ALSA: usb-audio: us144mkii: Add deep sleep command

Add a deep sleep vendor command to be sent during suspend, allowing the
device to enter a lower power state.

Signed-off-by: Šerif Rami <ramiserifpersia@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250814172222.9448-7-ramiserifpersia@gmail.com

sound/usb/usx2y/us144mkii.c

@@ -322,6 +322,13 @@ static int tascam_suspend(struct usb_interface *intf, pm_message_t message)
 	usb_kill_anchored_urbs(&tascam->midi_in_anchor);
 	usb_kill_anchored_urbs(&tascam->midi_out_anchor);
 
+	dev_info(&intf->dev, "sending deep sleep command\n");
+	int err = usb_control_msg(tascam->dev, usb_sndctrlpipe(tascam->dev, 0),
+				  VENDOR_REQ_DEEP_SLEEP, RT_H2D_VENDOR_DEV,
+				  0x0000, 0x0000, NULL, 0, USB_CTRL_TIMEOUT_MS);
+	if (err < 0)
+		dev_err(&intf->dev, "deep sleep command failed: %d\n", err);
+
 	return 0;
 }
 

sound/usb/usx2y/us144mkii.h

@@ -46,6 +46,7 @@ enum uac_control_selector {
 
 enum tascam_vendor_request {
 	VENDOR_REQ_REGISTER_WRITE = 0x41,
+	VENDOR_REQ_DEEP_SLEEP = 0x44,
 	VENDOR_REQ_MODE_CONTROL = 0x49,
 };