hardware/alsa/api.c

   1 /*
   2  * This file is part of the libsigrok project.
   3  *
   4  * Copyright (C) 2011 Daniel Ribeiro <drwyrm@gmail.com>
   5  * Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
   6  * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
   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
  23 #include <stdlib.h>
  24 #include <unistd.h>
  25 #include <string.h>
  26 #include "libsigrok.h"
  27 #include "libsigrok-internal.h"
  28 #include "protocol.h"
  29
  30 static const int hwcaps[] = {
  31         SR_CONF_SAMPLERATE,
  32         SR_CONF_LIMIT_SAMPLES,
  33         SR_CONF_CONTINUOUS,
  34         0,
  35 };
  36
  37 SR_PRIV struct sr_dev_driver alsa_driver_info;
  38 static struct sr_dev_driver *di = &alsa_driver_info;
  39
  40 static int clear_instances(void)
  41 {
  42         struct drv_context *drvc;
  43
  44         if (!(drvc = di->priv))
  45                 return SR_OK;
  46
  47         g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
  48         drvc->instances = NULL;
  49
  50         return SR_OK;
  51 }
  52
  53 static int hw_init(struct sr_context *sr_ctx)
  54 {
  55         struct drv_context *drvc;
  56
  57         if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
  58                 sr_err("Driver context malloc failed.");
  59                 return SR_ERR_MALLOC;
  60         }
  61
  62         drvc->sr_ctx = sr_ctx;
  63         di->priv = drvc;
  64
  65         return SR_OK;
  66 }
  67
  68 static GSList *hw_scan(GSList *options)
  69 {
  70         return alsa_scan(options, di);
  71 }
  72
  73 static GSList *hw_dev_list(void)
  74 {
  75         struct drv_context *drvc;
  76
  77         drvc = di->priv;
  78
  79         return drvc->instances;
  80 }
  81
  82 static int hw_dev_open(struct sr_dev_inst *sdi)
  83 {
  84         struct dev_context *devc;
  85         int ret;
  86
  87         devc = sdi->priv;
  88
  89         if (!(devc->hwdev)) {
  90                 sr_err("devc->hwdev was NULL.");
  91                 return SR_ERR_BUG;
  92         }
  93
  94         sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
  95         ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
  96                            SND_PCM_STREAM_CAPTURE, 0);
  97         if (ret < 0) {
  98                 sr_err("Can't open audio device: %s.", snd_strerror(ret));
  99                 return SR_ERR;
 100         }
 101
 102         sr_dbg("Initializing hardware parameter structure.");
 103         ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
 104         if (ret < 0) {
 105                 sr_err("Can't initialize hardware parameter structure: %s.",
 106                        snd_strerror(ret));
 107                 return SR_ERR;
 108         }
 109
 110         return SR_OK;
 111 }
 112
 113 static int hw_dev_close(struct sr_dev_inst *sdi)
 114 {
 115         int ret;
 116         struct dev_context *devc;
 117
 118         devc = sdi->priv;
 119
 120         sr_dbg("Closing device.");
 121
 122         if (devc->capture_handle) {
 123                 sr_dbg("Closing PCM device.");
 124                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 125                         sr_err("Failed to close device: %s.",
 126                                snd_strerror(ret));
 127                         devc->capture_handle = NULL;
 128                 }
 129         } else {
 130                 sr_dbg("No capture handle, no need to close audio device.");
 131         }
 132
 133         return SR_OK;
 134 }
 135
 136 static int hw_cleanup(void)
 137 {
 138         clear_instances();
 139
 140         return SR_OK;
 141 }
 142
 143 static int config_get(int id, const void **data, const struct sr_dev_inst *sdi)
 144 {
 145         struct dev_context *devc;
 146
 147         if (id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
 148                 devc = sdi->priv;
 149
 150         switch (id) {
 151         case SR_DI_HWCAPS:
 152                 *data = hwcaps;
 153                 break;
 154         case SR_DI_CUR_SAMPLERATE:
 155                 *data = &devc->cur_samplerate;
 156                 break;
 157         case SR_DI_SAMPLERATES:
 158                 if (!devc->supp_rates.list) {
 159                         sr_err("Instance did not contain a samplerate list.");
 160                         return SR_ERR_ARG;
 161                 }
 162                 *data = &devc->supp_rates;
 163                 break;
 164         default:
 165                 return SR_ERR_ARG;
 166         }
 167
 168         return SR_OK;
 169 }
 170
 171 static int config_set(int id, const void *value, const struct sr_dev_inst *sdi)
 172 {
 173         struct dev_context *devc;
 174
 175         devc = sdi->priv;
 176
 177         switch (id) {
 178         case SR_CONF_SAMPLERATE:
 179                 alsa_set_samplerate(sdi, *(const uint64_t *)value);
 180                 break;
 181         case SR_CONF_LIMIT_SAMPLES:
 182                 devc->limit_samples = *(const uint64_t *)value;
 183                 break;
 184         default:
 185                 sr_err("Unknown capability: %d.", id);
 186                 return SR_ERR;
 187         }
 188
 189         return SR_OK;
 190 }
 191
 192 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 193                                     void *cb_data)
 194 {
 195         struct sr_datafeed_packet packet;
 196         struct sr_datafeed_header header;
 197         struct dev_context *devc;
 198         int count, ret;
 199         char *endianness;
 200
 201         devc = sdi->priv;
 202         devc->cb_data = cb_data;
 203         devc->num_samples = 0;
 204
 205         sr_dbg("Setting audio access type to RW/interleaved.");
 206         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 207                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 208         if (ret < 0) {
 209                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 210                 return SR_ERR;
 211         }
 212
 213         /* FIXME: Hardcoded for 16bits. */
 214         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 215                 endianness = "little endian";
 216         else
 217                 endianness = "big endian";
 218         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
 219         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 220                                            devc->hw_params,
 221                                            SND_PCM_FORMAT_S16);
 222         if (ret < 0) {
 223                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 224                 return SR_ERR;
 225         }
 226
 227         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 228                devc->cur_samplerate);
 229         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 230                                          (unsigned int)devc->cur_samplerate, 0);
 231         if (ret < 0) {
 232                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 233                 return SR_ERR;
 234         }
 235
 236         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 237         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 238                                              devc->hw_params, devc->num_probes);
 239         if (ret < 0) {
 240                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 241                 return SR_ERR;
 242         }
 243
 244         sr_dbg("Setting audio parameters.");
 245         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 246         if (ret < 0) {
 247                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 248                 return SR_ERR;
 249         }
 250
 251         sr_dbg("Preparing audio interface for use.");
 252         ret = snd_pcm_prepare(devc->capture_handle);
 253         if (ret < 0) {
 254                 sr_err("Can't prepare audio interface for use: %s.",
 255                        snd_strerror(ret));
 256                 return SR_ERR;
 257         }
 258
 259         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 260         if (count < 1) {
 261                 sr_err("Unable to obtain poll descriptors count.");
 262                 return SR_ERR;
 263         }
 264
 265         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 266                 sr_err("Failed to malloc ufds.");
 267                 return SR_ERR_MALLOC;
 268         }
 269
 270         sr_spew("Getting %d poll descriptors.", count);
 271         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 272         if (ret < 0) {
 273                 sr_err("Unable to obtain poll descriptors: %s.",
 274                        snd_strerror(ret));
 275                 g_free(devc->ufds);
 276                 return SR_ERR;
 277         }
 278
 279         /* Send header packet to the session bus. */
 280         sr_dbg("Sending SR_DF_HEADER packet.");
 281         packet.type = SR_DF_HEADER;
 282         packet.payload = (uint8_t *)&header;
 283         header.feed_version = 1;
 284         gettimeofday(&header.starttime, NULL);
 285         sr_session_send(devc->cb_data, &packet);
 286
 287         /* Poll every 10ms, or whenever some data comes in. */
 288         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 289                       alsa_receive_data, (void *)sdi);
 290
 291         // g_free(devc->ufds); /* FIXME */
 292
 293         return SR_OK;
 294 }
 295
 296 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 297 {
 298         struct sr_datafeed_packet packet;
 299         struct dev_context *devc;
 300
 301         devc = sdi->priv;
 302         devc->cb_data = cb_data;
 303
 304         sr_source_remove(devc->ufds[0].fd);
 305
 306         /* Send end packet to the session bus. */
 307         sr_dbg("Sending SR_DF_END packet.");
 308         packet.type = SR_DF_END;
 309         sr_session_send(cb_data, &packet);
 310
 311         return SR_OK;
 312 }
 313
 314 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 315         .name = "alsa",
 316         .longname = "ALSA driver",
 317         .api_version = 1,
 318         .init = hw_init,
 319         .cleanup = hw_cleanup,
 320         .scan = hw_scan,
 321         .dev_list = hw_dev_list,
 322         .dev_clear = clear_instances,
 323         .config_get = config_get,
 324         .config_set = config_set,
 325         .dev_open = hw_dev_open,
 326         .dev_close = hw_dev_close,
 327         .dev_acquisition_start = hw_dev_acquisition_start,
 328         .dev_acquisition_stop = hw_dev_acquisition_stop,
 329         .priv = NULL,
 330 };