[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 drv_context *drvc;
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	GSList *devices;
	gboolean status;
	int i;

	(void)options;

	drvc = di->context;
	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->driver = di;
	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);
	drvc->instances = g_slist_append(drvc->instances, sdi);

	return 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 drv_context *drvc;
	57	struct dev_context *devc;
	58	struct sr_dev_inst *sdi;
	59	GSList *devices;
	60	gboolean status;
	61	int i;
	62
	63	(void)options;
	64
	65	drvc = di->context;
	66	devices = NULL;
	67
	68	devc = g_malloc0(sizeof(struct dev_context));
	69	devc->samplerate = SR_HZ(10);
	70
	71	sdi = g_malloc0(sizeof(struct sr_dev_inst));
	72	sdi->status = SR_ST_INACTIVE;
	73	sdi->vendor = g_strdup("BayLibre");
	74	sdi->model = g_strdup("ACME");
	75	sdi->driver = di;
	76	sdi->priv = devc;
	77
	78	status = bl_acme_is_sane();
	79	if (!status)
	80	goto err_out;
	81
	82	/*
	83	* Iterate over all ACME connectors and check if any probes
	84	* are present.
	85	*/
	86	for (i = 0; i < MAX_PROBES; i++) {
	87	/*
	88	* First check if there's an energy probe on this connector. If
	89	* not, and we're already at the fifth probe - see if we can
	90	* detect a temperature probe.
	91	*/
	92	status = bl_acme_detect_probe(bl_acme_get_enrg_addr(i),
	93	PROBE_NUM(i), ENRG_PROBE_NAME);
	94	if (status) {
	95	/* Energy probe detected. */
	96	status = bl_acme_register_probe(sdi, PROBE_ENRG,
	97	bl_acme_get_enrg_addr(i), PROBE_NUM(i));
	98	if (!status) {
	99	sr_err("Error registering power probe %d",
	100	PROBE_NUM(i));
	101	continue;
	102	}
	103	} else if (i >= TEMP_PRB_START_INDEX) {
	104	status = bl_acme_detect_probe(bl_acme_get_temp_addr(i),
	105	PROBE_NUM(i), TEMP_PROBE_NAME);
	106	if (status) {
	107	/* Temperature probe detected. */
	108	status = bl_acme_register_probe(sdi,PROBE_TEMP,
	109	bl_acme_get_temp_addr(i), PROBE_NUM(i));
	110	if (!status) {
	111	sr_err("Error registering temp "
	112	"probe %d", PROBE_NUM(i));
	113	continue;
	114	}
	115	}
	116	}
	117	}
	118
	119	/*
	120	* Let's assume there's no ACME device present if no probe
	121	* has been registered.
	122	*/
	123	if (!sdi->channel_groups)
	124	goto err_out;
	125
	126	devices = g_slist_append(devices, sdi);
	127	drvc->instances = g_slist_append(drvc->instances, sdi);
	128
	129	return devices;
	130
	131	err_out:
	132	g_free(devc);
	133	sr_dev_inst_free(sdi);
	134
	135	return NULL;
	136	}
	137
	138	static int dev_open(struct sr_dev_inst *sdi)
	139	{
	140	(void)sdi;
	141
	142	sdi->status = SR_ST_ACTIVE;
	143
	144	return SR_OK;
	145	}
	146
	147	static int dev_close(struct sr_dev_inst *sdi)
	148	{
	149	(void)sdi;
	150
	151	sdi->status = SR_ST_INACTIVE;
	152
	153	return SR_OK;
	154	}
	155
	156	static int config_get(uint32_t key, GVariant **data,
	157	const struct sr_dev_inst *sdi,
	158	const struct sr_channel_group *cg)
	159	{
	160	struct dev_context *devc;
	161	int ret;
	162	uint64_t shunt;
	163	gboolean power_off;
	164
	165	devc = sdi->priv;
	166
	167	ret = SR_OK;
	168	switch (key) {
	169	case SR_CONF_LIMIT_SAMPLES:
	170	case SR_CONF_LIMIT_MSEC:
	171	ret = sr_sw_limits_config_get(&devc->limits, key, data);
	172	break;
	173	case SR_CONF_SAMPLERATE:
	174	*data = g_variant_new_uint64(devc->samplerate);
	175	break;
	176	case SR_CONF_PROBE_FACTOR:
	177	if (!cg)
	178	return SR_ERR_CHANNEL_GROUP;
	179	ret = bl_acme_get_shunt(cg, &shunt);
	180	if (ret == SR_OK)
	181	*data = g_variant_new_uint64(shunt);
	182	break;
	183	case SR_CONF_POWER_OFF:
	184	if (!cg)
	185	return SR_ERR_CHANNEL_GROUP;
	186	ret = bl_acme_read_power_state(cg, &power_off);
	187	if (ret == SR_OK)
	188	*data = g_variant_new_boolean(power_off);
	189	break;
	190	default:
	191	return SR_ERR_NA;
	192	}
	193
	194	return ret;
	195	}
	196
	197	static int config_set(uint32_t key, GVariant *data,
	198	const struct sr_dev_inst *sdi,
	199	const struct sr_channel_group *cg)
	200	{
	201	struct dev_context *devc;
	202	uint64_t samplerate;
	203	int ret;
	204
	205	if (sdi->status != SR_ST_ACTIVE)
	206	return SR_ERR_DEV_CLOSED;
	207
	208	devc = sdi->priv;
	209
	210	ret = SR_OK;
	211	switch (key) {
	212	case SR_CONF_LIMIT_SAMPLES:
	213	case SR_CONF_LIMIT_MSEC:
	214	ret = sr_sw_limits_config_set(&devc->limits, key, data);
	215	break;
	216	case SR_CONF_SAMPLERATE:
	217	samplerate = g_variant_get_uint64(data);
	218	if (samplerate > MAX_SAMPLE_RATE) {
	219	sr_err("Maximum sample rate is %d", MAX_SAMPLE_RATE);
	220	ret = SR_ERR_SAMPLERATE;
	221	break;
	222	}
	223	devc->samplerate = samplerate;
	224	bl_acme_maybe_set_update_interval(sdi, samplerate);
	225	break;
	226	case SR_CONF_PROBE_FACTOR:
	227	if (!cg)
	228	return SR_ERR_CHANNEL_GROUP;
	229	ret = bl_acme_set_shunt(cg, g_variant_get_uint64(data));
	230	break;
	231	case SR_CONF_POWER_OFF:
	232	if (!cg)
	233	return SR_ERR_CHANNEL_GROUP;
	234	ret = bl_acme_set_power_off(cg, g_variant_get_boolean(data));
	235	break;
	236	default:
	237	ret = SR_ERR_NA;
	238	}
	239
	240	return ret;
	241	}
	242
	243	static int config_list(uint32_t key, GVariant **data,
	244	const struct sr_dev_inst *sdi,
	245	const struct sr_channel_group *cg)
	246	{
	247	uint32_t devopts_cg[MAX_DEVOPTS_CG];
	248	GVariant *gvar;
	249	GVariantBuilder gvb;
	250	int ret, num_devopts_cg = 0;
	251
	252	(void)sdi;
	253	(void)cg;
	254
	255	ret = SR_OK;
	256	if (!cg) {
	257	switch (key) {
	258	case SR_CONF_DEVICE_OPTIONS:
	259	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	260	devopts, ARRAY_SIZE(devopts), sizeof(uint32_t));
	261	break;
	262	case SR_CONF_SAMPLERATE:
	263	g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
	264	gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
	265	samplerates, ARRAY_SIZE(samplerates), sizeof(uint64_t));
	266	g_variant_builder_add(&gvb, "{sv}",
	267	"samplerate-steps", gvar);
	268	*data = g_variant_builder_end(&gvb);
	269	break;
	270	default:
	271	return SR_ERR_NA;
	272	}
	273	} else {
	274	switch (key) {
	275	case SR_CONF_DEVICE_OPTIONS:
	276	if (bl_acme_get_probe_type(cg) == PROBE_ENRG)
	277	devopts_cg[num_devopts_cg++] = HAS_PROBE_FACTOR;
	278	if (bl_acme_probe_has_pws(cg))
	279	devopts_cg[num_devopts_cg++] = HAS_POWER_OFF;
	280
	281	*data = g_variant_new_fixed_array(G_VARIANT_TYPE_UINT32,
	282	devopts_cg, num_devopts_cg, sizeof(uint32_t));
	283	break;
	284	default:
	285	return SR_ERR_NA;
	286	}
	287	}
	288
	289	return ret;
	290	}
	291
	292	static void dev_acquisition_close(const struct sr_dev_inst *sdi)
	293	{
	294	GSList *chl;
	295	struct sr_channel *ch;
	296
	297	for (chl = sdi->channels; chl; chl = chl->next) {
	298	ch = chl->data;
	299	bl_acme_close_channel(ch);
	300	}
	301	}
	302
	303	static int dev_acquisition_open(const struct sr_dev_inst *sdi)
	304	{
	305	GSList *chl;
	306	struct sr_channel *ch;
	307
	308	for (chl = sdi->channels; chl; chl = chl->next) {
	309	ch = chl->data;
	310	if (bl_acme_open_channel(ch)) {
	311	sr_err("Error opening channel %s", ch->name);
	312	dev_acquisition_close(sdi);
	313	return SR_ERR;
	314	}
	315	}
	316
	317	return 0;
	318	}
	319
	320	static int dev_acquisition_start(const struct sr_dev_inst *sdi)
	321	{
	322	struct dev_context *devc;
	323	struct itimerspec tspec = {
	324	.it_interval = { 0, 0 },
	325	.it_value = { 0, 0 }
	326	};
	327
	328	if (sdi->status != SR_ST_ACTIVE)
	329	return SR_ERR_DEV_CLOSED;
	330
	331	if (dev_acquisition_open(sdi))
	332	return SR_ERR;
	333
	334	devc = sdi->priv;
	335	devc->samples_missed = 0;
	336	devc->timer_fd = timerfd_create(CLOCK_MONOTONIC, 0);
	337	if (devc->timer_fd < 0) {
	338	sr_err("Error creating timer fd");
	339	return SR_ERR;
	340	}
	341
	342	tspec.it_interval.tv_sec = 0;
	343	tspec.it_interval.tv_nsec = SR_HZ_TO_NS(devc->samplerate);
	344	tspec.it_value = tspec.it_interval;
	345
	346	if (timerfd_settime(devc->timer_fd, 0, &tspec, NULL)) {
	347	sr_err("Failed to set timer");
	348	close(devc->timer_fd);
	349	return SR_ERR;
	350	}
	351
	352	devc->channel = g_io_channel_unix_new(devc->timer_fd);
	353	g_io_channel_set_flags(devc->channel, G_IO_FLAG_NONBLOCK, NULL);
	354	g_io_channel_set_encoding(devc->channel, NULL, NULL);
	355	g_io_channel_set_buffered(devc->channel, FALSE);
	356
	357	sr_session_source_add_channel(sdi->session, devc->channel,
	358	G_IO_IN \| G_IO_ERR, 1000, bl_acme_receive_data, (void *)sdi);
	359
	360	std_session_send_df_header(sdi, LOG_PREFIX);
	361	sr_sw_limits_acquisition_start(&devc->limits);
	362
	363	return SR_OK;
	364	}
	365
	366	static int dev_acquisition_stop(struct sr_dev_inst *sdi)
	367	{
	368	struct dev_context *devc;
	369
	370	devc = sdi->priv;
	371
	372	if (sdi->status != SR_ST_ACTIVE)
	373	return SR_ERR_DEV_CLOSED;
	374
	375	dev_acquisition_close(sdi);
	376	sr_session_source_remove_channel(sdi->session, devc->channel);
	377	g_io_channel_shutdown(devc->channel, FALSE, NULL);
	378	g_io_channel_unref(devc->channel);
	379	devc->channel = NULL;
	380
	381	std_session_send_df_end(sdi, LOG_PREFIX);
	382
	383	if (devc->samples_missed > 0)
	384	sr_warn("%" PRIu64 " samples missed", devc->samples_missed);
	385
	386	return SR_OK;
	387	}
	388
	389	static struct sr_dev_driver baylibre_acme_driver_info = {
	390	.name = "baylibre-acme",
	391	.longname = "BayLibre ACME (Another Cute Measurement Equipment)",
	392	.api_version = 1,
	393	.init = std_init,
	394	.cleanup = std_cleanup,
	395	.scan = scan,
	396	.dev_list = std_dev_list,
	397	.config_get = config_get,
	398	.config_set = config_set,
	399	.config_list = config_list,
	400	.dev_open = dev_open,
	401	.dev_close = dev_close,
	402	.dev_acquisition_start = dev_acquisition_start,
	403	.dev_acquisition_stop = dev_acquisition_stop,
	404	.context = NULL,
	405	};
	406	SR_REGISTER_DEV_DRIVER(baylibre_acme_driver_info);