on this address - but is
108	* there an actual probe connected?
109	*/
110	probe_hwmon_path(addr, path);
111	status = g_file_test(path->str, G_FILE_TEST_IS_DIR);
112	if (status) {
113	/* We have found an ACME probe. */
114	ret = TRUE;
115	}
116	}
117
118	g_free(buf);
119	g_string_free(path, TRUE);
120
121	return ret;
122	}
123
124	static int get_hwmon_index(unsigned int addr)
125	{
126	int status, hwmon;
127	GString *path = g_string_sized_new(64);
128	GError *err = NULL;
129	GDir *dir;
130
131	probe_hwmon_path(addr, path);
132	dir = g_dir_open(path->str, 0, &err);
133	if (dir == NULL) {
134	sr_err("Error opening %s: %s", path->str, err->message);
135	g_string_free(path, TRUE);
136	return -1;
137	}
138
139	g_string_free(path, TRUE);
140
141	/*
142	* The directory should contain a single file named hwmonX where X
143	* is the hwmon index.
144	*/
145	status = sscanf(g_dir_read_name(dir), "hwmon%d", &hwmon);
146	g_dir_close(dir);
147	if (status != 1) {
148	sr_err("Unable to determine the hwmon entry");
149	return -1;
150	}
151
152	return hwmon;
153	}
154
155	static void append_channel(struct sr_dev_inst *sdi,
156	struct sr_channel_group *cg,
157	int index, int type)
158	{
159	struct channel_priv *cp;
160	struct dev_context *devc;
161	struct sr_channel *ch;
162	char *name;
163
164	devc = sdi->priv;
165
166	switch (type) {
167	case ENRG_PWR:
168	name = g_strdup_printf("P%d_ENRG_PWR", index);
169	break;
170	case ENRG_CURR:
171	name = g_strdup_printf("P%d_ENRG_CURR", index);
172	break;
173	case ENRG_VOL:
174	name = g_strdup_printf("P%d_ENRG_VOL", index);
175	break;
176	case TEMP_IN:
177	name = g_strdup_printf("P%d_TEMP_IN", index);
178	break;
179	case TEMP_OUT:
180	name = g_strdup_printf("P%d_TEMP_OUT", index);
181	break;
182	default:
183	sr_err("Bug in the code: invalid channel type!");
184	return;
185	}
186
187	cp = g_malloc0(sizeof(struct channel_priv));
188	cp->ch_type = type;
189	cp->probe = cg->priv;
190
191	ch = sr_channel_new(devc->num_channels++,
192	SR_CHANNEL_ANALOG, TRUE, name);
193	g_free(name);
194
195	ch->priv = cp;
196	cg->channels = g_slist_append(cg->channels, ch);
197	sdi->channels = g_slist_append(sdi->channels, ch);
198	}
199
200	SR_PRIV gboolean bl_acme_register_probe(struct sr_dev_inst *sdi, int type,
201	unsigned int addr, int prb_num)
202	{
203	struct sr_channel_group *cg;
204	struct channel_group_priv *cgp;
205	int hwmon;
206
207	/* Obtain the hwmon index. */
208	hwmon = get_hwmon_index(addr);
209	if (hwmon < 0)
210	return FALSE;
211
212	cg = g_malloc0(sizeof(struct sr_channel_group));
213	cgp = g_malloc0(sizeof(struct channel_group_priv));
214	cgp->hwmon_num = hwmon;
215	cg->name = g_strdup_printf("Probe_%d", prb_num);
216	cg->priv = cgp;
217
218	if (type == PROBE_ENRG) {
219	append_channel(sdi, cg, prb_num, ENRG_PWR);
220	append_channel(sdi, cg, prb_num, ENRG_CURR);
221	append_channel(sdi, cg, prb_num, ENRG_VOL);
222	} else if (type == PROBE_TEMP) {
223	append_channel(sdi, cg, prb_num, TEMP_IN);
224	append_channel(sdi, cg, prb_num, TEMP_OUT);
225	} else {
226	sr_err("Bug in the code: invalid probe type!");
227	}
228
229	sdi->channel_groups = g_slist_append(sdi->channel_groups, cg);
230
231	return TRUE;
232	}
233
234	static int channel_to_mq(struct sr_channel *ch)
dfaee1de	235	{
6b80b80d BG	236	struct channel_priv *chp;
	237
	238	chp = ch->priv;
	239
	240	switch (chp->ch_type) {
	241	case ENRG_PWR:
	242	return SR_MQ_POWER;
	243	case ENRG_CURR:
	244	return SR_MQ_CURRENT;
	245	case ENRG_VOL:
	246	return SR_MQ_VOLTAGE;
	247	case TEMP_IN:
	248	case TEMP_OUT:
	249	return SR_MQ_TEMPERATURE;
	250	default:
	251	return -1;
	252	}
	253	}
	254
	255	static int channel_to_unit(struct sr_channel *ch)
	256	{
	257	struct channel_priv *chp;
	258
	259	chp = ch->priv;
	260
	261	switch (chp->ch_type) {
	262	case ENRG_PWR:
	263	return SR_UNIT_WATT;
	264	case ENRG_CURR:
	265	return SR_UNIT_AMPERE;
	266	case ENRG_VOL:
	267	return SR_UNIT_VOLT;
	268	case TEMP_IN:
	269	case TEMP_OUT:
	270	return SR_UNIT_CELSIUS;
	271	default:
	272	return -1;
	273	}
	274	}
	275
	276	/* We need to scale measurements down from the units used by the drivers. */
	277	static float adjust_data(int val, int type)
	278	{
	279	switch (type) {
	280	case ENRG_PWR:
	281	return ((float)val) / 1000000.0;
	282	case ENRG_CURR:
	283	case ENRG_VOL:
	284	case TEMP_IN:
	285	case TEMP_OUT:
	286	return ((float)val) / 1000.0;
	287	default:
	288	return 0.0;
	289	}
	290	}
	291
	292	static float read_sample(struct sr_channel *ch)
	293	{
	294	struct channel_priv *chp;
	295	char path[64], *file, buf[16];
	296	ssize_t len;
	297	int fd;
	298
	299	chp = ch->priv;
300
301	switch (chp->ch_type) {
302	case ENRG_PWR: file = "power1_input"; break;
303	case ENRG_CURR: file = "curr1_input"; break;
304	case ENRG_VOL: file = "in1_input"; break;
305	case TEMP_IN: file = "temp1_input"; break;
306	case TEMP_OUT: file = "temp2_input"; break;
307	default:
308	sr_err("Bug in the code: invalid channel type!");
309	return -1.0;
310	}
311
312	snprintf(path, sizeof(path),
313	"/sys/class/hwmon/hwmon%d/%s",
314	chp->probe->hwmon_num, file);
315	fd = open(path, O_RDONLY);
316	if (fd < 0) {
317	sr_err("Error opening %s: %s", path, strerror(errno));
318	ch->enabled = FALSE;
319	return -1.0;
320	}
321
322	len = read(fd, buf, sizeof(buf));
323	close(fd);
324	if (len < 0) {
325	sr_err("error reading from %s: %s", path, strerror(errno));
326	ch->enabled = FALSE;
327	return -1.0;
328	}
329
330	return adjust_data(strtol(buf, NULL, 10), chp->ch_type);
331	}
332
333	SR_PRIV int bl_acme_receive_data(int fd, int revents, void *cb_data)
334	{
335	uint32_t cur_time, elapsed_time, diff_time;
336	int64_t time_to_sleep;
337	struct sr_datafeed_packet packet, framep;
338	struct sr_datafeed_analog analog;
339	struct sr_dev_inst *sdi;
340	struct sr_channel *ch;
dfaee1de	341	struct dev_context *devc;
6b80b80d BG	342	GSList *chl, chonly;
6b80b80d BG	343	float valf;
dfaee1de BG	344
dfaee1de BG	345	(void)fd;
6b80b80d BG	346	(void)revents;
	347
	348	sdi = cb_data;
	349	if (!sdi)
	350	return TRUE;
dfaee1de	351
6b80b80d BG	352	devc = sdi->priv;
6b80b80d BG	353	if (!devc)
dfaee1de BG	354	return TRUE;
dfaee1de BG	355
6b80b80d BG	356	packet.type = SR_DF_ANALOG;
	357	packet.payload = &analog;
	358	memset(&analog, 0, sizeof(analog));
	359	analog.data = &valf;
	360
	361	/*
	362	* Reading from sysfs takes some time - try to
	363	* keep up with samplerate.
	364	*/
	365	if (devc->samples_read) {
	366	cur_time = g_get_monotonic_time();
	367	diff_time = cur_time - devc->last_sample_fin;
	368	time_to_sleep = G_USEC_PER_SEC / devc->samplerate - diff_time;
	369	if (time_to_sleep > 0)
	370	g_usleep(time_to_sleep);
	371	}
	372
	373	framep.type = SR_DF_FRAME_BEGIN;
	374	sr_session_send(cb_data, &framep);
	375
	376	/*
	377	* Due to different units used in each channel we're sending
	378	* samples one-by-one.
	379	*/
	380	for (chl = sdi->channels; chl; chl = chl->next) {
	381	ch = chl->data;
	382	if (!ch->enabled)
	383	continue;
	384	chonly.next = NULL;
	385	chonly.data = ch;
	386	analog.channels = &chonly;
	387	analog.num_samples = 1;
	388	analog.mq = channel_to_mq(chl->data);
	389	analog.unit = channel_to_unit(ch);
	390
	391	valf = read_sample(ch);
	392
	393	sr_session_send(cb_data, &packet);
	394	}
	395
	396	framep.type = SR_DF_FRAME_END;
	397	sr_session_send(cb_data, &framep);
	398
	399	devc->samples_read++;
	400	if (devc->limit_samples > 0 &&
	401	devc->samples_read >= devc->limit_samples) {
	402	sr_info("Requested number of samples reached.");
	403	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	404	devc->last_sample_fin = g_get_monotonic_time();
dfaee1de	405	return TRUE;
6b80b80d BG	406	} else if (devc->limit_msec > 0) {
	407	cur_time = g_get_monotonic_time();
	408	elapsed_time = cur_time - devc->start_time;
dfaee1de	409
6b80b80d BG	410	if (elapsed_time >= devc->limit_msec) {
	411	sr_info("Sampling time limit reached.");
	412	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	413	devc->last_sample_fin = g_get_monotonic_time();
	414	return TRUE;
	415	}
dfaee1de BG	416	}
dfaee1de BG	417
6b80b80d	418	devc->last_sample_fin = g_get_monotonic_time();
dfaee1de BG	419	return TRUE;
dfaee1de BG	420	}