#include "libsigrok.h"
#include "libsigrok-internal.h"
+static void alsa_scan_handle_dev(GSList **devices,
+ const char *cardname, const char *alsaname,
+ struct sr_dev_driver *di,
+ snd_pcm_info_t *pcminfo)
+{
+ struct drv_context *drvc = NULL;
+ struct sr_dev_inst *sdi = NULL;
+ struct dev_context *devc = NULL;
+ struct sr_probe *probe;
+ int ret;
+ unsigned int i, channels;
+ snd_pcm_t *temp_handle = NULL;
+ snd_pcm_hw_params_t *hw_params = NULL;
+
+ 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
+ * situation, and pass this object in our dev_context->hw_params,
+ * eliminating the need to free() it and malloc() it later.
+ */
+ ret = snd_pcm_open(&temp_handle, alsaname, SND_PCM_STREAM_CAPTURE, 0);
+ if (ret < 0) {
+ sr_err("Cannot open device: %s.", snd_strerror(ret));
+ goto scan_error_cleanup;
+ }
+
+ ret = snd_pcm_hw_params_malloc(&hw_params);
+ if (ret < 0) {
+ sr_err("Error allocating hardware parameter structure: %s.",
+ snd_strerror(ret));
+ goto scan_error_cleanup;
+ }
+
+ ret = snd_pcm_hw_params_any(temp_handle, hw_params);
+ if (ret < 0) {
+ sr_err("Error initializing hardware parameter structure: %s.",
+ snd_strerror(ret));
+ goto scan_error_cleanup;
+ }
+
+ snd_pcm_hw_params_get_channels_max(hw_params, &channels);
+
+ snd_pcm_close(temp_handle);
+ 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.
+ */
+ 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.");
+ goto scan_error_cleanup;
+ }
+ if (!(devc = g_try_malloc0(sizeof(struct dev_context)))) {
+ sr_err("Device context malloc failed.");
+ goto scan_error_cleanup;
+ }
+
+ devc->hwdev = g_strdup(alsaname);
+ devc->num_probes = channels;
+ devc->hw_params = hw_params;
+ 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;
+ sdi->probes = g_slist_append(sdi->probes, probe);
+ }
+
+ drvc->instances = g_slist_append(drvc->instances, sdi);
+ *devices = g_slist_append(*devices, sdi);
+ return;
+
+scan_error_cleanup:
+ if (devc) {
+ if (devc->hwdev)
+ g_free((void*)devc->hwdev);
+ g_free(devc);
+ }
+ 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;
+}
+
+/**
+ * \brief Scan all alsa devices, and translate them to sigrok devices
+ *
+ * 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
+ * hw:2,0 == sigrok device 2
+ * 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
+ * those channels gets mapped to a different sigrok probe. A device with 4
+ * channels will have 4 probes from sigrok's perspective.
+ */
+SR_PRIV GSList *alsa_scan(GSList *options, struct sr_dev_driver *di)
+{
+ GSList *devices = NULL;
+ snd_ctl_t *handle;
+ int card, ret, dev;
+ snd_ctl_card_info_t *info;
+ snd_pcm_info_t *pcminfo;
+ const char* cardname;
+ /* TODO */
+ (void)options;
+
+ if (snd_ctl_card_info_malloc(&info) < 0) {
+ sr_err("Cannot malloc card info.");
+ return NULL;
+ }
+ if (snd_pcm_info_malloc(&pcminfo) < 0) {
+ sr_err("Cannot malloc pcm info.");
+ 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));
+ continue;
+ }
+ if ((ret = snd_ctl_card_info(handle, info)) < 0) {
+ sr_err("Cannot get hardware info (%i): %s",
+ card, snd_strerror(ret));
+ snd_ctl_close(handle);
+ 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
+ * explore the possibilities opened up by other
+ * subdevices. Most hardware only has subdevice 0.
+ */
+ snd_pcm_info_set_device(pcminfo, dev);
+ snd_pcm_info_set_subdevice(pcminfo, 0);
+ 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));
+ continue;
+ }
+
+ cardname = snd_ctl_card_info_get_name(info);
+ sr_info("card %i: %s [%s], device %i: %s [%s]",
+ card, snd_ctl_card_info_get_id(info), cardname,
+ dev, snd_pcm_info_get_id(pcminfo),
+ snd_pcm_info_get_name(pcminfo));
+
+ alsa_scan_handle_dev(&devices, cardname, hwdev,
+ di, pcminfo);
+ }
+ snd_ctl_close(handle);
+ }
+
+ snd_pcm_info_free(pcminfo);
+ snd_ctl_card_info_free(info);
+
+ return devices;
+}
+
+/*
+ * Helper to be used with g_slist_free_full(); for properly freeing an alsa
+ * dev instance.
+ */
+SR_PRIV void alsa_dev_inst_clear(struct sr_dev_inst *sdi)
+{
+ struct dev_context *devc;
+
+ if (!(devc = sdi->priv))
+ return;
+
+ snd_pcm_hw_params_free(devc->hw_params);
+ sr_dev_inst_free(sdi);
+}
+
SR_PRIV int alsa_receive_data(int fd, int revents, void *cb_data)
{
struct sr_dev_inst *sdi;
return TRUE;
}
+
projects / libsigrok.git / blobdiff