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