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         return SR_OK;
  96 }
  97
  98 static int hw_dev_close(struct sr_dev_inst *sdi)
  99 {
 100         int ret;
 101         struct dev_context *devc;
 102
 103         devc = sdi->priv;
 104
 105         if (devc->capture_handle) {
 106                 sr_dbg("Closing PCM device.");
 107                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 108                         sr_err("Failed to close device: %s.",
 109                                snd_strerror(ret));
 110                         devc->capture_handle = NULL;
 111                 }
 112         } else {
 113                 sr_dbg("No capture handle, no need to close audio device.");
 114         }
 115
 116         return SR_OK;
 117 }
 118
 119 static int hw_cleanup(void)
 120 {
 121         clear_instances();
 122
 123         return SR_OK;
 124 }
 125
 126 static int config_get(int id, GVariant **data, const struct sr_dev_inst *sdi)
 127 {
 128         struct dev_context *devc;
 129
 130         switch (id) {
 131         case SR_CONF_SAMPLERATE:
 132                 devc = sdi->priv;
 133                 *data = g_variant_new_uint64(devc->cur_samplerate);
 134                 break;
 135         default:
 136                 return SR_ERR_NA;
 137         }
 138
 139         return SR_OK;
 140 }
 141
 142 static int config_set(int id, GVariant *data, const struct sr_dev_inst *sdi)
 143 {
 144         struct dev_context *devc;
 145
 146         devc = sdi->priv;
 147
 148         switch (id) {
 149         case SR_CONF_SAMPLERATE:
 150                 alsa_set_samplerate(sdi, g_variant_get_uint64(data));
 151                 break;
 152         case SR_CONF_LIMIT_SAMPLES:
 153                 devc->limit_samples = g_variant_get_uint64(data);
 154                 break;
 155         default:
 156                 return SR_ERR_NA;
 157         }
 158
 159         return SR_OK;
 160 }
 161
 162 static int config_list(int key, GVariant **data, const struct sr_dev_inst *sdi)
 163 {
 164         struct dev_context *devc;
 165         GVariant *gvar;
 166         GVariantBuilder gvb;
 167         int i;
 168
 169         (void)sdi;
 170
 171         switch (key) {
 172         case SR_CONF_DEVICE_OPTIONS:
 173                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
 174                                 hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
 175                 break;
 176         case SR_CONF_SAMPLERATE:
 177                 if (!sdi || !sdi->priv)
 178                         return SR_ERR_ARG;
 179                 devc = sdi->priv;
 180                 if (!devc->samplerates) {
 181                         sr_err("Instance did not contain a samplerate list.");
 182                         return SR_ERR_ARG;
 183                 }
 184                 for (i = 0; devc->samplerates[i]; i++)
 185                         ;
 186                 g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
 187                 gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
 188                                 devc->samplerates, i, sizeof(uint64_t));
 189                 g_variant_builder_add(&gvb, "{sv}", "samplerates", gvar);
 190                 *data = g_variant_builder_end(&gvb);
 191                 break;
 192         default:
 193                 return SR_ERR_NA;
 194         }
 195
 196         return SR_OK;
 197 }
 198
 199 static int hw_dev_acquisition_start(const struct sr_dev_inst *sdi,
 200                                     void *cb_data)
 201 {
 202         struct dev_context *devc;
 203         int count, ret;
 204         char *endianness;
 205
 206         devc = sdi->priv;
 207         devc->cb_data = cb_data;
 208         devc->num_samples = 0;
 209
 210         sr_dbg("Setting audio access type to RW/interleaved.");
 211         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 212                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 213         if (ret < 0) {
 214                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 215                 return SR_ERR;
 216         }
 217
 218         /* FIXME: Hardcoded for 16bits. */
 219         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 220                 endianness = "little endian";
 221         else
 222                 endianness = "big endian";
 223         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
 224         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 225                                            devc->hw_params,
 226                                            SND_PCM_FORMAT_S16);
 227         if (ret < 0) {
 228                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 229                 return SR_ERR;
 230         }
 231
 232         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 233                devc->cur_samplerate);
 234         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 235                                          (unsigned int)devc->cur_samplerate, 0);
 236         if (ret < 0) {
 237                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 238                 return SR_ERR;
 239         }
 240
 241         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 242         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 243                                              devc->hw_params, devc->num_probes);
 244         if (ret < 0) {
 245                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 246                 return SR_ERR;
 247         }
 248
 249         sr_dbg("Setting audio parameters.");
 250         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 251         if (ret < 0) {
 252                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 253                 return SR_ERR;
 254         }
 255
 256         sr_dbg("Preparing audio interface for use.");
 257         ret = snd_pcm_prepare(devc->capture_handle);
 258         if (ret < 0) {
 259                 sr_err("Can't prepare audio interface for use: %s.",
 260                        snd_strerror(ret));
 261                 return SR_ERR;
 262         }
 263
 264         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 265         if (count < 1) {
 266                 sr_err("Unable to obtain poll descriptors count.");
 267                 return SR_ERR;
 268         }
 269
 270         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 271                 sr_err("Failed to malloc ufds.");
 272                 return SR_ERR_MALLOC;
 273         }
 274
 275         sr_spew("Getting %d poll descriptors.", count);
 276         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 277         if (ret < 0) {
 278                 sr_err("Unable to obtain poll descriptors: %s.",
 279                        snd_strerror(ret));
 280                 g_free(devc->ufds);
 281                 return SR_ERR;
 282         }
 283
 284         /* Send header packet to the session bus. */
 285         std_session_send_df_header(cb_data, DRIVER_LOG_DOMAIN);
 286
 287         /* Poll every 10ms, or whenever some data comes in. */
 288         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 289                       alsa_receive_data, (void *)sdi);
 290
 291         // g_free(devc->ufds); /* FIXME */
 292
 293         return SR_OK;
 294 }
 295
 296 static int hw_dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 297 {
 298         struct sr_datafeed_packet packet;
 299         struct dev_context *devc;
 300
 301         devc = sdi->priv;
 302         devc->cb_data = cb_data;
 303
 304         sr_source_remove(devc->ufds[0].fd);
 305
 306         /* Send end packet to the session bus. */
 307         sr_dbg("Sending SR_DF_END packet.");
 308         packet.type = SR_DF_END;
 309         sr_session_send(cb_data, &packet);
 310
 311         return SR_OK;
 312 }
 313
 314 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 315         .name = "alsa",
 316         .longname = "ALSA driver",
 317         .api_version = 1,
 318         .init = hw_init,
 319         .cleanup = hw_cleanup,
 320         .scan = hw_scan,
 321         .dev_list = hw_dev_list,
 322         .dev_clear = clear_instances,
 323         .config_get = config_get,
 324         .config_set = config_set,
 325         .config_list = config_list,
 326         .dev_open = hw_dev_open,
 327         .dev_close = hw_dev_close,
 328         .dev_acquisition_start = hw_dev_acquisition_start,
 329         .dev_acquisition_stop = hw_dev_acquisition_stop,
 330         .priv = NULL,
 331 };