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 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 hw_info_get(int info_id, const void **data,
 144                        const struct sr_dev_inst *sdi)
 145 {
 146         struct dev_context *devc;
 147
 148         if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
 149                 devc = sdi->priv;
 150
 151         switch (info_id) {
 152         case SR_DI_HWCAPS:
 153                 *data = hwcaps;
 154                 break;
 155         case SR_DI_CUR_SAMPLERATE:
 156                 *data = &devc->cur_samplerate;
 157                 break;
 158         case SR_DI_SAMPLERATES:
 159                 if (!devc->supp_rates.list) {
 160                         sr_err("Instance did not contain a samplerate list.");
 161                         return SR_ERR_ARG;
 162                 }
 163                 *data = &devc->supp_rates;
 164                 break;
 165         default:
 166                 sr_err("Invalid info_id: %d.", info_id);
 167                 return SR_ERR_ARG;
 168         }
 169
 170         return SR_OK;
 171 }
 172
 173 static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 174                              const void *value)
 175 {
 176         struct dev_context *devc;
 177
 178         devc = sdi->priv;
 179
 180         switch (hwcap) {
 181         case SR_HWCAP_SAMPLERATE:
 182                 alsa_set_samplerate(sdi, *(const uint64_t *)value);
 183                 break;
 184         case SR_HWCAP_LIMIT_SAMPLES:
 185                 devc->limit_samples = *(const uint64_t *)value;
 186                 break;
 187         default:
 188                 sr_err("Unknown capability: %d.", hwcap);
 189                 return SR_ERR;
 190         }
 191
 192         return SR_OK;
 193 }
 194
 195 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 196                                     void *cb_data)
 197 {
 198         struct sr_datafeed_packet packet;
 199         struct sr_datafeed_header header;
 200         struct sr_datafeed_meta_analog meta;
 201         struct dev_context *devc;
 202         int count, ret;
 203         char *endianness;
 204
 205         devc = sdi->priv;
 206         devc->cb_data = cb_data;
 207         devc->num_samples = 0;
 208
 209         sr_dbg("Setting audio access type to RW/interleaved.");
 210         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 211                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 212         if (ret < 0) {
 213                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 214                 return SR_ERR;
 215         }
 216
 217         /* FIXME: Hardcoded for 16bits. */
 218         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 219                 endianness = "little endian";
 220         else
 221                 endianness = "big endian";
 222         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
 223         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 224                                            devc->hw_params,
 225                                            SND_PCM_FORMAT_S16);
 226         if (ret < 0) {
 227                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 228                 return SR_ERR;
 229         }
 230
 231         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 232                devc->cur_samplerate);
 233         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 234                                          (unsigned int)devc->cur_samplerate, 0);
 235         if (ret < 0) {
 236                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 237                 return SR_ERR;
 238         }
 239
 240         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 241         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 242                                              devc->hw_params, devc->num_probes);
 243         if (ret < 0) {
 244                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 245                 return SR_ERR;
 246         }
 247
 248         sr_dbg("Setting audio parameters.");
 249         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 250         if (ret < 0) {
 251                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 252                 return SR_ERR;
 253         }
 254
 255         sr_dbg("Preparing audio interface for use.");
 256         ret = snd_pcm_prepare(devc->capture_handle);
 257         if (ret < 0) {
 258                 sr_err("Can't prepare audio interface for use: %s.",
 259                        snd_strerror(ret));
 260                 return SR_ERR;
 261         }
 262
 263         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 264         if (count < 1) {
 265                 sr_err("Unable to obtain poll descriptors count.");
 266                 return SR_ERR;
 267         }
 268
 269         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 270                 sr_err("Failed to malloc ufds.");
 271                 return SR_ERR_MALLOC;
 272         }
 273
 274         sr_err("Getting %d poll descriptors.", count);
 275         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 276         if (ret < 0) {
 277                 sr_err("Unable to obtain poll descriptors: %s.",
 278                        snd_strerror(ret));
 279                 g_free(devc->ufds);
 280                 return SR_ERR;
 281         }
 282
 283         /* Send header packet to the session bus. */
 284         sr_dbg("Sending SR_DF_HEADER packet.");
 285         packet.type = SR_DF_HEADER;
 286         packet.payload = (uint8_t *)&header;
 287         header.feed_version = 1;
 288         gettimeofday(&header.starttime, NULL);
 289         sr_session_send(devc->cb_data, &packet);
 290
 291         /* Send metadata about the SR_DF_ANALOG packets to come. */
 292         sr_dbg("Sending SR_DF_META_ANALOG packet.");
 293         packet.type = SR_DF_META_ANALOG;
 294         packet.payload = &meta;
 295         meta.num_probes = devc->num_probes;
 296         sr_session_send(devc->cb_data, &packet);
 297
 298         /* Poll every 10ms, or whenever some data comes in. */
 299         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 300                       alsa_receive_data, (void *)sdi);
 301
 302         // g_free(devc->ufds); /* FIXME */
 303
 304         return SR_OK;
 305 }
 306
 307 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 308 {
 309         struct sr_datafeed_packet packet;
 310         struct dev_context *devc;
 311
 312         devc = sdi->priv;
 313         devc->cb_data = cb_data;
 314
 315         sr_source_remove(devc->ufds[0].fd);
 316
 317         /* Send end packet to the session bus. */
 318         sr_dbg("Sending SR_DF_END packet.");
 319         packet.type = SR_DF_END;
 320         sr_session_send(cb_data, &packet);
 321
 322         return SR_OK;
 323 }
 324
 325 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 326         .name = "alsa",
 327         .longname = "ALSA driver",
 328         .api_version = 1,
 329         .init = hw_init,
 330         .cleanup = hw_cleanup,
 331         .scan = hw_scan,
 332         .dev_list = hw_dev_list,
 333         .dev_clear = clear_instances,
 334         .dev_open = hw_dev_open,
 335         .dev_close = hw_dev_close,
 336         .info_get = hw_info_get,
 337         .dev_config_set = hw_dev_config_set,
 338         .dev_acquisition_start = hw_dev_acquisition_start,
 339         .dev_acquisition_stop = hw_dev_acquisition_stop,
 340         .priv = NULL,
 341 };