[libsigrok.git] / src / hardware / baylibre-acme / api.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 <config.h>
#include "protocol.h"
#include <time.h>
#include <sys/timerfd.h>

static const uint32_t devopts[] = {
	SR_CONF_CONTINUOUS,
	SR_CONF_LIMIT_SAMPLES | SR_CONF_GET | SR_CONF_SET,
	SR_CONF_LIMIT_MSEC | SR_CONF_GET | SR_CONF_SET,
	SR_CONF_SAMPLERATE | SR_CONF_GET | SR_CONF_SET | SR_CONF_LIST,
};

/*
 * Currently there are two channel-group/probe options for ACME:
 *   - SR_CONF_PROBE_FACTOR - allows to modify current shunt resistance
 *     calibration
 *   - SR_CONF_POWER_OFF - allows to remotely cut-off/restore power to
 *     measured devices
 *
 * They are not static - we have to check each probe's capabilities in
 * config_list().
 */
#define MAX_DEVOPTS_CG		2
#define HAS_PROBE_FACTOR	(SR_CONF_PROBE_FACTOR | SR_CONF_GET | SR_CONF_SET)
#define HAS_POWER_OFF		(SR_CONF_POWER_OFF | SR_CONF_GET | SR_CONF_SET)

#define MAX_SAMPLE_RATE 500 /* In Hz */

static const uint64_t samplerates[] = {
	SR_HZ(1),
	SR_HZ(MAX_SAMPLE_RATE),
	SR_HZ(1),
};

static GSList *scan(struct sr_dev_driver *di, GSList *options)
{
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	GSList *devices;
	gboolean status;
	int i;

	(void)options;

	devices = NULL;

	devc = g_malloc0(sizeof(struct dev_context));
	devc->samplerate = SR_HZ(10);

	sdi = g_malloc0(sizeof(struct sr_dev_inst));
	sdi->status = SR_ST_INACTIVE;
	sdi->vendor = g_strdup("BayLibre");
	sdi->model = g_strdup("ACME");
	sdi->priv = devc;

	status = bl_acme_is_sane();
	if (!status)
		goto err_out;

	/*
	 * Iterate over all ACME connectors and check if any probes
	 * are present.
	 */
	for (i = 0; i < MAX_PROBES; i++) {
		/*
		 * First check if there's an energy probe on this connector. If
		 * not, and we're already at the fifth probe - see if we can
		 * detect a temperature probe.
		 */
		status = bl_acme_detect_probe(bl_acme_get_enrg_addr(i),
					      PROBE_NUM(i), ENRG_PROBE_NAME);
		if (status) {
			/* Energy probe detected. */
			status = bl_acme_register_probe(sdi, PROBE_ENRG,
					bl_acme_get_enrg_addr(i), PROBE_NUM(i));
			if (!status) {
				sr_err("Error registering power probe %d",
				       PROBE_NUM(i));
				continue;
			}
		} else if (i >= TEMP_PRB_START_INDEX) {
			status = bl_acme_detect_probe(bl_acme_get_temp_addr(i),
					      PROBE_NUM(i), TEMP_PROBE_NAME);
			if (status) {
				/* Temperature probe detected. */
				status = bl_acme_register_probe(sdi,PROBE_TEMP,
					bl_acme_get_temp_addr(i), PROBE_NUM(i));
				if (!status) {
					sr_err("Error registering temp "
					       "probe %d", PROBE_NUM(i));
					continue;
				}
			}
		}
	}

	/*
	 * Let's assume there's no ACME device present if no probe
	 * has been registered.
	 */
	if (!sdi->channel_groups)
		goto err_out;

	devices = g_slist_append(devices, sdi);

	return std_scan_complete(di, devices);

err_out:
	g_free(devc);
	sr_dev_inst_free(sdi);

	return NULL;
}

static int dev_open(struct sr_dev_inst *sdi)
{
	(void)sdi;

	sdi->status = SR_ST_ACTIVE;

	return SR_OK;
}

static int dev_close(struct sr_dev_inst *sdi)
{
	(void)sdi;

	sdi->status = SR_ST_INACTIVE;

	return SR_OK;
}

static int config_get(uint32_t key, GVariant **data,
		      const struct sr_dev_inst *sdi,
		      const struct sr_channel_group *cg)
{
	struct dev_context *devc;
	int ret;
	uint64_t shunt;
	gboolean power_off;

	devc = sdi->priv;

	ret = SR_OK;
	switch (key) {
	case SR_CONF_LIMIT_SAMPLES:
	case SR_CONF_LIMIT_MSEC:
		ret = sr_sw_limits_config_get(&devc->limits, key, data);
		break;
	case SR_CONF_SAMPLERATE:
		*data = g_variant_new_uint64(devc->samplerate);
		break;
	case SR_CONF_PROBE_FACTOR:
		if (!cg)
			return SR_ERR_CHANNEL_GROUP;
		ret = bl_acme_get_shunt(cg, &shunt);
		if (ret == SR_OK)
			*data = g_variant_new_uint64(shunt);
		break;
	case SR_CONF_POWER_OFF:
		if (!cg)
			return SR_ERR_CHANNEL_GROUP;
		ret = bl_acme_read_power_state(cg, &power_off);
		if (ret == SR_OK)
			*data = g_variant_new_boolean(power_off);
		break;
	default:
		return SR_ERR_NA;
	}

	return ret;
}

static int config_set(uint32_t key, GVariant *data,
		      const struct sr_dev_inst *sdi,
		      const struct sr_channel_group *cg)
{
	struct dev_context *devc;
	uint64_t samplerate;
	int ret;

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

	devc = sdi->priv;

	ret = SR_OK;
	switch (key) {
	case SR_CONF_LIMIT_SAMPLES:
	case SR_CONF_LIMIT_MSEC:
		ret = sr_sw_limits_config_set(&devc->limits, key, data);
		break;
	case SR_CONF_SAMPLERATE:
		samplerate = g_variant_get_uint64(data);
		if (samplerate > MAX_SAMPLE_RATE) {
			sr_err("Maximum sample rate is %d", MAX_SAMPLE_RATE);
			ret = SR_ERR_SAMPLERATE;
			break;
		}
		devc->samplerate = samplerate;
		bl_acme_maybe_set_update_interval(sdi, samplerate);
		break;
	case SR_CONF_PROBE_FACTOR:
		if (!cg)
			return SR_ERR_CHANNEL_GROUP;
		ret = bl_acme_set_shunt(cg, g_variant_get_uint64(data));
		break;
	case SR_CONF_POWER_OFF:
		if (!cg)
			return SR_ERR_CHANNEL_GROUP;
		ret = bl_acme_set_power_off(cg, g_variant_get_boolean(data));
		break;
	default:
		ret = SR_ERR_NA;
	}

	return ret;
}

static int config_list(uint32_t key, GVariant **data,
		       const struct sr_dev_inst *sdi,
		       const struct sr_channel_group *cg)
{
	uint32_t devopts_cg[MAX_DEVOPTS_CG];
	GVariant *gvar;
	GVariantBuilder gvb;
	int ret, num_devopts_cg = 0;

	(void)sdi;
	(void)cg;

	ret = SR_OK;
	if (!cg) {
		switch (key) {
		case SR_CONF_DEVICE_OPTIONS:
			*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
				devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
			break;
		case SR_CONF_SAMPLERATE:
			g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
			gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
				samplerates, ARRAY_SIZE(samplerates), sizeof(uint64_t));
			g_variant_builder_add(&gvb, "{sv}",
					      "samplerate-steps", gvar);
			*data = g_variant_builder_end(&gvb);
			break;
		default:
			return SR_ERR_NA;
		}
	} else {
		switch (key) {
		case SR_CONF_DEVICE_OPTIONS:
			if (bl_acme_get_probe_type(cg) == PROBE_ENRG)
				devopts_cg[num_devopts_cg++] = HAS_PROBE_FACTOR;
			if (bl_acme_probe_has_pws(cg))
				devopts_cg[num_devopts_cg++] = HAS_POWER_OFF;

			*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
				devopts_cg, num_devopts_cg, sizeof(uint32_t));
			break;
		default:
			return SR_ERR_NA;
		}
	}

	return ret;
}

static void dev_acquisition_close(const struct sr_dev_inst *sdi)
{
	GSList *chl;
	struct sr_channel *ch;

	for (chl = sdi->channels; chl; chl = chl->next) {
		ch = chl->data;
		bl_acme_close_channel(ch);
	}
}

static int dev_acquisition_open(const struct sr_dev_inst *sdi)
{
	GSList *chl;
	struct sr_channel *ch;

	for (chl = sdi->channels; chl; chl = chl->next) {
		ch = chl->data;
		if (bl_acme_open_channel(ch)) {
			sr_err("Error opening channel %s", ch->name);
			dev_acquisition_close(sdi);
			return SR_ERR;
		}
	}

	return 0;
}

static int dev_acquisition_start(const struct sr_dev_inst *sdi)
{
	struct dev_context *devc;
	struct itimerspec tspec = {
		.it_interval = { 0, 0 },
		.it_value = { 0, 0 }
	};

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

	if (dev_acquisition_open(sdi))
		return SR_ERR;

	devc = sdi->priv;
	devc->samples_missed = 0;
	devc->timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
	if (devc->timer_fd < 0) {
		sr_err("Error creating timer fd");
		return SR_ERR;
	}

	tspec.it_interval.tv_sec = 0;
	tspec.it_interval.tv_nsec = SR_HZ_TO_NS(devc->samplerate);
	tspec.it_value = tspec.it_interval;

	if (timerfd_settime(devc->timer_fd, 0, &tspec, NULL)) {
		sr_err("Failed to set timer");
		close(devc->timer_fd);
		return SR_ERR;
	}

	devc->channel = g_io_channel_unix_new(devc->timer_fd);
	g_io_channel_set_flags(devc->channel, G_IO_FLAG_NONBLOCK, NULL);
	g_io_channel_set_encoding(devc->channel, NULL, NULL);
	g_io_channel_set_buffered(devc->channel, FALSE);

	sr_session_source_add_channel(sdi->session, devc->channel,
		G_IO_IN | G_IO_ERR, 1000, bl_acme_receive_data, (void *)sdi);

	std_session_send_df_header(sdi, LOG_PREFIX);
	sr_sw_limits_acquisition_start(&devc->limits);

	return SR_OK;
}

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

	devc = sdi->priv;

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

	dev_acquisition_close(sdi);
	sr_session_source_remove_channel(sdi->session, devc->channel);
	g_io_channel_shutdown(devc->channel, FALSE, NULL);
	g_io_channel_unref(devc->channel);
	devc->channel = NULL;

	std_session_send_df_end(sdi, LOG_PREFIX);

	if (devc->samples_missed > 0)
		sr_warn("%" PRIu64 " samples missed", devc->samples_missed);

	return SR_OK;
}

static struct sr_dev_driver baylibre_acme_driver_info = {
	.name = "baylibre-acme",
	.longname = "BayLibre ACME (Another Cute Measurement Equipment)",
	.api_version = 1,
	.init = std_init,
	.cleanup = std_cleanup,
	.scan = scan,
	.dev_list = std_dev_list,
	.config_get = config_get,
	.config_set = config_set,
	.config_list = config_list,
	.dev_open = dev_open,
	.dev_close = dev_close,
	.dev_acquisition_start = dev_acquisition_start,
	.dev_acquisition_stop = dev_acquisition_stop,
	.context = NULL,
};
SR_REGISTER_DEV_DRIVER(baylibre_acme_driver_info);
Commit	Line	Data
	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
	20	#include <config.h>
	21	#include "protocol.h"
	22	#include <time.h>
	23	#include <sys/timerfd.h>
	24
	25	static const uint32_t devopts[] = {
	26	SR_CONF_CONTINUOUS,
	27	SR_CONF_LIMIT_SAMPLES \| SR_CONF_GET \| SR_CONF_SET,
	28	SR_CONF_LIMIT_MSEC \| SR_CONF_GET \| SR_CONF_SET,
	29	SR_CONF_SAMPLERATE \| SR_CONF_GET \| SR_CONF_SET \| SR_CONF_LIST,
	30	};
	31
	32	/*
	33	* Currently there are two channel-group/probe options for ACME:
	34	* - SR_CONF_PROBE_FACTOR - allows to modify current shunt resistance
	35	* calibration
	36	* - SR_CONF_POWER_OFF - allows to remotely cut-off/restore power to
	37	* measured devices
	38	*
	39	* They are not static - we have to check each probe's capabilities in
	40	* config_list().
	41	*/
	42	#define MAX_DEVOPTS_CG 2
	43	#define HAS_PROBE_FACTOR (SR_CONF_PROBE_FACTOR \| SR_CONF_GET \| SR_CONF_SET)
	44	#define HAS_POWER_OFF (SR_CONF_POWER_OFF \| SR_CONF_GET \| SR_CONF_SET)
	45
	46	#define MAX_SAMPLE_RATE 500 /* In Hz */
	47
	48	static const uint64_t samplerates[] = {
	49	SR_HZ(1),
	50	SR_HZ(MAX_SAMPLE_RATE),
	51	SR_HZ(1),
	52	};
	53
	54	static GSList scan(struct sr_dev_driver di, GSList *options)
	55	{
	56	struct dev_context *devc;
	57	struct sr_dev_inst *sdi;
	58	GSList *devices;
	59	gboolean status;
	60	int i;
	61
	62	(void)options;
	63
	64	devices = NULL;
	65
	66	devc = g_malloc0(sizeof(struct dev_context));
	67	devc->samplerate = SR_HZ(10);
	68
	69	sdi = g_malloc0(sizeof(struct sr_dev_inst));
	70	sdi->status = SR_ST_INACTIVE;
	71	sdi->vendor = g_strdup("BayLibre");
	72	sdi->model = g_strdup("ACME");
	73	sdi->priv = devc;
	74
	75	status = bl_acme_is_sane();
	76	if (!status)
	77	goto err_out;
	78
	79	/*
	80	* Iterate over all ACME connectors and check if any probes
	81	* are present.
	82	*/
	83	for (i = 0; i < MAX_PROBES; i++) {
	84	/*
	85	* First check if there's an energy probe on this connector. If
	86	* not, and we're already at the fifth probe - see if we can
	87	* detect a temperature probe.
	88	*/
	89	status = bl_acme_detect_probe(bl_acme_get_enrg_addr(i),
	90	PROBE_NUM(i), ENRG_PROBE_NAME);
	91	if (status) {
	92	/* Energy probe detected. */
	93	status = bl_acme_register_probe(sdi, PROBE_ENRG,
	94	bl_acme_get_enrg_addr(i), PROBE_NUM(i));
	95	if (!status) {
	96	sr_err("Error registering power probe %d",
	97	PROBE_NUM(i));
	98	continue;
	99	}
	100	} else if (i >= TEMP_PRB_START_INDEX) {
	101	status = bl_acme_detect_probe(bl_acme_get_temp_addr(i),
	102	PROBE_NUM(i), TEMP_PROBE_NAME);
	103	if (status) {
	104	/* Temperature probe detected. */
	105	status = bl_acme_register_probe(sdi,PROBE_TEMP,
	106	bl_acme_get_temp_addr(i), PROBE_NUM(i));
	107	if (!status) {
	108	sr_err("Error registering temp "
	109	"probe %d", PROBE_NUM(i));
	110	continue;
	111	}
	112	}
	113	}
	114	}
	115
	116	/*
	117	* Let's assume there's no ACME device present if no probe
	118	* has been registered.
	119	*/
	120	if (!sdi->channel_groups)
	121	goto err_out;
	122
	123	devices = g_slist_append(devices, sdi);
	124
	125	return std_scan_complete(di, devices);
	126
	127	err_out:
	128	g_free(devc);
	129	sr_dev_inst_free(sdi);
	130
	131	return NULL;
	132	}
	133
	134	static int dev_open(struct sr_dev_inst *sdi)
	135	{
	136	(void)sdi;
	137
	138	sdi->status = SR_ST_ACTIVE;
	139
	140	return SR_OK;
	141	}
	142
	143	static int dev_close(struct sr_dev_inst *sdi)
	144	{
	145	(void)sdi;
	146
	147	sdi->status = SR_ST_INACTIVE;
	148
	149	return SR_OK;
	150	}
	151
	152	static int config_get(uint32_t key, GVariant **data,
	153	const struct sr_dev_inst *sdi,
	154	const struct sr_channel_group *cg)
	155	{
	156	struct dev_context *devc;
	157	int ret;
	158	uint64_t shunt;
	159	gboolean power_off;
	160
	161	devc = sdi->priv;
	162
	163	ret = SR_OK;
	164	switch (key) {
	165	case SR_CONF_LIMIT_SAMPLES:
	166	case SR_CONF_LIMIT_MSEC:
	167	ret = sr_sw_limits_config_get(&devc->limits, key, data);
	168	break;
	169	case SR_CONF_SAMPLERATE:
	170	*data = g_variant_new_uint64(devc->samplerate);
	171	break;
	172	case SR_CONF_PROBE_FACTOR:
	173	if (!cg)
	174	return SR_ERR_CHANNEL_GROUP;
	175	ret = bl_acme_get_shunt(cg, &shunt);
	176	if (ret == SR_OK)
	177	*data = g_variant_new_uint64(shunt);
	178	break;
	179	case SR_CONF_POWER_OFF:
	180	if (!cg)
	181	return SR_ERR_CHANNEL_GROUP;
	182	ret = bl_acme_read_power_state(cg, &power_off);
	183	if (ret == SR_OK)
	184	*data = g_variant_new_boolean(power_off);
	185	break;
	186	default:
	187	return SR_ERR_NA;
	188	}
	189
	190	return ret;
	191	}
	192
	193	static int config_set(uint32_t key, GVariant *data,
	194	const struct sr_dev_inst *sdi,
	195	const struct sr_channel_group *cg)
	196	{
	197	struct dev_context *devc;
	198	uint64_t samplerate;
	199	int ret;
	200
	201	if (sdi->status != SR_ST_ACTIVE)
	202	return SR_ERR_DEV_CLOSED;
	203
	204	devc = sdi->priv;
	205
	206	ret = SR_OK;
	207	switch (key) {
	208	case SR_CONF_LIMIT_SAMPLES:
	209	case SR_CONF_LIMIT_MSEC:
	210	ret = sr_sw_limits_config_set(&devc->limits, key, data);
	211	break;
	212	case SR_CONF_SAMPLERATE:
	213	samplerate = g_variant_get_uint64(data);
	214	if (samplerate > MAX_SAMPLE_RATE) {
	215	sr_err("Maximum sample rate is %d", MAX_SAMPLE_RATE);
	216	ret = SR_ERR_SAMPLERATE;
	217	break;
	218	}
	219	devc->samplerate = samplerate;
	220	bl_acme_maybe_set_update_interval(sdi, samplerate);
	221	break;
	222	case SR_CONF_PROBE_FACTOR:
	223	if (!cg)
	224	return SR_ERR_CHANNEL_GROUP;
	225	ret = bl_acme_set_shunt(cg, g_variant_get_uint64(data));
	226	break;
	227	case SR_CONF_POWER_OFF:
	228	if (!cg)
	229	return SR_ERR_CHANNEL_GROUP;
	230	ret = bl_acme_set_power_off(cg, g_variant_get_boolean(data));
	231	break;
	232	default:
	233	ret = SR_ERR_NA;
	234	}
	235
	236	return ret;
	237	}
	238
	239	static int config_list(uint32_t key, GVariant **data,
	240	const struct sr_dev_inst *sdi,
	241	const struct sr_channel_group *cg)
	242	{
	243	uint32_t devopts_cg[MAX_DEVOPTS_CG];
	244	GVariant *gvar;
	245	GVariantBuilder gvb;
	246	int ret, num_devopts_cg = 0;
	247
	248	(void)sdi;
	249	(void)cg;
	250
	251	ret = SR_OK;
	252	if (!cg) {
	253	switch (key) {
	254	case SR_CONF_DEVICE_OPTIONS:
	255	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	256	devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
	257	break;
	258	case SR_CONF_SAMPLERATE:
	259	g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
	260	gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
	261	samplerates, ARRAY_SIZE(samplerates), sizeof(uint64_t));
	262	g_variant_builder_add(&gvb, "{sv}",
	263	"samplerate-steps", gvar);
	264	*data = g_variant_builder_end(&gvb);
	265	break;
	266	default:
	267	return SR_ERR_NA;
	268	}
	269	} else {
	270	switch (key) {
	271	case SR_CONF_DEVICE_OPTIONS:
	272	if (bl_acme_get_probe_type(cg) == PROBE_ENRG)
	273	devopts_cg[num_devopts_cg++] = HAS_PROBE_FACTOR;
	274	if (bl_acme_probe_has_pws(cg))
	275	devopts_cg[num_devopts_cg++] = HAS_POWER_OFF;
	276
	277	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	278	devopts_cg, num_devopts_cg, sizeof(uint32_t));
	279	break;
	280	default:
	281	return SR_ERR_NA;
	282	}
	283	}
	284
	285	return ret;
	286	}
	287
	288	static void dev_acquisition_close(const struct sr_dev_inst *sdi)
	289	{
	290	GSList *chl;
	291	struct sr_channel *ch;
	292
	293	for (chl = sdi->channels; chl; chl = chl->next) {
	294	ch = chl->data;
	295	bl_acme_close_channel(ch);
	296	}
	297	}
	298
	299	static int dev_acquisition_open(const struct sr_dev_inst *sdi)
	300	{
	301	GSList *chl;
	302	struct sr_channel *ch;
	303
	304	for (chl = sdi->channels; chl; chl = chl->next) {
	305	ch = chl->data;
	306	if (bl_acme_open_channel(ch)) {
	307	sr_err("Error opening channel %s", ch->name);
	308	dev_acquisition_close(sdi);
	309	return SR_ERR;
	310	}
	311	}
	312
	313	return 0;
	314	}
	315
	316	static int dev_acquisition_start(const struct sr_dev_inst *sdi)
	317	{
	318	struct dev_context *devc;
	319	struct itimerspec tspec = {
	320	.it_interval = { 0, 0 },
	321	.it_value = { 0, 0 }
	322	};
	323
	324	if (sdi->status != SR_ST_ACTIVE)
	325	return SR_ERR_DEV_CLOSED;
	326
	327	if (dev_acquisition_open(sdi))
	328	return SR_ERR;
	329
	330	devc = sdi->priv;
	331	devc->samples_missed = 0;
	332	devc->timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
	333	if (devc->timer_fd < 0) {
	334	sr_err("Error creating timer fd");
	335	return SR_ERR;
	336	}
	337
	338	tspec.it_interval.tv_sec = 0;
	339	tspec.it_interval.tv_nsec = SR_HZ_TO_NS(devc->samplerate);
	340	tspec.it_value = tspec.it_interval;
	341
	342	if (timerfd_settime(devc->timer_fd, 0, &tspec, NULL)) {
	343	sr_err("Failed to set timer");
	344	close(devc->timer_fd);
	345	return SR_ERR;
	346	}
	347
	348	devc->channel = g_io_channel_unix_new(devc->timer_fd);
	349	g_io_channel_set_flags(devc->channel, G_IO_FLAG_NONBLOCK, NULL);
	350	g_io_channel_set_encoding(devc->channel, NULL, NULL);
	351	g_io_channel_set_buffered(devc->channel, FALSE);
	352
	353	sr_session_source_add_channel(sdi->session, devc->channel,
	354	G_IO_IN \| G_IO_ERR, 1000, bl_acme_receive_data, (void *)sdi);
	355
	356	std_session_send_df_header(sdi, LOG_PREFIX);
	357	sr_sw_limits_acquisition_start(&devc->limits);
	358
	359	return SR_OK;
	360	}
	361
	362	static int dev_acquisition_stop(struct sr_dev_inst *sdi)
	363	{
	364	struct dev_context *devc;
	365
	366	devc = sdi->priv;
	367
	368	if (sdi->status != SR_ST_ACTIVE)
	369	return SR_ERR_DEV_CLOSED;
	370
	371	dev_acquisition_close(sdi);
	372	sr_session_source_remove_channel(sdi->session, devc->channel);
	373	g_io_channel_shutdown(devc->channel, FALSE, NULL);
	374	g_io_channel_unref(devc->channel);
	375	devc->channel = NULL;
	376
	377	std_session_send_df_end(sdi, LOG_PREFIX);
	378
	379	if (devc->samples_missed > 0)
	380	sr_warn("%" PRIu64 " samples missed", devc->samples_missed);
	381
	382	return SR_OK;
	383	}
	384
	385	static struct sr_dev_driver baylibre_acme_driver_info = {
	386	.name = "baylibre-acme",
	387	.longname = "BayLibre ACME (Another Cute Measurement Equipment)",
	388	.api_version = 1,
	389	.init = std_init,
	390	.cleanup = std_cleanup,
	391	.scan = scan,
	392	.dev_list = std_dev_list,
	393	.config_get = config_get,
	394	.config_set = config_set,
	395	.config_list = config_list,
	396	.dev_open = dev_open,
	397	.dev_close = dev_close,
	398	.dev_acquisition_start = dev_acquisition_start,
	399	.dev_acquisition_stop = dev_acquisition_stop,
	400	.context = NULL,
	401	};
	402	SR_REGISTER_DEV_DRIVER(baylibre_acme_driver_info);