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

/*
 * This file is part of the sigrok project.
 *
 * Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.com>
 * Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
 *
 * 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 <alsa/asoundlib.h>
#include "libsigrok.h"
#include "libsigrok-internal.h"

/* Message logging helpers with driver-specific prefix string. */
#define DRIVER_LOG_DOMAIN "alsa: "
#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)

#define NUM_PROBES		2
#define SAMPLE_WIDTH		16
#define DEFAULT_SAMPLERATE	44100
// #define AUDIO_DEV		"plughw:0,0"
#define AUDIO_DEV		"default"

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;

/** Private, per-device-instance driver context. */
struct dev_context {
	uint64_t cur_samplerate;
	uint64_t limit_samples;
	uint64_t num_samples;
	snd_pcm_t *capture_handle;
	snd_pcm_hw_params_t *hw_params;
	struct pollfd *ufds;
	void *cb_data;
};

static int clear_instances(void)
{
	/* TODO */

	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)
{
	struct drv_context *drvc;
	struct dev_context *devc;
	struct sr_dev_inst *sdi;
	struct sr_probe *probe;
	GSList *devices;
	int i;

	(void)options;

	drvc = di->priv;
	drvc->instances = NULL;

	devices = NULL;

	if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
		sr_err("Device context malloc failed.");
		return NULL;
	}

	if (!(sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL))) {
		sr_err("Failed to create device instance.");
		return NULL;
	}

	/* Set the samplerate to a default value for now. */
	devc->cur_samplerate = DEFAULT_SAMPLERATE;

	sdi->priv = devc;
	sdi->driver = di;

	for (i = 0; probe_names[i]; i++) {
		if (!(probe = sr_probe_new(i, SR_PROBE_ANALOG, TRUE,
					   probe_names[i]))) {
			sr_err("Failed to create probe.");
			return NULL;
		}
		sdi->probes = g_slist_append(sdi->probes, probe);
	}

	drvc->instances = g_slist_append(drvc->instances, sdi);
	devices = g_slist_append(devices, sdi);

	return devices;
}

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;

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

	sr_dbg("Allocating hardware parameter structure.");
	ret = snd_pcm_hw_params_malloc(&devc->hw_params);
	if (ret < 0) {
		sr_err("Can't allocate hardware parameter structure: %s.",
		       snd_strerror(ret));
		return SR_ERR_MALLOC;
	}

	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->hw_params) {
		sr_dbg("Freeing hardware parameters.");
		snd_pcm_hw_params_free(devc->hw_params);
	} else {
		sr_dbg("No hardware parameters, no need to free.");
	}

	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));
		}
	} 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 = GINT_TO_POINTER(NUM_PROBES);
		break;
	case SR_DI_PROBE_NAMES:
		*data = probe_names;
		break;
	case SR_DI_CUR_SAMPLERATE:
		*data = &devc->cur_samplerate;
		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:
		devc->cur_samplerate = *(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 receive_data(int fd, int revents, void *cb_data)
{
	struct sr_dev_inst *sdi;
	struct dev_context *devc;
	struct sr_datafeed_packet packet;
	struct sr_datafeed_analog analog;
	char inbuf[4096];
	int i, x, count, offset, samples_to_get;
	uint16_t tmp16;

	(void)fd;
	(void)revents;

	sdi = cb_data;
	devc = sdi->priv;

	memset(&analog, 0, sizeof(struct sr_datafeed_analog));
	memset(inbuf, 0, sizeof(inbuf));

	samples_to_get = MIN(4096 / 4, devc->limit_samples);

	sr_spew("Getting %d samples from audio device.", samples_to_get);
	count = snd_pcm_readi(devc->capture_handle, inbuf, samples_to_get);

	if (count < 0) {
		sr_err("Failed to read samples: %s.", snd_strerror(count));
		return FALSE;
	} else if (count != samples_to_get) {
		sr_spew("Only got %d/%d samples.", count, samples_to_get);
	}

	analog.data = g_try_malloc0(count * sizeof(float) * NUM_PROBES);
	if (!analog.data) {
		sr_err("Failed to malloc sample buffer.");
		return FALSE;
	}

	offset = 0;

	for (i = 0; i < count; i++) {
		for (x = 0; x < NUM_PROBES; x++) {
			tmp16 = *(uint16_t *)(inbuf + (i * 4) + (x * 2));
			analog.data[offset++] = (float)tmp16;
		}
	}

	/* Send a sample packet with the analog values. */
	analog.num_samples = count;
	analog.mq = SR_MQ_VOLTAGE; /* FIXME */
	analog.unit = SR_UNIT_VOLT; /* FIXME */
	packet.type = SR_DF_ANALOG;
	packet.payload = &analog;
	sr_session_send(devc->cb_data, &packet);

	g_free(analog.data);

	devc->num_samples += count;

	/* Stop acquisition if we acquired enough samples. */
	if (devc->limit_samples > 0) {
		if (devc->num_samples >= devc->limit_samples) {
			sr_info("Requested number of samples reached.");
			sdi->driver->dev_acquisition_stop(sdi, cb_data);
		}
	}

	return TRUE;
}

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;

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

	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. */
	sr_dbg("Setting audio sample format to signed 16bit (little endian).");
	ret = snd_pcm_hw_params_set_format(devc->capture_handle,
			devc->hw_params, SND_PCM_FORMAT_S16_LE);
	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_near(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.", NUM_PROBES);
	ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
					     devc->hw_params, 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;
	}
	sr_spew("Obtained poll descriptor count: %d.", count);

	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 = 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,
		      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
	1	/*
	2	* This file is part of the sigrok project.
	3	*
	4	* Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.com>
	5	* Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2 of the License, or
	10	* (at your option) any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this program; if not, write to the Free Software
	19	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	20	*/
	21
	22	#include <stdlib.h>
	23	#include <unistd.h>
	24	#include <string.h>
	25	#include <alsa/asoundlib.h>
	26	#include "libsigrok.h"
	27	#include "libsigrok-internal.h"
	28
	29	/* Message logging helpers with driver-specific prefix string. */
	30	#define DRIVER_LOG_DOMAIN "alsa: "
	31	#define sr_log(l, s, args...) sr_log(l, DRIVER_LOG_DOMAIN s, ## args)
	32	#define sr_spew(s, args...) sr_spew(DRIVER_LOG_DOMAIN s, ## args)
	33	#define sr_dbg(s, args...) sr_dbg(DRIVER_LOG_DOMAIN s, ## args)
	34	#define sr_info(s, args...) sr_info(DRIVER_LOG_DOMAIN s, ## args)
	35	#define sr_warn(s, args...) sr_warn(DRIVER_LOG_DOMAIN s, ## args)
	36	#define sr_err(s, args...) sr_err(DRIVER_LOG_DOMAIN s, ## args)
	37
	38	#define NUM_PROBES 2
	39	#define SAMPLE_WIDTH 16
	40	#define DEFAULT_SAMPLERATE 44100
	41	// #define AUDIO_DEV "plughw:0,0"
	42	#define AUDIO_DEV "default"
	43
	44	static const int hwcaps[] = {
	45	SR_HWCAP_SAMPLERATE,
	46	SR_HWCAP_LIMIT_SAMPLES,
	47	SR_HWCAP_CONTINUOUS,
	48	0,
	49	};
	50
	51	static const char *probe_names[] = {
	52	"Channel 0",
	53	"Channel 1",
	54	NULL,
	55	};
	56
	57	SR_PRIV struct sr_dev_driver alsa_driver_info;
	58	static struct sr_dev_driver *di = &alsa_driver_info;
	59
	60	/** Private, per-device-instance driver context. */
	61	struct dev_context {
	62	uint64_t cur_samplerate;
	63	uint64_t limit_samples;
	64	uint64_t num_samples;
	65	snd_pcm_t *capture_handle;
	66	snd_pcm_hw_params_t *hw_params;
	67	struct pollfd *ufds;
	68	void *cb_data;
	69	};
	70
	71	static int clear_instances(void)
	72	{
	73	/* TODO */
	74
	75	return SR_OK;
	76	}
	77
	78	static int hw_init(struct sr_context *sr_ctx)
	79	{
	80	struct drv_context *drvc;
	81
	82	if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
	83	sr_err("Driver context malloc failed.");
	84	return SR_ERR_MALLOC;
	85	}
	86
	87	drvc->sr_ctx = sr_ctx;
	88	di->priv = drvc;
	89
	90	return SR_OK;
	91	}
	92
	93	static GSList hw_scan(GSList options)
	94	{
	95	struct drv_context *drvc;
	96	struct dev_context *devc;
	97	struct sr_dev_inst *sdi;
	98	struct sr_probe *probe;
	99	GSList *devices;
	100	int i;
	101
	102	(void)options;
	103
	104	drvc = di->priv;
	105	drvc->instances = NULL;
	106
	107	devices = NULL;
	108
	109	if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
	110	sr_err("Device context malloc failed.");
	111	return NULL;
	112	}
	113
	114	if (!(sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL))) {
	115	sr_err("Failed to create device instance.");
	116	return NULL;
	117	}
	118
	119	/* Set the samplerate to a default value for now. */
	120	devc->cur_samplerate = DEFAULT_SAMPLERATE;
	121
	122	sdi->priv = devc;
	123	sdi->driver = di;
	124
	125	for (i = 0; probe_names[i]; i++) {
	126	if (!(probe = sr_probe_new(i, SR_PROBE_ANALOG, TRUE,
	127	probe_names[i]))) {
	128	sr_err("Failed to create probe.");
	129	return NULL;
	130	}
	131	sdi->probes = g_slist_append(sdi->probes, probe);
	132	}
	133
	134	drvc->instances = g_slist_append(drvc->instances, sdi);
	135	devices = g_slist_append(devices, sdi);
	136
	137	return devices;
	138	}
	139
	140	static GSList *hw_dev_list(void)
	141	{
	142	struct drv_context *drvc;
	143
	144	drvc = di->priv;
	145
	146	return drvc->instances;
	147	}
	148
	149	static int hw_dev_open(struct sr_dev_inst *sdi)
	150	{
	151	struct dev_context *devc;
	152	int ret;
	153
	154	devc = sdi->priv;
	155
	156	sr_dbg("Opening audio device '%s' for stream capture.", AUDIO_DEV);
	157	ret = snd_pcm_open(&devc->capture_handle, AUDIO_DEV,
	158	SND_PCM_STREAM_CAPTURE, 0);
	159	if (ret < 0) {
	160	sr_err("Can't open audio device: %s.", snd_strerror(ret));
	161	return SR_ERR;
	162	}
	163
	164	sr_dbg("Allocating hardware parameter structure.");
	165	ret = snd_pcm_hw_params_malloc(&devc->hw_params);
	166	if (ret < 0) {
	167	sr_err("Can't allocate hardware parameter structure: %s.",
	168	snd_strerror(ret));
	169	return SR_ERR_MALLOC;
	170	}
	171
	172	sr_dbg("Initializing hardware parameter structure.");
	173	ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
	174	if (ret < 0) {
	175	sr_err("Can't initialize hardware parameter structure: %s.",
	176	snd_strerror(ret));
	177	return SR_ERR;
	178	}
	179
	180	return SR_OK;
	181	}
	182
	183	static int hw_dev_close(struct sr_dev_inst *sdi)
	184	{
	185	int ret;
	186	struct dev_context *devc;
	187
	188	devc = sdi->priv;
	189
	190	sr_dbg("Closing device.");
	191
	192	if (devc->hw_params) {
	193	sr_dbg("Freeing hardware parameters.");
	194	snd_pcm_hw_params_free(devc->hw_params);
	195	} else {
	196	sr_dbg("No hardware parameters, no need to free.");
	197	}
	198
	199	if (devc->capture_handle) {
	200	sr_dbg("Closing PCM device.");
	201	if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
	202	sr_err("Failed to close device: %s.",
	203	snd_strerror(ret));
	204	}
	205	} else {
	206	sr_dbg("No capture handle, no need to close audio device.");
	207	}
	208
	209	return SR_OK;
	210	}
	211
	212	static int hw_cleanup(void)
	213	{
	214	clear_instances();
	215
	216	return SR_OK;
	217	}
	218
	219	static int hw_info_get(int info_id, const void **data,
	220	const struct sr_dev_inst *sdi)
	221	{
	222	struct dev_context *devc;
	223
	224	if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
	225	devc = sdi->priv;
	226
	227	switch (info_id) {
	228	case SR_DI_HWCAPS:
	229	*data = hwcaps;
	230	break;
	231	case SR_DI_NUM_PROBES:
	232	*data = GINT_TO_POINTER(NUM_PROBES);
	233	break;
	234	case SR_DI_PROBE_NAMES:
	235	*data = probe_names;
	236	break;
	237	case SR_DI_CUR_SAMPLERATE:
	238	*data = &devc->cur_samplerate;
	239	break;
	240	default:
	241	sr_err("Invalid info_id: %d.", info_id);
	242	return SR_ERR_ARG;
	243	}
	244
	245	return SR_OK;
	246	}
	247
	248	static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
	249	const void *value)
	250	{
	251	struct dev_context *devc;
	252
	253	devc = sdi->priv;
	254
	255	switch (hwcap) {
	256	case SR_HWCAP_SAMPLERATE:
	257	devc->cur_samplerate = (const uint64_t )value;
	258	break;
	259	case SR_HWCAP_LIMIT_SAMPLES:
	260	devc->limit_samples = (const uint64_t )value;
	261	break;
	262	default:
	263	sr_err("Unknown capability: %d.", hwcap);
	264	return SR_ERR;
	265	}
	266
	267	return SR_OK;
	268	}
	269
	270	static int receive_data(int fd, int revents, void *cb_data)
	271	{
	272	struct sr_dev_inst *sdi;
	273	struct dev_context *devc;
	274	struct sr_datafeed_packet packet;
	275	struct sr_datafeed_analog analog;
	276	char inbuf[4096];
	277	int i, x, count, offset, samples_to_get;
	278	uint16_t tmp16;
	279
	280	(void)fd;
	281	(void)revents;
	282
	283	sdi = cb_data;
	284	devc = sdi->priv;
	285
	286	memset(&analog, 0, sizeof(struct sr_datafeed_analog));
	287	memset(inbuf, 0, sizeof(inbuf));
	288
	289	samples_to_get = MIN(4096 / 4, devc->limit_samples);
	290
	291	sr_spew("Getting %d samples from audio device.", samples_to_get);
	292	count = snd_pcm_readi(devc->capture_handle, inbuf, samples_to_get);
	293
	294	if (count < 0) {
	295	sr_err("Failed to read samples: %s.", snd_strerror(count));
	296	return FALSE;
	297	} else if (count != samples_to_get) {
	298	sr_spew("Only got %d/%d samples.", count, samples_to_get);
	299	}
	300
	301	analog.data = g_try_malloc0(count * sizeof(float) * NUM_PROBES);
	302	if (!analog.data) {
	303	sr_err("Failed to malloc sample buffer.");
	304	return FALSE;
	305	}
	306
	307	offset = 0;
	308
	309	for (i = 0; i < count; i++) {
	310	for (x = 0; x < NUM_PROBES; x++) {
	311	tmp16 = (uint16_t )(inbuf + (i * 4) + (x * 2));
	312	analog.data[offset++] = (float)tmp16;
	313	}
	314	}
	315
	316	/* Send a sample packet with the analog values. */
	317	analog.num_samples = count;
	318	analog.mq = SR_MQ_VOLTAGE; /* FIXME */
	319	analog.unit = SR_UNIT_VOLT; /* FIXME */
	320	packet.type = SR_DF_ANALOG;
	321	packet.payload = &analog;
	322	sr_session_send(devc->cb_data, &packet);
	323
	324	g_free(analog.data);
	325
	326	devc->num_samples += count;
	327
	328	/* Stop acquisition if we acquired enough samples. */
	329	if (devc->limit_samples > 0) {
	330	if (devc->num_samples >= devc->limit_samples) {
	331	sr_info("Requested number of samples reached.");
	332	sdi->driver->dev_acquisition_stop(sdi, cb_data);
	333	}
	334	}
	335
	336	return TRUE;
	337	}
	338
	339	static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
	340	void *cb_data)
	341	{
	342	struct sr_datafeed_packet packet;
	343	struct sr_datafeed_header header;
	344	struct sr_datafeed_meta_analog meta;
	345	struct dev_context *devc;
	346	int count, ret;
	347
	348	devc = sdi->priv;
	349	devc->cb_data = cb_data;
	350
	351	sr_dbg("Setting audio access type to RW/interleaved.");
	352	ret = snd_pcm_hw_params_set_access(devc->capture_handle,
	353	devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
	354	if (ret < 0) {
	355	sr_err("Can't set audio access type: %s.", snd_strerror(ret));
	356	return SR_ERR;
	357	}
	358
	359	/* FIXME: Hardcoded for 16bits. */
	360	sr_dbg("Setting audio sample format to signed 16bit (little endian).");
	361	ret = snd_pcm_hw_params_set_format(devc->capture_handle,
	362	devc->hw_params, SND_PCM_FORMAT_S16_LE);
	363	if (ret < 0) {
	364	sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
	365	return SR_ERR;
	366	}
	367
	368	sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
	369	devc->cur_samplerate);
	370	ret = snd_pcm_hw_params_set_rate_near(devc->capture_handle,
	371	devc->hw_params, (unsigned int *)&devc->cur_samplerate, 0);
	372	if (ret < 0) {
	373	sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
	374	return SR_ERR;
	375	}
	376
	377	sr_dbg("Setting audio channel count to %d.", NUM_PROBES);
	378	ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
	379	devc->hw_params, NUM_PROBES);
	380	if (ret < 0) {
	381	sr_err("Can't set channel count: %s.", snd_strerror(ret));
	382	return SR_ERR;
	383	}
	384
	385	sr_dbg("Setting audio parameters.");
	386	ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
	387	if (ret < 0) {
	388	sr_err("Can't set parameters: %s.", snd_strerror(ret));
	389	return SR_ERR;
	390	}
	391
	392	sr_dbg("Preparing audio interface for use.");
	393	ret = snd_pcm_prepare(devc->capture_handle);
	394	if (ret < 0) {
	395	sr_err("Can't prepare audio interface for use: %s.",
	396	snd_strerror(ret));
	397	return SR_ERR;
	398	}
	399
	400	count = snd_pcm_poll_descriptors_count(devc->capture_handle);
	401	if (count < 1) {
	402	sr_err("Unable to obtain poll descriptors count.");
	403	return SR_ERR;
	404	}
	405	sr_spew("Obtained poll descriptor count: %d.", count);
	406
	407	if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
	408	sr_err("Failed to malloc ufds.");
	409	return SR_ERR_MALLOC;
	410	}
	411
	412	sr_err("Getting %d poll descriptors.", count);
	413	ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
	414	if (ret < 0) {
	415	sr_err("Unable to obtain poll descriptors: %s.",
	416	snd_strerror(ret));
	417	g_free(devc->ufds);
	418	return SR_ERR;
	419	}
	420
	421	/* Send header packet to the session bus. */
	422	sr_dbg("Sending SR_DF_HEADER packet.");
	423	packet.type = SR_DF_HEADER;
	424	packet.payload = (uint8_t *)&header;
	425	header.feed_version = 1;
	426	gettimeofday(&header.starttime, NULL);
	427	sr_session_send(devc->cb_data, &packet);
	428
	429	/* Send metadata about the SR_DF_ANALOG packets to come. */
	430	sr_dbg("Sending SR_DF_META_ANALOG packet.");
	431	packet.type = SR_DF_META_ANALOG;
	432	packet.payload = &meta;
	433	meta.num_probes = NUM_PROBES;
	434	sr_session_send(devc->cb_data, &packet);
	435
	436	/* Poll every 10ms, or whenever some data comes in. */
	437	sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
	438	receive_data, (void *)sdi);
	439
	440	// g_free(devc->ufds); /* FIXME */
	441
	442	return SR_OK;
	443	}
	444
	445	static int hw_dev_acquisition_stop(struct sr_dev_inst sdi, void cb_data)
	446	{
	447	struct sr_datafeed_packet packet;
	448	struct dev_context *devc;
	449
	450	devc = sdi->priv;
	451	devc->cb_data = cb_data;
	452
	453	sr_source_remove(devc->ufds[0].fd);
	454
	455	/* Send end packet to the session bus. */
	456	sr_dbg("Sending SR_DF_END packet.");
	457	packet.type = SR_DF_END;
	458	sr_session_send(cb_data, &packet);
	459
	460	return SR_OK;
	461	}
	462
	463	SR_PRIV struct sr_dev_driver alsa_driver_info = {
	464	.name = "alsa",
	465	.longname = "ALSA driver",
	466	.api_version = 1,
	467	.init = hw_init,
	468	.cleanup = hw_cleanup,
	469	.scan = hw_scan,
	470	.dev_list = hw_dev_list,
	471	.dev_clear = clear_instances,
	472	.dev_open = hw_dev_open,
	473	.dev_close = hw_dev_close,
	474	.info_get = hw_info_get,
	475	.dev_config_set = hw_dev_config_set,
	476	.dev_acquisition_start = hw_dev_acquisition_start,
	477	.dev_acquisition_stop = hw_dev_acquisition_stop,
	478	.priv = NULL,
	479	};