alsactl: implement 'info' command

It may be useful to collect the basic sound card information.
The output is in the YAML structured syntax (human and machine readable).

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

alsactl/Makefile.am

@@ -10,7 +10,7 @@ EXTRA_DIST=alsactl.1 alsactl_init.xml
 AM_CFLAGS = -D_GNU_SOURCE
 
 alsactl_SOURCES=alsactl.c state.c lock.c utils.c init_parse.c init_ucm.c \
-		daemon.c monitor.c clean.c
+		daemon.c monitor.c clean.c info.c
 
 alsactl_CFLAGS=$(AM_CFLAGS) -D__USE_GNU \
                -DSYS_ASOUNDRC=\"$(ASOUND_STATE_DIR)/asound.state\" \

alsactl/alsactl.1

@@ -8,6 +8,8 @@ alsactl \- advanced controls for ALSA soundcard driver
 
 \fBalsactl\fP \fImonitor\fP <card # or id>
 
+\fBalsactl\fP \fIinfo\fP <card # or id>
+
 \fBalsactl\fP [\fIclean\fP] <card # or id or device> [[control identifiers]]
 
 .SH DESCRIPTION
@@ -62,6 +64,11 @@ rescan, save_and_quit).
 This command is for monitoring the events received from the given
 control device.
 
+.SS info <card>
+
+This command shows the general information in the YAML format
+collected from the given control device (sound card).
+
 .SS clean <card> [filter]
 
 This command cleans the controls created by applications.

alsactl/alsactl.c

@@ -119,6 +119,7 @@ static struct arg args[] = {
 { CARDCMD, "rdaemon", "like daemon but do the state restore at first" },
 { KILLCMD, "kill", "notify daemon to quit, rescan or save_and_quit" },
 { CARDCMD, "monitor", "monitor control events" },
+{ CARDCMD, "info", "general information" },
 { CARDCMD, "clean", "clean application controls" },
 { EMPCMD, "dump-state", "dump the state (for all cards)" },
 { EMPCMD, "dump-cfg", "dump the configuration (expanded, for all cards)" },
@@ -465,6 +466,8 @@ int main(int argc, char *argv[])
 		res = state_daemon_kill(pidfile, cardname);
 	} else if (!strcmp(cmd, "monitor")) {
 		res = monitor(cardname);
+	} else if (!strcmp(cmd, "info")) {
+		res = general_info(cardname);
 	} else if (!strcmp(cmd, "clean")) {
 		res = clean(cardname, extra_args);
 	} else if (!strcmp(cmd, "dump-state")) {

alsactl/alsactl.h

@@ -62,6 +62,7 @@ int load_state(const char *cfgdir, const char *file,
 	       const char *cardname, int do_init);
 int power(const char *argv[], int argc);
 int monitor(const char *name);
+int general_info(const char *name);
 int state_daemon(const char *file, const char *cardname, int period,
 		 const char *pidfile);
 int state_daemon_kill(const char *pidfile, const char *cmd);

alsactl/info.c

@@ -0,0 +1,261 @@
+/*
+ *  Advanced Linux Sound Architecture Control Program - General info
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ *   This program is free software; you can redistribute it and/or modify
+ *   it under the terms of the GNU General Public License as published by
+ *   the Free Software Foundation; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   This program is distributed in the hope that it will be useful,
+ *   but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *   GNU General Public License for more details.
+ *
+ *   You should have received a copy of the GNU General Public License
+ *   along with this program; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include "aconfig.h"
+#include "alsactl.h"
+
+static int pcm_device_list(snd_ctl_t *ctl, snd_pcm_stream_t stream, bool *first)
+{
+#ifdef __ALSA_PCM_H
+	int err, dev, idx;
+	unsigned int count;
+	snd_pcm_info_t *pcminfo;
+	snd_pcm_info_alloca(&pcminfo);
+	bool streamfirst, subfirst;
+
+	dev = -1;
+	streamfirst = true;
+	while (1) {
+		if ((err = snd_ctl_pcm_next_device(ctl, &dev)) < 0) {
+			error("snd_ctl_pcm_next_device");
+			return err;
+		}
+		if (dev < 0)
+			break;
+		snd_pcm_info_set_device(pcminfo, dev);
+		snd_pcm_info_set_subdevice(pcminfo, 0);
+		snd_pcm_info_set_stream(pcminfo, stream);
+		if ((err = snd_ctl_pcm_info(ctl, pcminfo)) < 0) {
+			if (err != -ENOENT)
+				return err;
+			continue;
+		}
+		if (*first) {
+			printf("  pcm:\n");
+			*first = false;
+		}
+		if (streamfirst) {
+			printf("    - stream: %s\n      devices:\n", snd_pcm_stream_name(stream));
+			streamfirst = false;
+		}
+		printf("        - device: %d\n          id: %s\n          name: %s\n",
+				dev,
+				snd_pcm_info_get_id(pcminfo),
+				snd_pcm_info_get_name(pcminfo));
+		count = snd_pcm_info_get_subdevices_count(pcminfo);
+		subfirst = true;
+		for (idx = 0; idx < (int)count; idx++) {
+			snd_pcm_info_set_subdevice(pcminfo, idx);
+			if ((err = snd_ctl_pcm_info(ctl, pcminfo)) < 0) {
+				error("control digital audio playback info (%s): %s", snd_ctl_name(ctl), snd_strerror(err));
+				return err;
+			}
+			if (subfirst) {
+				printf("          subdevices:\n");
+				subfirst = false;
+			}
+			printf("            - subdevice: %d\n              name: %s\n",
+						idx, snd_pcm_info_get_subdevice_name(pcminfo));
+		}
+	}
+#endif
+	return 0;
+}
+
+static const char *snd_rawmidi_stream_name(snd_rawmidi_stream_t stream)
+{
+	if (stream == SND_RAWMIDI_STREAM_INPUT)
+		return "INPUT";
+	if (stream == SND_RAWMIDI_STREAM_OUTPUT)
+		return "OUTPUT";
+	return "???";
+}
+
+static int rawmidi_device_list(snd_ctl_t *ctl, snd_rawmidi_stream_t stream, bool *first)
+{
+#ifdef __ALSA_RAWMIDI_H
+	int err, dev, idx;
+	unsigned int count;
+	snd_rawmidi_info_t *info;
+	snd_rawmidi_info_alloca(&info);
+	bool streamfirst, subfirst;
+
+	dev = -1;
+	streamfirst = true;
+	while (1) {
+		if ((err = snd_ctl_rawmidi_next_device(ctl, &dev)) < 0) {
+			error("snd_ctl_rawmidi_next_device");
+			return err;
+		}
+		if (dev < 0)
+			break;
+		snd_rawmidi_info_set_device(info, dev);
+		snd_rawmidi_info_set_subdevice(info, 0);
+		snd_rawmidi_info_set_stream(info, stream);
+		if ((err = snd_ctl_rawmidi_info(ctl, info)) < 0) {
+			if (err != -ENOENT)
+				return err;
+			continue;
+		}
+		if (*first) {
+			printf("  rawmidi:\n");
+			*first = false;
+		}
+		if (streamfirst) {
+			printf("    - stream: %s\n      devices:\n", snd_rawmidi_stream_name(stream));
+			streamfirst = false;
+		}
+		printf("        - device: %d\n          id: %s\n          name: %s\n",
+				dev,
+				snd_rawmidi_info_get_id(info),
+				snd_rawmidi_info_get_name(info));
+		count = snd_rawmidi_info_get_subdevices_count(info);
+		subfirst = true;
+		for (idx = 0; idx < (int)count; idx++) {
+			snd_rawmidi_info_set_subdevice(info, idx);
+			if ((err = snd_ctl_rawmidi_info(ctl, info)) < 0) {
+				error("control digital audio playback info (%s): %s", snd_ctl_name(ctl), snd_strerror(err));
+				return err;
+			}
+			if (subfirst) {
+				printf("          subdevices:\n");
+				subfirst = false;
+			}
+			printf("            - subdevice: %d\n              name: %s\n",
+						idx, snd_rawmidi_info_get_subdevice_name(info));
+		}
+	}
+#endif
+	return 0;
+}
+
+static int hwdep_device_list(snd_ctl_t *ctl)
+{
+#ifdef __ALSA_HWDEP_H
+	int err, dev;
+	snd_hwdep_info_t *info;
+	snd_hwdep_info_alloca(&info);
+	bool first;
+
+	dev = -1;
+	first = true;
+	while (1) {
+		if ((err = snd_ctl_hwdep_next_device(ctl, &dev)) < 0) {
+			error("snd_ctl_pcm_next_device");
+			return err;
+		}
+		if (dev < 0)
+			break;
+		snd_hwdep_info_set_device(info, dev);
+		if ((err = snd_ctl_hwdep_info(ctl, info)) < 0) {
+			if (err != -ENOENT)
+				return err;
+			continue;
+		}
+		if (first) {
+			printf("  hwdep:\n");
+			first = false;
+		}
+		printf("    - device: %d\n      id: %s\n      name: %s\n      iface: %d\n",
+				dev,
+				snd_hwdep_info_get_id(info),
+				snd_hwdep_info_get_name(info),
+				snd_hwdep_info_get_iface(info));
+	}
+#endif
+	return 0;
+}
+
+static int card_info(snd_ctl_t *ctl)
+{
+	snd_ctl_card_info_t *info;
+	snd_ctl_elem_list_t *clist;
+	int err;
+
+	snd_ctl_card_info_alloca(&info);
+	snd_ctl_elem_list_alloca(&clist);
+
+	if ((err = snd_ctl_card_info(ctl, info)) < 0) {
+		error("Control device %s hw info error: %s", snd_ctl_name(ctl), snd_strerror(err));
+		return err;
+	}
+	printf("#\n# Sound card\n#\n");
+	printf("- card: %i\n  id: %s\n  name: %s\n  longname: %s\n",
+		snd_ctl_card_info_get_card(info),
+		snd_ctl_card_info_get_id(info),
+		snd_ctl_card_info_get_name(info),
+		snd_ctl_card_info_get_longname(info));
+	printf("  mixer_name: %s\n", snd_ctl_card_info_get_mixername(info));
+	printf("  components: %s\n", snd_ctl_card_info_get_components(info));
+	if ((err = snd_ctl_elem_list(ctl, clist)) < 0) {
+		error("snd_ctl_elem_list failure: %s", snd_strerror(err));
+	} else {
+		printf("  controls_count: %i\n", snd_ctl_elem_list_get_count(clist));
+	}
+	return err;
+}
+
+int general_card_info(int cardno)
+{
+	snd_ctl_t *ctl;
+	char dev[16];
+	bool first;
+	int err;
+
+	snprintf(dev, sizeof(dev), "hw:%i", cardno);
+	if ((err = snd_ctl_open(&ctl, dev, 0)) < 0) {
+		error("Control device %s open error: %s", dev, snd_strerror(err));
+		return err;
+	}
+	err = card_info(ctl);
+
+	first = true;
+	if (err >= 0)
+		err = pcm_device_list(ctl, SND_PCM_STREAM_PLAYBACK, &first);
+	if (err >= 0)
+		err = pcm_device_list(ctl, SND_PCM_STREAM_CAPTURE, &first);
+
+	first = true;
+	if (err >= 0)
+		err = rawmidi_device_list(ctl, SND_PCM_STREAM_PLAYBACK, &first);
+	if (err >= 0)
+		err = rawmidi_device_list(ctl, SND_PCM_STREAM_CAPTURE, &first);
+
+	if (err >= 0)
+		err = hwdep_device_list(ctl);
+	snd_ctl_close(ctl);
+	return err;
+}
+
+int general_info(const char *cardname)
+{
+	struct snd_card_iterator iter;
+	int err;
+
+	err = snd_card_iterator_sinit(&iter, cardname);
+	if (err < 0)
+		return err;
+	while (snd_card_iterator_next(&iter)) {
+		if ((err = general_card_info(iter.card)))
+			return err;
+	}
+	return snd_card_iterator_error(&iter);
+}