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 void clear_helper(void *priv)
  40 {
  41         struct dev_context *devc;
  42
  43         devc = priv;
  44
  45         snd_pcm_hw_params_free(devc->hw_params);
  46         g_free((void *)devc->samplerates);
  47 }
  48
  49 static int clear_instances(void)
  50 {
  51         return std_dev_clear(di, clear_helper);
  52 }
  53
  54 static int init(struct sr_context *sr_ctx)
  55 {
  56         return std_hw_init(sr_ctx, di, LOG_PREFIX);
  57 }
  58
  59 static GSList *scan(GSList *options)
  60 {
  61         return alsa_scan(options, di);
  62 }
  63
  64 static GSList *dev_list(void)
  65 {
  66         return ((struct drv_context *)(di->priv))->instances;
  67 }
  68
  69 static int dev_open(struct sr_dev_inst *sdi)
  70 {
  71         struct dev_context *devc;
  72         int ret;
  73
  74         devc = sdi->priv;
  75
  76         if (!(devc->hwdev)) {
  77                 sr_err("devc->hwdev was NULL.");
  78                 return SR_ERR_BUG;
  79         }
  80
  81         sr_dbg("Opening audio device '%s' for stream capture.", devc->hwdev);
  82         ret = snd_pcm_open(&devc->capture_handle, devc->hwdev,
  83                            SND_PCM_STREAM_CAPTURE, 0);
  84         if (ret < 0) {
  85                 sr_err("Can't open audio device: %s.", snd_strerror(ret));
  86                 return SR_ERR;
  87         }
  88
  89         sr_dbg("Initializing hardware parameter structure.");
  90         ret = snd_pcm_hw_params_any(devc->capture_handle, devc->hw_params);
  91         if (ret < 0) {
  92                 sr_err("Can't initialize hardware parameter structure: %s.",
  93                        snd_strerror(ret));
  94                 return SR_ERR;
  95         }
  96
  97         sdi->status = SR_ST_ACTIVE;
  98
  99         return SR_OK;
 100 }
 101
 102 static int dev_close(struct sr_dev_inst *sdi)
 103 {
 104         int ret;
 105         struct dev_context *devc;
 106
 107         devc = sdi->priv;
 108
 109         if (devc->capture_handle) {
 110                 sr_dbg("Closing PCM device.");
 111                 if ((ret = snd_pcm_close(devc->capture_handle)) < 0) {
 112                         sr_err("Failed to close device: %s.",
 113                                snd_strerror(ret));
 114                         devc->capture_handle = NULL;
 115             sdi->status = SR_ST_INACTIVE;
 116                 }
 117         } else {
 118                 sr_dbg("No capture handle, no need to close audio device.");
 119         }
 120
 121         return SR_OK;
 122 }
 123
 124 static int cleanup(void)
 125 {
 126         return clear_instances();
 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         switch (key) {
 176         case SR_CONF_DEVICE_OPTIONS:
 177                 *data = g_variant_new_fixed_array(G_VARIANT_TYPE_INT32,
 178                                 hwcaps, ARRAY_SIZE(hwcaps), sizeof(int32_t));
 179                 break;
 180         case SR_CONF_SAMPLERATE:
 181                 if (!sdi || !sdi->priv)
 182                         return SR_ERR_ARG;
 183                 devc = sdi->priv;
 184                 if (!devc->samplerates) {
 185                         sr_err("Instance did not contain a samplerate list.");
 186                         return SR_ERR_ARG;
 187                 }
 188                 for (i = 0; devc->samplerates[i]; i++)
 189                         ;
 190                 g_variant_builder_init(&gvb, G_VARIANT_TYPE("a{sv}"));
 191                 gvar = g_variant_new_fixed_array(G_VARIANT_TYPE("t"),
 192                                 devc->samplerates, i, sizeof(uint64_t));
 193                 g_variant_builder_add(&gvb, "{sv}", "samplerates", gvar);
 194                 *data = g_variant_builder_end(&gvb);
 195                 break;
 196         default:
 197                 return SR_ERR_NA;
 198         }
 199
 200         return SR_OK;
 201 }
 202
 203 static int dev_acquisition_start(const struct sr_dev_inst *sdi, void *cb_data)
 204 {
 205         struct dev_context *devc;
 206         int count, ret;
 207         char *endianness;
 208
 209         if (sdi->status != SR_ST_ACTIVE)
 210                 return SR_ERR_DEV_CLOSED;
 211
 212         devc = sdi->priv;
 213         devc->cb_data = cb_data;
 214         devc->num_samples = 0;
 215
 216         sr_dbg("Setting audio access type to RW/interleaved.");
 217         ret = snd_pcm_hw_params_set_access(devc->capture_handle,
 218                         devc->hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
 219         if (ret < 0) {
 220                 sr_err("Can't set audio access type: %s.", snd_strerror(ret));
 221                 return SR_ERR;
 222         }
 223
 224         /* FIXME: Hardcoded for 16bits. */
 225         if (SND_PCM_FORMAT_S16 == SND_PCM_FORMAT_S16_LE)
 226                 endianness = "little endian";
 227         else
 228                 endianness = "big endian";
 229         sr_dbg("Setting audio sample format to signed 16bit (%s).", endianness);
 230         ret = snd_pcm_hw_params_set_format(devc->capture_handle,
 231                                            devc->hw_params,
 232                                            SND_PCM_FORMAT_S16);
 233         if (ret < 0) {
 234                 sr_err("Can't set audio sample format: %s.", snd_strerror(ret));
 235                 return SR_ERR;
 236         }
 237
 238         sr_dbg("Setting audio samplerate to %" PRIu64 "Hz.",
 239                devc->cur_samplerate);
 240         ret = snd_pcm_hw_params_set_rate(devc->capture_handle, devc->hw_params,
 241                                          (unsigned int)devc->cur_samplerate, 0);
 242         if (ret < 0) {
 243                 sr_err("Can't set audio sample rate: %s.", snd_strerror(ret));
 244                 return SR_ERR;
 245         }
 246
 247         sr_dbg("Setting audio channel count to %d.", devc->num_probes);
 248         ret = snd_pcm_hw_params_set_channels(devc->capture_handle,
 249                                              devc->hw_params, devc->num_probes);
 250         if (ret < 0) {
 251                 sr_err("Can't set channel count: %s.", snd_strerror(ret));
 252                 return SR_ERR;
 253         }
 254
 255         sr_dbg("Setting audio parameters.");
 256         ret = snd_pcm_hw_params(devc->capture_handle, devc->hw_params);
 257         if (ret < 0) {
 258                 sr_err("Can't set parameters: %s.", snd_strerror(ret));
 259                 return SR_ERR;
 260         }
 261
 262         sr_dbg("Preparing audio interface for use.");
 263         ret = snd_pcm_prepare(devc->capture_handle);
 264         if (ret < 0) {
 265                 sr_err("Can't prepare audio interface for use: %s.",
 266                        snd_strerror(ret));
 267                 return SR_ERR;
 268         }
 269
 270         count = snd_pcm_poll_descriptors_count(devc->capture_handle);
 271         if (count < 1) {
 272                 sr_err("Unable to obtain poll descriptors count.");
 273                 return SR_ERR;
 274         }
 275
 276         if (!(devc->ufds = g_try_malloc(count * sizeof(struct pollfd)))) {
 277                 sr_err("Failed to malloc ufds.");
 278                 return SR_ERR_MALLOC;
 279         }
 280
 281         sr_spew("Getting %d poll descriptors.", count);
 282         ret = snd_pcm_poll_descriptors(devc->capture_handle, devc->ufds, count);
 283         if (ret < 0) {
 284                 sr_err("Unable to obtain poll descriptors: %s.",
 285                        snd_strerror(ret));
 286                 g_free(devc->ufds);
 287                 return SR_ERR;
 288         }
 289
 290         /* Send header packet to the session bus. */
 291         std_session_send_df_header(cb_data, LOG_PREFIX);
 292
 293         /* Poll every 10ms, or whenever some data comes in. */
 294         sr_source_add(devc->ufds[0].fd, devc->ufds[0].events, 10,
 295                       alsa_receive_data, (void *)sdi);
 296
 297         // g_free(devc->ufds); /* FIXME */
 298
 299         return SR_OK;
 300 }
 301
 302 static int dev_acquisition_stop(struct sr_dev_inst *sdi, void *cb_data)
 303 {
 304         struct sr_datafeed_packet packet;
 305         struct dev_context *devc;
 306
 307         devc = sdi->priv;
 308         devc->cb_data = cb_data;
 309
 310         sr_source_remove(devc->ufds[0].fd);
 311
 312         /* Send end packet to the session bus. */
 313         sr_dbg("Sending SR_DF_END packet.");
 314         packet.type = SR_DF_END;
 315         sr_session_send(cb_data, &packet);
 316
 317         return SR_OK;
 318 }
 319
 320 SR_PRIV struct sr_dev_driver alsa_driver_info = {
 321         .name = "alsa",
 322         .longname = "ALSA driver",
 323         .api_version = 1,
 324         .init = init,
 325         .cleanup = cleanup,
 326         .scan = scan,
 327         .dev_list = dev_list,
 328         .dev_clear = clear_instances,
 329         .config_get = config_get,
 330         .config_set = config_set,
 331         .config_list = config_list,
 332         .dev_open = dev_open,
 333         .dev_close = dev_close,
 334         .dev_acquisition_start = dev_acquisition_start,
 335         .dev_acquisition_stop = dev_acquisition_stop,
 336         .priv = NULL,
 337 };