usb: gadget: midi2: More flexible MIDI 1.0 configuration

This patch allows users to set up MIDI 1.0 ports more flexibly.
Namely, instead of the fixed mapping only from FB 0, now multiple
block definitions are applied to build up the MIDI 1.0 mapping.

The each block config has midi1_first_group and midi1_num_groups
attributes, and those specify which Groups are used for MIDI 1.0.
Those fields must be within the UMP Groups defined in the block
itself.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20230725062206.9674-8-tiwai@suse.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/ABI/testing/configfs-usb-gadget-midi2

@@ -39,14 +39,16 @@ Description:
 
 		The attributes:
 
-		===============	===============================================
-		name		Function Block name string
-		direction	1: input, 2: output, 3: bidirectional
-		first_group	The first UMP Group number (0-15)
-		num_groups	The number of groups in this FB (1-16)
-		ui_hint		0: unknown, 1: receiver, 2: sender, 3: both
-		midi_ci_verison	Supported MIDI-CI version number (8 bit)
-		is_midi1	Legacy MIDI 1.0 device (0, 1 or 2)
-		sysex8_streams	Max number of SysEx8 streams (8 bit)
-		active		Active FB flag (0 or 1)
-		===============	===============================================
+		=================	==============================================
+		name			Function Block name string
+		direction		1: input, 2: output, 3: bidirectional
+		first_group		The first UMP Group number (0-15)
+		num_groups		The number of groups in this FB (1-16)
+		midi1_first_group	The first UMP Group number for MIDI 1.0 (0-15)
+		midi1_num_groups	The number of groups for MIDI 1.0 (0-16)
+		ui_hint			0: unknown, 1: receiver, 2: sender, 3: both
+		midi_ci_verison		Supported MIDI-CI version number (8 bit)
+		is_midi1		Legacy MIDI 1.0 device (0, 1 or 2)
+		sysex8_streams		Max number of SysEx8 streams (8 bit)
+		active			Active FB flag (0 or 1)
+		=================	==============================================

Documentation/usb/gadget-testing.rst

@@ -1009,22 +1009,24 @@ Each Endpoint subdirectory contains a subdirectory "block.0", which
 represents the Function Block for Block 0 information.
 Its attributes are:
 
-	===============	===============================================
-	name		Function Block name string
-	direction	Direction of this FB
-			1: input, 2: output, or 3: bidirectional
-	first_group	The first UMP Group number (0-15)
-	num_groups	The number of groups in this FB (1-16)
-	ui_hint		UI-hint of this FB
-			0: unknown, 1: receiver, 2: sender, 3: both
-	midi_ci_verison	Supported MIDI-CI version number (8 bit)
-	is_midi1	Legacy MIDI 1.0 device (0-2)
-			0: MIDI 2.0 device,
-			1: MIDI 1.0 without restriction, or
-			2: MIDI 1.0 with low speed
-	sysex8_streams	Max number of SysEx8 streams (8 bit)
-	active		Bool flag for FB activity (0 or 1)
-	===============	===============================================
+	=================	===============================================
+	name			Function Block name string
+	direction		Direction of this FB
+				1: input, 2: output, or 3: bidirectional
+	first_group		The first UMP Group number (0-15)
+	num_groups		The number of groups in this FB (1-16)
+	midi1_first_group	The first UMP Group number for MIDI 1.0 (0-15)
+	midi1_num_groups	The number of groups for MIDI 1.0 (0-16)
+	ui_hint			UI-hint of this FB
+				0: unknown, 1: receiver, 2: sender, 3: both
+	midi_ci_verison		Supported MIDI-CI version number (8 bit)
+	is_midi1		Legacy MIDI 1.0 device (0-2)
+				0: MIDI 2.0 device,
+				1: MIDI 1.0 without restriction, or
+				2: MIDI 1.0 with low speed
+	sysex8_streams		Max number of SysEx8 streams (8 bit)
+	active			Bool flag for FB activity (0 or 1)
+	=================	===============================================
 
 If multiple Function Blocks are required, you can add more Function
 Blocks by creating subdirectories "block.<num>" with the corresponding

drivers/usb/gadget/function/u_midi2.h

@@ -18,6 +18,8 @@ struct f_midi2_block_info {
 	unsigned int direction;		/* FB direction: 1-3 */
 	unsigned int first_group;	/* first UMP group: 0-15 */
 	unsigned int num_groups;	/* number of UMP groups: 1-16 */
+	unsigned int midi1_first_group;	/* first UMP group for MIDI 1.0 */
+	unsigned int midi1_num_groups;	/* number of UMP groups for MIDI 1.0 */
 	unsigned int ui_hint;		/* UI-hint: 0-3 */
 	unsigned int midi_ci_version;	/* MIDI-CI version: 0-255 */
 	unsigned int sysex8_streams;	/* number of sysex8 streams: 0-255 */