From 9a446c6b727ecbf17072f04f5df41037de507ba6 Mon Sep 17 00:00:00 2001
From: Alexandre Ratchov <alex@caoua.org>
Date: Thu, 18 Jun 2020 06:27:36 +0200
Subject: [PATCH] Allow alternate devices to be switched with sndioctl

---
 sndiod/dev.c     | 43 ++++++++++++++++++++++++++++++++++++++++++-
 sndiod/dev.h     |  3 ++-
 sndiod/siofile.c | 14 +++++++++++++-
 sndiod/sndiod.8  |  5 +++++
 4 files changed, 62 insertions(+), 3 deletions(-)

diff --git a/sndiod/dev.c b/sndiod/dev.c
index 3c4b8d3..aaf933d 100644
--- a/sndiod/dev.c
+++ b/sndiod/dev.c
@@ -68,6 +68,7 @@ int dev_init(struct dev *);
 void dev_done(struct dev *);
 struct dev *dev_bynum(int);
 void dev_del(struct dev *);
+void dev_setalt(struct dev *, unsigned int);
 unsigned int dev_roundof(struct dev *, unsigned int);
 void dev_wakeup(struct dev *);
 void dev_sync_attach(struct dev *);
@@ -1088,6 +1089,30 @@ dev_addname(struct dev *d, char *name)
 	return 1;
 }
 
+/*
+ * set prefered alt device name
+ */
+void
+dev_setalt(struct dev *d, unsigned int idx)
+{
+	struct dev_alt **pa, *a;
+
+	/* find alt with given index */
+	for (pa = &d->alt_list; (a = *pa)->idx != idx; pa = &a->next)
+		;
+
+	/* detach from list */
+	*pa = a->next;
+
+	/* attach at head */
+	a->next = d->alt_list;
+	d->alt_list = a;
+
+	/* reopen device with the new alt */
+	if (idx != d->alt_num)
+		dev_reopen(d);
+}
+
 /*
  * adjust device parameters and mode
  */
@@ -1177,6 +1202,7 @@ dev_open(struct dev *d)
 {
 	int i;
 	char name[CTL_NAMEMAX];
+	struct dev_alt *a;
 
 	d->master_enabled = 0;
 	d->mode = d->reqmode;
@@ -1210,6 +1236,15 @@ dev_open(struct dev *d)
 		    NULL, -1, 127, d->slot[i].vol);
 	}
 
+	for (a = d->alt_list; a != NULL; a = a->next) {
+		/* XXX: may already exist, move to hw/ group ? */
+		snprintf(name, sizeof(name), "%d", a->idx);
+		dev_addctl(d, "", CTL_SEL,
+		    CTLADDR_ALT_SEL + a->idx,
+		    "device", -1, "select",
+		    name, -1, 1, a->idx == d->alt_num);
+	}
+
 	d->pstate = DEV_INIT;
 	return 1;
 }
@@ -2473,7 +2508,13 @@ dev_setctl(struct dev *d, int addr, int val)
 		c->dirty = 1;
 		dev_ref(d);
 	} else {
-		if (addr == CTLADDR_MASTER) {
+		if (addr >= CTLADDR_ALT_SEL) {
+			if (val) {
+				num = addr - CTLADDR_ALT_SEL;
+				dev_setalt(d, num);
+			}
+			return 1;
+		} else if (addr == CTLADDR_MASTER) {
 			if (d->master_enabled) {
 				dev_master(d, val);
 				dev_midi_master(d);
diff --git a/sndiod/dev.h b/sndiod/dev.h
index cbca055..9b1abd8 100644
--- a/sndiod/dev.h
+++ b/sndiod/dev.h
@@ -24,7 +24,8 @@
 
 #define CTLADDR_SLOT_LEVEL(n)	(n)
 #define CTLADDR_MASTER		(DEV_NSLOT)
-#define CTLADDR_END		(DEV_NSLOT + 1)
+#define CTLADDR_ALT_SEL		(CTLADDR_MASTER + 1)
+#define CTLADDR_END		(CTLADDR_ALT_SEL + DEV_NMAX)
 
 /*
  * audio stream state structure
diff --git a/sndiod/siofile.c b/sndiod/siofile.c
index 5aef2dd..322ec6c 100644
--- a/sndiod/siofile.c
+++ b/sndiod/siofile.c
@@ -95,7 +95,8 @@ dev_sio_openlist(struct dev *d, unsigned int mode, struct sioctl_hdl **rctlhdl)
 	struct dev_alt *n;
 	struct sio_hdl *hdl;
 	struct sioctl_hdl *ctlhdl;
-	int idx;
+	struct ctl *c;
+	int val;
 
 	for (n = d->alt_list; n != NULL; n = n->next) {
 		if (d->alt_num == n->idx)
@@ -117,6 +118,17 @@ dev_sio_openlist(struct dev *d, unsigned int mode, struct sioctl_hdl **rctlhdl)
 				}
 			}
 			d->alt_num = n->idx;
+			for (c = d->ctl_list; c != NULL; c = c->next) {
+				if (c->addr < CTLADDR_ALT_SEL ||
+				    c->addr >= CTLADDR_ALT_SEL + DEV_NMAX)
+					continue;
+				val = (c->addr - CTLADDR_ALT_SEL) == n->idx;
+				if (c->curval == val)
+					continue;
+				c->curval = val;
+				if (val)
+					c->val_mask = ~0U;
+			}
 			*rctlhdl = ctlhdl;
 			return hdl;
 		}
diff --git a/sndiod/sndiod.8 b/sndiod/sndiod.8
index 40b9ef2..b28a91e 100644
--- a/sndiod/sndiod.8
+++ b/sndiod/sndiod.8
@@ -196,6 +196,11 @@ PCI device allows
 .Nm
 to use the USB one preferably when it's connected
 and to fall back to the PCI one when it's disconnected.
+Alternate devices may be switched with the
+.Va device.select
+control of the
+.Xr sndioctl 1
+utility.
 .It Fl f Ar device
 Add this
 .Xr sndio 7