ALSA: drivers: Constify snd_kcontrol_new items

Most of snd_kcontrol_new definitions are read-only and passed as-is.
Let's declare them as const for further optimization.
Constify snd_kcontrol_new items

There should be no functional changes by this patch.

Link: https://lore.kernel.org/r/20200103081714.9560-34-tiwai@suse.deSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/drivers/aloop.c

@@ -1496,7 +1496,7 @@ static int loopback_channels_get(struct snd_kcontrol *kcontrol,
 	return 0;
 }
 
-static struct snd_kcontrol_new loopback_controls[]  = {
+static const struct snd_kcontrol_new loopback_controls[]  = {
 {
 	.iface =        SNDRV_CTL_ELEM_IFACE_PCM,
 	.name =         "PCM Rate Shift 100000",

sound/drivers/dummy.c

@@ -849,7 +849,7 @@ static int snd_dummy_iobox_put(struct snd_kcontrol *kcontrol,
 	return changed;
 }
 
-static struct snd_kcontrol_new snd_dummy_controls[] = {
+static const struct snd_kcontrol_new snd_dummy_controls[] = {
 DUMMY_VOLUME("Master Volume", 0, MIXER_ADDR_MASTER),
 DUMMY_CAPSRC("Master Capture Switch", 0, MIXER_ADDR_MASTER),
 DUMMY_VOLUME("Synth Volume", 0, MIXER_ADDR_SYNTH),

sound/drivers/mts64.c

@@ -467,7 +467,7 @@ static int snd_mts64_ctl_smpte_switch_put(struct snd_kcontrol* kctl,
 	return changed;
 }
 
-static struct snd_kcontrol_new mts64_ctl_smpte_switch = {
+static const struct snd_kcontrol_new mts64_ctl_smpte_switch = {
 	.iface = SNDRV_CTL_ELEM_IFACE_RAWMIDI,
 	.name  = "SMPTE Playback Switch",
 	.index = 0,
@@ -540,7 +540,7 @@ static int snd_mts64_ctl_smpte_time_put(struct snd_kcontrol *kctl,
 	return changed;
 }
 
-static struct snd_kcontrol_new mts64_ctl_smpte_time_hours = {
+static const struct snd_kcontrol_new mts64_ctl_smpte_time_hours = {
 	.iface = SNDRV_CTL_ELEM_IFACE_RAWMIDI,
 	.name  = "SMPTE Time Hours",
 	.index = 0,
@@ -551,7 +551,7 @@ static struct snd_kcontrol_new mts64_ctl_smpte_time_hours = {
 	.put  = snd_mts64_ctl_smpte_time_put
 };
 
-static struct snd_kcontrol_new mts64_ctl_smpte_time_minutes = {
+static const struct snd_kcontrol_new mts64_ctl_smpte_time_minutes = {
 	.iface = SNDRV_CTL_ELEM_IFACE_RAWMIDI,
 	.name  = "SMPTE Time Minutes",
 	.index = 0,
@@ -562,7 +562,7 @@ static struct snd_kcontrol_new mts64_ctl_smpte_time_minutes = {
 	.put  = snd_mts64_ctl_smpte_time_put
 };
 
-static struct snd_kcontrol_new mts64_ctl_smpte_time_seconds = {
+static const struct snd_kcontrol_new mts64_ctl_smpte_time_seconds = {
 	.iface = SNDRV_CTL_ELEM_IFACE_RAWMIDI,
 	.name  = "SMPTE Time Seconds",
 	.index = 0,
@@ -573,7 +573,7 @@ static struct snd_kcontrol_new mts64_ctl_smpte_time_seconds = {
 	.put  = snd_mts64_ctl_smpte_time_put
 };
 
-static struct snd_kcontrol_new mts64_ctl_smpte_time_frames = {
+static const struct snd_kcontrol_new mts64_ctl_smpte_time_frames = {
 	.iface = SNDRV_CTL_ELEM_IFACE_RAWMIDI,
 	.name  = "SMPTE Time Frames",
 	.index = 0,
@@ -625,7 +625,7 @@ static int snd_mts64_ctl_smpte_fps_put(struct snd_kcontrol *kctl,
 	return changed;
 }
 
-static struct snd_kcontrol_new mts64_ctl_smpte_fps = {
+static const struct snd_kcontrol_new mts64_ctl_smpte_fps = {
 	.iface = SNDRV_CTL_ELEM_IFACE_RAWMIDI,
 	.name  = "SMPTE Fps",
 	.index = 0,
@@ -641,7 +641,7 @@ static int snd_mts64_ctl_create(struct snd_card *card,
 				struct mts64 *mts)
 {
 	int err, i;
-	static struct snd_kcontrol_new *control[] = {
+	static const struct snd_kcontrol_new *control[] = {
 		&mts64_ctl_smpte_switch,
 		&mts64_ctl_smpte_time_hours,
 		&mts64_ctl_smpte_time_minutes,

sound/drivers/opl4/opl4_mixer.c

@@ -47,7 +47,7 @@ static int snd_opl4_ctl_put(struct snd_kcontrol *kcontrol, struct snd_ctl_elem_v
 	return value != old_value;
 }
 
-static struct snd_kcontrol_new snd_opl4_controls[] = {
+static const struct snd_kcontrol_new snd_opl4_controls[] = {
 	{
 		.iface = SNDRV_CTL_ELEM_IFACE_MIXER,
 		.name = "FM Playback Volume",

sound/drivers/pcsp/pcsp_mixer.c

@@ -120,17 +120,17 @@ static int pcsp_pcspkr_put(struct snd_kcontrol *kcontrol,
 	.put =		pcsp_##ctl_type##_put, \
 }
 
-static struct snd_kcontrol_new snd_pcsp_controls_pcm[] = {
+static const struct snd_kcontrol_new snd_pcsp_controls_pcm[] = {
 	PCSP_MIXER_CONTROL(enable, "Master Playback Switch"),
 	PCSP_MIXER_CONTROL(treble, "BaseFRQ Playback Volume"),
 };
 
-static struct snd_kcontrol_new snd_pcsp_controls_spkr[] = {
+static const struct snd_kcontrol_new snd_pcsp_controls_spkr[] = {
 	PCSP_MIXER_CONTROL(pcspkr, "Beep Playback Switch"),
 };
 
 static int snd_pcsp_ctls_add(struct snd_pcsp *chip,
-			     struct snd_kcontrol_new *ctls, int num)
+			     const struct snd_kcontrol_new *ctls, int num)
 {
 	int i, err;
 	struct snd_card *card = chip->card;