X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=hardware%2Falsa%2Fprotocol.c;h=74326205042a48511e5a5a824152c5d058b7ca55;hb=82b904b173f1443c4d6bdebdf1a7f0dda01c4982;hp=a501ec8f97bb9b7d048169a9cce7c0e2ea2d0ff2;hpb=729850c9e7dfa2c08c11a025d5a54b8e8e803f3c;p=libsigrok.git diff --git a/hardware/alsa/protocol.c b/hardware/alsa/protocol.c index a501ec8f..74326205 100644 --- a/hardware/alsa/protocol.c +++ b/hardware/alsa/protocol.c @@ -20,9 +20,40 @@ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ -#include "protocol.h" #include "libsigrok.h" #include "libsigrok-internal.h" +#include "protocol.h" + +/* + * There is no way to get a list of supported samplerates from ALSA. We could + * use the 'plughw' interface of ALSA, in which case any format and/or + * samplerate conversion would be performed by ALSA. However, we are interested + * in the hardware capabilities, and have the infrastructure in sigrok to do so. + * We therefore use the 'hw' interface. The downside is that the code gets a + * little bulkier, as we have to keep track of the hardware capabilities, and + * only use those that the hardware supports. Case in point, ALSA will not give + * us a list of capabilities; we have to test for each one individually. Hence, + * we keep lists of the capabilities we are interested in. + */ +static const unsigned int rates[] = { + 5512, + 8000, + 11025, + 12000, + 16000, + 22050, + 24000, + 32000, + 44100, + 48000, + 64000, + 88200, + 96000, + 176400, + 192000, + 384000, + 768000, /* Yes, there are sound cards that go this high. */ +}; static void alsa_scan_handle_dev(GSList **devices, const char *cardname, const char *alsaname, @@ -34,17 +65,21 @@ static void alsa_scan_handle_dev(GSList **devices, struct dev_context *devc = NULL; struct sr_probe *probe; int ret; - unsigned int i, channels; + unsigned int i, offset, channels, minrate, maxrate, rate; + uint64_t hwrates[ARRAY_SIZE(rates)]; + uint64_t *devrates = NULL; snd_pcm_t *temp_handle = NULL; snd_pcm_hw_params_t *hw_params = NULL; + char p_name[32]; drvc = di->priv; /* - * Get the number of input channels. Those are our sigrok probes. - * Getting this information needs a detour. We need to open the device, - * then query it for the number of channels. A side-effect of is that we - * create a snd_pcm_hw_params_t object. We take advantage of the + * Get hardware parameters: + * The number of channels, for example, are our sigrok probes. Getting + * this information needs a detour. We need to open the device, then + * query it and/or test different parameters. A side-effect of is that + * we create a snd_pcm_hw_params_t object. We take advantage of the * situation, and pass this object in our dev_context->hw_params, * eliminating the need to free() it and malloc() it later. */ @@ -70,32 +105,59 @@ static void alsa_scan_handle_dev(GSList **devices, snd_pcm_hw_params_get_channels_max(hw_params, &channels); - snd_pcm_close(temp_handle); + /* + * We need to test if each samplerate between min and max is supported. + * Unfortunately, ALSA won't just throw a list at us. + */ + snd_pcm_hw_params_get_rate_min(hw_params, &minrate, 0); + snd_pcm_hw_params_get_rate_max(hw_params, &maxrate, 0); + for (i = 0, offset = 0; i < ARRAY_SIZE(rates); i++) { + rate = rates[i]; + if (rate < minrate) + continue; + if (rate > maxrate) + break; + ret = snd_pcm_hw_params_test_rate(temp_handle, hw_params, + rate, 0); + if (ret >= 0) + hwrates[offset++] = rate; + } + hwrates[offset++] = 0; + + if ((ret = snd_pcm_close(temp_handle)) < 0) + sr_err("Failed to close device: %s.", snd_strerror(ret)); temp_handle = NULL; /* - * Now we are done querying the number of channels - * If we made it here, then it's time to create our sigrok device. + * Now we are done querying the hardware parameters. + * If we made it here, we know everything we want to know, and it's + * time to create our sigrok device. */ sr_info("Device %s has %d channels.", alsaname, channels); if (!(sdi = sr_dev_inst_new(0, SR_ST_INACTIVE, "ALSA:", cardname, snd_pcm_info_get_name(pcminfo)))) { - sr_err("Device instance malloc failed."); + sr_err("Failed to create device instance."); goto scan_error_cleanup; } if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) { sr_err("Device context malloc failed."); goto scan_error_cleanup; } + if (!(devrates = g_try_malloc(offset * sizeof(uint64_t)))) { + sr_err("Samplerate list malloc failed."); + goto scan_error_cleanup; + } devc->hwdev = g_strdup(alsaname); devc->num_probes = channels; devc->hw_params = hw_params; + memcpy(devrates, hwrates, offset * sizeof(uint64_t)); + devc->samplerates = devrates; + sdi->priv = devc; sdi->driver = di; for (i = 0; i < devc->num_probes; i++) { - char p_name[32]; snprintf(p_name, sizeof(p_name), "Ch_%d", i); if (!(probe = sr_probe_new(0, SR_PROBE_ANALOG, TRUE, p_name))) goto scan_error_cleanup; @@ -109,22 +171,27 @@ static void alsa_scan_handle_dev(GSList **devices, scan_error_cleanup: if (devc) { if (devc->hwdev) - g_free((void*)devc->hwdev); + g_free(devc->hwdev); g_free(devc); } + if (devrates) + g_free(devrates); if (sdi) sr_dev_inst_free(sdi); if (hw_params) snd_pcm_hw_params_free(hw_params); if (temp_handle) - snd_pcm_close(temp_handle); - return; + if ((ret = snd_pcm_close(temp_handle)) < 0) { + sr_err("Failed to close device: %s.", + snd_strerror(ret)); + } } /** - * \brief Scan all alsa devices, and translate them to sigrok devices + * Scan all alsa devices, and translate them to sigrok devices. + * + * Each alsa device (not alsa card) gets its own sigrok device. * - * Each alsa device (not alsa card) gets its own sigrok device * For example, * hw:1,0 == sigrok device 0 * hw:1,1 == sigrok device 1 @@ -132,9 +199,9 @@ scan_error_cleanup: * hw:2,1 == sigrok device 3 * hw:2,2 == sigrok device 4 * [...] - * \n + * * We don't currently look at alsa subdevices. We only use subdevice 0. - * Every input device will have a its own channels (Left, Right, etc). Each of + * Every input device will have its own channels (left, right, etc). Each of * those channels gets mapped to a different sigrok probe. A device with 4 * channels will have 4 probes from sigrok's perspective. */ @@ -145,36 +212,39 @@ SR_PRIV GSList *alsa_scan(GSList *options, struct sr_dev_driver *di) int card, ret, dev; snd_ctl_card_info_t *info; snd_pcm_info_t *pcminfo; - const char* cardname; + const char *cardname; + char hwcard[32], hwdev[32]; + /* TODO */ (void)options; - if (snd_ctl_card_info_malloc(&info) < 0) { - sr_err("Cannot malloc card info."); + if ((ret = snd_ctl_card_info_malloc(&info)) < 0) { + sr_dbg("Failed to malloc card info: %s.", snd_strerror(ret)); return NULL; } - if (snd_pcm_info_malloc(&pcminfo) < 0) { - sr_err("Cannot malloc pcm info."); + if ((ret = snd_pcm_info_malloc(&pcminfo) < 0)) { + sr_dbg("Cannot malloc pcm info: %s.", snd_strerror(ret)); return NULL; } card = -1; while (snd_card_next(&card) >= 0 && card >= 0) { - char hwcard[32]; snprintf(hwcard, sizeof(hwcard), "hw:%d", card); if ((ret = snd_ctl_open(&handle, hwcard, 0)) < 0) { - sr_err("Cannot open (%i): %s", card, snd_strerror(ret)); + sr_dbg("Cannot open (%d): %s.", card, snd_strerror(ret)); continue; } if ((ret = snd_ctl_card_info(handle, info)) < 0) { - sr_err("Cannot get hardware info (%i): %s", + sr_dbg("Cannot get hardware info (%d): %s.", card, snd_strerror(ret)); - snd_ctl_close(handle); + if ((ret = snd_ctl_close(handle)) < 0) { + sr_dbg("Cannot close device (%d): %s.", + card, snd_strerror(ret)); + } continue; } dev = -1; while (snd_ctl_pcm_next_device(handle, &dev) >= 0 && dev >= 0) { - char hwdev[32]; snprintf(hwdev, sizeof(hwdev), "%s,%d", hwcard, dev); /* * TODO: We always use subdevice 0, but we have yet to @@ -186,13 +256,13 @@ SR_PRIV GSList *alsa_scan(GSList *options, struct sr_dev_driver *di) snd_pcm_info_set_stream(pcminfo, SND_PCM_STREAM_CAPTURE); if ((ret = snd_ctl_pcm_info(handle, pcminfo)) < 0) { - sr_err("Cannot get device info: %s", - snd_strerror(ret)); + sr_dbg("Cannot get device info (%s): %s.", + hwdev, snd_strerror(ret)); continue; } cardname = snd_ctl_card_info_get_name(info); - sr_info("card %i: %s [%s], device %i: %s [%s]", + sr_info("card %d: %s [%s], device %d: %s [%s]", card, snd_ctl_card_info_get_id(info), cardname, dev, snd_pcm_info_get_id(pcminfo), snd_pcm_info_get_name(pcminfo)); @@ -200,7 +270,10 @@ SR_PRIV GSList *alsa_scan(GSList *options, struct sr_dev_driver *di) alsa_scan_handle_dev(&devices, cardname, hwdev, di, pcminfo); } - snd_ctl_close(handle); + if ((ret = snd_ctl_close(handle)) < 0) { + sr_dbg("Cannot close device (%d): %s.", + card, snd_strerror(ret)); + } } snd_pcm_info_free(pcminfo); @@ -221,9 +294,53 @@ SR_PRIV void alsa_dev_inst_clear(struct sr_dev_inst *sdi) return; snd_pcm_hw_params_free(devc->hw_params); + g_free((void*)devc->samplerates); sr_dev_inst_free(sdi); } +/** + * Set the samplerate of the ALSA device. + * + * Changes the samplerate of the given ALSA device if the specified samplerate + * is supported by the hardware. + * + * The new samplerate is recorded, but it is not applied to the hardware. The + * samplerate is applied to the hardware only when acquisition is started via + * dev_acquisition_start(), and cannot be changed during acquisition. To change + * the samplerate, several steps are needed: + * + * 1) If acquisition is running, it must first be stopped. + * 2) dev_config_set() must be called with the new samplerate. + * 3) When starting a new acquisition, the new samplerate is applied. + * + */ +SR_PRIV int alsa_set_samplerate(const struct sr_dev_inst *sdi, + uint64_t newrate) +{ + struct dev_context *devc; + size_t i; + uint64_t rate = 0; + + if (!(devc = sdi->priv)) + return SR_ERR_ARG; + + i = 0; + do { + if (newrate == devc->samplerates[i]) { + rate = newrate; + break; + } + } while (devc->samplerates[i++] != 0); + + if (!rate) { + sr_err("Sample rate %" PRIu64 " not supported.", newrate); + return SR_ERR_ARG; + } + + devc->cur_samplerate = rate; + return SR_OK; +} + SR_PRIV int alsa_receive_data(int fd, int revents, void *cb_data) { struct sr_dev_inst *sdi; @@ -233,7 +350,7 @@ SR_PRIV int alsa_receive_data(int fd, int revents, void *cb_data) int16_t inbuf[4096]; int i, x, count, offset, samples_to_get; int16_t tmp16; - const float s16norm = 1 / (float)(1<<15); + const float s16norm = 1 / (float)(1 << 15); (void)fd; (void)revents; @@ -273,12 +390,13 @@ SR_PRIV int alsa_receive_data(int fd, int revents, void *cb_data) */ for (i = 0; i < count; i += devc->num_probes) { for (x = 0; x < devc->num_probes; x++) { - tmp16 = inbuf[i+x]; + tmp16 = inbuf[i + x]; analog.data[offset++] = tmp16 * s16norm; } } /* Send a sample packet with the analog values. */ + analog.probes = sdi->probes; analog.num_samples = count; analog.mq = SR_MQ_VOLTAGE; /* FIXME */ analog.unit = SR_UNIT_VOLT; /* FIXME */ @@ -298,4 +416,3 @@ SR_PRIV int alsa_receive_data(int fd, int revents, void *cb_data) return TRUE; } -