The Focusrite Scarlett Gen 2/3 interfaces with internal mixers have a "standalone" mode. When the interface is not connected to a USB host and standalone mode is enabled, the interface will pass audio as previously configured. This patch adds an ALSA control to allow enabling/disabling that mode.
Signed-off-by: Geoffrey D. Bennett g@b4.vu --- sound/usb/mixer_scarlett_gen2.c | 97 ++++++++++++++++++++++++++++++--- 1 file changed, 90 insertions(+), 7 deletions(-)
diff --git a/sound/usb/mixer_scarlett_gen2.c b/sound/usb/mixer_scarlett_gen2.c index 22e442208550..710586c8dedc 100644 --- a/sound/usb/mixer_scarlett_gen2.c +++ b/sound/usb/mixer_scarlett_gen2.c @@ -60,6 +60,7 @@ * - phantom power, direct monitor, speaker switching, and talkback * controls * - disable/enable MSD mode + * - disable/enable standalone mode * * <ditaa> * /--------------\ 18chn 20chn /--------------\ @@ -411,6 +412,7 @@ struct scarlett2_data { u8 talkback_switch; u8 talkback_map[SCARLETT2_OUTPUT_MIX_MAX]; u8 msd_switch; + u8 standalone_switch; struct snd_kcontrol *sync_ctl; struct snd_kcontrol *master_vol_ctl; struct snd_kcontrol *vol_ctls[SCARLETT2_ANALOGUE_MAX]; @@ -936,13 +938,14 @@ enum { SCARLETT2_CONFIG_PAD_SWITCH = 5, SCARLETT2_CONFIG_MSD_SWITCH = 6, SCARLETT2_CONFIG_AIR_SWITCH = 7, - SCARLETT2_CONFIG_PHANTOM_SWITCH = 8, - SCARLETT2_CONFIG_PHANTOM_PERSISTENCE = 9, - SCARLETT2_CONFIG_DIRECT_MONITOR = 10, - SCARLETT2_CONFIG_MONITOR_OTHER_SWITCH = 11, - SCARLETT2_CONFIG_MONITOR_OTHER_ENABLE = 12, - SCARLETT2_CONFIG_TALKBACK_MAP = 13, - SCARLETT2_CONFIG_COUNT = 14 + SCARLETT2_CONFIG_STANDALONE_SWITCH = 8, + SCARLETT2_CONFIG_PHANTOM_SWITCH = 9, + SCARLETT2_CONFIG_PHANTOM_PERSISTENCE = 10, + SCARLETT2_CONFIG_DIRECT_MONITOR = 11, + SCARLETT2_CONFIG_MONITOR_OTHER_SWITCH = 12, + SCARLETT2_CONFIG_MONITOR_OTHER_ENABLE = 13, + SCARLETT2_CONFIG_TALKBACK_MAP = 14, + SCARLETT2_CONFIG_COUNT = 15 };
/* Location, size, and activation command number for the configuration @@ -998,6 +1001,9 @@ static const struct scarlett2_config [SCARLETT2_CONFIG_PAD_SWITCH] = { .offset = 0x84, .size = 8, .activate = 8 },
+ [SCARLETT2_CONFIG_STANDALONE_SWITCH] = { + .offset = 0x8d, .size = 8, .activate = 6 }, + /* Gen 3 devices: 4i4, 8i6, 18i8, 18i20 */ }, { [SCARLETT2_CONFIG_DIM_MUTE] = { @@ -1021,6 +1027,9 @@ static const struct scarlett2_config [SCARLETT2_CONFIG_AIR_SWITCH] = { .offset = 0x8c, .size = 8, .activate = 8 },
+ [SCARLETT2_CONFIG_STANDALONE_SWITCH] = { + .offset = 0x95, .size = 8, .activate = 6 }, + [SCARLETT2_CONFIG_PHANTOM_SWITCH] = { .offset = 0x9c, .size = 1, .activate = 8 },
@@ -3502,6 +3511,69 @@ static int scarlett2_add_msd_ctl(struct usb_mixer_interface *mixer) 0, 1, "MSD Mode Switch", NULL); }
+/*** Standalone Control ***/ + +static int scarlett2_standalone_ctl_get(struct snd_kcontrol *kctl, + struct snd_ctl_elem_value *ucontrol) +{ + struct usb_mixer_elem_info *elem = kctl->private_data; + struct scarlett2_data *private = elem->head.mixer->private_data; + + ucontrol->value.integer.value[0] = private->standalone_switch; + return 0; +} + +static int scarlett2_standalone_ctl_put(struct snd_kcontrol *kctl, + struct snd_ctl_elem_value *ucontrol) +{ + struct usb_mixer_elem_info *elem = kctl->private_data; + struct usb_mixer_interface *mixer = elem->head.mixer; + struct scarlett2_data *private = mixer->private_data; + + int oval, val, err = 0; + + mutex_lock(&private->data_mutex); + + oval = private->standalone_switch; + val = !!ucontrol->value.integer.value[0]; + + if (oval == val) + goto unlock; + + private->standalone_switch = val; + + /* Send switch change to the device */ + err = scarlett2_usb_set_config(mixer, + SCARLETT2_CONFIG_STANDALONE_SWITCH, + 0, val); + if (err == 0) + err = 1; + +unlock: + mutex_unlock(&private->data_mutex); + return err; +} + +static const struct snd_kcontrol_new scarlett2_standalone_ctl = { + .iface = SNDRV_CTL_ELEM_IFACE_MIXER, + .name = "", + .info = snd_ctl_boolean_mono_info, + .get = scarlett2_standalone_ctl_get, + .put = scarlett2_standalone_ctl_put, +}; + +static int scarlett2_add_standalone_ctl(struct usb_mixer_interface *mixer) +{ + struct scarlett2_data *private = mixer->private_data; + + if (private->info->config_set == SCARLETT2_CONFIG_SET_NO_MIXER) + return 0; + + /* Add standalone control */ + return scarlett2_add_new_ctl(mixer, &scarlett2_standalone_ctl, + 0, 1, "Standalone Switch", NULL); +} + /*** Cleanup/Suspend Callbacks ***/
static void scarlett2_private_free(struct usb_mixer_interface *mixer) @@ -3663,6 +3735,12 @@ static int scarlett2_read_configs(struct usb_mixer_interface *mixer) if (info->config_set == SCARLETT2_CONFIG_SET_NO_MIXER) return 0;
+ err = scarlett2_usb_get_config( + mixer, SCARLETT2_CONFIG_STANDALONE_SWITCH, + 1, &private->standalone_switch); + if (err < 0) + return err; + err = scarlett2_update_sync(mixer); if (err < 0) return err; @@ -3985,6 +4063,11 @@ static int snd_scarlett_gen2_controls_create(struct usb_mixer_interface *mixer) if (err < 0) return err;
+ /* Create the standalone control */ + err = scarlett2_add_standalone_ctl(mixer); + if (err < 0) + return err; + /* Set up the interrupt polling */ err = scarlett2_init_notify(mixer); if (err < 0)