ALSA: usb-audio: scarlett2: Add scarlett2_vol_ctl_write() helper

Add helper function for setting the read/write status of a volume
control. This will simplify the upcoming mute control support.

Signed-off-by: Geoffrey D. Bennett <g@b4.vu>
Link: https://lore.kernel.org/r/00dd57e1abb3fa379fb51d4ac8537dbddc09f0ea.1624294591.git.g@b4.vu
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c
index ded99ba..e156119 100644 (file)
--- a/sound/usb/mixer_scarlett_gen2.c
+++ b/sound/usb/mixer_scarlett_gen2.c
@@ -1344,6 +1344,24 @@ static int scarlett2_sw_hw_enum_ctl_get(struct snd_kcontrol *kctl,
        return 0;
 }
 
+static void scarlett2_vol_ctl_set_writable(struct usb_mixer_interface *mixer,
+                                          int index, int value)
+{
+       struct scarlett2_data *private = mixer->private_data;
+
+       /* Set/Clear write bit */
+       if (value)
+               private->vol_ctls[index]->vd[0].access |=
+                       SNDRV_CTL_ELEM_ACCESS_WRITE;
+       else
+               private->vol_ctls[index]->vd[0].access &=
+                       ~SNDRV_CTL_ELEM_ACCESS_WRITE;
+
+       /* Notify of write bit change */
+       snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_INFO,
+                      &private->vol_ctls[index]->id);
+}
+
 static int scarlett2_sw_hw_enum_ctl_put(struct snd_kcontrol *kctl,
                                        struct snd_ctl_elem_value *ucontrol)
 {
@@ -1367,12 +1385,7 @@ static int scarlett2_sw_hw_enum_ctl_put(struct snd_kcontrol *kctl,
        /* Change access mode to RO (hardware controlled volume)
         * or RW (software controlled volume)
         */
-       if (val)
-               private->vol_ctls[index]->vd[0].access &=
-                       ~SNDRV_CTL_ELEM_ACCESS_WRITE;
-       else
-               private->vol_ctls[index]->vd[0].access |=
-                       SNDRV_CTL_ELEM_ACCESS_WRITE;
+       scarlett2_vol_ctl_set_writable(mixer, index, !val);
 
        /* Reset volume to master volume */
        private->vol[index] = private->master_vol;
@@ -1384,10 +1397,6 @@ static int scarlett2_sw_hw_enum_ctl_put(struct snd_kcontrol *kctl,
        if (err < 0)
                goto unlock;
 
-       /* Notify of RO/RW change */
-       snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_INFO,
-                      &private->vol_ctls[index]->id);
-
        /* Send SW/HW switch change to the device */
        err = scarlett2_usb_set_config(mixer, SCARLETT2_CONFIG_SW_HW_SWITCH,
                                       index, val);
@@ -1620,8 +1629,7 @@ static int scarlett2_add_line_out_ctls(struct usb_mixer_interface *mixer)
 
                /* Make the fader read-only if the SW/HW switch is set to HW */
                if (private->vol_sw_hw_switch[i])
-                       private->vol_ctls[i]->vd[0].access &=
-                               ~SNDRV_CTL_ELEM_ACCESS_WRITE;
+                       scarlett2_vol_ctl_set_writable(mixer, i, 0);
 
                /* SW/HW Switch */
                if (info->line_out_hw_vol) {