expose a volume knob in the sndio API: add sio_setvol(3) and

sio_onvol(3) functions. The audio(4) backend tries to use the
inputs.dac, outputs.dac, outputs.output and outputs.master
controls (in this order). Add a sample file in
regress/lib/libsndio/vol/vol.c

8 files changed, 314 insertions, 59 deletions

diff --git a/lib/libsndio/Makefile b/lib/libsndio/Makefile
index 6c0943fa968..e4eee6a8c61 100644
--- a/lib/libsndio/Makefile
+++ b/lib/libsndio/Makefile
@@ -1,4 +1,4 @@
-#	$OpenBSD: Makefile,v 1.1 2008/10/27 00:26:33 ratchov Exp $
+#	$OpenBSD: Makefile,v 1.2 2008/11/11 19:39:35 ratchov Exp $
 
 LIB=	sndio
 MAN=	sio_open.3
@@ -20,6 +20,8 @@ MLINKS = \
 	sio_open.3 sio_pollfd.3 \
 	sio_open.3 sio_revents.3 \
 	sio_open.3 sio_eof.3 \
+	sio_open.3 sio_setvol.3 \
+	sio_open.3 sio_onvol.3 \
 	sio_open.3 sio_initpar.3
 
 includes:
diff --git a/lib/libsndio/aucat.c b/lib/libsndio/aucat.c
index 83689a16e37..14d6fc393ed 100644
--- a/lib/libsndio/aucat.c
+++ b/lib/libsndio/aucat.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: aucat.c,v 1.1 2008/10/27 00:26:33 ratchov Exp $	*/
+/*	$OpenBSD: aucat.c,v 1.2 2008/11/11 19:39:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -40,6 +40,7 @@ struct aucat_hdl {
 	unsigned rbpf, wbpf;		/* read and write bytes-per-frame */
 	int maxwrite;			/* latency constraint */
 	int events;			/* events the user requested */
+	unsigned curvol, reqvol;	/* current and requested volume */
 };
 
 void aucat_close(struct sio_hdl *);
@@ -52,6 +53,8 @@ size_t aucat_read(struct sio_hdl *, void *, size_t);
 size_t aucat_write(struct sio_hdl *, void *, size_t);
 int aucat_pollfd(struct sio_hdl *, struct pollfd *, int);
 int aucat_revents(struct sio_hdl *, struct pollfd *);
+int aucat_setvol(struct sio_hdl *, unsigned);
+void aucat_getvol(struct sio_hdl *);
 
 struct sio_ops aucat_ops = {
 	aucat_close,
@@ -63,7 +66,9 @@ struct sio_ops aucat_ops = {
 	aucat_start,
 	aucat_stop,
 	aucat_pollfd,
-	aucat_revents
+	aucat_revents,
+	aucat_setvol,
+	aucat_getvol
 };
 
 struct sio_hdl *
@@ -101,6 +106,8 @@ sio_open_aucat(char *path, unsigned mode, int nbio)
 	hdl->rtodo = 0xdeadbeef;
 	hdl->wstate = STATE_IDLE;
 	hdl->wtodo = 0xdeadbeef;
+	hdl->curvol = SIO_MAXVOL;
+	hdl->reqvol = SIO_MAXVOL;
 	return (struct sio_hdl *)hdl;
 }
 
@@ -434,15 +441,19 @@ aucat_read(struct sio_hdl *sh, void *buf, size_t len)
 	return n;
 }
 
-size_t
-aucat_write(struct sio_hdl *sh, void *buf, size_t len)
+int
+aucat_buildmsg(struct aucat_hdl *hdl, size_t len)
 {
-	struct aucat_hdl *hdl = (struct aucat_hdl *)sh;
 	unsigned sz;
-	ssize_t n;
 
-	switch (hdl->wstate) {
-	case STATE_IDLE:
+	if (hdl->curvol != hdl->reqvol) {
+		hdl->wstate = STATE_MSG;
+		hdl->wtodo = sizeof(struct amsg);
+		hdl->wmsg.cmd = AMSG_SETVOL;
+		hdl->wmsg.u.vol.ctl = hdl->reqvol;
+		hdl->curvol = hdl->reqvol;
+		return 1;
+	} else if (len > 0) {
 		sz = (len < AMSG_DATAMAX) ? len : AMSG_DATAMAX;
 		sz -= sz % hdl->wbpf;
 		if (sz == 0)
@@ -451,44 +462,63 @@ aucat_write(struct sio_hdl *sh, void *buf, size_t len)
 		hdl->wtodo = sizeof(struct amsg);
 		hdl->wmsg.cmd = AMSG_DATA;
 		hdl->wmsg.u.data.size = sz;
-		/* PASSTHROUGH */
-	case STATE_MSG:
-		if (!aucat_wmsg(hdl))
-			return 0;
-		hdl->wstate = STATE_DATA;
-		hdl->wtodo = hdl->wmsg.u.data.size;
-		/* PASSTHROUGH */
-	case STATE_DATA:
-		if (hdl->maxwrite <= 0)
-			return 0;
-		if (len > hdl->maxwrite)
-			len = hdl->maxwrite;
-		if (len > hdl->wtodo)
-			len = hdl->wtodo;
-		if (len == 0) {
-			fprintf(stderr, "aucat_write: len == 0\n");
+		return 1;
+	}
+	return 0;
+}
+
+size_t
+aucat_write(struct sio_hdl *sh, void *buf, size_t len)
+{
+	struct aucat_hdl *hdl = (struct aucat_hdl *)sh;
+	ssize_t n;
+
+	while (hdl->wstate != STATE_DATA) {
+		switch (hdl->wstate) {
+		case STATE_IDLE:
+			if (!aucat_buildmsg(hdl, len))
+				return 0;
+			/* PASSTHROUGH */
+		case STATE_MSG:
+			if (!aucat_wmsg(hdl))
+				return 0;
+			if (hdl->wmsg.cmd == AMSG_DATA) {
+				hdl->wstate = STATE_DATA;
+				hdl->wtodo = hdl->wmsg.u.data.size;
+			} else
+				hdl->wstate = STATE_IDLE;
+			break;
+		default:
+			fprintf(stderr, "aucat_read: bad state\n");
 			abort();
 		}
-		while ((n = write(hdl->fd, buf, len)) < 0) {
-			if (errno == EINTR)
-				continue;
-			if (errno != EAGAIN) {
-				hdl->sa.eof = 1;
-				perror("aucat_read: read");
-			}
-			return 0;
-		}
-		hdl->maxwrite -= n;
-		hdl->wtodo -= n;
-		if (hdl->wtodo == 0) {
-			hdl->wstate = STATE_IDLE;
-			hdl->wtodo = 0xdeadbeef;
-		}
-		return n;
-	default:
-		fprintf(stderr, "aucat_read: bad state\n");
+	}
+	if (hdl->maxwrite <= 0)
+		return 0;
+	if (len > hdl->maxwrite)
+		len = hdl->maxwrite;
+	if (len > hdl->wtodo)
+		len = hdl->wtodo;
+	if (len == 0) {
+		fprintf(stderr, "aucat_write: len == 0\n");
 		abort();
 	}
+	while ((n = write(hdl->fd, buf, len)) < 0) {
+		if (errno == EINTR)
+			continue;
+		if (errno != EAGAIN) {
+			hdl->sa.eof = 1;
+			perror("aucat_read: read");
+		}
+		return 0;
+	}
+	hdl->maxwrite -= n;
+	hdl->wtodo -= n;
+	if (hdl->wtodo == 0) {
+		hdl->wstate = STATE_IDLE;
+		hdl->wtodo = 0xdeadbeef;
+	}
+	return n;
 }
 
 int
@@ -526,3 +556,21 @@ aucat_revents(struct sio_hdl *sh, struct pollfd *pfd)
 	}
 	return revents & hdl->events;
 }
+
+int
+aucat_setvol(struct sio_hdl *sh, unsigned vol)
+{
+	struct aucat_hdl *hdl = (struct aucat_hdl *)sh;
+
+	hdl->reqvol = vol;
+	return 1;
+}
+
+void
+aucat_getvol(struct sio_hdl *sh)
+{
+	struct aucat_hdl *hdl = (struct aucat_hdl *)sh;
+
+	sio_onvol_cb(&hdl->sa, hdl->reqvol);
+	return;
+}
diff --git a/lib/libsndio/shlib_version b/lib/libsndio/shlib_version
index 012c14171d3..3f0196ebf4a 100644
--- a/lib/libsndio/shlib_version
+++ b/lib/libsndio/shlib_version
@@ -1,2 +1,2 @@
 major=3
-minor=0
+minor=1
diff --git a/lib/libsndio/sio_open.3 b/lib/libsndio/sio_open.3
index 4a2eca2c59e..883d74ed07c 100644
--- a/lib/libsndio/sio_open.3
+++ b/lib/libsndio/sio_open.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: sio_open.3,v 1.4 2008/11/09 19:49:10 naddy Exp $
+.\" $OpenBSD: sio_open.3,v 1.5 2008/11/11 19:39:35 ratchov Exp $
 .\"
 .\" Copyright (c) 2007 Alexandre Ratchov <alex@caoua.org>
 .\"
@@ -14,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: November 9 2008 $
+.Dd $Mdocdate: November 11 2008 $
 .Dt SIO_OPEN 3
 .Os
 .Sh NAME
@@ -32,6 +32,8 @@
 .Nm sio_pollfd ,
 .Nm sio_revents ,
 .Nm sio_eof ,
+.Nm sio_setvol ,
+.Nm sio_onvol ,
 .Nm sio_initpar
 .Nd interface to bidirectional audio streams
 .Sh SYNOPSIS
@@ -64,6 +66,10 @@
 .Fn "sio_revents" "struct sio_hdl *hdl" "struct pollfd *pfd"
 .Ft "int"
 .Fn "sio_eof" "struct sio_hdl *hdl"
+.Ft "int"
+.Fn "sio_setvol" "struct sio_hdl *hdl" "unsigned vol"
+.Ft "void"
+.Fn "sio_onvol" "struct sio_hdl *hdl" "void (*cb)(void *arg, unsigned vol)" "void *arg"
 .Ft "void"
 .Fn "sio_initpar" "struct sio_par *par"
 .\"Fd #define SIO_BPS(bits)
@@ -624,6 +630,37 @@ This mode is mostly useful for testing; portable
 applications shouldn't depend on it, since it's not available
 on other systems.
 .El
+.Ss Controlling the volume
+The
+.Fn sio_setvol
+function can be used to set the playback attenuation.
+The
+.Va vol
+parameter takes a value between 0 (maximum attenuation)
+and
+.Va SIO_MAXVOL
+(no attenuation).
+This parameter gives the weight the audio subsystem will
+give to this stream.
+It is not meant to control hardware parameters like the
+speakers gain, the
+.Xr mixer
+interface should be used for that purpose instead.
+.Pp
+An application can use the
+.Fn sio_onvol
+function to register a call-back function that
+will be called each time the volume is changed, including
+when
+.Fn sio_setvol
+is used.
+The call-back is always invoked when
+.Fn sio_onvol
+function is called in order to provide the initial volume.
+The application can safely assume that once
+.Fn sio_onvol
+returns, the call-back was already invoked and thus
+the current volume is available.
 .Ss Error handling
 Errors related to the audio subsystem
 (like hardware errors, dropped connections) and
diff --git a/lib/libsndio/sndio.c b/lib/libsndio/sndio.c
index 6089320b403..afc9b36013c 100644
--- a/lib/libsndio/sndio.c
+++ b/lib/libsndio/sndio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sndio.c,v 1.5 2008/11/09 15:32:50 ratchov Exp $	*/
+/*	$OpenBSD: sndio.c,v 1.6 2008/11/11 19:39:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -188,7 +188,8 @@ sio_create(struct sio_hdl *hdl, struct sio_ops *ops, unsigned mode, int nbio)
 	hdl->nbio = nbio;
 	hdl->started = 0;
 	hdl->eof = 0;
-	hdl->cb_pos = 0;
+	hdl->move_cb = NULL;
+	hdl->vol_cb = NULL;
 }
 
 void
@@ -487,8 +488,8 @@ sio_onmove(struct sio_hdl *hdl, void (*cb)(void *, int), void *addr)
 		hdl->eof = 1;
 		return;
 	}
-	hdl->cb_pos = cb;
-	hdl->cb_addr = addr;
+	hdl->move_cb = cb;
+	hdl->move_addr = addr;
 }
 
 void
@@ -515,6 +516,37 @@ sio_onmove_cb(struct sio_hdl *hdl, int delta)
 		    hdl->realpos < 0 ? playpos : playpos - hdl->realpos);
 	}
 #endif
-	if (hdl->cb_pos)
-		hdl->cb_pos(hdl->cb_addr, delta);
+	if (hdl->move_cb)
+		hdl->move_cb(hdl->move_addr, delta);
+}
+
+int
+sio_setvol(struct sio_hdl *hdl, unsigned ctl)
+{
+	if (hdl->eof)
+		return 0;
+	if (!hdl->ops->setvol(hdl, ctl))
+		return 0;
+	hdl->ops->getvol(hdl);
+	return 1;
+}
+
+void
+sio_onvol(struct sio_hdl *hdl, void (*cb)(void *, unsigned), void *addr)
+{
+	if (hdl->started) {
+		fprintf(stderr, "sio_onmove: already started\n");
+		hdl->eof = 1;
+		return;
+	}
+	hdl->vol_cb = cb;
+	hdl->vol_addr = addr;
+	hdl->ops->getvol(hdl);
+}
+
+void
+sio_onvol_cb(struct sio_hdl *hdl, unsigned ctl)
+{
+	if (hdl->vol_cb)
+		hdl->vol_cb(hdl->vol_addr, ctl);	
 }
diff --git a/lib/libsndio/sndio.h b/lib/libsndio/sndio.h
index 9ddd12f414d..ec0afaa468d 100644
--- a/lib/libsndio/sndio.h
+++ b/lib/libsndio/sndio.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sndio.h,v 1.2 2008/10/28 23:00:08 jsg Exp $	*/
+/*	$OpenBSD: sndio.h,v 1.3 2008/11/11 19:39:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -112,6 +112,11 @@ struct sio_cap {
  */
 #define SIO_AUCAT_PATH	"/tmp/aucat.sock"
 
+/*
+ * maximum value of volume, eg. for sio_setvol()
+ */
+#define SIO_MAXVOL 127
+
 int sio_strtoenc(struct sio_par *, char *);
 int sio_enctostr(struct sio_par *, char *);
 void sio_initpar(struct sio_par *);
@@ -135,5 +140,7 @@ int sio_nfds(struct sio_hdl *);
 int sio_pollfd(struct sio_hdl *, struct pollfd *, int);
 int sio_revents(struct sio_hdl *, struct pollfd *);
 int sio_eof(struct sio_hdl *);
+int sio_setvol(struct sio_hdl *, unsigned);
+void sio_onvol(struct sio_hdl *, void (*)(void *, unsigned), void *);
 
-#endif /* !defined(LIBSIO_H) */
+#endif /* !defined(SNDIO_H) */
diff --git a/lib/libsndio/sndio_priv.h b/lib/libsndio/sndio_priv.h
index 080adf2c72c..44284cf61e1 100644
--- a/lib/libsndio/sndio_priv.h
+++ b/lib/libsndio/sndio_priv.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sndio_priv.h,v 1.1 2008/10/27 00:26:33 ratchov Exp $	*/
+/*	$OpenBSD: sndio_priv.h,v 1.2 2008/11/11 19:39:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -25,8 +25,10 @@
  */
 struct sio_hdl {
 	struct sio_ops *ops;
-	void (*cb_pos)(void *, int);	/* call-back for realpos changes */
-	void *cb_addr;			/* user priv. data */
+	void (*move_cb)(void *, int);	/* call-back for realpos changes */
+	void *move_addr;		/* user priv. data for move_cb */
+	void (*vol_cb)(void *, unsigned); /* call-back for volume changes */
+	void *vol_addr;			/* user priv. data for vol_cb */
 	unsigned mode;			/* SIO_PLAY | SIO_REC */
 	int started;			/* true if started */
 	int nbio;			/* true if non-blocking io */
@@ -56,10 +58,13 @@ struct sio_ops {
 	int (*stop)(struct sio_hdl *);
 	int (*pollfd)(struct sio_hdl *, struct pollfd *, int);
 	int (*revents)(struct sio_hdl *, struct pollfd *);
+	int (*setvol)(struct sio_hdl *, unsigned);
+	void (*getvol)(struct sio_hdl *);
 };
 
 void sio_create(struct sio_hdl *, struct sio_ops *, unsigned, int);
 void sio_destroy(struct sio_hdl *);
 void sio_onmove_cb(struct sio_hdl *, int);
+void sio_onvol_cb(struct sio_hdl *, unsigned);
 
 #endif /* !defined(LIBSIO_PRIV_H) */
diff --git a/lib/libsndio/sun.c b/lib/libsndio/sun.c
index a0e2384cca0..7755d46c4ed 100644
--- a/lib/libsndio/sun.c
+++ b/lib/libsndio/sun.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sun.c,v 1.4 2008/11/07 21:01:15 ratchov Exp $	*/
+/*	$OpenBSD: sun.c,v 1.5 2008/11/11 19:39:35 ratchov Exp $	*/
 /*
  * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
  *
@@ -29,6 +29,8 @@
 #include <sys/types.h>
 #include <sys/ioctl.h>
 #include <sys/audioio.h>
+#include <sys/stat.h>
+#include <limits.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <poll.h>
@@ -48,6 +50,9 @@ struct sun_hdl {
 	unsigned ierr, oerr;		/* frames the hw dropped */
 	int offset;			/* frames play is ahead of record */
 	int idelta, odelta;		/* position reported to client */
+	int mix_fd, mix_index;		/* /dev/mixerN stuff */
+	int voltodo;			/* 1 if vol initialization pending */
+	unsigned curvol;
 };
 
 void sun_close(struct sio_hdl *);
@@ -60,6 +65,8 @@ size_t sun_read(struct sio_hdl *, void *, size_t);
 size_t sun_write(struct sio_hdl *, void *, size_t);
 int sun_pollfd(struct sio_hdl *, struct pollfd *, int);
 int sun_revents(struct sio_hdl *, struct pollfd *);
+int sun_setvol(struct sio_hdl *, unsigned);
+void sun_getvol(struct sio_hdl *);
 
 struct sio_ops sun_ops = {
 	sun_close,
@@ -71,7 +78,22 @@ struct sio_ops sun_ops = {
 	sun_start,
 	sun_stop,
 	sun_pollfd,
-	sun_revents
+	sun_revents,
+	sun_setvol,
+	sun_getvol
+};
+
+/*
+ * prefered controls for the volume knob, in reverse order of preference
+ */
+struct sun_pref {
+	char *cls, *dev;
+} sun_vols[] = {
+	{ AudioCoutputs, AudioNmaster },
+	{ AudioCoutputs, AudioNoutput },
+	{ AudioCoutputs, AudioNdac },
+	{ AudioCinputs, AudioNdac },
+	{ NULL, NULL}
 };
 
 /*
@@ -318,6 +340,106 @@ sun_getcap(struct sio_hdl *sh, struct sio_cap *cap)
 #undef NRATES
 }
 
+/*
+ * initialize volume knob
+ */
+void
+sun_initvol(struct sun_hdl *hdl)
+{
+	int i, fd, index = -1, last_pref = -1;
+	struct sun_pref *p;
+	struct stat sb;
+	struct mixer_devinfo mi, cl;
+	struct mixer_ctrl m;
+	char path[PATH_MAX];
+
+	if (fstat(hdl->fd, &sb) < 0)
+		return;
+	if (!S_ISCHR(sb.st_mode))
+		return;
+	snprintf(path, PATH_MAX, "/dev/mixer%d", sb.st_rdev & 0xf);
+	fd = open(path, O_RDWR);	
+	if (fd < 0) {
+		fprintf(stderr, "%s: couldn't open mixer\n", path);
+		return;
+	}
+
+	for (mi.index = 0; ; mi.index++) {
+		if (ioctl(fd, AUDIO_MIXER_DEVINFO, &mi) < 0)
+			break;
+		if (mi.type == AUDIO_MIXER_CLASS || mi.prev != -1)
+			continue;
+		cl.index = mi.mixer_class;
+		if (ioctl(fd, AUDIO_MIXER_DEVINFO, &cl) < 0)
+			continue;
+		/*
+		 * find prefered input gain and output gain
+		 */
+		for (i = 0, p = sun_vols; p->cls != NULL; i++, p++) {
+			if (strcmp(p->cls, cl.label.name) != 0 ||
+			    strcmp(p->dev, mi.label.name) != 0)
+				continue;
+			if (last_pref < i) {
+				index = mi.index;
+				last_pref = i;
+			}
+			break;
+		}
+	}
+	hdl->mix_fd = fd;
+	hdl->mix_index = index;
+	if (index >= 0) {
+		m.dev = index;
+		m.type = AUDIO_MIXER_VALUE;
+		m.un.value.num_channels = 1;
+		if (ioctl(hdl->mix_fd, AUDIO_MIXER_READ, &m) < 0) {
+			fprintf(stderr, "sun_getvol: %d: failed to get volume\n", m.dev);
+			hdl->sa.eof = 1;
+			return;
+		}
+		hdl->curvol = m.un.value.level[0] / 2;
+	} else 
+		hdl->curvol = SIO_MAXVOL;
+	return;
+}
+
+void
+sun_getvol(struct sio_hdl *sh)
+{
+	struct sun_hdl *hdl = (struct sun_hdl *)sh;
+
+	if (hdl->voltodo) {
+		sun_initvol(hdl);
+		hdl->voltodo = 0;
+	}
+	sio_onvol_cb(&hdl->sa, hdl->curvol);
+}
+
+int
+sun_setvol(struct sio_hdl *sh, unsigned vol)
+{
+	struct sun_hdl *hdl = (struct sun_hdl *)sh;
+	struct mixer_ctrl m;
+	
+	if (hdl->voltodo) {
+		sun_initvol(hdl);
+		hdl->voltodo = 0;
+	}
+	if (hdl->mix_fd == -1 || hdl->mix_index == -1)
+		return 0;
+	m.dev = hdl->mix_index;
+	m.type = AUDIO_MIXER_VALUE;
+	m.un.value.num_channels = 1;
+	m.un.value.level[0] = 2 * vol;
+	if (ioctl(hdl->mix_fd, AUDIO_MIXER_WRITE, &m) < 0) {
+		fprintf(stderr, "sun_setvol: failed to set volume\n");
+		hdl->sa.eof = 1;
+		return 0;
+	}
+	hdl->curvol = vol;
+	return 1;
+}
+
 struct sio_hdl *
 sio_open_sun(char *path, unsigned mode, int nbio)
 {
@@ -348,6 +470,7 @@ sio_open_sun(char *path, unsigned mode, int nbio)
 		goto bad_free;
 	}
 	hdl->fd = fd;
+	hdl->voltodo = 1;
 
 	/*
 	 * If both play and record are requested then
@@ -816,3 +939,4 @@ sun_revents(struct sio_hdl *sh, struct pollfd *pfd)
 		revents |= POLLOUT;
 	return revents;
 }
+