Commit f2ebf92c authored by Ben Williamson's avatar Ben Williamson Committed by Greg Kroah-Hartman

USB: gmidi: New USB MIDI Gadget class driver.

This driver is glue between the USB gadget interface
and the ALSA MIDI interface. It allows us to appear
as a MIDI Streaming device to a host system on the
other end of a USB cable.

This includes linux/usb/audio.h and linux/usb/midi.h
containing definitions from the relevant USB specifications
for USB audio and USB MIDI devices.

The following changes have been made since the first RFC
posting:

* Bug fixes to endpoint handling.
* Workaround for USB_REQ_SET_CONFIGURATION handling,
  not understood yet.
* Added SND and SND_RAWMIDI dependencies in Kconfig.
* Moved usb_audio.h and usb_midi.h to usb/*.h
* Added module parameters for ALSA card index and id.
* Added module parameters for USB descriptor IDs and strings.
* Removed some unneeded stuff inherited from zero.c, more to go.
* Provide DECLARE_* macros for the variable-length structs.
* Use kmalloc instead of usb_ep_alloc_buffer.
* Limit source to 80 columns.
* Return actual error code instead of -ENOMEM in a few places.
Signed-off-by: default avatarBen Williamson <ben.williamson@greyinnovation.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ba307f58
......@@ -404,6 +404,20 @@ config USB_G_SERIAL
which includes instructions and a "driver info file" needed to
make MS-Windows work with this driver.
config USB_MIDI_GADGET
tristate "MIDI Gadget (EXPERIMENTAL)"
depends on SND && EXPERIMENTAL
select SND_RAWMIDI
help
The MIDI Gadget acts as a USB Audio device, with one MIDI
input and one MIDI output. These MIDI jacks appear as
a sound "card" in the ALSA sound system. Other MIDI
connections can then be made on the gadget system, using
ALSA's aconnect utility etc.
Say "y" to link the driver statically, or "m" to build a
dynamically linked module called "g_midi".
# put drivers that need isochronous transfer support (for audio
# or video class gadget drivers), or specific hardware, here.
......
......@@ -15,6 +15,7 @@ obj-$(CONFIG_USB_AT91) += at91_udc.o
g_zero-objs := zero.o usbstring.o config.o epautoconf.o
g_ether-objs := ether.o usbstring.o config.o epautoconf.o
g_serial-objs := serial.o usbstring.o config.o epautoconf.o
g_midi-objs := gmidi.o usbstring.o config.o epautoconf.o
gadgetfs-objs := inode.o
g_file_storage-objs := file_storage.o usbstring.o config.o \
epautoconf.o
......@@ -28,4 +29,5 @@ obj-$(CONFIG_USB_ETH) += g_ether.o
obj-$(CONFIG_USB_GADGETFS) += gadgetfs.o
obj-$(CONFIG_USB_FILE_STORAGE) += g_file_storage.o
obj-$(CONFIG_USB_G_SERIAL) += g_serial.o
obj-$(CONFIG_USB_MIDI_GADGET) += g_midi.o
This diff is collapsed.
/*
* <linux/usb/audio.h> -- USB Audio definitions.
*
* Copyright (C) 2006 Thumtronics Pty Ltd.
* Developed for Thumtronics by Grey Innovation
* Ben Williamson <ben.williamson@greyinnovation.com>
*
* This software is distributed under the terms of the GNU General Public
* License ("GPL") version 2, as published by the Free Software Foundation.
*
* This file holds USB constants and structures defined
* by the USB Device Class Definition for Audio Devices.
* Comments below reference relevant sections of that document:
*
* http://www.usb.org/developers/devclass_docs/audio10.pdf
*/
#ifndef __LINUX_USB_AUDIO_H
#define __LINUX_USB_AUDIO_H
#include <linux/types.h>
/* A.2 Audio Interface Subclass Codes */
#define USB_SUBCLASS_AUDIOCONTROL 0x01
#define USB_SUBCLASS_AUDIOSTREAMING 0x02
#define USB_SUBCLASS_MIDISTREAMING 0x03
/* 4.3.2 Class-Specific AC Interface Descriptor */
struct usb_ac_header_descriptor {
__u8 bLength; // 8+n
__u8 bDescriptorType; // USB_DT_CS_INTERFACE
__u8 bDescriptorSubtype; // USB_MS_HEADER
__le16 bcdADC; // 0x0100
__le16 wTotalLength; // includes Unit and Terminal desc.
__u8 bInCollection; // n
__u8 baInterfaceNr[]; // [n]
} __attribute__ ((packed));
#define USB_DT_AC_HEADER_SIZE(n) (8+(n))
/* As above, but more useful for defining your own descriptors: */
#define DECLARE_USB_AC_HEADER_DESCRIPTOR(n) \
struct usb_ac_header_descriptor_##n { \
__u8 bLength; \
__u8 bDescriptorType; \
__u8 bDescriptorSubtype; \
__le16 bcdADC; \
__le16 wTotalLength; \
__u8 bInCollection; \
__u8 baInterfaceNr[n]; \
} __attribute__ ((packed))
#endif
/*
* <linux/usb/midi.h> -- USB MIDI definitions.
*
* Copyright (C) 2006 Thumtronics Pty Ltd.
* Developed for Thumtronics by Grey Innovation
* Ben Williamson <ben.williamson@greyinnovation.com>
*
* This software is distributed under the terms of the GNU General Public
* License ("GPL") version 2, as published by the Free Software Foundation.
*
* This file holds USB constants and structures defined
* by the USB Device Class Definition for MIDI Devices.
* Comments below reference relevant sections of that document:
*
* http://www.usb.org/developers/devclass_docs/midi10.pdf
*/
#ifndef __LINUX_USB_MIDI_H
#define __LINUX_USB_MIDI_H
#include <linux/types.h>
/* A.1 MS Class-Specific Interface Descriptor Subtypes */
#define USB_MS_HEADER 0x01
#define USB_MS_MIDI_IN_JACK 0x02
#define USB_MS_MIDI_OUT_JACK 0x03
#define USB_MS_ELEMENT 0x04
/* A.2 MS Class-Specific Endpoint Descriptor Subtypes */
#define USB_MS_GENERAL 0x01
/* A.3 MS MIDI IN and OUT Jack Types */
#define USB_MS_EMBEDDED 0x01
#define USB_MS_EXTERNAL 0x02
/* 6.1.2.1 Class-Specific MS Interface Header Descriptor */
struct usb_ms_header_descriptor {
__u8 bLength;
__u8 bDescriptorType;
__u8 bDescriptorSubtype;
__le16 bcdMSC;
__le16 wTotalLength;
} __attribute__ ((packed));
#define USB_DT_MS_HEADER_SIZE 7
/* 6.1.2.2 MIDI IN Jack Descriptor */
struct usb_midi_in_jack_descriptor {
__u8 bLength;
__u8 bDescriptorType; // USB_DT_CS_INTERFACE
__u8 bDescriptorSubtype; // USB_MS_MIDI_IN_JACK
__u8 bJackType; // USB_MS_EMBEDDED/EXTERNAL
__u8 bJackID;
__u8 iJack;
} __attribute__ ((packed));
#define USB_DT_MIDI_IN_SIZE 6
struct usb_midi_source_pin {
__u8 baSourceID;
__u8 baSourcePin;
} __attribute__ ((packed));
/* 6.1.2.3 MIDI OUT Jack Descriptor */
struct usb_midi_out_jack_descriptor {
__u8 bLength;
__u8 bDescriptorType; // USB_DT_CS_INTERFACE
__u8 bDescriptorSubtype; // USB_MS_MIDI_OUT_JACK
__u8 bJackType; // USB_MS_EMBEDDED/EXTERNAL
__u8 bJackID;
__u8 bNrInputPins; // p
struct usb_midi_source_pin pins[]; // [p]
/*__u8 iJack; -- ommitted due to variable-sized pins[] */
} __attribute__ ((packed));
#define USB_DT_MIDI_OUT_SIZE(p) (7 + 2 * (p))
/* As above, but more useful for defining your own descriptors: */
#define DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(p) \
struct usb_midi_out_jack_descriptor_##p { \
__u8 bLength; \
__u8 bDescriptorType; \
__u8 bDescriptorSubtype; \
__u8 bJackType; \
__u8 bJackID; \
__u8 bNrInputPins; \
struct usb_midi_source_pin pins[p]; \
__u8 iJack; \
} __attribute__ ((packed))
/* 6.2.2 Class-Specific MS Bulk Data Endpoint Descriptor */
struct usb_ms_endpoint_descriptor {
__u8 bLength; // 4+n
__u8 bDescriptorType; // USB_DT_CS_ENDPOINT
__u8 bDescriptorSubtype; // USB_MS_GENERAL
__u8 bNumEmbMIDIJack; // n
__u8 baAssocJackID[]; // [n]
} __attribute__ ((packed));
#define USB_DT_MS_ENDPOINT_SIZE(n) (4 + (n))
/* As above, but more useful for defining your own descriptors: */
#define DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(n) \
struct usb_ms_endpoint_descriptor_##n { \
__u8 bLength; \
__u8 bDescriptorType; \
__u8 bDescriptorSubtype; \
__u8 bNumEmbMIDIJack; \
__u8 baAssocJackID[n]; \
} __attribute__ ((packed))
#endif
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