libsigrok/hardware/alsa/alsa.c

414 lines
9.5 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 "libsigrok.h"
#include "libsigrok-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 const int hwcaps[] = {
SR_HWCAP_SAMPLERATE,
SR_HWCAP_LIMIT_SAMPLES,
SR_HWCAP_CONTINUOUS,
};
/* TODO: Which probe names/numbers to use? */
static const char *probe_names[NUM_PROBES + 1] = {
"0",
"1",
NULL,
};
static GSList *dev_insts = NULL;
/* Private, per-device-instance driver context. */
struct context {
uint64_t cur_rate;
uint64_t limit_samples;
snd_pcm_t *capture_handle;
snd_pcm_hw_params_t *hw_params;
void *session_dev_id;
};
static int hw_init(const char *devinfo)
{
struct sr_dev_inst *sdi;
struct context *ctx;
/* Avoid compiler warnings. */
(void)devinfo;
if (!(ctx = g_try_malloc0(sizeof(struct context)))) {
sr_err("alsa: %s: ctx malloc failed", __func__);
return 0;
}
if (!(sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, "alsa", NULL, NULL))) {
sr_err("alsa: %s: sdi was NULL", __func__);
goto free_ctx;
}
sdi->priv = ctx;
dev_insts = g_slist_append(dev_insts, sdi);
return 1;
free_ctx:
g_free(ctx);
return 0;
}
static int hw_dev_open(int dev_index)
{
struct sr_dev_inst *sdi;
struct context *ctx;
int ret;
if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
return SR_ERR;
ctx = sdi->priv;
ret = snd_pcm_open(&ctx->capture_handle, AUDIO_DEV,
SND_PCM_STREAM_CAPTURE, 0);
if (ret < 0) {
sr_err("alsa: can't open audio device %s (%s)", AUDIO_DEV,
snd_strerror(ret));
return SR_ERR;
}
ret = snd_pcm_hw_params_malloc(&ctx->hw_params);
if (ret < 0) {
sr_err("alsa: can't allocate hardware parameter structure (%s)",
snd_strerror(ret));
return SR_ERR;
}
ret = snd_pcm_hw_params_any(ctx->capture_handle, ctx->hw_params);
if (ret < 0) {
sr_err("alsa: can't initialize hardware parameter structure "
"(%s)", snd_strerror(ret));
return SR_ERR;
}
return SR_OK;
}
static int hw_dev_close(int dev_index)
{
struct sr_dev_inst *sdi;
struct context *ctx;
if (!(sdi = sr_dev_inst_get(dev_insts, dev_index))) {
sr_err("alsa: %s: sdi was NULL", __func__);
return SR_ERR_BUG;
}
if (!(ctx = sdi->priv)) {
sr_err("alsa: %s: sdi->priv was NULL", __func__);
return SR_ERR_BUG;
}
// TODO: Return values of snd_*?
if (ctx->hw_params)
snd_pcm_hw_params_free(ctx->hw_params);
if (ctx->capture_handle)
snd_pcm_close(ctx->capture_handle);
return SR_OK;
}
static int hw_cleanup(void)
{
struct sr_dev_inst *sdi;
if (!(sdi = sr_dev_inst_get(dev_insts, 0))) {
sr_err("alsa: %s: sdi was NULL", __func__);
return SR_ERR_BUG;
}
sr_dev_inst_free(sdi);
return SR_OK;
}
static const void *hw_dev_info_get(int dev_index, int dev_info_id)
{
struct sr_dev_inst *sdi;
struct context *ctx;
void *info = NULL;
if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
return NULL;
ctx = sdi->priv;
switch (dev_info_id) {
case SR_DI_INST:
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 = &ctx->cur_rate;
break;
// case SR_DI_PROBE_TYPE:
// info = GINT_TO_POINTER(SR_PROBE_TYPE_ANALOG);
// break;
}
return info;
}
static int hw_dev_status_get(int dev_index)
{
/* Avoid compiler warnings. */
dev_index = dev_index;
return SR_ST_ACTIVE;
}
static const int *hw_hwcap_get_all(void)
{
return hwcaps;
}
static int hw_dev_config_set(int dev_index, int hwcap, const void *value)
{
struct sr_dev_inst *sdi;
struct context *ctx;
if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
return SR_ERR;
ctx = sdi->priv;
switch (hwcap) {
case SR_HWCAP_PROBECONFIG:
return SR_OK;
case SR_HWCAP_SAMPLERATE:
ctx->cur_rate = *(const uint64_t *)value;
return SR_OK;
case SR_HWCAP_LIMIT_SAMPLES:
ctx->limit_samples = *(const uint64_t *)value;
return SR_OK;
default:
return SR_ERR;
}
}
static int receive_data(int fd, int revents, void *cb_data)
{
struct sr_dev_inst *sdi = cb_data;
struct context *ctx = 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(ctx->capture_handle, inb,
MIN(4096 / 4, ctx->limit_samples));
if (count < 1) {
sr_err("alsa: 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_send(sdi, &packet);
g_free(outb);
ctx->limit_samples -= count;
} while (ctx->limit_samples > 0);
packet.type = SR_DF_END;
sr_session_send(sdi, &packet);
return TRUE;
}
static int hw_dev_acquisition_start(int dev_index, void *cb_data)
{
struct sr_dev_inst *sdi;
struct context *ctx;
struct sr_datafeed_packet packet;
struct sr_datafeed_header header;
struct pollfd *ufds;
int count;
int ret;
if (!(sdi = sr_dev_inst_get(dev_insts, dev_index)))
return SR_ERR;
ctx = sdi->priv;
ret = snd_pcm_hw_params_set_access(ctx->capture_handle,
ctx->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
if (ret < 0) {
sr_err("alsa: can't set access type (%s)", snd_strerror(ret));
return SR_ERR;
}
/* FIXME: Hardcoded for 16bits */
ret = snd_pcm_hw_params_set_format(ctx->capture_handle,
ctx->hw_params, SND_PCM_FORMAT_S16_LE);
if (ret < 0) {
sr_err("alsa: can't set sample format (%s)", snd_strerror(ret));
return SR_ERR;
}
ret = snd_pcm_hw_params_set_rate_near(ctx->capture_handle,
ctx->hw_params, (unsigned int *)&ctx->cur_rate, 0);
if (ret < 0) {
sr_err("alsa: can't set sample rate (%s)", snd_strerror(ret));
return SR_ERR;
}
ret = snd_pcm_hw_params_set_channels(ctx->capture_handle,
ctx->hw_params, NUM_PROBES);
if (ret < 0) {
sr_err("alsa: can't set channel count (%s)", snd_strerror(ret));
return SR_ERR;
}
ret = snd_pcm_hw_params(ctx->capture_handle, ctx->hw_params);
if (ret < 0) {
sr_err("alsa: can't set parameters (%s)", snd_strerror(ret));
return SR_ERR;
}
ret = snd_pcm_prepare(ctx->capture_handle);
if (ret < 0) {
sr_err("alsa: can't prepare audio interface for use (%s)",
snd_strerror(ret));
return SR_ERR;
}
count = snd_pcm_poll_descriptors_count(ctx->capture_handle);
if (count < 1) {
sr_err("alsa: 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;
}
ret = snd_pcm_poll_descriptors(ctx->capture_handle, ufds, count);
if (ret < 0) {
sr_err("alsa: Unable to obtain poll descriptors (%s)",
snd_strerror(ret));
g_free(ufds);
return SR_ERR;
}
ctx->session_dev_id = cb_data;
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 = ctx->cur_rate;
header.num_analog_probes = NUM_PROBES;
header.num_logic_probes = 0;
header.protocol_id = SR_PROTO_RAW;
sr_session_send(cb_data, &packet);
g_free(ufds);
return SR_OK;
}
/* TODO: This stops acquisition on ALL devices, ignoring dev_index. */
static int hw_dev_acquisition_stop(int dev_index, void *cb_data)
{
/* Avoid compiler warnings. */
(void)dev_index;
(void)cb_data;
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,
.dev_open = hw_dev_open,
.dev_close = hw_dev_close,
.dev_info_get = hw_dev_info_get,
.dev_status_get = hw_dev_status_get,
.hwcap_get_all = hw_hwcap_get_all,
.dev_config_set = hw_dev_config_set,
.dev_acquisition_start = hw_dev_acquisition_start,
.dev_acquisition_stop = hw_dev_acquisition_stop,
};