libsigrok/hardware/alsa/alsa.c

406 lines
9.6 KiB
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
*/
/* Note: This driver doesn't compile, analog support in sigrok is WIP. */
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <alsa/asoundlib.h>
#include "sigrok.h"
#include "sigrok-internal.h"
#define NUM_PROBES 2
#define SAMPLE_WIDTH 16
#define AUDIO_DEV "plughw:0,0"
struct sr_analog_probe {
uint8_t att;
uint8_t res; /* Needs to be a power of 2, FIXME */
uint16_t val; /* Max hardware ADC width is 16bits */
};
struct sr_analog_sample {
uint8_t num_probes; /* Max hardware probes is 256 */
struct sr_analog_probe probes[];
};
static int capabilities[] = {
SR_HWCAP_SAMPLERATE,
SR_HWCAP_LIMIT_SAMPLES,
SR_HWCAP_CONTINUOUS,
};
static const char *probe_names[NUM_PROBES + 1] = {
"0",
"1",
NULL,
};
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;
if (!(alsa = g_try_malloc0(sizeof(struct alsa)))) {
sr_err("alsa: %s: alsa malloc failed", __func__);
return 0;
}
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:
g_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_err("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_err("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_err("cannot initialize hardware parameter structure (%s)",
snd_strerror(err));
return SR_ERR;
}
return SR_OK;
}
static int hw_closedev(int device_index)
{
struct sr_device_instance *sdi;
struct alsa *alsa;
if (!(sdi = sr_get_device_instance(device_instances, device_index))) {
sr_err("alsa: %s: sdi was NULL", __func__);
return SR_ERR; /* TODO: SR_ERR_ARG? */
}
if (!(alsa = sdi->priv)) {
sr_err("alsa: %s: sdi->priv was NULL", __func__);
return SR_ERR; /* TODO: SR_ERR_ARG? */
}
// TODO: Return values of snd_*?
if (alsa->hw_params)
snd_pcm_hw_params_free(alsa->hw_params);
if (alsa->capture_handle)
snd_pcm_close(alsa->capture_handle);
return SR_OK;
}
static void hw_cleanup(void)
{
struct sr_device_instance *sdi;
if (!(sdi = sr_get_device_instance(device_instances, 0)))
return;
g_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_PROBE_NAMES:
info = probe_names;
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_err("Failed to read samples");
return FALSE;
}
if (!(outb = g_try_malloc(sample_size * count))) {
sr_err("alsa: %s: outb malloc failed", __func__);
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);
g_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_err("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_err("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_err("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_err("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_err("cannot set parameters (%s)", snd_strerror(err));
return SR_ERR;
}
err = snd_pcm_prepare(alsa->capture_handle);
if (err < 0) {
sr_err("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_err("Unable to obtain poll descriptors count");
return SR_ERR;
}
if (!(ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
sr_err("alsa: %s: ufds malloc failed", __func__);
return SR_ERR_MALLOC;
}
err = snd_pcm_poll_descriptors(alsa->capture_handle, ufds, count);
if (err < 0) {
sr_err("Unable to obtain poll descriptors (%s)",
snd_strerror(err));
g_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);
g_free(ufds);
return SR_OK;
}
static int hw_stop_acquisition(int device_index, gpointer session_device_id)
{
/* Avoid compiler warnings. */
device_index = device_index;
session_device_id = session_device_id;
return SR_OK;
}
SR_PRIV struct sr_device_plugin alsa_plugin_info = {
.name = "alsa",
.longname = "ALSA driver",
.api_version = 1,
.init = hw_init,
.cleanup = hw_cleanup,
.opendev = hw_opendev,
.closedev = hw_closedev,
.get_device_info = hw_get_device_info,
.get_status = hw_get_status,
.get_capabilities = hw_get_capabilities,
.set_configuration = hw_set_configuration,
.start_acquisition = hw_start_acquisition,
.stop_acquisition = hw_stop_acquisition,
};