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_HWCAP_SAMPLERATE,
  32         SR_HWCAP_LIMIT_SAMPLES,
  33         SR_HWCAP_CONTINUOUS,
  34         0,
  35 };
  36
  37 static const char *probe_names[] = {
  38         "Channel 0", "Channel 1",
  39         NULL,
  40 };
  41
  42 SR_PRIV struct sr_dev_driver alsa_driver_info;
  43 static struct sr_dev_driver *di = &alsa_driver_info;
  44
  45 static int clear_instances(void)
  46 {
  47         struct drv_context *drvc;
  48
  49         if (!(drvc = di->priv))
  50                 return SR_OK;
  51
  52         g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
  53         drvc->instances = NULL;
  54
  55         return SR_OK;
  56 }
  57
  58 static int hw_init(struct sr_context *sr_ctx)
  59 {
  60         struct drv_context *drvc;
  61
  62         if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
  63                 sr_err("Driver context malloc failed.");
  64                 return SR_ERR_MALLOC;
  65         }
  66
  67         drvc->sr_ctx = sr_ctx;
  68         di->priv = drvc;
  69
  70         return SR_OK;
  71 }
  72
  73 static GSList *hw_scan(GSList *options)
  74 {
  75         return alsa_scan(options, di);
  76 }
  77
  78 static GSList *hw_dev_list(void)
  79 {
  80         struct drv_context *drvc;
  81
  82         drvc = di->priv;
  83
  84         return drvc->instances;
  85 }
  86
  87 static int hw_dev_open(struct sr_dev_inst *sdi)
  88 {
  89         struct dev_context *devc;
  90         int ret;
  91
  92         devc = sdi->priv;
  93
  94         if (!(devc->hwdev)) {
  95                 sr_err("devc->hwdev was NULL.");
  96                 return SR_ERR_BUG;
  97         }
  98
  99         sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
 100         ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
 101                            SND_PCM_STREAM_CAPTURE, 0);
 102         if (ret < 0) {
 103                 sr_err("Can't open audio device: %s.", snd_strerror(ret));
 104                 return SR_ERR;
 105         }
 106
 107         sr_dbg("Initializing hardware parameter structure.");
 108         ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
 109         if (ret < 0) {
 110                 sr_err("Can't initialize hardware parameter structure: %s.",
 111                        snd_strerror(ret));
 112                 return SR_ERR;
 113         }
 114
 115         return SR_OK;
 116 }
 117
 118 static int hw_dev_close(struct sr_dev_inst *sdi)
 119 {
 120         int ret;
 121         struct dev_context *devc;
 122
 123         devc = sdi->priv;
 124
 125         sr_dbg("Closing device.");
 126
 127         if (devc->capture_handle) {
 128                 sr_dbg("Closing PCM device.");
 129                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 130                         sr_err("Failed to close device: %s.",
 131                                snd_strerror(ret));
 132                         devc->capture_handle = NULL;
 133                 }
 134         } else {
 135                 sr_dbg("No capture handle, no need to close audio device.");
 136         }
 137
 138         return SR_OK;
 139 }
 140
 141 static int hw_cleanup(void)
 142 {
 143         clear_instances();
 144
 145         return SR_OK;
 146 }
 147
 148 static int hw_info_get(int info_id, const void **data,
 149                        const struct sr_dev_inst *sdi)
 150 {
 151         struct dev_context *devc;
 152
 153         if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
 154                 devc = sdi->priv;
 155
 156         switch (info_id) {
 157         case SR_DI_HWCAPS:
 158                 *data = hwcaps;
 159                 break;
 160         case SR_DI_NUM_PROBES:
 161                 *data = &devc->num_probes;
 162                 break;
 163         case SR_DI_PROBE_NAMES:
 164                 *data = probe_names;
 165                 break;
 166         case SR_DI_CUR_SAMPLERATE:
 167                 *data = &devc->cur_samplerate;
 168                 break;
 169         case SR_DI_SAMPLERATES:
 170                 if (!devc->supp_rates.list) {
 171                         sr_err("Instance did not contain a samplerate list.");
 172                         return SR_ERR_ARG;
 173                 }
 174                 *data = &devc->supp_rates;
 175                 break;
 176         default:
 177                 sr_err("Invalid info_id: %d.", info_id);
 178                 return SR_ERR_ARG;
 179         }
 180
 181         return SR_OK;
 182 }
 183
 184 static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 185                              const void *value)
 186 {
 187         struct dev_context *devc;
 188
 189         devc = sdi->priv;
 190
 191         switch (hwcap) {
 192         case SR_HWCAP_SAMPLERATE:
 193                 alsa_set_samplerate(sdi, *(const uint64_t *)value);
 194                 break;
 195         case SR_HWCAP_LIMIT_SAMPLES:
 196                 devc->limit_samples = *(const uint64_t *)value;
 197                 break;
 198         default:
 199                 sr_err("Unknown capability: %d.", hwcap);
 200                 return SR_ERR;
 201         }
 202
 203         return SR_OK;
 204 }
 205
 206 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 207                                     void *cb_data)
 208 {
 209         struct sr_datafeed_packet packet;
 210         struct sr_datafeed_header header;
 211         struct sr_datafeed_meta_analog meta;
 212         struct dev_context *devc;
 213         int count, ret;
 214         char *endianness;
 215
 216         devc = sdi->priv;
 217         devc->cb_data = cb_data;
 218         devc->num_samples = 0;
 219
 220         sr_dbg("Setting audio access type to RW/interleaved.");
 221         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 222                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 223         if (ret < 0) {
 224                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 225                 return SR_ERR;
 226         }
 227
 228         /* FIXME: Hardcoded for 16bits. */
 229         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 230                 endianness = "little endian";
 231         else
 232                 endianness = "big endian";
 233         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
 234         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 235                                            devc->hw_params,
 236                                            SND_PCM_FORMAT_S16);
 237         if (ret < 0) {
 238                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 239                 return SR_ERR;
 240         }
 241
 242         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 243                devc->cur_samplerate);
 244         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 245                                          (unsigned int)devc->cur_samplerate, 0);
 246         if (ret < 0) {
 247                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 248                 return SR_ERR;
 249         }
 250
 251         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 252         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 253                                              devc->hw_params, devc->num_probes);
 254         if (ret < 0) {
 255                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 256                 return SR_ERR;
 257         }
 258
 259         sr_dbg("Setting audio parameters.");
 260         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 261         if (ret < 0) {
 262                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 263                 return SR_ERR;
 264         }
 265
 266         sr_dbg("Preparing audio interface for use.");
 267         ret = snd_pcm_prepare(devc->capture_handle);
 268         if (ret < 0) {
 269                 sr_err("Can't prepare audio interface for use: %s.",
 270                        snd_strerror(ret));
 271                 return SR_ERR;
 272         }
 273
 274         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 275         if (count < 1) {
 276                 sr_err("Unable to obtain poll descriptors count.");
 277                 return SR_ERR;
 278         }
 279
 280         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 281                 sr_err("Failed to malloc ufds.");
 282                 return SR_ERR_MALLOC;
 283         }
 284
 285         sr_err("Getting %d poll descriptors.", count);
 286         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 287         if (ret < 0) {
 288                 sr_err("Unable to obtain poll descriptors: %s.",
 289                        snd_strerror(ret));
 290                 g_free(devc->ufds);
 291                 return SR_ERR;
 292         }
 293
 294         /* Send header packet to the session bus. */
 295         sr_dbg("Sending SR_DF_HEADER packet.");
 296         packet.type = SR_DF_HEADER;
 297         packet.payload = (uint8_t *)&header;
 298         header.feed_version = 1;
 299         gettimeofday(&header.starttime, NULL);
 300         sr_session_send(devc->cb_data, &packet);
 301
 302         /* Send metadata about the SR_DF_ANALOG packets to come. */
 303         sr_dbg("Sending SR_DF_META_ANALOG packet.");
 304         packet.type = SR_DF_META_ANALOG;
 305         packet.payload = &meta;
 306         meta.num_probes = devc->num_probes;
 307         sr_session_send(devc->cb_data, &packet);
 308
 309         /* Poll every 10ms, or whenever some data comes in. */
 310         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 311                       alsa_receive_data, (void *)sdi);
 312
 313         // g_free(devc->ufds); /* FIXME */
 314
 315         return SR_OK;
 316 }
 317
 318 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 319 {
 320         struct sr_datafeed_packet packet;
 321         struct dev_context *devc;
 322
 323         devc = sdi->priv;
 324         devc->cb_data = cb_data;
 325
 326         sr_source_remove(devc->ufds[0].fd);
 327
 328         /* Send end packet to the session bus. */
 329         sr_dbg("Sending SR_DF_END packet.");
 330         packet.type = SR_DF_END;
 331         sr_session_send(cb_data, &packet);
 332
 333         return SR_OK;
 334 }
 335
 336 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 337         .name = "alsa",
 338         .longname = "ALSA driver",
 339         .api_version = 1,
 340         .init = hw_init,
 341         .cleanup = hw_cleanup,
 342         .scan = hw_scan,
 343         .dev_list = hw_dev_list,
 344         .dev_clear = clear_instances,
 345         .dev_open = hw_dev_open,
 346         .dev_close = hw_dev_close,
 347         .info_get = hw_info_get,
 348         .dev_config_set = hw_dev_config_set,
 349         .dev_acquisition_start = hw_dev_acquisition_start,
 350         .dev_acquisition_stop = hw_dev_acquisition_stop,
 351         .priv = NULL,
 352 };