Constify struct {audio,midi,radio,video}_hw_if. No functional change.

ok mpi@ ratchov@ "More const is good" deraadt@

64 files changed, 188 insertions, 180 deletions

diff --git a/sys/arch/hppa/gsc/harmony.c b/sys/arch/hppa/gsc/harmony.c
index 118d89aadba..ade991c17c2 100644
--- a/sys/arch/hppa/gsc/harmony.c
+++ b/sys/arch/hppa/gsc/harmony.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: harmony.c,v 1.37 2022/03/13 08:04:38 mpi Exp $	*/
+/*	$OpenBSD: harmony.c,v 1.38 2022/03/21 19:22:39 miod Exp $	*/
 
 /*
  * Copyright (c) 2003 Jason L. Wright (jason@thought.net)
@@ -73,7 +73,7 @@ int     harmony_trigger_output(void *, void *, void *, int,
 int     harmony_trigger_input(void *, void *, void *, int,
     void (*intr)(void *), void *, struct audio_params *);
 
-struct audio_hw_if harmony_sa_hw_if = {
+const struct audio_hw_if harmony_sa_hw_if = {
 	harmony_open,
 	harmony_close,
 	harmony_set_params,
diff --git a/sys/arch/luna88k/cbus/nec86.c b/sys/arch/luna88k/cbus/nec86.c
index ed86c021355..eec75a8f4ac 100644
--- a/sys/arch/luna88k/cbus/nec86.c
+++ b/sys/arch/luna88k/cbus/nec86.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nec86.c,v 1.4 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: nec86.c,v 1.5 2022/03/21 19:22:39 miod Exp $	*/
 /*	$NecBSD: nec86.c,v 1.11 1999/07/23 11:04:39 honda Exp $	*/
 /*	$NetBSD$	*/
 
@@ -67,7 +67,7 @@
  * Define our interface to the higher level audio driver.
  */
 
-struct audio_hw_if nec86_hw_if = {
+const struct audio_hw_if nec86_hw_if = {
 	.open		= nec86hw_open,
 	.close		= nec86hw_close,
 	.set_params	= nec86hw_set_params,
diff --git a/sys/arch/luna88k/cbus/nec86var.h b/sys/arch/luna88k/cbus/nec86var.h
index 921a3b9a067..7154a8fc525 100644
--- a/sys/arch/luna88k/cbus/nec86var.h
+++ b/sys/arch/luna88k/cbus/nec86var.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nec86var.h,v 1.1 2014/12/28 13:03:18 aoyama Exp $	*/
+/*	$OpenBSD: nec86var.h,v 1.2 2022/03/21 19:22:39 miod Exp $	*/
 /*	$NecBSD: nec86var.h,v 1.6 1998/03/14 07:04:57 kmatsuda Exp $	*/
 /*	$NetBSD$	*/
 
@@ -55,7 +55,7 @@ struct nec86_softc {
 	int sc_intlevel;
 };
 
-extern  struct  audio_hw_if nec86_hw_if;
+extern  const struct  audio_hw_if nec86_hw_if;
 int	nec86_probesubr(bus_space_tag_t, bus_space_handle_t,
 	    bus_space_handle_t);
 void	nec86_attachsubr(struct nec86_softc *);
diff --git a/sys/arch/macppc/dev/aoa.c b/sys/arch/macppc/dev/aoa.c
index dcaf17392f0..f6372876a4d 100644
--- a/sys/arch/macppc/dev/aoa.c
+++ b/sys/arch/macppc/dev/aoa.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: aoa.c,v 1.13 2022/03/13 12:33:01 mpi Exp $	*/
+/*	$OpenBSD: aoa.c,v 1.14 2022/03/21 19:22:39 miod Exp $	*/
 
 /*-
  * Copyright (c) 2005 Tsubai Masanari.  All rights reserved.
@@ -65,7 +65,7 @@ struct cfdriver aoa_cd = {
 	NULL, "aoa", DV_DULL
 };
 
-struct audio_hw_if aoa_hw_if = {
+const struct audio_hw_if aoa_hw_if = {
 	i2s_open,
 	i2s_close,
 	i2s_set_params,
diff --git a/sys/arch/macppc/dev/awacs.c b/sys/arch/macppc/dev/awacs.c
index c0e9cfb408f..38c7ed6b411 100644
--- a/sys/arch/macppc/dev/awacs.c
+++ b/sys/arch/macppc/dev/awacs.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: awacs.c,v 1.36 2022/03/13 12:33:01 mpi Exp $	*/
+/*	$OpenBSD: awacs.c,v 1.37 2022/03/21 19:22:39 miod Exp $	*/
 /*	$NetBSD: awacs.c,v 1.4 2001/02/26 21:07:51 wiz Exp $	*/
 
 /*-
@@ -126,7 +126,7 @@ struct cfdriver awacs_cd = {
 	NULL, "awacs", DV_DULL
 };
 
-struct audio_hw_if awacs_hw_if = {
+const struct audio_hw_if awacs_hw_if = {
 	awacs_open,
 	awacs_close,
 	awacs_set_params,
diff --git a/sys/arch/macppc/dev/daca.c b/sys/arch/macppc/dev/daca.c
index bc44d162907..178b1daeb59 100644
--- a/sys/arch/macppc/dev/daca.c
+++ b/sys/arch/macppc/dev/daca.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: daca.c,v 1.12 2022/03/13 12:33:01 mpi Exp $	*/
+/*	$OpenBSD: daca.c,v 1.13 2022/03/21 19:22:39 miod Exp $	*/
 
 /*-
  * Copyright (c) 2002,2003 Tsubai Masanari.  All rights reserved.
@@ -71,7 +71,7 @@ struct cfdriver daca_cd = {
 	NULL, "daca", DV_DULL
 };
 
-struct audio_hw_if daca_hw_if = {
+const struct audio_hw_if daca_hw_if = {
 	i2s_open,
 	i2s_close,
 	i2s_set_params,
diff --git a/sys/arch/macppc/dev/onyx.c b/sys/arch/macppc/dev/onyx.c
index a7b72541b40..989ed3db5d5 100644
--- a/sys/arch/macppc/dev/onyx.c
+++ b/sys/arch/macppc/dev/onyx.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: onyx.c,v 1.14 2022/03/13 12:33:01 mpi Exp $	*/
+/*	$OpenBSD: onyx.c,v 1.15 2022/03/21 19:22:39 miod Exp $	*/
 
 /*-
  * Copyright (c) 2005 Tsubai Masanari.  All rights reserved.
@@ -80,7 +80,7 @@ struct cfdriver onyx_cd = {
 	NULL, "onyx", DV_DULL
 };
 
-struct audio_hw_if onyx_hw_if = {
+const struct audio_hw_if onyx_hw_if = {
 	i2s_open,
 	i2s_close,
 	i2s_set_params,
diff --git a/sys/arch/macppc/dev/snapper.c b/sys/arch/macppc/dev/snapper.c
index 9ccde482ae5..e4ce4077064 100644
--- a/sys/arch/macppc/dev/snapper.c
+++ b/sys/arch/macppc/dev/snapper.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: snapper.c,v 1.41 2022/03/13 12:33:01 mpi Exp $	*/
+/*	$OpenBSD: snapper.c,v 1.42 2022/03/21 19:22:39 miod Exp $	*/
 /*	$NetBSD: snapper.c,v 1.1 2003/12/27 02:19:34 grant Exp $	*/
 
 /*-
@@ -77,7 +77,7 @@ struct cfdriver snapper_cd = {
 	NULL, "snapper", DV_DULL
 };
 
-struct audio_hw_if snapper_hw_if = {
+const struct audio_hw_if snapper_hw_if = {
 	i2s_open,
 	i2s_close,
 	i2s_set_params,
diff --git a/sys/arch/macppc/dev/tumbler.c b/sys/arch/macppc/dev/tumbler.c
index 91298692632..fbc343b7c66 100644
--- a/sys/arch/macppc/dev/tumbler.c
+++ b/sys/arch/macppc/dev/tumbler.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tumbler.c,v 1.11 2022/03/13 12:33:01 mpi Exp $	*/
+/*	$OpenBSD: tumbler.c,v 1.12 2022/03/21 19:22:39 miod Exp $	*/
 
 /*-
  * Copyright (c) 2001,2003 Tsubai Masanari.  All rights reserved.
@@ -75,7 +75,7 @@ struct cfdriver tumbler_cd = {
 	NULL, "tumbler", DV_DULL
 };
 
-struct audio_hw_if tumbler_hw_if = {
+const struct audio_hw_if tumbler_hw_if = {
 	i2s_open,
 	i2s_close,
 	i2s_set_params,
diff --git a/sys/arch/sparc64/dev/ce4231.c b/sys/arch/sparc64/dev/ce4231.c
index 5e220907150..edd74d38c86 100644
--- a/sys/arch/sparc64/dev/ce4231.c
+++ b/sys/arch/sparc64/dev/ce4231.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ce4231.c,v 1.38 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: ce4231.c,v 1.39 2022/03/21 19:22:39 miod Exp $	*/
 
 /*
  * Copyright (c) 1999 Jason L. Wright (jason@thought.net)
@@ -150,7 +150,7 @@ int	ce4231_trigger_output(void *, void *, void *, int,
 int	ce4231_trigger_input(void *, void *, void *, int,
     void (*intr)(void *), void *arg, struct audio_params *);
 
-struct audio_hw_if ce4231_sa_hw_if = {
+const struct audio_hw_if ce4231_sa_hw_if = {
 	ce4231_open,
 	ce4231_close,
 	ce4231_set_params,
diff --git a/sys/dev/audio.c b/sys/dev/audio.c
index 27184919c33..7f560e011f6 100644
--- a/sys/dev/audio.c
+++ b/sys/dev/audio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: audio.c,v 1.197 2022/02/22 07:34:06 visa Exp $	*/
+/*	$OpenBSD: audio.c,v 1.198 2022/03/21 19:22:39 miod Exp $	*/
 /*
  * Copyright (c) 2015 Alexandre Ratchov <alex@caoua.org>
  *
@@ -113,7 +113,7 @@ struct mixer_ev {
  */
 struct audio_softc {
 	struct device dev;
-	struct audio_hw_if *ops;	/* driver funcs */
+	const struct audio_hw_if *ops;	/* driver funcs */
 	void *cookie;			/* wskbd cookie */
 	void *arg;			/* first arg to driver funcs */
 	int mode;			/* bitmask of AUMODE_* */
@@ -1225,7 +1225,7 @@ audio_attach(struct device *parent, struct device *self, void *aux)
 {
 	struct audio_softc *sc = (void *)self;
 	struct audio_attach_args *sa = aux;
-	struct audio_hw_if *ops = sa->hwif;
+	const struct audio_hw_if *ops = sa->hwif;
 	struct mixer_devinfo *mi;
 	struct mixer_ctrl *ent;
 	void *arg = sa->hdl;
@@ -1487,7 +1487,8 @@ audio_submatch(struct device *parent, void *match, void *aux)
 }
 
 struct device *
-audio_attach_mi(struct audio_hw_if *ops, void *arg, void *cookie, struct device *dev)
+audio_attach_mi(const struct audio_hw_if *ops, void *arg, void *cookie,
+    struct device *dev)
 {
 	struct audio_attach_args aa;
 
diff --git a/sys/dev/audio_if.h b/sys/dev/audio_if.h
index 4f43d0e39aa..c5adaf579cd 100644
--- a/sys/dev/audio_if.h
+++ b/sys/dev/audio_if.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: audio_if.h,v 1.37 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: audio_if.h,v 1.38 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: audio_if.h,v 1.24 1998/01/10 14:07:25 tv Exp $	*/
 
 /*
@@ -141,7 +141,7 @@ struct audio_hw_if {
 
 struct audio_attach_args {
 	int	type;
-	void	*hwif;		/* either audio_hw_if * or midi_hw_if * */
+	const void *hwif;		/* either audio_hw_if * or midi_hw_if * */
 	void	*hdl;
 	void	*cookie;
 };
@@ -152,7 +152,8 @@ struct audio_attach_args {
 #define AUDIODEV_TYPE_RADIO	4
 
 /* Attach the MI driver(s) to the MD driver. */
-struct device *audio_attach_mi(struct audio_hw_if *, void *, void *, struct device *);
+struct device *audio_attach_mi(const struct audio_hw_if *, void *, void *,
+		   struct device *);
 int	       audioprint(void *, const char *);
 int	       audio_blksz_bytes(int,
 		   struct audio_params *, struct audio_params *, int);
diff --git a/sys/dev/fdt/es8316ac.c b/sys/dev/fdt/es8316ac.c
index 5423972f70f..57d1734f261 100644
--- a/sys/dev/fdt/es8316ac.c
+++ b/sys/dev/fdt/es8316ac.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: es8316ac.c,v 1.1 2020/06/11 00:04:28 patrick Exp $ */
+/* $OpenBSD: es8316ac.c,v 1.2 2022/03/21 19:22:40 miod Exp $ */
 /* $NetBSD: es8316ac.c,v 1.2 2020/01/03 01:00:08 jmcneill Exp $ */
 /*-
  * Copyright (c) 2020 Jared McNeill <jmcneill@invisible.ca>
@@ -132,7 +132,7 @@ int escodec_set_port(void *, mixer_ctrl_t *);
 int escodec_get_port(void *, mixer_ctrl_t *);
 int escodec_query_devinfo(void *, mixer_devinfo_t *);
 
-struct audio_hw_if escodec_hw_if = {
+const struct audio_hw_if escodec_hw_if = {
 	.set_port = escodec_set_port,
 	.get_port = escodec_get_port,
 	.query_devinfo = escodec_query_devinfo,
diff --git a/sys/dev/fdt/graphaudio.c b/sys/dev/fdt/graphaudio.c
index 900daf57226..d09e08ecea7 100644
--- a/sys/dev/fdt/graphaudio.c
+++ b/sys/dev/fdt/graphaudio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: graphaudio.c,v 1.2 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: graphaudio.c,v 1.3 2022/03/21 19:22:40 miod Exp $	*/
 /*
  * Copyright (c) 2020 Patrick Wildt <patrick@blueri.se>
  * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
@@ -65,7 +65,7 @@ int	graphaudio_trigger_input(void *, void *, void *, int,
 int	graphaudio_halt_output(void *);
 int	graphaudio_halt_input(void *);
 
-struct audio_hw_if graphaudio_hw_if = {
+const struct audio_hw_if graphaudio_hw_if = {
 	.open = graphaudio_open,
 	.close = graphaudio_close,
 	.set_params = graphaudio_set_params,
@@ -206,7 +206,7 @@ graphaudio_open(void *cookie, int flags)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int error;
 
 	dai = sc->sc_dai_cpu;
@@ -237,7 +237,7 @@ graphaudio_close(void *cookie)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 
 	dai = sc->sc_dai_codec;
 	hwif = dai->dd_hw_if;
@@ -256,7 +256,7 @@ graphaudio_set_params(void *cookie, int setmode, int usemode,
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	uint32_t rate;
 	int error;
 
@@ -308,7 +308,7 @@ graphaudio_allocm(void *cookie, int direction, size_t size, int type,
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->allocm)
 		return hwif->allocm(dai->dd_cookie,
@@ -322,7 +322,7 @@ graphaudio_freem(void *cookie, void *addr, int type)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->freem)
 		hwif->freem(dai->dd_cookie, addr, type);
@@ -333,7 +333,7 @@ graphaudio_set_port(void *cookie, mixer_ctrl_t *cp)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_codec;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->set_port)
 		return hwif->set_port(dai->dd_cookie, cp);
@@ -346,7 +346,7 @@ graphaudio_get_port(void *cookie, mixer_ctrl_t *cp)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_codec;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->get_port)
 		return hwif->get_port(dai->dd_cookie, cp);
@@ -359,7 +359,7 @@ graphaudio_query_devinfo(void *cookie, mixer_devinfo_t *dip)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_codec;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->query_devinfo)
 		return hwif->query_devinfo(dai->dd_cookie, dip);
@@ -372,7 +372,7 @@ graphaudio_get_props(void *cookie)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->get_props)
 		return hwif->get_props(dai->dd_cookie);
@@ -385,7 +385,7 @@ graphaudio_round_blocksize(void *cookie, int block)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->round_blocksize)
 		return hwif->round_blocksize(dai->dd_cookie, block);
@@ -398,7 +398,7 @@ graphaudio_round_buffersize(void *cookie, int direction, size_t bufsize)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->round_buffersize)
 		return hwif->round_buffersize(dai->dd_cookie,
@@ -413,7 +413,7 @@ graphaudio_trigger_output(void *cookie, void *start, void *end, int blksize,
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int error;
 
 	dai = sc->sc_dai_codec;
@@ -447,7 +447,7 @@ graphaudio_trigger_input(void *cookie, void *start, void *end, int blksize,
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int error;
 
 	dai = sc->sc_dai_codec;
@@ -480,7 +480,7 @@ graphaudio_halt_output(void *cookie)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 
 	dai = sc->sc_dai_codec;
 	hwif = dai->dd_hw_if;
@@ -500,7 +500,7 @@ graphaudio_halt_input(void *cookie)
 {
 	struct graphaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 
 	dai = sc->sc_dai_codec;
 	hwif = dai->dd_hw_if;
diff --git a/sys/dev/fdt/rkiis.c b/sys/dev/fdt/rkiis.c
index bf170513447..baf3c1d6bf3 100644
--- a/sys/dev/fdt/rkiis.c
+++ b/sys/dev/fdt/rkiis.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rkiis.c,v 1.1 2020/06/11 00:02:08 patrick Exp $ */
+/* $OpenBSD: rkiis.c,v 1.2 2022/03/21 19:22:40 miod Exp $ */
 /* $NetBSD: rk_i2s.c,v 1.3 2020/02/29 05:51:10 isaki Exp $ */
 /*-
  * Copyright (c) 2019 Jared McNeill <jmcneill@invisible.ca>
@@ -200,7 +200,7 @@ struct rkiis_softc {
 	struct dai_device	sc_dai;
 };
 
-struct audio_hw_if rkiis_hw_if = {
+const struct audio_hw_if rkiis_hw_if = {
 	.set_params = rkiis_set_params,
 	.get_props = rkiis_get_props,
 	.allocm = rkiis_allocm,
diff --git a/sys/dev/fdt/simpleamp.c b/sys/dev/fdt/simpleamp.c
index 1d49d65c401..23617d4ab8e 100644
--- a/sys/dev/fdt/simpleamp.c
+++ b/sys/dev/fdt/simpleamp.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: simpleamp.c,v 1.2 2022/02/14 00:53:40 jsg Exp $	*/
+/*	$OpenBSD: simpleamp.c,v 1.3 2022/03/21 19:22:40 miod Exp $	*/
 /*
  * Copyright (c) 2020 Patrick Wildt <patrick@blueri.se>
  *
@@ -46,7 +46,7 @@ struct simpleamp_softc {
 	uint32_t		sc_vcc;
 };
 
-struct audio_hw_if simpleamp_hw_if = {
+const struct audio_hw_if simpleamp_hw_if = {
 	.open = simpleamp_open,
 	.close = simpleamp_close,
 };
diff --git a/sys/dev/fdt/simpleaudio.c b/sys/dev/fdt/simpleaudio.c
index 9ed72558849..482c453d5fc 100644
--- a/sys/dev/fdt/simpleaudio.c
+++ b/sys/dev/fdt/simpleaudio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: simpleaudio.c,v 1.3 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: simpleaudio.c,v 1.4 2022/03/21 19:22:40 miod Exp $	*/
 /*
  * Copyright (c) 2020 Patrick Wildt <patrick@blueri.se>
  *
@@ -67,7 +67,7 @@ int simpleaudio_trigger_input(void *, void *, void *, int,
 int simpleaudio_halt_output(void *);
 int simpleaudio_halt_input(void *);
 
-struct audio_hw_if simpleaudio_hw_if = {
+const struct audio_hw_if simpleaudio_hw_if = {
 	.open = simpleaudio_open,
 	.close = simpleaudio_close,
 	.set_params = simpleaudio_set_params,
@@ -226,7 +226,7 @@ simpleaudio_open(void *cookie, int flags)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int error, i;
 
 	dai = sc->sc_dai_cpu;
@@ -269,7 +269,7 @@ simpleaudio_close(void *cookie)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int i;
 
 	for (i = 0; i < sc->sc_dai_naux; i++) {
@@ -296,7 +296,7 @@ simpleaudio_set_params(void *cookie, int setmode, int usemode,
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	uint32_t rate;
 	int error;
 
@@ -348,7 +348,7 @@ simpleaudio_allocm(void *cookie, int direction, size_t size, int type,
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->allocm)
 		return hwif->allocm(dai->dd_cookie,
@@ -362,7 +362,7 @@ simpleaudio_freem(void *cookie, void *addr, int type)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->freem)
 		hwif->freem(dai->dd_cookie, addr, type);
@@ -373,7 +373,7 @@ simpleaudio_set_port(void *cookie, mixer_ctrl_t *cp)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_codec;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->set_port)
 		return hwif->set_port(dai->dd_cookie, cp);
@@ -386,7 +386,7 @@ simpleaudio_get_port(void *cookie, mixer_ctrl_t *cp)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_codec;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->get_port)
 		return hwif->get_port(dai->dd_cookie, cp);
@@ -399,7 +399,7 @@ simpleaudio_query_devinfo(void *cookie, mixer_devinfo_t *dip)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_codec;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->query_devinfo)
 		return hwif->query_devinfo(dai->dd_cookie, dip);
@@ -412,7 +412,7 @@ simpleaudio_get_props(void *cookie)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->get_props)
 		return hwif->get_props(dai->dd_cookie);
@@ -425,7 +425,7 @@ simpleaudio_round_blocksize(void *cookie, int block)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->round_blocksize)
 		return hwif->round_blocksize(dai->dd_cookie, block);
@@ -438,7 +438,7 @@ simpleaudio_round_buffersize(void *cookie, int direction, size_t bufsize)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai = sc->sc_dai_cpu;
-	struct audio_hw_if *hwif = dai->dd_hw_if;
+	const struct audio_hw_if *hwif = dai->dd_hw_if;
 
 	if (hwif->round_buffersize)
 		return hwif->round_buffersize(dai->dd_cookie,
@@ -453,7 +453,7 @@ simpleaudio_trigger_output(void *cookie, void *start, void *end, int blksize,
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int error, i;
 
 	for (i = 0; i < sc->sc_dai_naux; i++) {
@@ -500,7 +500,7 @@ simpleaudio_trigger_input(void *cookie, void *start, void *end, int blksize,
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int error, i;
 
 	for (i = 0; i < sc->sc_dai_naux; i++) {
@@ -545,7 +545,7 @@ int simpleaudio_halt_output(void *cookie)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int i;
 
 	for (i = 0; i < sc->sc_dai_naux; i++) {
@@ -572,7 +572,7 @@ int simpleaudio_halt_input(void *cookie)
 {
 	struct simpleaudio_softc *sc = cookie;
 	struct dai_device *dai;
-	struct audio_hw_if *hwif;
+	const struct audio_hw_if *hwif;
 	int i;
 
 	for (i = 0; i < sc->sc_dai_naux; i++) {
diff --git a/sys/dev/fdt/tascodec.c b/sys/dev/fdt/tascodec.c
index 83f0faaf85c..48c7e355b49 100644
--- a/sys/dev/fdt/tascodec.c
+++ b/sys/dev/fdt/tascodec.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: tascodec.c,v 1.2 2022/02/14 14:57:00 kettenis Exp $	*/
+/*	$OpenBSD: tascodec.c,v 1.3 2022/03/21 19:22:40 miod Exp $	*/
 /*
  * Copyright (c) 2022 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -82,7 +82,7 @@ int	tascodec_trigger_output(void *, void *, void *, int,
 	    void (*)(void *), void *, struct audio_params *);
 int	tascodec_halt_output(void *);
 
-struct audio_hw_if tascodec_hw_if = {
+const struct audio_hw_if tascodec_hw_if = {
 	.set_port = tascodec_set_port,
 	.get_port = tascodec_get_port,
 	.query_devinfo = tascodec_query_devinfo,
diff --git a/sys/dev/ic/arcofi.c b/sys/dev/ic/arcofi.c
index 3bf44fbc1ce..5152f2df8d9 100644
--- a/sys/dev/ic/arcofi.c
+++ b/sys/dev/ic/arcofi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: arcofi.c,v 1.18 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: arcofi.c,v 1.19 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2011 Miodrag Vallat.
@@ -208,7 +208,7 @@ int	arcofi_set_port(void *, mixer_ctrl_t *);
 int	arcofi_start_input(void *, void *, int, void (*)(void *), void *);
 int	arcofi_start_output(void *, void *, int, void (*)(void *), void *);
 
-/* const */ struct audio_hw_if arcofi_hw_if = {
+const struct audio_hw_if arcofi_hw_if = {
 	.open = arcofi_open,
 	.close = arcofi_close,
 	.set_params = arcofi_set_params,
diff --git a/sys/dev/ic/mpuvar.h b/sys/dev/ic/mpuvar.h
index 35d76a70671..9abd511bf1f 100644
--- a/sys/dev/ic/mpuvar.h
+++ b/sys/dev/ic/mpuvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpuvar.h,v 1.6 2008/06/26 05:42:15 ray Exp $	*/
+/*	$OpenBSD: mpuvar.h,v 1.7 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: mpu401var.h,v 1.3 1998/11/25 22:17:06 augustss Exp $	*/
 
 /*
@@ -39,7 +39,7 @@ struct mpu_softc {
 	void	*arg;			/* arg for intr() */
 };
 
-extern struct midi_hw_if mpu_midi_hw_if;
+extern const struct midi_hw_if mpu_midi_hw_if;
 
 int	mpu_intr(void *);
 int	mpu_find(void *);
diff --git a/sys/dev/isa/ess.c b/sys/dev/isa/ess.c
index 86df2f0f815..c0298cacfb4 100644
--- a/sys/dev/isa/ess.c
+++ b/sys/dev/isa/ess.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ess.c,v 1.27 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: ess.c,v 1.28 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: ess.c,v 1.44.4.1 1999/06/21 01:18:00 thorpej Exp $	*/
 
 /*
@@ -197,7 +197,7 @@ static char *essmodel[] = {
  * Define our interface to the higher level audio driver.
  */
 
-struct audio_hw_if ess_1788_hw_if = {
+const struct audio_hw_if ess_1788_hw_if = {
 	ess_open,
 	ess_1788_close,
 	ess_set_params,
@@ -222,7 +222,7 @@ struct audio_hw_if ess_1788_hw_if = {
 	ess_audio1_trigger_input
 };
 
-struct audio_hw_if ess_1888_hw_if = {
+const struct audio_hw_if ess_1888_hw_if = {
 	ess_open,
 	ess_1888_close,
 	ess_set_params,
diff --git a/sys/dev/isa/gus.c b/sys/dev/isa/gus.c
index 8ff717032c8..77c381a1fdd 100644
--- a/sys/dev/isa/gus.c
+++ b/sys/dev/isa/gus.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gus.c,v 1.49 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: gus.c,v 1.50 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: gus.c,v 1.51 1998/01/25 23:48:06 mycroft Exp $	*/
 
 /*-
@@ -260,7 +260,7 @@ static const unsigned short gus_log_volumes[512] = {
 /*
  * Interface to higher level audio driver
  */
-struct audio_hw_if gus_hw_if = {
+const struct audio_hw_if gus_hw_if = {
 	gusopen,
 	gusclose,
 	gus_set_params,
@@ -291,7 +291,7 @@ struct audio_hw_if gus_hw_if = {
 	NULL
 };
 
-static struct audio_hw_if gusmax_hw_if = {
+const static struct audio_hw_if gusmax_hw_if = {
 	gusmaxopen,
 	gusmax_close,
 	gusmax_set_params,
@@ -2082,7 +2082,6 @@ gus_init_cs4231(struct gus_softc *sc)
 		sc->sc_codec.parent = sc;
 		sc->sc_codec.sc_drq = sc->sc_recdrq;
 		sc->sc_codec.sc_recdrq = sc->sc_drq;
-		gus_hw_if = gusmax_hw_if;
 		/* enable line in and mic in the GUS mixer; the codec chip
 		   will do the real mixing for them. */
 		sc->sc_mixcontrol &= ~GUSMASK_LINE_IN; /* 0 enables. */
@@ -3397,8 +3396,12 @@ gus_subattach(struct gus_softc *sc, struct isa_attach_args *ia)
 	 * Attach to the generic audio layer
 	 */
 
-	audio_attach_mi(&gus_hw_if, HAS_CODEC(sc) ? (void *)&sc->sc_codec :
-	    (void *)sc, NULL, &sc->sc_dev);
+	if (HAS_CODEC(sc)) {
+		audio_attach_mi(&gusmax_hw_if, (void *)&sc->sc_codec, NULL,
+		    &sc->sc_dev);
+	} else {
+		audio_attach_mi(&gus_hw_if, (void *)sc, NULL, &sc->sc_dev);
+	}
 }
 
 /*
diff --git a/sys/dev/isa/gusvar.h b/sys/dev/isa/gusvar.h
index 4422948542b..e979f53c6ac 100644
--- a/sys/dev/isa/gusvar.h
+++ b/sys/dev/isa/gusvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: gusvar.h,v 1.10 2016/09/19 06:46:44 ratchov Exp $	*/
+/*	$OpenBSD: gusvar.h,v 1.11 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: gus.c,v 1.51 1998/01/25 23:48:06 mycroft Exp $	*/
 
 /*-
@@ -406,7 +406,7 @@ extern const int gus_addrs;
 
 #define splgus splaudio
 
-extern struct audio_hw_if gus_hw_if;
+extern const struct audio_hw_if gus_hw_if;
 
 #define FLIP_REV	5		/* This rev has flipped mixer chans */
 
diff --git a/sys/dev/isa/mpu401.c b/sys/dev/isa/mpu401.c
index cacab0e6442..60e5d635417 100644
--- a/sys/dev/isa/mpu401.c
+++ b/sys/dev/isa/mpu401.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpu401.c,v 1.16 2021/03/07 06:17:04 jsg Exp $	*/
+/*	$OpenBSD: mpu401.c,v 1.17 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: mpu401.c,v 1.3 1998/11/25 22:17:06 augustss Exp $	*/
 
 /*
@@ -68,7 +68,7 @@ struct cfdriver mpu_cd = {
 	NULL, "mpu", DV_DULL
 };
 
-struct midi_hw_if mpu_midi_hw_if = {
+const struct midi_hw_if mpu_midi_hw_if = {
 	mpu_open,
 	mpu_close,
 	mpu_output,
diff --git a/sys/dev/isa/pas.c b/sys/dev/isa/pas.c
index cb206ec4f4f..d475b2d81ac 100644
--- a/sys/dev/isa/pas.c
+++ b/sys/dev/isa/pas.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: pas.c,v 1.31 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: pas.c,v 1.32 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: pas.c,v 1.37 1998/01/12 09:43:43 thorpej Exp $	*/
 
 /*
@@ -108,7 +108,7 @@ void	pasconf(int, int, int, int);
  * Define our interface to the higher level audio driver.
  */
 
-struct audio_hw_if pas_hw_if = {
+const struct audio_hw_if pas_hw_if = {
 	sbdsp_open,
 	sbdsp_close,
 	sbdsp_set_params,
diff --git a/sys/dev/isa/sb.c b/sys/dev/isa/sb.c
index 2a7ae30b936..75779266311 100644
--- a/sys/dev/isa/sb.c
+++ b/sys/dev/isa/sb.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sb.c,v 1.31 2022/02/16 06:21:18 anton Exp $	*/
+/*	$OpenBSD: sb.c,v 1.32 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: sb.c,v 1.57 1998/01/12 09:43:46 thorpej Exp $	*/
 
 /*
@@ -70,7 +70,7 @@ void	sb_mpu401_close(void *);
 int	sb_mpu401_output(void *, int);
 void	sb_mpu401_getinfo(void *, struct midi_info *);
 
-struct midi_hw_if sb_midi_hw_if = {
+const struct midi_hw_if sb_midi_hw_if = {
 	sbdsp_midi_open,
 	sbdsp_midi_close,
 	sbdsp_midi_output,
@@ -79,7 +79,7 @@ struct midi_hw_if sb_midi_hw_if = {
 	0,			/* ioctl */
 };
 
-struct midi_hw_if sb_mpu401_hw_if = {
+const struct midi_hw_if sb_mpu401_hw_if = {
 	sb_mpu401_open,
 	sb_mpu401_close,
 	sb_mpu401_output,
@@ -93,7 +93,7 @@ struct midi_hw_if sb_mpu401_hw_if = {
  * Define our interface to the higher level audio driver.
  */
 
-struct audio_hw_if sb_hw_if = {
+const struct audio_hw_if sb_hw_if = {
 	sbdsp_open,
 	sbdsp_close,
 	sbdsp_set_params,
@@ -243,7 +243,7 @@ sbattach(struct sbdsp_softc *sc)
 {
 	struct audio_attach_args arg;
 #if NMIDI > 0
-	struct midi_hw_if *mhw = &sb_midi_hw_if;
+	const struct midi_hw_if *mhw = &sb_midi_hw_if;
 #endif
 
 	sc->sc_ih = isa_intr_establish(sc->sc_ic, sc->sc_irq,
diff --git a/sys/dev/midi.c b/sys/dev/midi.c
index bcef144fbdc..73000a32c82 100644
--- a/sys/dev/midi.c
+++ b/sys/dev/midi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midi.c,v 1.52 2021/10/30 12:48:11 ratchov Exp $	*/
+/*	$OpenBSD: midi.c,v 1.53 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2003, 2004 Alexandre Ratchov
@@ -549,7 +549,7 @@ midiattach(struct device *parent, struct device *self, void *aux)
 	struct midi_info	  mi;
 	struct midi_softc        *sc = (struct midi_softc *)self;
 	struct audio_attach_args *sa = (struct audio_attach_args *)aux;
-	struct midi_hw_if        *hwif = sa->hwif;
+	const struct midi_hw_if  *hwif = sa->hwif;
 	void  			 *hdl = sa->hdl;
 
 #ifdef DIAGNOSTIC
@@ -645,7 +645,7 @@ midiprint(void *aux, const char *pnp)
 }
 
 struct device *
-midi_attach_mi(struct midi_hw_if *hwif, void *hdl, struct device *dev)
+midi_attach_mi(const struct midi_hw_if *hwif, void *hdl, struct device *dev)
 {
 	struct audio_attach_args arg;
 
diff --git a/sys/dev/midi_if.h b/sys/dev/midi_if.h
index bfe3ec72fa3..09755cbe062 100644
--- a/sys/dev/midi_if.h
+++ b/sys/dev/midi_if.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midi_if.h,v 1.9 2015/05/16 10:04:20 ratchov Exp $	*/
+/*	$OpenBSD: midi_if.h,v 1.10 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: midi_if.h,v 1.3 1998/11/25 22:17:07 augustss Exp $	*/
 
 /*
@@ -52,6 +52,7 @@ struct midi_hw_if {
 	int	(*ioctl)(void *, u_long, caddr_t, int, struct proc *);
 };
 
-struct device *midi_attach_mi(struct midi_hw_if *, void *, struct device *);
+struct device *midi_attach_mi(const struct midi_hw_if *, void *,
+	    struct device *);
 
 #endif /* _SYS_DEV_MIDI_IF_H_ */
diff --git a/sys/dev/midivar.h b/sys/dev/midivar.h
index d62daec694d..ff14ecbb343 100644
--- a/sys/dev/midivar.h
+++ b/sys/dev/midivar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: midivar.h,v 1.12 2021/10/30 12:26:26 ratchov Exp $	*/
+/*	$OpenBSD: midivar.h,v 1.13 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2003, 2004 Alexandre Ratchov
@@ -72,7 +72,7 @@ struct midi_buffer {
 
 struct midi_softc {
 	struct device	    dev;
-	struct midi_hw_if  *hw_if;
+	const struct midi_hw_if *hw_if;
 	void		   *hw_hdl;
 	int		    isbusy;		/* concerns only the output */
 	int		    flags;		/* open flags */
diff --git a/sys/dev/ofw/ofw_misc.h b/sys/dev/ofw/ofw_misc.h
index 2dfa800a820..9aee48a0f22 100644
--- a/sys/dev/ofw/ofw_misc.h
+++ b/sys/dev/ofw/ofw_misc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ofw_misc.h,v 1.23 2022/03/02 12:00:46 kettenis Exp $	*/
+/*	$OpenBSD: ofw_misc.h,v 1.24 2022/03/21 19:22:40 miod Exp $	*/
 /*
  * Copyright (c) 2017-2021 Mark Kettenis
  *
@@ -191,7 +191,7 @@ void	*endpoint_get_cookie(struct endpoint *);
 struct dai_device {
 	int	dd_node;
 	void	*dd_cookie;
-	void	*dd_hw_if;
+	const void *dd_hw_if;
 	int	(*dd_set_format)(void *, uint32_t, uint32_t, uint32_t);
 	int	(*dd_set_sysclk)(void *, uint32_t);
 
diff --git a/sys/dev/pci/auacer.c b/sys/dev/pci/auacer.c
index d42892bbbbd..ad840a08458 100644
--- a/sys/dev/pci/auacer.c
+++ b/sys/dev/pci/auacer.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: auacer.c,v 1.24 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: auacer.c,v 1.25 2022/03/21 19:22:40 miod Exp $	*/
 /*	$NetBSD: auacer.c,v 1.3 2004/11/10 04:20:26 kent Exp $	*/
 
 /*-
@@ -179,7 +179,7 @@ void	auacer_finish_attach(struct device *);
 
 static	void auacer_reset(struct auacer_softc *sc);
 
-struct audio_hw_if auacer_hw_if = {
+const struct audio_hw_if auacer_hw_if = {
 	auacer_open,
 	auacer_close,
 	auacer_set_params,
diff --git a/sys/dev/pci/auglx.c b/sys/dev/pci/auglx.c
index 8316136cef3..7902c382002 100644
--- a/sys/dev/pci/auglx.c
+++ b/sys/dev/pci/auglx.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: auglx.c,v 1.19 2022/03/11 18:00:45 mpi Exp $	*/
+/*      $OpenBSD: auglx.c,v 1.20 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2008 Marc Balmer <mbalmer@openbsd.org>
@@ -234,7 +234,7 @@ void auglx_free_prd(struct auglx_softc *sc, struct auglx_ring *bm);
 int auglx_allocmem(struct auglx_softc *, size_t, size_t, struct auglx_dma *);
 void auglx_freemem(struct auglx_softc *, struct auglx_dma *);
 
-struct audio_hw_if auglx_hw_if = {
+const struct audio_hw_if auglx_hw_if = {
 	auglx_open,
 	auglx_close,
 	auglx_set_params,
diff --git a/sys/dev/pci/auich.c b/sys/dev/pci/auich.c
index bc27d233f21..f03c0e3bdb1 100644
--- a/sys/dev/pci/auich.c
+++ b/sys/dev/pci/auich.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: auich.c,v 1.115 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: auich.c,v 1.116 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2000,2001 Michael Shalayeff
@@ -315,7 +315,7 @@ void auich_freemem(struct auich_softc *, struct auich_dma *);
 
 void auich_resume(struct auich_softc *);
 
-struct audio_hw_if auich_hw_if = {
+const struct audio_hw_if auich_hw_if = {
 	auich_open,
 	auich_close,
 	auich_set_params,
diff --git a/sys/dev/pci/auixp.c b/sys/dev/pci/auixp.c
index dca3dfa3007..92f57fd2676 100644
--- a/sys/dev/pci/auixp.c
+++ b/sys/dev/pci/auixp.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auixp.c,v 1.47 2022/03/11 18:00:45 mpi Exp $ */
+/* $OpenBSD: auixp.c,v 1.48 2022/03/21 19:22:40 miod Exp $ */
 /* $NetBSD: auixp.c,v 1.9 2005/06/27 21:13:09 thorpej Exp $ */
 
 /*
@@ -154,7 +154,7 @@ void	auixp_update_busbusy(struct auixp_softc *);
 #define DPRINTF(x)
 #endif
 
-struct audio_hw_if auixp_hw_if = {
+const struct audio_hw_if auixp_hw_if = {
 	auixp_open,
 	auixp_close,
 	auixp_set_params,
diff --git a/sys/dev/pci/autri.c b/sys/dev/pci/autri.c
index 39db4333a40..306aa674509 100644
--- a/sys/dev/pci/autri.c
+++ b/sys/dev/pci/autri.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: autri.c,v 1.46 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: autri.c,v 1.47 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2001 SOMEYA Yoshihiko and KUROSAWA Takahiro.
@@ -139,7 +139,7 @@ int	autri_query_devinfo(void *addr, mixer_devinfo_t *dip);
 
 int	autri_get_portnum_by_name(struct autri_softc *, char *, char *, char *);
 
-struct audio_hw_if autri_hw_if = {
+const struct audio_hw_if autri_hw_if = {
 	autri_open,
 	autri_close,
 	autri_set_params,
@@ -171,7 +171,7 @@ int	autri_midi_open(void *, int, void (*)(void *, int),
 			   void (*)(void *), void *);
 int	autri_midi_output(void *, int);
 
-struct midi_hw_if autri_midi_hw_if = {
+const struct midi_hw_if autri_midi_hw_if = {
 	autri_midi_open,
 	autri_midi_close,
 	autri_midi_output,
diff --git a/sys/dev/pci/auvia.c b/sys/dev/pci/auvia.c
index 8281f448621..a2b7923f3a7 100644
--- a/sys/dev/pci/auvia.c
+++ b/sys/dev/pci/auvia.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: auvia.c,v 1.62 2022/03/11 18:00:45 mpi Exp $ */
+/*	$OpenBSD: auvia.c,v 1.63 2022/03/21 19:22:41 miod Exp $ */
 /*	$NetBSD: auvia.c,v 1.28 2002/11/04 16:38:49 kent Exp $	*/
 
 /*-
@@ -178,7 +178,7 @@ const struct cfattach auvia_ca = {
 
 #define TIMEOUT	50
 
-struct audio_hw_if auvia_hw_if = {
+const struct audio_hw_if auvia_hw_if = {
 	auvia_open,
 	auvia_close,
 	auvia_set_params,
diff --git a/sys/dev/pci/azalia.c b/sys/dev/pci/azalia.c
index b3ae4463941..27f799ea4a1 100644
--- a/sys/dev/pci/azalia.c
+++ b/sys/dev/pci/azalia.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: azalia.c,v 1.270 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: azalia.c,v 1.271 2022/03/21 19:22:41 miod Exp $	*/
 /*	$NetBSD: azalia.c,v 1.20 2006/05/07 08:31:44 kent Exp $	*/
 
 /*-
@@ -289,7 +289,7 @@ struct cfdriver azalia_cd = {
 	NULL, "azalia", DV_DULL, CD_SKIPHIBERNATE
 };
 
-struct audio_hw_if azalia_hw_if = {
+const struct audio_hw_if azalia_hw_if = {
 	azalia_open,
 	azalia_close,
 	azalia_set_params,
diff --git a/sys/dev/pci/bktr/bktr_os.c b/sys/dev/pci/bktr/bktr_os.c
index cb266015d07..8b463c49160 100644
--- a/sys/dev/pci/bktr/bktr_os.c
+++ b/sys/dev/pci/bktr/bktr_os.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bktr_os.c,v 1.35 2022/03/11 18:00:53 mpi Exp $	*/
+/*	$OpenBSD: bktr_os.c,v 1.36 2022/03/21 19:22:41 miod Exp $	*/
 /* $FreeBSD: src/sys/dev/bktr/bktr_os.c,v 1.20 2000/10/20 08:16:53 roger Exp $ */
 
 /*
@@ -123,7 +123,7 @@ struct cfdriver bktr_cd = {
 int	bktr_get_info(void *, struct radio_info *);
 int	bktr_set_info(void *, struct radio_info *);
 
-struct radio_hw_if bktr_hw_if = {
+const struct radio_hw_if bktr_hw_if = {
 	NULL,	/* open */
 	NULL,	/* close */
 	bktr_get_info,
diff --git a/sys/dev/pci/cmpci.c b/sys/dev/pci/cmpci.c
index 278400b3042..416db69f4d9 100644
--- a/sys/dev/pci/cmpci.c
+++ b/sys/dev/pci/cmpci.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cmpci.c,v 1.48 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: cmpci.c,v 1.49 2022/03/21 19:22:41 miod Exp $	*/
 /*	$NetBSD: cmpci.c,v 1.25 2004/10/26 06:32:20 xtraeme Exp $	*/
 
 /*
@@ -149,7 +149,7 @@ int cmpci_trigger_input(void *, void *, void *, int,
 				    void (*)(void *), void *,
 				    struct audio_params *);
 
-struct audio_hw_if cmpci_hw_if = {
+const struct audio_hw_if cmpci_hw_if = {
 	cmpci_open,		/* open */
 	cmpci_close,		/* close */
 	cmpci_set_params,	/* set_params */
diff --git a/sys/dev/pci/cs4280.c b/sys/dev/pci/cs4280.c
index ee0b09132c3..6f8d7f31ea4 100644
--- a/sys/dev/pci/cs4280.c
+++ b/sys/dev/pci/cs4280.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cs4280.c,v 1.56 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: cs4280.c,v 1.57 2022/03/21 19:22:41 miod Exp $	*/
 /*	$NetBSD: cs4280.c,v 1.5 2000/06/26 04:56:23 simonb Exp $	*/
 
 /*
@@ -233,7 +233,7 @@ int	cs4280_midi_open(void *, int, void (*)(void *, int),
 int	cs4280_midi_output(void *, int);
 #endif
 
-struct audio_hw_if cs4280_hw_if = {
+const struct audio_hw_if cs4280_hw_if = {
 	cs4280_open,
 	cs4280_close,
 	cs4280_set_params,
@@ -259,7 +259,7 @@ struct audio_hw_if cs4280_hw_if = {
 };
 
 #if NMIDI > 0
-struct midi_hw_if cs4280_midi_hw_if = {
+const struct midi_hw_if cs4280_midi_hw_if = {
 	cs4280_midi_open,
 	cs4280_midi_close,
 	cs4280_midi_output,
diff --git a/sys/dev/pci/cs4281.c b/sys/dev/pci/cs4281.c
index 0c9c1d962c4..f8bc2564982 100644
--- a/sys/dev/pci/cs4281.c
+++ b/sys/dev/pci/cs4281.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cs4281.c,v 1.41 2022/03/11 18:00:45 mpi Exp $ */
+/*	$OpenBSD: cs4281.c,v 1.42 2022/03/21 19:22:41 miod Exp $ */
 /*	$Tera: cs4281.c,v 1.18 2000/12/27 14:24:45 tacha Exp $	*/
 
 /*
@@ -194,7 +194,7 @@ int cs4281_debug = 5;
 #define DPRINTFN(n,x)
 #endif
 
-struct audio_hw_if cs4281_hw_if = {
+const struct audio_hw_if cs4281_hw_if = {
 	cs4281_open,
 	cs4281_close,
 	cs4281_set_params,
@@ -227,7 +227,7 @@ int cs4281_midi_open(void *, int, void (*)(void *, int),
 		     void (*)(void *), void *);
 int cs4281_midi_output(void *, int);
 
-struct midi_hw_if cs4281_midi_hw_if = {
+const struct midi_hw_if cs4281_midi_hw_if = {
 	cs4281_midi_open,
 	cs4281_midi_close,
 	cs4281_midi_output,
diff --git a/sys/dev/pci/eap.c b/sys/dev/pci/eap.c
index 9a0eb2a4125..53c8acfae5f 100644
--- a/sys/dev/pci/eap.c
+++ b/sys/dev/pci/eap.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: eap.c,v 1.60 2022/03/11 18:00:45 mpi Exp $ */
+/*      $OpenBSD: eap.c,v 1.61 2022/03/21 19:22:41 miod Exp $ */
 /*	$NetBSD: eap.c,v 1.46 2001/09/03 15:07:37 reinoud Exp $ */
 
 /*
@@ -194,7 +194,7 @@ int	eap_midi_open(void *, int, void (*)(void *, int),
 int	eap_midi_output(void *, int);
 #endif
 
-struct audio_hw_if eap1370_hw_if = {
+const struct audio_hw_if eap1370_hw_if = {
 	eap_open,
 	eap_close,
 	eap_set_params,
@@ -219,7 +219,7 @@ struct audio_hw_if eap1370_hw_if = {
 	eap_trigger_input
 };
 
-struct audio_hw_if eap1371_hw_if = {
+const struct audio_hw_if eap1371_hw_if = {
 	eap_open,
 	eap_close,
 	eap_set_params,
@@ -245,7 +245,7 @@ struct audio_hw_if eap1371_hw_if = {
 };
 
 #if NMIDI > 0
-struct midi_hw_if eap_midi_hw_if = {
+const struct midi_hw_if eap_midi_hw_if = {
 	eap_midi_open,
 	eap_midi_close,
 	eap_midi_output,
@@ -433,7 +433,7 @@ eap_attach(struct device *parent, struct device *self, void *aux)
 	struct eap_softc *sc = (struct eap_softc *)self;
 	struct pci_attach_args *pa = (struct pci_attach_args *)aux;
 	pci_chipset_tag_t pc = pa->pa_pc;
-	struct audio_hw_if *eap_hw_if;
+	const struct audio_hw_if *eap_hw_if;
 	char const *intrstr;
 	pci_intr_handle_t ih;
 	mixer_ctrl_t ctl;
diff --git a/sys/dev/pci/emuxki.c b/sys/dev/pci/emuxki.c
index aeb8e731790..998f722d4a5 100644
--- a/sys/dev/pci/emuxki.c
+++ b/sys/dev/pci/emuxki.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: emuxki.c,v 1.57 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: emuxki.c,v 1.58 2022/03/21 19:22:41 miod Exp $	*/
 /*	$NetBSD: emuxki.c,v 1.1 2001/10/17 18:39:41 jdolecek Exp $	*/
 
 /*-
@@ -211,7 +211,7 @@ const struct cfattach emu_ca = {
 	emuxki_activate
 };
 
-struct audio_hw_if emuxki_hw_if = {
+const struct audio_hw_if emuxki_hw_if = {
 	emuxki_open,
 	emuxki_close,
 	emuxki_set_params,
diff --git a/sys/dev/pci/envy.c b/sys/dev/pci/envy.c
index 04b985cc131..51689997017 100644
--- a/sys/dev/pci/envy.c
+++ b/sys/dev/pci/envy.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: envy.c,v 1.83 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: envy.c,v 1.84 2022/03/21 19:22:41 miod Exp $	*/
 /*
  * Copyright (c) 2007 Alexandre Ratchov <alex@caoua.org>
  *
@@ -179,7 +179,7 @@ struct cfdriver envy_cd = {
 	NULL, "envy", DV_DULL
 };
 
-struct audio_hw_if envy_hw_if = {
+const struct audio_hw_if envy_hw_if = {
 	envy_open,		/* open */
 	envy_close,		/* close */
 	envy_set_params,	/* set_params */
@@ -205,7 +205,7 @@ struct audio_hw_if envy_hw_if = {
 };
 
 #if NMIDI > 0
-struct midi_hw_if envy_midi_hw_if = {
+const struct midi_hw_if envy_midi_hw_if = {
 	envy_midi_open,
 	envy_midi_close,
 	envy_midi_output,
diff --git a/sys/dev/pci/esa.c b/sys/dev/pci/esa.c
index 4374f7a63e7..63c864db22f 100644
--- a/sys/dev/pci/esa.c
+++ b/sys/dev/pci/esa.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: esa.c,v 1.37 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: esa.c,v 1.38 2022/03/21 19:22:41 miod Exp $	*/
 /* $NetBSD: esa.c,v 1.12 2002/03/24 14:17:35 jmcneill Exp $ */
 
 /*
@@ -151,7 +151,7 @@ void		esa_remove_list(struct esa_voice *, struct esa_list *, int);
 void		esa_suspend(struct esa_softc *);
 void		esa_resume(struct esa_softc *);
 
-struct audio_hw_if esa_hw_if = {
+const struct audio_hw_if esa_hw_if = {
 	esa_open,
 	esa_close,
 	esa_set_params,
diff --git a/sys/dev/pci/eso.c b/sys/dev/pci/eso.c
index 7444529845d..b700ddecbdc 100644
--- a/sys/dev/pci/eso.c
+++ b/sys/dev/pci/eso.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: eso.c,v 1.49 2022/03/11 18:00:45 mpi Exp $	*/
+/*	$OpenBSD: eso.c,v 1.50 2022/03/21 19:22:41 miod Exp $	*/
 /*	$NetBSD: eso.c,v 1.48 2006/12/18 23:13:39 kleink Exp $	*/
 
 /*
@@ -123,7 +123,7 @@ int	eso_trigger_input(void *, void *, void *, int,
 		    void (*)(void *), void *, struct audio_params *);
 void	eso_setup(struct eso_softc *, int, int);
 
-struct audio_hw_if eso_hw_if = {
+const struct audio_hw_if eso_hw_if = {
 	eso_open,
 	eso_close,
 	eso_set_params,
diff --git a/sys/dev/pci/fms.c b/sys/dev/pci/fms.c
index c242371c6b4..8e18364f857 100644
--- a/sys/dev/pci/fms.c
+++ b/sys/dev/pci/fms.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fms.c,v 1.32 2022/03/11 18:00:45 mpi Exp $ */
+/*	$OpenBSD: fms.c,v 1.33 2022/03/21 19:22:41 miod Exp $ */
 /*	$NetBSD: fms.c,v 1.5.4.1 2000/06/30 16:27:50 simonb Exp $	*/
 
 /*-
@@ -99,7 +99,7 @@ const struct cfattach fms_ca = {
 	sizeof (struct fms_softc), fms_match, fms_attach
 };
 
-struct audio_hw_if fms_hw_if = {
+const struct audio_hw_if fms_hw_if = {
 	fms_open,
 	fms_close,
 	fms_set_params,
diff --git a/sys/dev/pci/fmsradio.c b/sys/dev/pci/fmsradio.c
index b87e84818ee..26f34732dd3 100644
--- a/sys/dev/pci/fmsradio.c
+++ b/sys/dev/pci/fmsradio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: fmsradio.c,v 1.7 2021/11/23 00:17:59 jsg Exp $	*/
+/*	$OpenBSD: fmsradio.c,v 1.8 2022/03/21 19:22:41 miod Exp $	*/
 
 /*
  * Copyright (c) 2002 Vladimir Popov <jumbo@narod.ru>
@@ -136,7 +136,7 @@ int	fmsradio_get_info(void *, struct radio_info *);
 int	fmsradio_set_info(void *, struct radio_info *);
 int	fmsradio_search(void *, int);
 
-struct radio_hw_if fmsradio_hw_if = {
+const struct radio_hw_if fmsradio_hw_if = {
 	NULL,   /* open */
 	NULL,   /* close */
 	fmsradio_get_info,
diff --git a/sys/dev/pci/maestro.c b/sys/dev/pci/maestro.c
index 19bc93c07b3..d6ceb0cae2c 100644
--- a/sys/dev/pci/maestro.c
+++ b/sys/dev/pci/maestro.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: maestro.c,v 1.45 2022/03/11 18:00:50 mpi Exp $	*/
+/*	$OpenBSD: maestro.c,v 1.46 2022/03/21 19:22:41 miod Exp $	*/
 /* $FreeBSD: /c/ncvs/src/sys/dev/sound/pci/maestro.c,v 1.3 2000/11/21 12:22:11 julian Exp $ */
 /*
  * FreeBSD's ESS Agogo/Maestro driver 
@@ -527,7 +527,7 @@ const struct cfattach maestro_ca = {
 	NULL, maestro_activate
 };
 
-struct audio_hw_if maestro_hw_if = {
+const struct audio_hw_if maestro_hw_if = {
 	maestro_open,
 	maestro_close,
 	maestro_set_params,
diff --git a/sys/dev/pci/neo.c b/sys/dev/pci/neo.c
index aed3bc2e771..b6f984d26e1 100644
--- a/sys/dev/pci/neo.c
+++ b/sys/dev/pci/neo.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: neo.c,v 1.36 2022/03/11 18:00:51 mpi Exp $       */
+/*      $OpenBSD: neo.c,v 1.37 2022/03/21 19:22:41 miod Exp $       */
 
 /*
  * Copyright (c) 1999 Cameron Grant <gandalf@vilnya.demon.co.uk>
@@ -237,7 +237,7 @@ static int samplerates[9] = {
 
 /* -------------------------------------------------------------------- */
 
-struct audio_hw_if neo_hw_if = {
+const struct audio_hw_if neo_hw_if = {
 	neo_open,
 	neo_close,
 	neo_set_params,
diff --git a/sys/dev/pci/sv.c b/sys/dev/pci/sv.c
index 15ddfcbd617..9f902d3d961 100644
--- a/sys/dev/pci/sv.c
+++ b/sys/dev/pci/sv.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: sv.c,v 1.39 2022/03/11 18:00:51 mpi Exp $ */
+/*      $OpenBSD: sv.c,v 1.40 2022/03/21 19:22:41 miod Exp $ */
 
 /*
  * Copyright (c) 1998 Constantine Paul Sapuntzakis
@@ -146,7 +146,7 @@ int	sv_get_props(void *);
 
 void    sv_dumpregs(struct sv_softc *sc);
 
-struct audio_hw_if sv_hw_if = {
+const struct audio_hw_if sv_hw_if = {
 	sv_open,
 	sv_close,
 	sv_set_params,
diff --git a/sys/dev/pci/yds.c b/sys/dev/pci/yds.c
index 91eb5a4faff..d4910b587c7 100644
--- a/sys/dev/pci/yds.c
+++ b/sys/dev/pci/yds.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: yds.c,v 1.58 2022/03/11 18:00:52 mpi Exp $	*/
+/*	$OpenBSD: yds.c,v 1.59 2022/03/21 19:22:41 miod Exp $	*/
 /*	$NetBSD: yds.c,v 1.5 2001/05/21 23:55:04 minoura Exp $	*/
 
 /*
@@ -199,7 +199,7 @@ static void yds_dump_play_slot(struct yds_softc *, int);
 #define	YDS_DUMP_PLAY_SLOT(n,sc,bank)
 #endif /* AUDIO_DEBUG */
 
-static struct audio_hw_if yds_hw_if = {
+const static struct audio_hw_if yds_hw_if = {
 	yds_open,
 	yds_close,
 	yds_set_params,
diff --git a/sys/dev/radio.c b/sys/dev/radio.c
index 5f916dfd231..fc08c25ddf4 100644
--- a/sys/dev/radio.c
+++ b/sys/dev/radio.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: radio.c,v 1.11 2016/09/22 00:47:19 jsg Exp $ */
+/* $OpenBSD: radio.c,v 1.12 2022/03/21 19:22:40 miod Exp $ */
 /* $RuOBSD: radio.c,v 1.7 2001/12/04 06:03:05 tm Exp $ */
 
 /*
@@ -152,7 +152,7 @@ radioioctl(dev_t dev, u_long cmd, caddr_t data, int flags, struct proc *p)
  */
 
 struct device *
-radio_attach_mi(struct radio_hw_if *rhwp, void *hdlp, struct device *dev)
+radio_attach_mi(const struct radio_hw_if *rhwp, void *hdlp, struct device *dev)
 {
 	struct audio_attach_args arg;
 
diff --git a/sys/dev/radio_if.h b/sys/dev/radio_if.h
index 969a6052eaf..9223d0f09e2 100644
--- a/sys/dev/radio_if.h
+++ b/sys/dev/radio_if.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: radio_if.h,v 1.3 2002/05/30 15:22:26 mickey Exp $ */
+/* $OpenBSD: radio_if.h,v 1.4 2022/03/21 19:22:40 miod Exp $ */
 /* $RuOBSD: radio_if.h,v 1.6 2001/10/18 16:51:36 pva Exp $ */
 
 /*
@@ -47,6 +47,7 @@ struct radio_hw_if {
 	int     (*search)(void *, int);
 };
 
-struct device  *radio_attach_mi(struct radio_hw_if *, void *, struct device *);
+struct device  *radio_attach_mi(const struct radio_hw_if *, void *,
+	    struct device *);
 
 #endif /* _SYS_DEV_RADIO_IF_H */
diff --git a/sys/dev/radiovar.h b/sys/dev/radiovar.h
index 921f9ec400d..a4b50e92e2c 100644
--- a/sys/dev/radiovar.h
+++ b/sys/dev/radiovar.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: radiovar.h,v 1.3 2002/01/05 02:23:03 mickey Exp $ */
+/* $OpenBSD: radiovar.h,v 1.4 2022/03/21 19:22:40 miod Exp $ */
 /* $RuOBSD: radiovar.h,v 1.3 2001/09/29 17:10:16 pva Exp $ */
 
 /*
@@ -33,7 +33,7 @@ struct radio_softc {
 	struct device	dev;
 	void		*hw_hdl;	/* hardware driver handle */
 	struct device	*sc_dev;	/* hardware device struct */
-	struct radio_hw_if *hw_if;	/* hardware interface */
+	const struct radio_hw_if *hw_if; /* hardware interface */
 	char		sc_dying;	/* device detached */
 };
 
diff --git a/sys/dev/sbus/cs4231.c b/sys/dev/sbus/cs4231.c
index 06b090fc736..2672609ae1a 100644
--- a/sys/dev/sbus/cs4231.c
+++ b/sys/dev/sbus/cs4231.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: cs4231.c,v 1.40 2022/03/13 13:34:54 mpi Exp $	*/
+/*	$OpenBSD: cs4231.c,v 1.41 2022/03/21 19:22:41 miod Exp $	*/
 
 /*
  * Copyright (c) 1999 Jason L. Wright (jason@thought.net)
@@ -151,7 +151,7 @@ int	cs4231_trigger_output(void *, void *, void *, int,
 int	cs4231_trigger_input(void *, void *, void *, int,
     void (*)(void *), void *, struct audio_params *);
 
-struct audio_hw_if cs4231_sa_hw_if = {
+const struct audio_hw_if cs4231_sa_hw_if = {
 	cs4231_open,
 	cs4231_close,
 	cs4231_set_params,
diff --git a/sys/dev/tc/bba.c b/sys/dev/tc/bba.c
index 1c774d5ef6e..840e7e85eda 100644
--- a/sys/dev/tc/bba.c
+++ b/sys/dev/tc/bba.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: bba.c,v 1.8 2022/02/16 06:21:19 anton Exp $	*/
+/*	$OpenBSD: bba.c,v 1.9 2022/03/21 19:22:41 miod Exp $	*/
 /* $NetBSD: bba.c,v 1.38 2011/06/04 01:27:57 tsutsui Exp $ */
 /*
  * Copyright (c) 2011 Miodrag Vallat.
@@ -152,7 +152,7 @@ int	bba_trigger_output(void *, void *, void *, int,
 int	bba_trigger_input(void *, void *, void *, int,
 	    void (*)(void *), void *, struct audio_params *);
 
-struct audio_hw_if bba_hw_if = {
+const struct audio_hw_if bba_hw_if = {
 	am7930_open,
 	am7930_close,
 	am7930_set_params,
diff --git a/sys/dev/usb/uaudio.c b/sys/dev/usb/uaudio.c
index 8dafe8ffe75..3b301fed636 100644
--- a/sys/dev/usb/uaudio.c
+++ b/sys/dev/usb/uaudio.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uaudio.c,v 1.168 2022/02/21 14:21:58 jsg Exp $	*/
+/*	$OpenBSD: uaudio.c,v 1.169 2022/03/21 19:22:42 miod Exp $	*/
 /*
  * Copyright (c) 2018 Alexandre Ratchov <alex@caoua.org>
  *
@@ -468,7 +468,7 @@ const struct cfattach uaudio_ca = {
 	sizeof(struct uaudio_softc), uaudio_match, uaudio_attach, uaudio_detach
 };
 
-struct audio_hw_if uaudio_hw_if = {
+const struct audio_hw_if uaudio_hw_if = {
 	uaudio_open,		/* open */
 	uaudio_close,		/* close */
 	uaudio_set_params,	/* set_params */
diff --git a/sys/dev/usb/udsbr.c b/sys/dev/usb/udsbr.c
index 1ba3d96d2e7..3960e03e31d 100644
--- a/sys/dev/usb/udsbr.c
+++ b/sys/dev/usb/udsbr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: udsbr.c,v 1.27 2016/11/06 12:58:01 mpi Exp $	*/
+/*	$OpenBSD: udsbr.c,v 1.28 2022/03/21 19:22:42 miod Exp $	*/
 /*	$NetBSD: udsbr.c,v 1.7 2002/07/11 21:14:27 augustss Exp $	*/
 
 /*
@@ -65,7 +65,7 @@ int	udsbrdebug = 0;
 int     udsbr_get_info(void *, struct radio_info *);
 int     udsbr_set_info(void *, struct radio_info *);
 
-struct radio_hw_if udsbr_hw_if = {
+const struct radio_hw_if udsbr_hw_if = {
 	NULL, /* open */
 	NULL, /* close */
 	udsbr_get_info,
diff --git a/sys/dev/usb/umidi.c b/sys/dev/usb/umidi.c
index 9d65d186427..1f4e2cb615c 100644
--- a/sys/dev/usb/umidi.c
+++ b/sys/dev/usb/umidi.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: umidi.c,v 1.54 2020/07/31 10:49:33 mglocker Exp $	*/
+/*	$OpenBSD: umidi.c,v 1.55 2022/03/21 19:22:42 miod Exp $	*/
 /*	$NetBSD: umidi.c,v 1.16 2002/07/11 21:14:32 augustss Exp $	*/
 /*
  * Copyright (c) 2001 The NetBSD Foundation, Inc.
@@ -116,7 +116,7 @@ static void out_intr(struct usbd_xfer *, void *, usbd_status);
 static int out_build_packet(int, struct umidi_packet *, uByte, u_char *);
 
 
-struct midi_hw_if umidi_hw_if = {
+const struct midi_hw_if umidi_hw_if = {
 	umidi_open,
 	umidi_close,
 	umidi_output,
diff --git a/sys/dev/usb/utvfu.c b/sys/dev/usb/utvfu.c
index 87e9bcee943..7e39c3b9eb7 100644
--- a/sys/dev/usb/utvfu.c
+++ b/sys/dev/usb/utvfu.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: utvfu.c,v 1.16 2022/02/16 06:21:19 anton Exp $ */
+/*	$OpenBSD: utvfu.c,v 1.17 2022/03/21 19:22:42 miod Exp $ */
 /*
  * Copyright (c) 2013 Lubomir Rintel
  * Copyright (c) 2013 Federico Simoncelli
@@ -813,7 +813,7 @@ const struct cfattach utvfu_ca = {
 	NULL
 };
 
-struct video_hw_if utvfu_vid_hw_if = {
+const struct video_hw_if utvfu_vid_hw_if = {
 	utvfu_open,		/* open */
 	utvfu_close,		/* close */
 	utvfu_querycap,		/* VIDIOC_QUERYCAP */
@@ -842,7 +842,7 @@ struct video_hw_if utvfu_vid_hw_if = {
 	utvfu_start_read	/* start stream for read */
 };
 
-struct audio_hw_if utvfu_au_hw_if = {
+const struct audio_hw_if utvfu_au_hw_if = {
 	utvfu_audio_open,		/* open hardware */
 	utvfu_audio_close,		/* close hardware */
 	utvfu_audio_set_params,
diff --git a/sys/dev/usb/uvideo.c b/sys/dev/usb/uvideo.c
index 595da2844b8..e5c7425818b 100644
--- a/sys/dev/usb/uvideo.c
+++ b/sys/dev/usb/uvideo.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: uvideo.c,v 1.215 2022/01/09 05:43:02 jsg Exp $ */
+/*	$OpenBSD: uvideo.c,v 1.216 2022/03/21 19:22:42 miod Exp $ */
 
 /*
  * Copyright (c) 2008 Robert Nagy <robert@openbsd.org>
@@ -271,7 +271,7 @@ const struct cfattach uvideo_ca = {
 	sizeof(struct uvideo_softc), uvideo_match, uvideo_attach, uvideo_detach
 };
 
-struct video_hw_if uvideo_hw_if = {
+const struct video_hw_if uvideo_hw_if = {
 	uvideo_open,		/* open */
 	uvideo_close,		/* close */
 	uvideo_querycap,	/* VIDIOC_QUERYCAP */
diff --git a/sys/dev/video.c b/sys/dev/video.c
index 3ec200e0f37..7319074c27b 100644
--- a/sys/dev/video.c
+++ b/sys/dev/video.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: video.c,v 1.54 2021/02/17 17:21:58 mglocker Exp $	*/
+/*	$OpenBSD: video.c,v 1.55 2022/03/21 19:22:40 miod Exp $	*/
 
 /*
  * Copyright (c) 2008 Robert Nagy <robert@openbsd.org>
@@ -46,7 +46,7 @@ struct video_softc {
 	struct device		 dev;
 	void			*hw_hdl;	/* hardware driver handle */
 	struct device		*sc_dev;	/* hardware device struct */
-	struct video_hw_if	*hw_if;		/* hardware interface */
+	const struct video_hw_if *hw_if;	/* hardware interface */
 	char			 sc_dying;	/* device detached */
 	struct process		*sc_owner;	/* owner process */
 	uint8_t			 sc_open;	/* device opened */
@@ -562,7 +562,7 @@ video_submatch(struct device *parent, void *match, void *aux)
  * probed/attached to the hardware driver
  */
 struct device *
-video_attach_mi(struct video_hw_if *rhwp, void *hdlp, struct device *dev)
+video_attach_mi(const struct video_hw_if *rhwp, void *hdlp, struct device *dev)
 {
 	struct video_attach_args arg;
 
diff --git a/sys/dev/video_if.h b/sys/dev/video_if.h
index 3f0cbd20352..9c1ba23ab6d 100644
--- a/sys/dev/video_if.h
+++ b/sys/dev/video_if.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: video_if.h,v 1.18 2014/10/18 08:01:34 armani Exp $	*/
+/*	$OpenBSD: video_if.h,v 1.19 2022/03/21 19:22:40 miod Exp $	*/
 /*
  * Copyright (c) 2008 Robert Nagy <robert@openbsd.org>
  * Copyright (c) 2008 Marcus Glocker <mglocker@openbsd.org>
@@ -63,10 +63,11 @@ struct video_hw_if {
 };
 
 struct video_attach_args {
-        void	*hwif;
+        const void *hwif;
         void	*hdl;
 };
 
-struct device  *video_attach_mi(struct video_hw_if *, void *, struct device *);
+struct device  *video_attach_mi(const struct video_hw_if *, void *,
+	    struct device *);
 
 #endif /* _SYS_DEV_VIDEO_IF_H */