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