samples: subsys: usb: midi: demonstrate usage of UMP Stream responder

Update the USB-MIDI2.0 sample to use the newly introduced
UMP Stream Responder library. This allows the host to discover the
topology and function block names (if supported by the host OS).

Signed-off-by: Titouan Christophe <[email protected]>

Author: titouanc

samples/subsys/usb/midi/app.overlay

@@ -10,10 +10,12 @@
 		status = "okay";
 		#address-cells = <1>;
 		#size-cells = <1>;
+		label = "Zephyr USB-MIDI Sample";
 
 		midi_in_out@0 {
 			reg = <0 1>;
 			protocol = "midi1-up-to-128b";
+			label = "MIDI-IN-OUT";
 		};
 	};
 };

samples/subsys/usb/midi/prj.conf

@@ -10,3 +10,5 @@ CONFIG_INPUT=y
 CONFIG_LOG=y
 CONFIG_USBD_LOG_LEVEL_WRN=y
 CONFIG_UDC_DRIVER_LOG_LEVEL_WRN=y
+
+CONFIG_MIDI2_UMP_STREAM_RESPONDER=y

samples/subsys/usb/midi/src/main.c

@@ -14,10 +14,14 @@
 #include <zephyr/input/input.h>
 #include <zephyr/usb/class/usbd_midi2.h>
 
+#include <ump_stream_responder.h>
+
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(sample_usb_midi, LOG_LEVEL_INF);
 
-static const struct device *const midi = DEVICE_DT_GET(DT_NODELABEL(usb_midi));
+#define USB_MIDI_DT_NODE DT_NODELABEL(usb_midi)
+
+static const struct device *const midi = DEVICE_DT_GET(USB_MIDI_DT_NODE);
 
 static struct gpio_dt_spec led = GPIO_DT_SPEC_GET_OR(DT_ALIAS(led0), gpios, {0});
 
@@ -38,15 +42,29 @@ static void key_press(struct input_event *evt, void *user_data)
 }
 INPUT_CALLBACK_DEFINE(NULL, key_press, NULL);
 
+static const struct ump_endpoint_dt_spec ump_ep_dt =
+	UMP_ENDPOINT_DT_SPEC_GET(USB_MIDI_DT_NODE);
+
+const struct ump_stream_responder_cfg responder_cfg = {
+	.dev = midi,
+	.send = (void (*)(void *, const struct midi_ump)) usbd_midi_send,
+	.ep_spec = &ump_ep_dt,
+};
+
 static void on_midi_packet(const struct device *dev, const struct midi_ump ump)
 {
 	LOG_INF("Received MIDI packet (MT=%X)", UMP_MT(ump));
 
-	/* Only send MIDI1 channel voice messages back to the host */
-	if (UMP_MT(ump) == UMP_MT_MIDI1_CHANNEL_VOICE) {
+	switch (UMP_MT(ump)) {
+	case UMP_MT_MIDI1_CHANNEL_VOICE:
+		/* Only send MIDI1 channel voice messages back to the host */
 		LOG_INF("Send back MIDI1 message %02X %02X %02X", UMP_MIDI_STATUS(ump),
 			UMP_MIDI1_P1(ump), UMP_MIDI1_P2(ump));
 		usbd_midi_send(dev, ump);
+		break;
+	case UMP_MT_UMP_STREAM:
+		ump_stream_respond(&responder_cfg, ump);
+		break;
 	}
 }