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

/*
 * This file is part of the sigrok project.
 *
 * Copyright (C) 2011 Daniel Ribeiro <drwyrm@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 <sigrok.h>
#include <alsa/asoundlib.h>
#include "config.h"

#define NUM_PROBES 2
#define SAMPLE_WIDTH 16
#define AUDIO_DEV "plughw:0,0"

static int capabilities[] = {
	SR_HWCAP_SAMPLERATE,
	SR_HWCAP_LIMIT_SAMPLES,
	SR_HWCAP_CONTINUOUS,
};

static GSList *device_instances = NULL;

struct alsa {
	uint64_t cur_rate;
	uint64_t limit_samples;
	snd_pcm_t *capture_handle;
	snd_pcm_hw_params_t *hw_params;
	gpointer session_id;
};

static int hw_init(const char *deviceinfo)
{
	struct sr_device_instance *sdi;
	struct alsa *alsa;

	/* Avoid compiler warnings. */
	deviceinfo = deviceinfo;

	alsa = malloc(sizeof(struct alsa));
	if (!alsa)
		return 0;
	memset(alsa, 0, sizeof(struct alsa));

	sdi = sr_device_instance_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL);
	if (!sdi)
		goto free_alsa;

	sdi->priv = alsa;

	device_instances = g_slist_append(device_instances, sdi);

	return 1;
free_alsa:
	free(alsa);
	return 0;
}

static int hw_opendev(int device_index)
{
	struct sr_device_instance *sdi;
	struct alsa *alsa;
	int err;

	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
		return SR_ERR;
	alsa = sdi->priv;

	err = snd_pcm_open(&alsa->capture_handle, AUDIO_DEV,
					SND_PCM_STREAM_CAPTURE, 0);
	if (err < 0) {
		sr_warn("cannot open audio device %s (%s)", AUDIO_DEV,
				snd_strerror(err));
		return SR_ERR;
	}

	err = snd_pcm_hw_params_malloc(&alsa->hw_params);
	if (err < 0) {
		sr_warn("cannot allocate hardware parameter structure (%s)",
				snd_strerror(err));
		return SR_ERR;
	}

	err = snd_pcm_hw_params_any(alsa->capture_handle, alsa->hw_params);
	if (err < 0) {
		sr_warn("cannot initialize hardware parameter structure (%s)",
				snd_strerror(err));
		return SR_ERR;
	}

	return SR_OK;
}

static void hw_closedev(int device_index)
{
	struct sr_device_instance *sdi;
	struct alsa *alsa;

	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
		return;
	alsa = sdi->priv;
	if (!alsa)
		return;

	if (alsa->hw_params)
		snd_pcm_hw_params_free(alsa->hw_params);
	if (alsa->capture_handle)
		snd_pcm_close(alsa->capture_handle);
}

static void hw_cleanup(void)
{
	struct sr_device_instance *sdi;

	if (!(sdi = sr_get_device_instance(device_instances, 0)))
		return;

	free(sdi->priv);
	sr_device_instance_free(sdi);
}

static void *hw_get_device_info(int device_index, int device_info_id)
{
	struct sr_device_instance *sdi;
	struct alsa *alsa;
	void *info = NULL;

	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
		return NULL;
	alsa = sdi->priv;

	switch (device_info_id) {
	case SR_DI_INSTANCE:
		info = sdi;
		break;
	case SR_DI_NUM_PROBES:
		info = GINT_TO_POINTER(NUM_PROBES);
		break;
	case SR_DI_CUR_SAMPLERATE:
		info = &alsa->cur_rate;
		break;
	// case SR_DI_PROBE_TYPE:
	// 	info = GINT_TO_POINTER(SR_PROBE_TYPE_ANALOG);
	// 	break;
	}

	return info;
}

static int hw_get_status(int device_index)
{
	/* Avoid compiler warnings. */
	device_index = device_index;

	return SR_ST_ACTIVE;
}

static int *hw_get_capabilities(void)
{
	return capabilities;
}

static int hw_set_configuration(int device_index, int capability, void *value)
{
	struct sr_device_instance *sdi;
	struct alsa *alsa;

	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
		return SR_ERR;
	alsa = sdi->priv;

	switch (capability) {
	case SR_HWCAP_PROBECONFIG:
		return SR_OK;
	case SR_HWCAP_SAMPLERATE:
		alsa->cur_rate = *(uint64_t *) value;
		return SR_OK;
	case SR_HWCAP_LIMIT_SAMPLES:
		alsa->limit_samples = *(uint64_t *) value;
		return SR_OK;
	default:
		return SR_ERR;
	}
}

static int receive_data(int fd, int revents, void *user_data)
{
	struct sr_device_instance *sdi = user_data;
	struct alsa *alsa = sdi->priv;
	struct sr_datafeed_packet packet;
	struct sr_analog_sample *sample;
	unsigned int sample_size = sizeof(struct sr_analog_sample) +
		(NUM_PROBES * sizeof(struct sr_analog_probe));
	char *outb;
	char inb[4096];
	int i, x, count;

	fd = fd;
	revents = revents;

	do {
		memset(inb, 0, sizeof(inb));
		count = snd_pcm_readi(alsa->capture_handle, inb,
			MIN(4096/4, alsa->limit_samples));
		if (count < 1) {
			sr_warn("Failed to read samples");
			return FALSE;
		}

		outb = malloc(sample_size * count);
		if (!outb)
			return FALSE;

		for (i = 0; i < count; i++) {
			sample = (struct sr_analog_sample *)
						(outb + (i * sample_size));
			sample->num_probes = NUM_PROBES;

			for (x = 0; x < NUM_PROBES; x++) {
				sample->probes[x].val =
					*(uint16_t *) (inb + (i * 4) + (x * 2));
				sample->probes[x].val &= ((1 << 16) - 1);
				sample->probes[x].res = 16;
			}
		}

		packet.type = SR_DF_ANALOG;
		packet.length = count * sample_size;
		packet.unitsize = sample_size;
		packet.payload = outb;
		sr_session_bus(user_data, &packet);
		free(outb);
		alsa->limit_samples -= count;

	} while (alsa->limit_samples > 0);

	packet.type = SR_DF_END;
	sr_session_bus(user_data, &packet);

	return TRUE;
}

static int hw_start_acquisition(int device_index, gpointer session_device_id)
{
	struct sr_device_instance *sdi;
	struct alsa *alsa;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_header header;
	struct pollfd *ufds;
	int count;
	int err;

	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
		return SR_ERR;
	alsa = sdi->priv;

	err = snd_pcm_hw_params_set_access(alsa->capture_handle,
			alsa->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
	if (err < 0) {
		sr_warn("cannot set access type (%s)", snd_strerror(err));
		return SR_ERR;
	}

	/* FIXME: Hardcoded for 16bits */
	err = snd_pcm_hw_params_set_format(alsa->capture_handle,
			alsa->hw_params, SND_PCM_FORMAT_S16_LE);
	if (err < 0) {
		sr_warn("cannot set sample format (%s)", snd_strerror(err));
		return SR_ERR;
	}

	err = snd_pcm_hw_params_set_rate_near(alsa->capture_handle,
			alsa->hw_params, (unsigned int *) &alsa->cur_rate, 0);
	if (err < 0) {
		sr_warn("cannot set sample rate (%s)", snd_strerror(err));
		return SR_ERR;
	}

	err = snd_pcm_hw_params_set_channels(alsa->capture_handle,
			alsa->hw_params, NUM_PROBES);
	if (err < 0) {
		sr_warn("cannot set channel count (%s)", snd_strerror(err));
		return SR_ERR;
	}

	err = snd_pcm_hw_params(alsa->capture_handle, alsa->hw_params);
	if (err < 0) {
		sr_warn("cannot set parameters (%s)", snd_strerror(err));
		return SR_ERR;
	}

	err = snd_pcm_prepare(alsa->capture_handle);
	if (err < 0) {
		sr_warn("cannot prepare audio interface for use (%s)",
				snd_strerror(err));
		return SR_ERR;
	}

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

	ufds = malloc(count * sizeof(struct pollfd));
	if (!ufds)
		return SR_ERR_MALLOC;

	err = snd_pcm_poll_descriptors(alsa->capture_handle, ufds, count);
	if (err < 0) {
		sr_warn("Unable to obtain poll descriptors (%s)",
				snd_strerror(err));
		free(ufds);
		return SR_ERR;
	}

	alsa->session_id = session_device_id;
	sr_source_add(ufds[0].fd, ufds[0].events, 10, receive_data, sdi);

	packet.type = SR_DF_HEADER;
	packet.length = sizeof(struct sr_datafeed_header);
	packet.payload = (unsigned char *) &header;
	header.feed_version = 1;
	gettimeofday(&header.starttime, NULL);
	header.samplerate = alsa->cur_rate;
	header.num_analog_probes = NUM_PROBES;
	header.num_logic_probes = 0;
	header.protocol_id = SR_PROTO_RAW;
	sr_session_bus(session_device_id, &packet);
	free(ufds);

	return SR_OK;
}

static void hw_stop_acquisition(int device_index, gpointer session_device_id)
{
	/* Avoid compiler warnings. */
	device_index = device_index;
	session_device_id = session_device_id;
}

struct sr_device_plugin alsa_plugin_info = {
	"alsa",
	"ALSA driver",
	1,
	hw_init,
	hw_cleanup,
	hw_opendev,
	hw_closedev,
	hw_get_device_info,
	hw_get_status,
	hw_get_capabilities,
	hw_set_configuration,
	hw_start_acquisition,
	hw_stop_acquisition,
};
Commit	Line	Data
6ed4f044 DR	1	/*
	2	* This file is part of the sigrok project.
	3	*
	4	* Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.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 2 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, write to the Free Software
	18	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
	21	#include <stdlib.h>
	22	#include <unistd.h>
	23	#include <string.h>
	24	#include <sigrok.h>
	25	#include <alsa/asoundlib.h>
	26	#include "config.h"
	27
	28	#define NUM_PROBES 2
	29	#define SAMPLE_WIDTH 16
	30	#define AUDIO_DEV "plughw:0,0"
	31
	32	static int capabilities[] = {
5a2326a7 UH	33	SR_HWCAP_SAMPLERATE,
	34	SR_HWCAP_LIMIT_SAMPLES,
	35	SR_HWCAP_CONTINUOUS,
6ed4f044 DR	36	};
	37
	38	static GSList *device_instances = NULL;
	39
	40	struct alsa {
	41	uint64_t cur_rate;
	42	uint64_t limit_samples;
	43	snd_pcm_t *capture_handle;
	44	snd_pcm_hw_params_t *hw_params;
	45	gpointer session_id;
	46	};
	47
54ac5277	48	static int hw_init(const char *deviceinfo)
6ed4f044	49	{
a00ba012	50	struct sr_device_instance *sdi;
6ed4f044 DR	51	struct alsa *alsa;
	52
	53	/* Avoid compiler warnings. */
	54	deviceinfo = deviceinfo;
	55
	56	alsa = malloc(sizeof(struct alsa));
	57	if (!alsa)
	58	return 0;
	59	memset(alsa, 0, sizeof(struct alsa));
	60
5a2326a7	61	sdi = sr_device_instance_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL);
6ed4f044 DR	62	if (!sdi)
	63	goto free_alsa;
	64
	65	sdi->priv = alsa;
	66
	67	device_instances = g_slist_append(device_instances, sdi);
	68
	69	return 1;
	70	free_alsa:
	71	free(alsa);
	72	return 0;
	73	}
	74
	75	static int hw_opendev(int device_index)
	76	{
a00ba012	77	struct sr_device_instance *sdi;
6ed4f044 DR	78	struct alsa *alsa;
	79	int err;
	80
d32d961d	81	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
e46b8fb1	82	return SR_ERR;
6ed4f044 DR	83	alsa = sdi->priv;
	84
	85	err = snd_pcm_open(&alsa->capture_handle, AUDIO_DEV,
	86	SND_PCM_STREAM_CAPTURE, 0);
	87	if (err < 0) {
b08024a8	88	sr_warn("cannot open audio device %s (%s)", AUDIO_DEV,
6ed4f044	89	snd_strerror(err));
e46b8fb1	90	return SR_ERR;
6ed4f044 DR	91	}
	92
	93	err = snd_pcm_hw_params_malloc(&alsa->hw_params);
	94	if (err < 0) {
b08024a8	95	sr_warn("cannot allocate hardware parameter structure (%s)",
6ed4f044	96	snd_strerror(err));
e46b8fb1	97	return SR_ERR;
6ed4f044 DR	98	}
	99
	100	err = snd_pcm_hw_params_any(alsa->capture_handle, alsa->hw_params);
	101	if (err < 0) {
b08024a8	102	sr_warn("cannot initialize hardware parameter structure (%s)",
6ed4f044	103	snd_strerror(err));
e46b8fb1	104	return SR_ERR;
6ed4f044 DR	105	}
6ed4f044 DR	106
e46b8fb1	107	return SR_OK;
6ed4f044 DR	108	}
	109
	110	static void hw_closedev(int device_index)
	111	{
a00ba012	112	struct sr_device_instance *sdi;
6ed4f044 DR	113	struct alsa *alsa;
6ed4f044 DR	114
d32d961d	115	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
6ed4f044 DR	116	return;
	117	alsa = sdi->priv;
	118	if (!alsa)
	119	return;
	120
	121	if (alsa->hw_params)
	122	snd_pcm_hw_params_free(alsa->hw_params);
	123	if (alsa->capture_handle)
	124	snd_pcm_close(alsa->capture_handle);
	125	}
	126
	127	static void hw_cleanup(void)
	128	{
a00ba012	129	struct sr_device_instance *sdi;
6ed4f044	130
d32d961d	131	if (!(sdi = sr_get_device_instance(device_instances, 0)))
6ed4f044 DR	132	return;
	133
	134	free(sdi->priv);
a00ba012	135	sr_device_instance_free(sdi);
6ed4f044 DR	136	}
	137
	138	static void *hw_get_device_info(int device_index, int device_info_id)
	139	{
a00ba012	140	struct sr_device_instance *sdi;
6ed4f044 DR	141	struct alsa *alsa;
	142	void *info = NULL;
	143
d32d961d	144	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
6ed4f044 DR	145	return NULL;
	146	alsa = sdi->priv;
	147
	148	switch (device_info_id) {
5a2326a7	149	case SR_DI_INSTANCE:
6ed4f044 DR	150	info = sdi;
6ed4f044 DR	151	break;
5a2326a7	152	case SR_DI_NUM_PROBES:
6ed4f044 DR	153	info = GINT_TO_POINTER(NUM_PROBES);
6ed4f044 DR	154	break;
5a2326a7	155	case SR_DI_CUR_SAMPLERATE:
6ed4f044 DR	156	info = &alsa->cur_rate;
6ed4f044 DR	157	break;
5a2326a7 UH	158	// case SR_DI_PROBE_TYPE:
5a2326a7 UH	159	// info = GINT_TO_POINTER(SR_PROBE_TYPE_ANALOG);
da692373	160	// break;
6ed4f044 DR	161	}
	162
	163	return info;
	164	}
	165
	166	static int hw_get_status(int device_index)
	167	{
	168	/* Avoid compiler warnings. */
	169	device_index = device_index;
	170
5a2326a7	171	return SR_ST_ACTIVE;
6ed4f044 DR	172	}
	173
	174	static int *hw_get_capabilities(void)
	175	{
	176	return capabilities;
	177	}
	178
	179	static int hw_set_configuration(int device_index, int capability, void *value)
	180	{
a00ba012	181	struct sr_device_instance *sdi;
6ed4f044 DR	182	struct alsa *alsa;
6ed4f044 DR	183
d32d961d	184	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
e46b8fb1	185	return SR_ERR;
6ed4f044 DR	186	alsa = sdi->priv;
	187
	188	switch (capability) {
5a2326a7	189	case SR_HWCAP_PROBECONFIG:
e46b8fb1	190	return SR_OK;
5a2326a7	191	case SR_HWCAP_SAMPLERATE:
6ed4f044	192	alsa->cur_rate = (uint64_t ) value;
e46b8fb1	193	return SR_OK;
5a2326a7	194	case SR_HWCAP_LIMIT_SAMPLES:
6ed4f044	195	alsa->limit_samples = (uint64_t ) value;
e46b8fb1	196	return SR_OK;
6ed4f044	197	default:
e46b8fb1	198	return SR_ERR;
6ed4f044 DR	199	}
	200	}
	201
6ed4f044 DR	202	static int receive_data(int fd, int revents, void *user_data)
6ed4f044 DR	203	{
a00ba012	204	struct sr_device_instance *sdi = user_data;
6ed4f044	205	struct alsa *alsa = sdi->priv;
b9c735a2	206	struct sr_datafeed_packet packet;
809c5f20 UH	207	struct sr_analog_sample *sample;
	208	unsigned int sample_size = sizeof(struct sr_analog_sample) +
	209	(NUM_PROBES * sizeof(struct sr_analog_probe));
58330ab8 DR	210	char *outb;
	211	char inb[4096];
	212	int i, x, count;
	213
cdbc51d9 DR	214	fd = fd;
	215	revents = revents;
	216
58330ab8 DR	217	do {
	218	memset(inb, 0, sizeof(inb));
	219	count = snd_pcm_readi(alsa->capture_handle, inb,
	220	MIN(4096/4, alsa->limit_samples));
	221	if (count < 1) {
b08024a8	222	sr_warn("Failed to read samples");
58330ab8 DR	223	return FALSE;
58330ab8 DR	224	}
6ed4f044	225
58330ab8 DR	226	outb = malloc(sample_size * count);
58330ab8 DR	227	if (!outb)
6ed4f044	228	return FALSE;
58330ab8 DR	229
58330ab8 DR	230	for (i = 0; i < count; i++) {
809c5f20	231	sample = (struct sr_analog_sample *)
58330ab8 DR	232	(outb + (i * sample_size));
	233	sample->num_probes = NUM_PROBES;
	234
	235	for (x = 0; x < NUM_PROBES; x++) {
	236	sample->probes[x].val =
	237	(uint16_t ) (inb + (i * 4) + (x * 2));
	238	sample->probes[x].val &= ((1 << 16) - 1);
	239	sample->probes[x].res = 16;
	240	}
6ed4f044	241	}
58330ab8	242
5a2326a7	243	packet.type = SR_DF_ANALOG;
58330ab8 DR	244	packet.length = count * sample_size;
	245	packet.unitsize = sample_size;
	246	packet.payload = outb;
8a2efef2	247	sr_session_bus(user_data, &packet);
58330ab8 DR	248	free(outb);
	249	alsa->limit_samples -= count;
	250
	251	} while (alsa->limit_samples > 0);
	252
5a2326a7	253	packet.type = SR_DF_END;
8a2efef2	254	sr_session_bus(user_data, &packet);
6ed4f044 DR	255
	256	return TRUE;
	257	}
	258
	259	static int hw_start_acquisition(int device_index, gpointer session_device_id)
	260	{
a00ba012	261	struct sr_device_instance *sdi;
6ed4f044	262	struct alsa *alsa;
b9c735a2 UH	263	struct sr_datafeed_packet packet;
b9c735a2 UH	264	struct sr_datafeed_header header;
6ed4f044 DR	265	struct pollfd *ufds;
	266	int count;
	267	int err;
	268
d32d961d	269	if (!(sdi = sr_get_device_instance(device_instances, device_index)))
e46b8fb1	270	return SR_ERR;
6ed4f044 DR	271	alsa = sdi->priv;
	272
	273	err = snd_pcm_hw_params_set_access(alsa->capture_handle,
	274	alsa->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
	275	if (err < 0) {
b08024a8	276	sr_warn("cannot set access type (%s)", snd_strerror(err));
e46b8fb1	277	return SR_ERR;
6ed4f044 DR	278	}
	279
	280	/* FIXME: Hardcoded for 16bits */
	281	err = snd_pcm_hw_params_set_format(alsa->capture_handle,
	282	alsa->hw_params, SND_PCM_FORMAT_S16_LE);
	283	if (err < 0) {
b08024a8	284	sr_warn("cannot set sample format (%s)", snd_strerror(err));
e46b8fb1	285	return SR_ERR;
6ed4f044 DR	286	}
	287
	288	err = snd_pcm_hw_params_set_rate_near(alsa->capture_handle,
	289	alsa->hw_params, (unsigned int *) &alsa->cur_rate, 0);
	290	if (err < 0) {
b08024a8	291	sr_warn("cannot set sample rate (%s)", snd_strerror(err));
e46b8fb1	292	return SR_ERR;
6ed4f044 DR	293	}
	294
	295	err = snd_pcm_hw_params_set_channels(alsa->capture_handle,
	296	alsa->hw_params, NUM_PROBES);
	297	if (err < 0) {
b08024a8	298	sr_warn("cannot set channel count (%s)", snd_strerror(err));
e46b8fb1	299	return SR_ERR;
6ed4f044 DR	300	}
	301
	302	err = snd_pcm_hw_params(alsa->capture_handle, alsa->hw_params);
	303	if (err < 0) {
b08024a8	304	sr_warn("cannot set parameters (%s)", snd_strerror(err));
e46b8fb1	305	return SR_ERR;
6ed4f044 DR	306	}
	307
	308	err = snd_pcm_prepare(alsa->capture_handle);
	309	if (err < 0) {
b08024a8	310	sr_warn("cannot prepare audio interface for use (%s)",
6ed4f044	311	snd_strerror(err));
e46b8fb1	312	return SR_ERR;
6ed4f044 DR	313	}
	314
	315	count = snd_pcm_poll_descriptors_count(alsa->capture_handle);
	316	if (count < 1) {
b08024a8	317	sr_warn("Unable to obtain poll descriptors count");
e46b8fb1	318	return SR_ERR;
6ed4f044 DR	319	}
	320
	321	ufds = malloc(count * sizeof(struct pollfd));
	322	if (!ufds)
e46b8fb1	323	return SR_ERR_MALLOC;
6ed4f044 DR	324
	325	err = snd_pcm_poll_descriptors(alsa->capture_handle, ufds, count);
	326	if (err < 0) {
b08024a8	327	sr_warn("Unable to obtain poll descriptors (%s)",
6ed4f044 DR	328	snd_strerror(err));
6ed4f044 DR	329	free(ufds);
e46b8fb1	330	return SR_ERR;
6ed4f044 DR	331	}
	332
	333	alsa->session_id = session_device_id;
6f1be0a2	334	sr_source_add(ufds[0].fd, ufds[0].events, 10, receive_data, sdi);
6ed4f044	335
5a2326a7	336	packet.type = SR_DF_HEADER;
b9c735a2	337	packet.length = sizeof(struct sr_datafeed_header);
6ed4f044 DR	338	packet.payload = (unsigned char *) &header;
	339	header.feed_version = 1;
	340	gettimeofday(&header.starttime, NULL);
	341	header.samplerate = alsa->cur_rate;
	342	header.num_analog_probes = NUM_PROBES;
	343	header.num_logic_probes = 0;
5a2326a7	344	header.protocol_id = SR_PROTO_RAW;
8a2efef2	345	sr_session_bus(session_device_id, &packet);
6ed4f044 DR	346	free(ufds);
6ed4f044 DR	347
e46b8fb1	348	return SR_OK;
6ed4f044 DR	349	}
	350
	351	static void hw_stop_acquisition(int device_index, gpointer session_device_id)
	352	{
	353	/* Avoid compiler warnings. */
	354	device_index = device_index;
	355	session_device_id = session_device_id;
	356	}
	357
5c2d46d1	358	struct sr_device_plugin alsa_plugin_info = {
6ed4f044	359	"alsa",
9f8274a5	360	"ALSA driver",
6ed4f044 DR	361	1,
	362	hw_init,
	363	hw_cleanup,
	364	hw_opendev,
	365	hw_closedev,
	366	hw_get_device_info,
	367	hw_get_status,
	368	hw_get_capabilities,
	369	hw_set_configuration,
	370	hw_start_acquisition,
	371	hw_stop_acquisition,
	372	};