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 "protocol.h"
  24 #include "libsigrok.h"
  25 #include "libsigrok-internal.h"
  26
  27 #include <stdlib.h>
  28 #include <unistd.h>
  29 #include <string.h>
  30
  31 #define DEFAULT_PROBES          2
  32 #define SAMPLE_WIDTH            16
  33 #define DEFAULT_SAMPLERATE      44100
  34
  35 static const int hwcaps[] = {
  36         SR_HWCAP_SAMPLERATE,
  37         SR_HWCAP_LIMIT_SAMPLES,
  38         SR_HWCAP_CONTINUOUS,
  39         0,
  40 };
  41
  42 static const char *probe_names[] = {
  43         "Channel 0", "Channel 1",
  44         NULL,
  45 };
  46
  47 SR_PRIV struct sr_dev_driver alsa_driver_info;
  48 static struct sr_dev_driver *di = &alsa_driver_info;
  49
  50 static int clear_instances(void)
  51 {
  52         struct drv_context *drvc;
  53
  54         if (!(drvc = di->priv))
  55                 return SR_OK;
  56
  57         g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
  58         drvc->instances = NULL;
  59
  60         return SR_OK;
  61 }
  62
  63 static int hw_init(struct sr_context *sr_ctx)
  64 {
  65         struct drv_context *drvc;
  66
  67         if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
  68                 sr_err("Driver context malloc failed.");
  69                 return SR_ERR_MALLOC;
  70         }
  71
  72         drvc->sr_ctx = sr_ctx;
  73         di->priv = drvc;
  74
  75         return SR_OK;
  76 }
  77
  78 static GSList *hw_scan(GSList *options)
  79 {
  80         return alsa_scan(options, di);
  81 }
  82
  83 static GSList *hw_dev_list(void)
  84 {
  85         struct drv_context *drvc;
  86
  87         drvc = di->priv;
  88
  89         return drvc->instances;
  90 }
  91
  92 static int hw_dev_open(struct sr_dev_inst *sdi)
  93 {
  94         struct dev_context *devc;
  95         int ret;
  96
  97         devc = sdi->priv;
  98
  99         if (!(devc->hwdev)) {
 100                 sr_err("devc->hwdev was NULL.");
 101                 return SR_ERR_BUG;
 102         }
 103
 104         sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
 105         ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
 106                            SND_PCM_STREAM_CAPTURE, 0);
 107         if (ret < 0) {
 108                 sr_err("Can't open audio device: %s.", snd_strerror(ret));
 109                 return SR_ERR;
 110         }
 111
 112         sr_dbg("Initializing hardware parameter structure.");
 113         ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
 114         if (ret < 0) {
 115                 sr_err("Can't initialize hardware parameter structure: %s.",
 116                        snd_strerror(ret));
 117                 return SR_ERR;
 118         }
 119
 120         return SR_OK;
 121 }
 122
 123 static int hw_dev_close(struct sr_dev_inst *sdi)
 124 {
 125         int ret;
 126         struct dev_context *devc;
 127
 128         devc = sdi->priv;
 129
 130         sr_dbg("Closing device.");
 131
 132         if (devc->capture_handle) {
 133                 sr_dbg("Closing PCM device.");
 134                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 135                         sr_err("Failed to close device: %s.",
 136                                snd_strerror(ret));
 137                         devc->capture_handle = NULL;
 138                 }
 139         } else {
 140                 sr_dbg("No capture handle, no need to close audio device.");
 141         }
 142
 143         return SR_OK;
 144 }
 145
 146 static int hw_cleanup(void)
 147 {
 148         clear_instances();
 149
 150         return SR_OK;
 151 }
 152
 153 static int hw_info_get(int info_id, const void **data,
 154                        const struct sr_dev_inst *sdi)
 155 {
 156         struct dev_context *devc;
 157
 158         if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
 159                 devc = sdi->priv;
 160
 161         switch (info_id) {
 162         case SR_DI_HWCAPS:
 163                 *data = hwcaps;
 164                 break;
 165         case SR_DI_NUM_PROBES:
 166                 *data = &devc->num_probes;
 167                 break;
 168         case SR_DI_PROBE_NAMES:
 169                 *data = probe_names;
 170                 break;
 171         case SR_DI_CUR_SAMPLERATE:
 172                 *data = &devc->cur_samplerate;
 173                 break;
 174         default:
 175                 sr_err("Invalid info_id: %d.", info_id);
 176                 return SR_ERR_ARG;
 177         }
 178
 179         return SR_OK;
 180 }
 181
 182 static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 183                              const void *value)
 184 {
 185         struct dev_context *devc;
 186
 187         devc = sdi->priv;
 188
 189         switch (hwcap) {
 190         case SR_HWCAP_SAMPLERATE:
 191                 devc->cur_samplerate = *(const uint64_t *)value;
 192                 break;
 193         case SR_HWCAP_LIMIT_SAMPLES:
 194                 devc->limit_samples = *(const uint64_t *)value;
 195                 break;
 196         default:
 197                 sr_err("Unknown capability: %d.", hwcap);
 198                 return SR_ERR;
 199         }
 200
 201         return SR_OK;
 202 }
 203
 204 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 205                                     void *cb_data)
 206 {
 207         struct sr_datafeed_packet packet;
 208         struct sr_datafeed_header header;
 209         struct sr_datafeed_meta_analog meta;
 210         struct dev_context *devc;
 211         int count, ret;
 212         char *endianess;
 213
 214         devc = sdi->priv;
 215         devc->cb_data = cb_data;
 216         devc->num_samples = 0;
 217
 218         sr_dbg("Setting audio access type to RW/interleaved.");
 219         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 220                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 221         if (ret < 0) {
 222                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 223                 return SR_ERR;
 224         }
 225
 226         /* FIXME: Hardcoded for 16bits. */
 227         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 228                 endianess = "lilltle endian";
 229         else
 230                 endianess = "big endian";
 231         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianess);
 232         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 233                                            devc->hw_params,
 234                                            SND_PCM_FORMAT_S16);
 235         if (ret < 0) {
 236                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 237                 return SR_ERR;
 238         }
 239
 240         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 241                devc->cur_samplerate);
 242         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 243                                          (unsigned int)devc->cur_samplerate, 0);
 244         if (ret < 0) {
 245                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 246                 return SR_ERR;
 247         }
 248
 249         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 250         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 251                                              devc->hw_params, devc->num_probes);
 252         if (ret < 0) {
 253                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 254                 return SR_ERR;
 255         }
 256
 257         sr_dbg("Setting audio parameters.");
 258         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 259         if (ret < 0) {
 260                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 261                 return SR_ERR;
 262         }
 263
 264         sr_dbg("Preparing audio interface for use.");
 265         ret = snd_pcm_prepare(devc->capture_handle);
 266         if (ret < 0) {
 267                 sr_err("Can't prepare audio interface for use: %s.",
 268                        snd_strerror(ret));
 269                 return SR_ERR;
 270         }
 271
 272         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 273         if (count < 1) {
 274                 sr_err("Unable to obtain poll descriptors count.");
 275                 return SR_ERR;
 276         }
 277         sr_spew("Obtained poll descriptor count: %d.", count);
 278
 279         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 280                 sr_err("Failed to malloc ufds.");
 281                 return SR_ERR_MALLOC;
 282         }
 283
 284         sr_err("Getting %d poll descriptors.", count);
 285         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 286         if (ret < 0) {
 287                 sr_err("Unable to obtain poll descriptors: %s.",
 288                        snd_strerror(ret));
 289                 g_free(devc->ufds);
 290                 return SR_ERR;
 291         }
 292
 293         /* Send header packet to the session bus. */
 294         sr_dbg("Sending SR_DF_HEADER packet.");
 295         packet.type = SR_DF_HEADER;
 296         packet.payload = (uint8_t *)&header;
 297         header.feed_version = 1;
 298         gettimeofday(&header.starttime, NULL);
 299         sr_session_send(devc->cb_data, &packet);
 300
 301         /* Send metadata about the SR_DF_ANALOG packets to come. */
 302         sr_dbg("Sending SR_DF_META_ANALOG packet.");
 303         packet.type = SR_DF_META_ANALOG;
 304         packet.payload = &meta;
 305         meta.num_probes = devc->num_probes;
 306         sr_session_send(devc->cb_data, &packet);
 307
 308         /* Poll every 10ms, or whenever some data comes in. */
 309         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 310                       alsa_receive_data, (void *)sdi);
 311
 312         // g_free(devc->ufds); /* FIXME */
 313
 314         return SR_OK;
 315 }
 316
 317 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 318 {
 319         struct sr_datafeed_packet packet;
 320         struct dev_context *devc;
 321
 322         devc = sdi->priv;
 323         devc->cb_data = cb_data;
 324
 325         sr_source_remove(devc->ufds[0].fd);
 326
 327         /* Send end packet to the session bus. */
 328         sr_dbg("Sending SR_DF_END packet.");
 329         packet.type = SR_DF_END;
 330         sr_session_send(cb_data, &packet);
 331
 332         return SR_OK;
 333 }
 334
 335 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 336         .name = "alsa",
 337         .longname = "ALSA driver",
 338         .api_version = 1,
 339         .init = hw_init,
 340         .cleanup = hw_cleanup,
 341         .scan = hw_scan,
 342         .dev_list = hw_dev_list,
 343         .dev_clear = clear_instances,
 344         .dev_open = hw_dev_open,
 345         .dev_close = hw_dev_close,
 346         .info_get = hw_info_get,
 347         .dev_config_set = hw_dev_config_set,
 348         .dev_acquisition_start = hw_dev_acquisition_start,
 349         .dev_acquisition_stop = hw_dev_acquisition_stop,
 350         .priv = NULL,
 351 };