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 int32_t hwcaps[] = {
  31         SR_CONF_SAMPLERATE,
  32         SR_CONF_LIMIT_SAMPLES,
  33         SR_CONF_CONTINUOUS,
  34 };
  35
  36 SR_PRIV struct sr_dev_driver alsa_driver_info;
  37 static struct sr_dev_driver *di = &alsa_driver_info;
  38
  39 static int clear_instances(void)
  40 {
  41         struct drv_context *drvc;
  42
  43         if (!(drvc = di->priv))
  44                 return SR_OK;
  45
  46         g_slist_free_full(drvc->instances, (GDestroyNotify)alsa_dev_inst_clear);
  47         drvc->instances = NULL;
  48
  49         return SR_OK;
  50 }
  51
  52 static int hw_init(struct sr_context *sr_ctx)
  53 {
  54         return std_hw_init(sr_ctx, di, DRIVER_LOG_DOMAIN);
  55 }
  56
  57 static GSList *hw_scan(GSList *options)
  58 {
  59         return alsa_scan(options, di);
  60 }
  61
  62 static GSList *hw_dev_list(void)
  63 {
  64         return ((struct drv_context *)(di->priv))->instances;
  65 }
  66
  67 static int hw_dev_open(struct sr_dev_inst *sdi)
  68 {
  69         struct dev_context *devc;
  70         int ret;
  71
  72         devc = sdi->priv;
  73
  74         if (!(devc->hwdev)) {
  75                 sr_err("devc->hwdev was NULL.");
  76                 return SR_ERR_BUG;
  77         }
  78
  79         sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
  80         ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
  81                            SND_PCM_STREAM_CAPTURE, 0);
  82         if (ret < 0) {
  83                 sr_err("Can't open audio device: %s.", snd_strerror(ret));
  84                 return SR_ERR;
  85         }
  86
  87         sr_dbg("Initializing hardware parameter structure.");
  88         ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
  89         if (ret < 0) {
  90                 sr_err("Can't initialize hardware parameter structure: %s.",
  91                        snd_strerror(ret));
  92                 return SR_ERR;
  93         }
  94
  95         sdi->status = SR_ST_ACTIVE;
  96
  97         return SR_OK;
  98 }
  99
 100 static int hw_dev_close(struct sr_dev_inst *sdi)
 101 {
 102         int ret;
 103         struct dev_context *devc;
 104
 105         devc = sdi->priv;
 106
 107         if (devc->capture_handle) {
 108                 sr_dbg("Closing PCM device.");
 109                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 110                         sr_err("Failed to close device: %s.",
 111                                snd_strerror(ret));
 112                         devc->capture_handle = NULL;
 113             sdi->status = SR_ST_INACTIVE;
 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, GVariant **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 = g_variant_new_uint64(devc->cur_samplerate);
 137                 break;
 138         default:
 139                 return SR_ERR_NA;
 140         }
 141
 142         return SR_OK;
 143 }
 144
 145 static int config_set(int id, GVariant *data, const struct sr_dev_inst *sdi)
 146 {
 147         struct dev_context *devc;
 148
 149         if (sdi->status != SR_ST_ACTIVE)
 150                 return SR_ERR_DEV_CLOSED;
 151
 152         devc = sdi->priv;
 153
 154         switch (id) {
 155         case SR_CONF_SAMPLERATE:
 156                 alsa_set_samplerate(sdi, g_variant_get_uint64(data));
 157                 break;
 158         case SR_CONF_LIMIT_SAMPLES:
 159                 devc->limit_samples = g_variant_get_uint64(data);
 160                 break;
 161         default:
 162                 return SR_ERR_NA;
 163         }
 164
 165         return SR_OK;
 166 }
 167
 168 static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi)
 169 {
 170         struct dev_context *devc;
 171         GVariant *gvar;
 172         GVariantBuilder gvb;
 173         int i;
 174
 175         (void)sdi;
 176
 177         switch (key) {
 178         case SR_CONF_DEVICE_OPTIONS:
 179                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
 180                                 hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
 181                 break;
 182         case SR_CONF_SAMPLERATE:
 183                 if (!sdi || !sdi->priv)
 184                         return SR_ERR_ARG;
 185                 devc = sdi->priv;
 186                 if (!devc->samplerates) {
 187                         sr_err("Instance did not contain a samplerate list.");
 188                         return SR_ERR_ARG;
 189                 }
 190                 for (i = 0; devc->samplerates[i]; i++)
 191                         ;
 192                 g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
 193                 gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
 194                                 devc->samplerates, i, sizeof(uint64_t));
 195                 g_variant_builder_add(&gvb, "{sv}", "samplerates", gvar);
 196                 *data = g_variant_builder_end(&gvb);
 197                 break;
 198         default:
 199                 return SR_ERR_NA;
 200         }
 201
 202         return SR_OK;
 203 }
 204
 205 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 206                                     void *cb_data)
 207 {
 208         struct dev_context *devc;
 209         int count, ret;
 210         char *endianness;
 211
 212         if (sdi->status != SR_ST_ACTIVE)
 213                 return SR_ERR_DEV_CLOSED;
 214
 215         devc = sdi->priv;
 216         devc->cb_data = cb_data;
 217         devc->num_samples = 0;
 218
 219         sr_dbg("Setting audio access type to RW/interleaved.");
 220         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 221                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 222         if (ret < 0) {
 223                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 224                 return SR_ERR;
 225         }
 226
 227         /* FIXME: Hardcoded for 16bits. */
 228         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 229                 endianness = "little endian";
 230         else
 231                 endianness = "big endian";
 232         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
 233         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 234                                            devc->hw_params,
 235                                            SND_PCM_FORMAT_S16);
 236         if (ret < 0) {
 237                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 238                 return SR_ERR;
 239         }
 240
 241         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 242                devc->cur_samplerate);
 243         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 244                                          (unsigned int)devc->cur_samplerate, 0);
 245         if (ret < 0) {
 246                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 247                 return SR_ERR;
 248         }
 249
 250         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 251         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 252                                              devc->hw_params, devc->num_probes);
 253         if (ret < 0) {
 254                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 255                 return SR_ERR;
 256         }
 257
 258         sr_dbg("Setting audio parameters.");
 259         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 260         if (ret < 0) {
 261                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 262                 return SR_ERR;
 263         }
 264
 265         sr_dbg("Preparing audio interface for use.");
 266         ret = snd_pcm_prepare(devc->capture_handle);
 267         if (ret < 0) {
 268                 sr_err("Can't prepare audio interface for use: %s.",
 269                        snd_strerror(ret));
 270                 return SR_ERR;
 271         }
 272
 273         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 274         if (count < 1) {
 275                 sr_err("Unable to obtain poll descriptors count.");
 276                 return SR_ERR;
 277         }
 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_spew("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         std_session_send_df_header(cb_data, DRIVER_LOG_DOMAIN);
 295
 296         /* Poll every 10ms, or whenever some data comes in. */
 297         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 298                       alsa_receive_data, (void *)sdi);
 299
 300         // g_free(devc->ufds); /* FIXME */
 301
 302         return SR_OK;
 303 }
 304
 305 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 306 {
 307         struct sr_datafeed_packet packet;
 308         struct dev_context *devc;
 309
 310         devc = sdi->priv;
 311         devc->cb_data = cb_data;
 312
 313         sr_source_remove(devc->ufds[0].fd);
 314
 315         /* Send end packet to the session bus. */
 316         sr_dbg("Sending SR_DF_END packet.");
 317         packet.type = SR_DF_END;
 318         sr_session_send(cb_data, &packet);
 319
 320         return SR_OK;
 321 }
 322
 323 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 324         .name = "alsa",
 325         .longname = "ALSA driver",
 326         .api_version = 1,
 327         .init = hw_init,
 328         .cleanup = hw_cleanup,
 329         .scan = hw_scan,
 330         .dev_list = hw_dev_list,
 331         .dev_clear = clear_instances,
 332         .config_get = config_get,
 333         .config_set = config_set,
 334         .config_list = config_list,
 335         .dev_open = hw_dev_open,
 336         .dev_close = hw_dev_close,
 337         .dev_acquisition_start = hw_dev_acquisition_start,
 338         .dev_acquisition_stop = hw_dev_acquisition_stop,
 339         .priv = NULL,
 340 };