[libsigrok.git] / hardware / alsa / api.c

/*
 * This file is part of the libsigrok project.
 *
 * Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.com>
 * Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
 */

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"
#include "protocol.h"

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

static const char *probe_names[] = {
	"Channel 0", "Channel 1",
	NULL,
};

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

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

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

	g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
	drvc->instances = NULL;

	return SR_OK;
}

static int hw_init(struct sr_context *sr_ctx)
{
	struct drv_context *drvc;

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

	drvc->sr_ctx = sr_ctx;
	di->priv = drvc;

	return SR_OK;
}

static GSList *hw_scan(GSList *options)
{
	return alsa_scan(options, di);
}

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;
	int ret;

	devc = sdi->priv;

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

	sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
	ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
			   SND_PCM_STREAM_CAPTURE, 0);
	if (ret < 0) {
		sr_err("Can't open audio device: %s.", snd_strerror(ret));
		return SR_ERR;
	}

	sr_dbg("Initializing hardware parameter structure.");
	ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
	if (ret < 0) {
		sr_err("Can't initialize hardware parameter structure: %s.",
		       snd_strerror(ret));
		return SR_ERR;
	}

	return SR_OK;
}

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

	devc = sdi->priv;

	sr_dbg("Closing device.");

	if (devc->capture_handle) {
		sr_dbg("Closing PCM device.");
		if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
			sr_err("Failed to close device: %s.",
			       snd_strerror(ret));
			devc->capture_handle = NULL;
		}
	} else {
		sr_dbg("No capture handle, no need to close audio device.");
	}

	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)
{
	struct dev_context *devc;

	if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
		devc = sdi->priv;

	switch (info_id) {
	case SR_DI_HWCAPS:
		*data = hwcaps;
		break;
	case SR_DI_NUM_PROBES:
		*data = &devc->num_probes;
		break;
	case SR_DI_PROBE_NAMES:
		*data = probe_names;
		break;
	case SR_DI_CUR_SAMPLERATE:
		*data = &devc->cur_samplerate;
		break;
	case SR_DI_SAMPLERATES:
		if (!devc->supp_rates.list) {
			sr_err("Instance did not contain a samplerate list.");
			return SR_ERR_ARG;
		}
		*data = &devc->supp_rates;
		break;
	default:
		sr_err("Invalid info_id: %d.", info_id);
		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;

	devc = sdi->priv;

	switch (hwcap) {
	case SR_HWCAP_SAMPLERATE:
		alsa_set_samplerate(sdi, *(const uint64_t *)value);
		break;
	case SR_HWCAP_LIMIT_SAMPLES:
		devc->limit_samples = *(const uint64_t *)value;
		break;
	default:
		sr_err("Unknown capability: %d.", hwcap);
		return SR_ERR;
	}

	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;
	int count, ret;
	char *endianness;

	devc = sdi->priv;
	devc->cb_data = cb_data;
	devc->num_samples = 0;

	sr_dbg("Setting audio access type to RW/interleaved.");
	ret = snd_pcm_hw_params_set_access(devc->capture_handle,
			devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
	if (ret < 0) {
		sr_err("Can't set audio access type: %s.", snd_strerror(ret));
		return SR_ERR;
	}

	/* FIXME: Hardcoded for 16bits. */
	if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
		endianness = "little endian";
	else
		endianness = "big endian";
	sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
	ret = snd_pcm_hw_params_set_format(devc->capture_handle,
					   devc->hw_params,
					   SND_PCM_FORMAT_S16);
	if (ret < 0) {
		sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
		return SR_ERR;
	}

	sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
	       devc->cur_samplerate);
	ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
					 (unsigned int)devc->cur_samplerate, 0);
	if (ret < 0) {
		sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
		return SR_ERR;
	}

	sr_dbg("Setting audio channel count to %d.", devc->num_probes);
	ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
					     devc->hw_params, devc->num_probes);
	if (ret < 0) {
		sr_err("Can't set channel count: %s.", snd_strerror(ret));
		return SR_ERR;
	}

	sr_dbg("Setting audio parameters.");
	ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
	if (ret < 0) {
		sr_err("Can't set parameters: %s.", snd_strerror(ret));
		return SR_ERR;
	}

	sr_dbg("Preparing audio interface for use.");
	ret = snd_pcm_prepare(devc->capture_handle);
	if (ret < 0) {
		sr_err("Can't prepare audio interface for use: %s.",
		       snd_strerror(ret));
		return SR_ERR;
	}

	count = snd_pcm_poll_descriptors_count(devc->capture_handle);
	if (count < 1) {
		sr_err("Unable to obtain poll descriptors count.");
		return SR_ERR;
	}

	if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
		sr_err("Failed to malloc ufds.");
		return SR_ERR_MALLOC;
	}

	sr_err("Getting %d poll descriptors.", count);
	ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
	if (ret < 0) {
		sr_err("Unable to obtain poll descriptors: %s.",
		       snd_strerror(ret));
		g_free(devc->ufds);
		return SR_ERR;
	}

	/* Send header packet to the session bus. */
	sr_dbg("Sending SR_DF_HEADER packet.");
	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.");
	packet.type = SR_DF_META_ANALOG;
	packet.payload = &meta;
	meta.num_probes = devc->num_probes;
	sr_session_send(devc->cb_data, &packet);

	/* Poll every 10ms, or whenever some data comes in. */
	sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
		      alsa_receive_data, (void *)sdi);

	// g_free(devc->ufds); /* FIXME */

	return SR_OK;
}

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

	devc = sdi->priv;
	devc->cb_data = cb_data;

	sr_source_remove(devc->ufds[0].fd);

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

	return SR_OK;
}

SR_PRIV struct sr_dev_driver alsa_driver_info = {
	.name = "alsa",
	.longname = "ALSA driver",
	.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
6ed4f044	1	/*
6944b2d0	2	* This file is part of the libsigrok project.
6ed4f044 DR	3	*
6ed4f044 DR	4	* Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.com>
0254651d	5	* Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
6944b2d0	6	* Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
6ed4f044 DR	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	21	*/
	22
9cd9f6b7 AG	23	#include <stdlib.h>
	24	#include <unistd.h>
	25	#include <string.h>
721ecf3d UH	26	#include "libsigrok.h"
	27	#include "libsigrok-internal.h"
	28	#include "protocol.h"
472bbb46	29
915f7cc8	30	static const int hwcaps[] = {
5a2326a7 UH	31	SR_HWCAP_SAMPLERATE,
	32	SR_HWCAP_LIMIT_SAMPLES,
	33	SR_HWCAP_CONTINUOUS,
0254651d	34	0,
6ed4f044 DR	35	};
6ed4f044 DR	36
0254651d	37	static const char *probe_names[] = {
78693401	38	"Channel 0", "Channel 1",
464d12c7 KS	39	NULL,
	40	};
	41
0254651d UH	42	SR_PRIV struct sr_dev_driver alsa_driver_info;
0254651d UH	43	static struct sr_dev_driver *di = &alsa_driver_info;
6ed4f044	44
0254651d UH	45	static int clear_instances(void)
0254651d UH	46	{
6944b2d0 AG	47	struct drv_context *drvc;
	48
	49	if (!(drvc = di->priv))
	50	return SR_OK;
	51
	52	g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
	53	drvc->instances = NULL;
0254651d UH	54
	55	return SR_OK;
	56	}
	57
34f06b90	58	static int hw_init(struct sr_context *sr_ctx)
6ed4f044	59	{
0254651d	60	struct drv_context *drvc;
6ed4f044	61
0254651d UH	62	if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
0254651d UH	63	sr_err("Driver context malloc failed.");
886a52b6	64	return SR_ERR_MALLOC;
92b3101c	65	}
6ed4f044	66
0254651d UH	67	drvc->sr_ctx = sr_ctx;
	68	di->priv = drvc;
	69
	70	return SR_OK;
	71	}
	72
	73	static GSList hw_scan(GSList options)
	74	{
6944b2d0	75	return alsa_scan(options, di);
6ed4f044 DR	76	}
6ed4f044 DR	77
0254651d	78	static GSList *hw_dev_list(void)
6ed4f044	79	{
0254651d UH	80	struct drv_context *drvc;
	81
	82	drvc = di->priv;
	83
	84	return drvc->instances;
	85	}
	86
	87	static int hw_dev_open(struct sr_dev_inst *sdi)
	88	{
	89	struct dev_context *devc;
ebc34738	90	int ret;
6ed4f044	91
0254651d	92	devc = sdi->priv;
6ed4f044	93
6944b2d0 AG	94	if (!(devc->hwdev)) {
	95	sr_err("devc->hwdev was NULL.");
	96	return SR_ERR_BUG;
	97	}
	98
	99	sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
	100	ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
ea9cfed7	101	SND_PCM_STREAM_CAPTURE, 0);
ebc34738	102	if (ret < 0) {
0254651d	103	sr_err("Can't open audio device: %s.", snd_strerror(ret));
e46b8fb1	104	return SR_ERR;
6ed4f044 DR	105	}
6ed4f044 DR	106
0254651d UH	107	sr_dbg("Initializing hardware parameter structure.");
0254651d UH	108	ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
ebc34738	109	if (ret < 0) {
0254651d	110	sr_err("Can't initialize hardware parameter structure: %s.",
472bbb46	111	snd_strerror(ret));
e46b8fb1	112	return SR_ERR;
6ed4f044 DR	113	}
6ed4f044 DR	114
e46b8fb1	115	return SR_OK;
6ed4f044 DR	116	}
6ed4f044 DR	117
0254651d	118	static int hw_dev_close(struct sr_dev_inst *sdi)
6ed4f044	119	{
0254651d UH	120	int ret;
0254651d UH	121	struct dev_context *devc;
6ed4f044	122
0254651d UH	123	devc = sdi->priv;
	124
	125	sr_dbg("Closing device.");
6ed4f044	126
0254651d UH	127	if (devc->capture_handle) {
	128	sr_dbg("Closing PCM device.");
	129	if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
	130	sr_err("Failed to close device: %s.",
	131	snd_strerror(ret));
6944b2d0	132	devc->capture_handle = NULL;
0254651d UH	133	}
	134	} else {
	135	sr_dbg("No capture handle, no need to close audio device.");
	136	}
697785d1 UH	137
697785d1 UH	138	return SR_OK;
6ed4f044 DR	139	}
6ed4f044 DR	140
57ab7d9f	141	static int hw_cleanup(void)
6ed4f044	142	{
0254651d	143	clear_instances();
57ab7d9f UH	144
57ab7d9f UH	145	return SR_OK;
6ed4f044 DR	146	}
6ed4f044 DR	147
0254651d UH	148	static int hw_info_get(int info_id, const void **data,
0254651d UH	149	const struct sr_dev_inst *sdi)
6ed4f044	150	{
0254651d	151	struct dev_context *devc;
6ed4f044	152
0254651d UH	153	if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
0254651d UH	154	devc = sdi->priv;
6ed4f044	155
0254651d UH	156	switch (info_id) {
	157	case SR_DI_HWCAPS:
	158	*data = hwcaps;
6ed4f044	159	break;
5a2326a7	160	case SR_DI_NUM_PROBES:
6944b2d0	161	*data = &devc->num_probes;
6ed4f044	162	break;
464d12c7	163	case SR_DI_PROBE_NAMES:
0254651d	164	*data = probe_names;
464d12c7	165	break;
5a2326a7	166	case SR_DI_CUR_SAMPLERATE:
0254651d	167	*data = &devc->cur_samplerate;
6ed4f044	168	break;
65faa197 AG	169	case SR_DI_SAMPLERATES:
65faa197 AG	170	if (!devc->supp_rates.list) {
721ecf3d	171	sr_err("Instance did not contain a samplerate list.");
65faa197 AG	172	return SR_ERR_ARG;
	173	}
	174	*data = &devc->supp_rates;
	175	break;
0254651d UH	176	default:
	177	sr_err("Invalid info_id: %d.", info_id);
	178	return SR_ERR_ARG;
6ed4f044 DR	179	}
6ed4f044 DR	180
0254651d	181	return SR_OK;
6ed4f044 DR	182	}
6ed4f044 DR	183
0254651d UH	184	static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
0254651d UH	185	const void *value)
6ed4f044	186	{
0254651d	187	struct dev_context *devc;
6ed4f044	188
0254651d	189	devc = sdi->priv;
6ed4f044	190
ffedd0bf	191	switch (hwcap) {
5a2326a7	192	case SR_HWCAP_SAMPLERATE:
65faa197	193	alsa_set_samplerate(sdi, (const uint64_t )value);
0254651d	194	break;
5a2326a7	195	case SR_HWCAP_LIMIT_SAMPLES:
0254651d UH	196	devc->limit_samples = (const uint64_t )value;
0254651d UH	197	break;
6ed4f044	198	default:
0254651d	199	sr_err("Unknown capability: %d.", hwcap);
e46b8fb1	200	return SR_ERR;
6ed4f044	201	}
0254651d UH	202
0254651d UH	203	return SR_OK;
6ed4f044 DR	204	}
6ed4f044 DR	205
0254651d UH	206	static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
0254651d UH	207	void *cb_data)
6ed4f044	208	{
b9c735a2 UH	209	struct sr_datafeed_packet packet;
b9c735a2 UH	210	struct sr_datafeed_header header;
0254651d UH	211	struct sr_datafeed_meta_analog meta;
	212	struct dev_context *devc;
	213	int count, ret;
721ecf3d	214	char *endianness;
6ed4f044	215
0254651d UH	216	devc = sdi->priv;
0254651d UH	217	devc->cb_data = cb_data;
729850c9	218	devc->num_samples = 0;
6ed4f044	219
0254651d UH	220	sr_dbg("Setting audio access type to RW/interleaved.");
	221	ret = snd_pcm_hw_params_set_access(devc->capture_handle,
	222	devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
ebc34738	223	if (ret < 0) {
0254651d	224	sr_err("Can't set audio access type: %s.", snd_strerror(ret));
e46b8fb1	225	return SR_ERR;
6ed4f044 DR	226	}
6ed4f044 DR	227
0254651d	228	/* FIXME: Hardcoded for 16bits. */
729850c9	229	if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
721ecf3d	230	endianness = "little endian";
729850c9	231	else
721ecf3d UH	232	endianness = "big endian";
721ecf3d UH	233	sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
0254651d	234	ret = snd_pcm_hw_params_set_format(devc->capture_handle,
729850c9 AG	235	devc->hw_params,
729850c9 AG	236	SND_PCM_FORMAT_S16);
ebc34738	237	if (ret < 0) {
0254651d	238	sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
e46b8fb1	239	return SR_ERR;
6ed4f044 DR	240	}
6ed4f044 DR	241
0254651d UH	242	sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
0254651d UH	243	devc->cur_samplerate);
0d6ff103 AG	244	ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
0d6ff103 AG	245	(unsigned int)devc->cur_samplerate, 0);
ebc34738	246	if (ret < 0) {
0254651d	247	sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
e46b8fb1	248	return SR_ERR;
6ed4f044 DR	249	}
6ed4f044 DR	250
9cd9f6b7	251	sr_dbg("Setting audio channel count to %d.", devc->num_probes);
0254651d	252	ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
9cd9f6b7	253	devc->hw_params, devc->num_probes);
ebc34738	254	if (ret < 0) {
0254651d	255	sr_err("Can't set channel count: %s.", snd_strerror(ret));
e46b8fb1	256	return SR_ERR;
6ed4f044 DR	257	}
6ed4f044 DR	258
0254651d UH	259	sr_dbg("Setting audio parameters.");
0254651d UH	260	ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
ebc34738	261	if (ret < 0) {
0254651d	262	sr_err("Can't set parameters: %s.", snd_strerror(ret));
e46b8fb1	263	return SR_ERR;
6ed4f044 DR	264	}
6ed4f044 DR	265
0254651d UH	266	sr_dbg("Preparing audio interface for use.");
0254651d UH	267	ret = snd_pcm_prepare(devc->capture_handle);
ebc34738	268	if (ret < 0) {
0254651d	269	sr_err("Can't prepare audio interface for use: %s.",
ebc34738	270	snd_strerror(ret));
e46b8fb1	271	return SR_ERR;
6ed4f044 DR	272	}
6ed4f044 DR	273
0254651d	274	count = snd_pcm_poll_descriptors_count(devc->capture_handle);
6ed4f044	275	if (count < 1) {
472bbb46	276	sr_err("Unable to obtain poll descriptors count.");
e46b8fb1	277	return SR_ERR;
6ed4f044 DR	278	}
6ed4f044 DR	279
0254651d UH	280	if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
0254651d UH	281	sr_err("Failed to malloc ufds.");
e46b8fb1	282	return SR_ERR_MALLOC;
92b3101c	283	}
6ed4f044	284
0254651d UH	285	sr_err("Getting %d poll descriptors.", count);
0254651d UH	286	ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
ebc34738	287	if (ret < 0) {
0254651d	288	sr_err("Unable to obtain poll descriptors: %s.",
ebc34738	289	snd_strerror(ret));
0254651d	290	g_free(devc->ufds);
e46b8fb1	291	return SR_ERR;
6ed4f044 DR	292	}
6ed4f044 DR	293
0254651d UH	294	/* Send header packet to the session bus. */
0254651d UH	295	sr_dbg("Sending SR_DF_HEADER packet.");
5a2326a7	296	packet.type = SR_DF_HEADER;
0254651d	297	packet.payload = (uint8_t *)&header;
6ed4f044 DR	298	header.feed_version = 1;
6ed4f044 DR	299	gettimeofday(&header.starttime, NULL);
0254651d UH	300	sr_session_send(devc->cb_data, &packet);
	301
	302	/* Send metadata about the SR_DF_ANALOG packets to come. */
	303	sr_dbg("Sending SR_DF_META_ANALOG packet.");
	304	packet.type = SR_DF_META_ANALOG;
	305	packet.payload = &meta;
9cd9f6b7	306	meta.num_probes = devc->num_probes;
0254651d UH	307	sr_session_send(devc->cb_data, &packet);
	308
	309	/* Poll every 10ms, or whenever some data comes in. */
	310	sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
9cd9f6b7	311	alsa_receive_data, (void *)sdi);
0254651d UH	312
0254651d UH	313	// g_free(devc->ufds); /* FIXME */
6ed4f044	314
e46b8fb1	315	return SR_OK;
6ed4f044 DR	316	}
6ed4f044 DR	317
0254651d	318	static int hw_dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data)
6ed4f044	319	{
0254651d UH	320	struct sr_datafeed_packet packet;
	321	struct dev_context *devc;
	322
	323	devc = sdi->priv;
	324	devc->cb_data = cb_data;
	325
	326	sr_source_remove(devc->ufds[0].fd);
	327
	328	/* Send end packet to the session bus. */
	329	sr_dbg("Sending SR_DF_END packet.");
	330	packet.type = SR_DF_END;
	331	sr_session_send(cb_data, &packet);
3010f21c UH	332
3010f21c UH	333	return SR_OK;
6ed4f044 DR	334	}
6ed4f044 DR	335
c09f0b57	336	SR_PRIV struct sr_dev_driver alsa_driver_info = {
e519ba86 UH	337	.name = "alsa",
	338	.longname = "ALSA driver",
	339	.api_version = 1,
	340	.init = hw_init,
	341	.cleanup = hw_cleanup,
0254651d UH	342	.scan = hw_scan,
	343	.dev_list = hw_dev_list,
	344	.dev_clear = clear_instances,
e7eb703f UH	345	.dev_open = hw_dev_open,
e7eb703f UH	346	.dev_close = hw_dev_close,
0254651d	347	.info_get = hw_info_get,
a9a245b4	348	.dev_config_set = hw_dev_config_set,
69040b7c UH	349	.dev_acquisition_start = hw_dev_acquisition_start,
69040b7c UH	350	.dev_acquisition_stop = hw_dev_acquisition_stop,
0254651d	351	.priv = NULL,
6ed4f044	352	};