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 static const int hwcaps[] = {
  32         SR_HWCAP_SAMPLERATE,
  33         SR_HWCAP_LIMIT_SAMPLES,
  34         SR_HWCAP_CONTINUOUS,
  35         0,
  36 };
  37
  38 static const char *probe_names[] = {
  39         "Channel 0", "Channel 1",
  40         NULL,
  41 };
  42
  43 SR_PRIV struct sr_dev_driver alsa_driver_info;
  44 static struct sr_dev_driver *di = &alsa_driver_info;
  45
  46 static int clear_instances(void)
  47 {
  48         struct drv_context *drvc;
  49
  50         if (!(drvc = di->priv))
  51                 return SR_OK;
  52
  53         g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
  54         drvc->instances = NULL;
  55
  56         return SR_OK;
  57 }
  58
  59 static int hw_init(struct sr_context *sr_ctx)
  60 {
  61         struct drv_context *drvc;
  62
  63         if (!(drvc = g_try_malloc0(sizeof(struct drv_context)))) {
  64                 sr_err("Driver context malloc failed.");
  65                 return SR_ERR_MALLOC;
  66         }
  67
  68         drvc->sr_ctx = sr_ctx;
  69         di->priv = drvc;
  70
  71         return SR_OK;
  72 }
  73
  74 static GSList *hw_scan(GSList *options)
  75 {
  76         return alsa_scan(options, di);
  77 }
  78
  79 static GSList *hw_dev_list(void)
  80 {
  81         struct drv_context *drvc;
  82
  83         drvc = di->priv;
  84
  85         return drvc->instances;
  86 }
  87
  88 static int hw_dev_open(struct sr_dev_inst *sdi)
  89 {
  90         struct dev_context *devc;
  91         int ret;
  92
  93         devc = sdi->priv;
  94
  95         if (!(devc->hwdev)) {
  96                 sr_err("devc->hwdev was NULL.");
  97                 return SR_ERR_BUG;
  98         }
  99
 100         sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
 101         ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
 102                            SND_PCM_STREAM_CAPTURE, 0);
 103         if (ret < 0) {
 104                 sr_err("Can't open audio device: %s.", snd_strerror(ret));
 105                 return SR_ERR;
 106         }
 107
 108         sr_dbg("Initializing hardware parameter structure.");
 109         ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
 110         if (ret < 0) {
 111                 sr_err("Can't initialize hardware parameter structure: %s.",
 112                        snd_strerror(ret));
 113                 return SR_ERR;
 114         }
 115
 116         return SR_OK;
 117 }
 118
 119 static int hw_dev_close(struct sr_dev_inst *sdi)
 120 {
 121         int ret;
 122         struct dev_context *devc;
 123
 124         devc = sdi->priv;
 125
 126         sr_dbg("Closing device.");
 127
 128         if (devc->capture_handle) {
 129                 sr_dbg("Closing PCM device.");
 130                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 131                         sr_err("Failed to close device: %s.",
 132                                snd_strerror(ret));
 133                         devc->capture_handle = NULL;
 134                 }
 135         } else {
 136                 sr_dbg("No capture handle, no need to close audio device.");
 137         }
 138
 139         return SR_OK;
 140 }
 141
 142 static int hw_cleanup(void)
 143 {
 144         clear_instances();
 145
 146         return SR_OK;
 147 }
 148
 149 static int hw_info_get(int info_id, const void **data,
 150                        const struct sr_dev_inst *sdi)
 151 {
 152         struct dev_context *devc;
 153
 154         if (info_id != SR_DI_HWCAPS) /* For SR_DI_HWCAPS sdi will be NULL. */
 155                 devc = sdi->priv;
 156
 157         switch (info_id) {
 158         case SR_DI_HWCAPS:
 159                 *data = hwcaps;
 160                 break;
 161         case SR_DI_NUM_PROBES:
 162                 *data = &devc->num_probes;
 163                 break;
 164         case SR_DI_PROBE_NAMES:
 165                 *data = probe_names;
 166                 break;
 167         case SR_DI_CUR_SAMPLERATE:
 168                 *data = &devc->cur_samplerate;
 169                 break;
 170         case SR_DI_SAMPLERATES:
 171                 if (!devc->supp_rates.list) {
 172                         sr_err("Instance did not contain a samplerate list");
 173                         return SR_ERR_ARG;
 174                 }
 175                 *data = &devc->supp_rates;
 176                 break;
 177         default:
 178                 sr_err("Invalid info_id: %d.", info_id);
 179                 return SR_ERR_ARG;
 180         }
 181
 182         return SR_OK;
 183 }
 184
 185 static int hw_dev_config_set(const struct sr_dev_inst *sdi, int hwcap,
 186                              const void *value)
 187 {
 188         struct dev_context *devc;
 189
 190         devc = sdi->priv;
 191
 192         switch (hwcap) {
 193         case SR_HWCAP_SAMPLERATE:
 194                 alsa_set_samplerate(sdi, *(const uint64_t *)value);
 195                 break;
 196         case SR_HWCAP_LIMIT_SAMPLES:
 197                 devc->limit_samples = *(const uint64_t *)value;
 198                 break;
 199         default:
 200                 sr_err("Unknown capability: %d.", hwcap);
 201                 return SR_ERR;
 202         }
 203
 204         return SR_OK;
 205 }
 206
 207 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 208                                     void *cb_data)
 209 {
 210         struct sr_datafeed_packet packet;
 211         struct sr_datafeed_header header;
 212         struct sr_datafeed_meta_analog meta;
 213         struct dev_context *devc;
 214         int count, ret;
 215         char *endianess;
 216
 217         devc = sdi->priv;
 218         devc->cb_data = cb_data;
 219         devc->num_samples = 0;
 220
 221         sr_dbg("Setting audio access type to RW/interleaved.");
 222         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 223                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 224         if (ret < 0) {
 225                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 226                 return SR_ERR;
 227         }
 228
 229         /* FIXME: Hardcoded for 16bits. */
 230         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 231                 endianess = "lilltle endian";
 232         else
 233                 endianess = "big endian";
 234         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianess);
 235         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 236                                            devc->hw_params,
 237                                            SND_PCM_FORMAT_S16);
 238         if (ret < 0) {
 239                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 240                 return SR_ERR;
 241         }
 242
 243         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 244                devc->cur_samplerate);
 245         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 246                                          (unsigned int)devc->cur_samplerate, 0);
 247         if (ret < 0) {
 248                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 249                 return SR_ERR;
 250         }
 251
 252         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 253         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 254                                              devc->hw_params, devc->num_probes);
 255         if (ret < 0) {
 256                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 257                 return SR_ERR;
 258         }
 259
 260         sr_dbg("Setting audio parameters.");
 261         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 262         if (ret < 0) {
 263                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 264                 return SR_ERR;
 265         }
 266
 267         sr_dbg("Preparing audio interface for use.");
 268         ret = snd_pcm_prepare(devc->capture_handle);
 269         if (ret < 0) {
 270                 sr_err("Can't prepare audio interface for use: %s.",
 271                        snd_strerror(ret));
 272                 return SR_ERR;
 273         }
 274
 275         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 276         if (count < 1) {
 277                 sr_err("Unable to obtain poll descriptors count.");
 278                 return SR_ERR;
 279         }
 280         sr_spew("Obtained poll descriptor count: %d.", count);
 281
 282         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 283                 sr_err("Failed to malloc ufds.");
 284                 return SR_ERR_MALLOC;
 285         }
 286
 287         sr_err("Getting %d poll descriptors.", count);
 288         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 289         if (ret < 0) {
 290                 sr_err("Unable to obtain poll descriptors: %s.",
 291                        snd_strerror(ret));
 292                 g_free(devc->ufds);
 293                 return SR_ERR;
 294         }
 295
 296         /* Send header packet to the session bus. */
 297         sr_dbg("Sending SR_DF_HEADER packet.");
 298         packet.type = SR_DF_HEADER;
 299         packet.payload = (uint8_t *)&header;
 300         header.feed_version = 1;
 301         gettimeofday(&header.starttime, NULL);
 302         sr_session_send(devc->cb_data, &packet);
 303
 304         /* Send metadata about the SR_DF_ANALOG packets to come. */
 305         sr_dbg("Sending SR_DF_META_ANALOG packet.");
 306         packet.type = SR_DF_META_ANALOG;
 307         packet.payload = &meta;
 308         meta.num_probes = devc->num_probes;
 309         sr_session_send(devc->cb_data, &packet);
 310
 311         /* Poll every 10ms, or whenever some data comes in. */
 312         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 313                       alsa_receive_data, (void *)sdi);
 314
 315         // g_free(devc->ufds); /* FIXME */
 316
 317         return SR_OK;
 318 }
 319
 320 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 321 {
 322         struct sr_datafeed_packet packet;
 323         struct dev_context *devc;
 324
 325         devc = sdi->priv;
 326         devc->cb_data = cb_data;
 327
 328         sr_source_remove(devc->ufds[0].fd);
 329
 330         /* Send end packet to the session bus. */
 331         sr_dbg("Sending SR_DF_END packet.");
 332         packet.type = SR_DF_END;
 333         sr_session_send(cb_data, &packet);
 334
 335         return SR_OK;
 336 }
 337
 338 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 339         .name = "alsa",
 340         .longname = "ALSA driver",
 341         .api_version = 1,
 342         .init = hw_init,
 343         .cleanup = hw_cleanup,
 344         .scan = hw_scan,
 345         .dev_list = hw_dev_list,
 346         .dev_clear = clear_instances,
 347         .dev_open = hw_dev_open,
 348         .dev_close = hw_dev_close,
 349         .info_get = hw_info_get,
 350         .dev_config_set = hw_dev_config_set,
 351         .dev_acquisition_start = hw_dev_acquisition_start,
 352         .dev_acquisition_stop = hw_dev_acquisition_stop,
 353         .priv = NULL,
 354 };