USB: gmidi: New USB MIDI Gadget class driver.
authorBen Williamson <ben.williamson@greyinnovation.com>
Tue, 1 Aug 2006 01:28:16 +0000 (11:28 +1000)
committerGreg Kroah-Hartman <gregkh@suse.de>
Wed, 27 Sep 2006 18:58:52 +0000 (11:58 -0700)
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: Ben Williamson <ben.williamson@greyinnovation.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/gadget/Kconfig
drivers/usb/gadget/Makefile
drivers/usb/gadget/gmidi.c [new file with mode: 0644]
include/linux/usb/audio.h [new file with mode: 0644]
include/linux/usb/midi.h [new file with mode: 0644]

index 1a32d96..4301e96 100644 (file)
@@ -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.
index 5a28e61..e71e086 100644 (file)
@@ -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
 
diff --git a/drivers/usb/gadget/gmidi.c b/drivers/usb/gadget/gmidi.c
new file mode 100644 (file)
index 0000000..b68cecd
--- /dev/null
@@ -0,0 +1,1337 @@
+/*
+ * gmidi.c -- USB MIDI Gadget Driver
+ *
+ * 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 code is based in part on:
+ *
+ * Gadget Zero driver, Copyright (C) 2003-2004 David Brownell.
+ * USB Audio driver, Copyright (C) 2002 by Takashi Iwai.
+ * USB MIDI driver, Copyright (C) 2002-2005 Clemens Ladisch.
+ *
+ * Refer to the USB Device Class Definition for MIDI Devices:
+ * http://www.usb.org/developers/devclass_docs/midi10.pdf
+ */
+
+#define DEBUG 1
+// #define VERBOSE
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/utsname.h>
+#include <linux/device.h>
+#include <linux/moduleparam.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/initval.h>
+#include <sound/rawmidi.h>
+
+#include <linux/usb_ch9.h>
+#include <linux/usb_gadget.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/midi.h>
+
+#include "gadget_chips.h"
+
+MODULE_AUTHOR("Ben Williamson");
+MODULE_LICENSE("GPL v2");
+
+#define DRIVER_VERSION "25 Jul 2006"
+
+static const char shortname[] = "g_midi";
+static const char longname[] = "MIDI Gadget";
+
+static int index = SNDRV_DEFAULT_IDX1;
+static char *id = SNDRV_DEFAULT_STR1;
+
+module_param(index, int, 0444);
+MODULE_PARM_DESC(index, "Index value for the USB MIDI Gadget adapter.");
+module_param(id, charp, 0444);
+MODULE_PARM_DESC(id, "ID string for the USB MIDI Gadget adapter.");
+
+/* Some systems will want different product identifers published in the
+ * device descriptor, either numbers or strings or both.  These string
+ * parameters are in UTF-8 (superset of ASCII's 7 bit characters).
+ */
+
+static ushort idVendor;
+module_param(idVendor, ushort, S_IRUGO);
+MODULE_PARM_DESC(idVendor, "USB Vendor ID");
+
+static ushort idProduct;
+module_param(idProduct, ushort, S_IRUGO);
+MODULE_PARM_DESC(idProduct, "USB Product ID");
+
+static ushort bcdDevice;
+module_param(bcdDevice, ushort, S_IRUGO);
+MODULE_PARM_DESC(bcdDevice, "USB Device version (BCD)");
+
+static char *iManufacturer;
+module_param(iManufacturer, charp, S_IRUGO);
+MODULE_PARM_DESC(iManufacturer, "USB Manufacturer string");
+
+static char *iProduct;
+module_param(iProduct, charp, S_IRUGO);
+MODULE_PARM_DESC(iProduct, "USB Product string");
+
+static char *iSerialNumber;
+module_param(iSerialNumber, charp, S_IRUGO);
+MODULE_PARM_DESC(iSerialNumber, "SerialNumber");
+
+/*
+ * this version autoconfigures as much as possible,
+ * which is reasonable for most "bulk-only" drivers.
+ */
+static const char *EP_IN_NAME;
+static const char *EP_OUT_NAME;
+
+
+/* big enough to hold our biggest descriptor */
+#define USB_BUFSIZ 256
+
+
+/* This is a gadget, and the IN/OUT naming is from the host's perspective.
+   USB -> OUT endpoint -> rawmidi
+   USB <- IN endpoint  <- rawmidi */
+struct gmidi_in_port {
+       struct gmidi_device* dev;
+       int active;
+       uint8_t cable;          /* cable number << 4 */
+       uint8_t state;
+#define STATE_UNKNOWN  0
+#define STATE_1PARAM   1
+#define STATE_2PARAM_1 2
+#define STATE_2PARAM_2 3
+#define STATE_SYSEX_0  4
+#define STATE_SYSEX_1  5
+#define STATE_SYSEX_2  6
+       uint8_t data[2];
+};
+
+struct gmidi_device {
+       spinlock_t              lock;
+       struct usb_gadget       *gadget;
+       struct usb_request      *req;           /* for control responses */
+       u8                      config;
+       struct usb_ep           *in_ep, *out_ep;
+       struct snd_card         *card;
+       struct snd_rawmidi      *rmidi;
+       struct snd_rawmidi_substream *in_substream;
+       struct snd_rawmidi_substream *out_substream;
+
+       /* For the moment we only support one port in
+          each direction, but in_port is kept as a
+          separate struct so we can have more later. */
+       struct gmidi_in_port    in_port;
+       unsigned long           out_triggered;
+       struct tasklet_struct   tasklet;
+};
+
+static void gmidi_transmit(struct gmidi_device* dev, struct usb_request* req);
+
+
+#define xprintk(d,level,fmt,args...) \
+       dev_printk(level , &(d)->gadget->dev , fmt , ## args)
+
+#ifdef DEBUG
+#define DBG(dev,fmt,args...) \
+       xprintk(dev , KERN_DEBUG , fmt , ## args)
+#else
+#define DBG(dev,fmt,args...) \
+       do { } while (0)
+#endif /* DEBUG */
+
+#ifdef VERBOSE
+#define VDBG   DBG
+#else
+#define VDBG(dev,fmt,args...) \
+       do { } while (0)
+#endif /* VERBOSE */
+
+#define ERROR(dev,fmt,args...) \
+       xprintk(dev , KERN_ERR , fmt , ## args)
+#define WARN(dev,fmt,args...) \
+       xprintk(dev , KERN_WARNING , fmt , ## args)
+#define INFO(dev,fmt,args...) \
+       xprintk(dev , KERN_INFO , fmt , ## args)
+
+
+static unsigned buflen = 256;
+static unsigned qlen = 32;
+
+module_param(buflen, uint, S_IRUGO);
+module_param(qlen, uint, S_IRUGO);
+
+
+/* Thanks to Grey Innovation for donating this product ID.
+ *
+ * DO NOT REUSE THESE IDs with a protocol-incompatible driver!!  Ever!!
+ * Instead:  allocate your own, using normal USB-IF procedures.
+ */
+#define DRIVER_VENDOR_NUM      0x17b3          /* Grey Innovation */
+#define DRIVER_PRODUCT_NUM     0x0004          /* Linux-USB "MIDI Gadget" */
+
+
+/*
+ * DESCRIPTORS ... most are static, but strings and (full)
+ * configuration descriptors are built on demand.
+ */
+
+#define STRING_MANUFACTURER    25
+#define STRING_PRODUCT         42
+#define STRING_SERIAL          101
+#define STRING_MIDI_GADGET     250
+
+/* We only have the one configuration, it's number 1. */
+#define        GMIDI_CONFIG            1
+
+/* We have two interfaces- AudioControl and MIDIStreaming */
+#define GMIDI_AC_INTERFACE     0
+#define GMIDI_MS_INTERFACE     1
+#define GMIDI_NUM_INTERFACES   2
+
+DECLARE_USB_AC_HEADER_DESCRIPTOR(1);
+DECLARE_USB_MIDI_OUT_JACK_DESCRIPTOR(1);
+DECLARE_USB_MS_ENDPOINT_DESCRIPTOR(1);
+
+/* B.1  Device Descriptor */
+static struct usb_device_descriptor device_desc = {
+       .bLength =              USB_DT_DEVICE_SIZE,
+       .bDescriptorType =      USB_DT_DEVICE,
+       .bcdUSB =               __constant_cpu_to_le16(0x0200),
+       .bDeviceClass =         USB_CLASS_PER_INTERFACE,
+       .idVendor =             __constant_cpu_to_le16(DRIVER_VENDOR_NUM),
+       .idProduct =            __constant_cpu_to_le16(DRIVER_PRODUCT_NUM),
+       .iManufacturer =        STRING_MANUFACTURER,
+       .iProduct =             STRING_PRODUCT,
+       .bNumConfigurations =   1,
+};
+
+/* B.2  Configuration Descriptor */
+static struct usb_config_descriptor config_desc = {
+       .bLength =              USB_DT_CONFIG_SIZE,
+       .bDescriptorType =      USB_DT_CONFIG,
+       /* compute wTotalLength on the fly */
+       .bNumInterfaces =       GMIDI_NUM_INTERFACES,
+       .bConfigurationValue =  GMIDI_CONFIG,
+       .iConfiguration =       STRING_MIDI_GADGET,
+       /*
+        * FIXME: When embedding this driver in a device,
+        * these need to be set to reflect the actual
+        * power properties of the device. Is it selfpowered?
+        */
+       .bmAttributes =         USB_CONFIG_ATT_ONE,
+       .bMaxPower =            1,
+};
+
+/* B.3.1  Standard AC Interface Descriptor */
+static const struct usb_interface_descriptor ac_interface_desc = {
+       .bLength =              USB_DT_INTERFACE_SIZE,
+       .bDescriptorType =      USB_DT_INTERFACE,
+       .bInterfaceNumber =     GMIDI_AC_INTERFACE,
+       .bNumEndpoints =        0,
+       .bInterfaceClass =      USB_CLASS_AUDIO,
+       .bInterfaceSubClass =   USB_SUBCLASS_AUDIOCONTROL,
+       .iInterface =           STRING_MIDI_GADGET,
+};
+
+/* B.3.2  Class-Specific AC Interface Descriptor */
+static const struct usb_ac_header_descriptor_1 ac_header_desc = {
+       .bLength =              USB_DT_AC_HEADER_SIZE(1),
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   USB_MS_HEADER,
+       .bcdADC =               __constant_cpu_to_le16(0x0100),
+       .wTotalLength =         USB_DT_AC_HEADER_SIZE(1),
+       .bInCollection =        1,
+       .baInterfaceNr = {
+               [0] =           GMIDI_MS_INTERFACE,
+       }
+};
+
+/* B.4.1  Standard MS Interface Descriptor */
+static const struct usb_interface_descriptor ms_interface_desc = {
+       .bLength =              USB_DT_INTERFACE_SIZE,
+       .bDescriptorType =      USB_DT_INTERFACE,
+       .bInterfaceNumber =     GMIDI_MS_INTERFACE,
+       .bNumEndpoints =        2,
+       .bInterfaceClass =      USB_CLASS_AUDIO,
+       .bInterfaceSubClass =   USB_SUBCLASS_MIDISTREAMING,
+       .iInterface =           STRING_MIDI_GADGET,
+};
+
+/* B.4.2  Class-Specific MS Interface Descriptor */
+static const struct usb_ms_header_descriptor ms_header_desc = {
+       .bLength =              USB_DT_MS_HEADER_SIZE,
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   USB_MS_HEADER,
+       .bcdMSC =               __constant_cpu_to_le16(0x0100),
+       .wTotalLength =         USB_DT_MS_HEADER_SIZE
+                               + 2*USB_DT_MIDI_IN_SIZE
+                               + 2*USB_DT_MIDI_OUT_SIZE(1),
+};
+
+#define JACK_IN_EMB    1
+#define JACK_IN_EXT    2
+#define JACK_OUT_EMB   3
+#define JACK_OUT_EXT   4
+
+/* B.4.3  MIDI IN Jack Descriptors */
+static const struct usb_midi_in_jack_descriptor jack_in_emb_desc = {
+       .bLength =              USB_DT_MIDI_IN_SIZE,
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   USB_MS_MIDI_IN_JACK,
+       .bJackType =            USB_MS_EMBEDDED,
+       .bJackID =              JACK_IN_EMB,
+};
+
+static const struct usb_midi_in_jack_descriptor jack_in_ext_desc = {
+       .bLength =              USB_DT_MIDI_IN_SIZE,
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   USB_MS_MIDI_IN_JACK,
+       .bJackType =            USB_MS_EXTERNAL,
+       .bJackID =              JACK_IN_EXT,
+};
+
+/* B.4.4  MIDI OUT Jack Descriptors */
+static const struct usb_midi_out_jack_descriptor_1 jack_out_emb_desc = {
+       .bLength =              USB_DT_MIDI_OUT_SIZE(1),
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   USB_MS_MIDI_OUT_JACK,
+       .bJackType =            USB_MS_EMBEDDED,
+       .bJackID =              JACK_OUT_EMB,
+       .bNrInputPins =         1,
+       .pins = {
+               [0] = {
+                       .baSourceID =   JACK_IN_EXT,
+                       .baSourcePin =  1,
+               }
+       }
+};
+
+static const struct usb_midi_out_jack_descriptor_1 jack_out_ext_desc = {
+       .bLength =              USB_DT_MIDI_OUT_SIZE(1),
+       .bDescriptorType =      USB_DT_CS_INTERFACE,
+       .bDescriptorSubtype =   USB_MS_MIDI_OUT_JACK,
+       .bJackType =            USB_MS_EXTERNAL,
+       .bJackID =              JACK_OUT_EXT,
+       .bNrInputPins =         1,
+       .pins = {
+               [0] = {
+                       .baSourceID =   JACK_IN_EMB,
+                       .baSourcePin =  1,
+               }
+       }
+};
+
+/* B.5.1  Standard Bulk OUT Endpoint Descriptor */
+static struct usb_endpoint_descriptor bulk_out_desc = {
+       .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+       .bEndpointAddress =     USB_DIR_OUT,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+/* B.5.2  Class-specific MS Bulk OUT Endpoint Descriptor */
+static const struct usb_ms_endpoint_descriptor_1 ms_out_desc = {
+       .bLength =              USB_DT_MS_ENDPOINT_SIZE(1),
+       .bDescriptorType =      USB_DT_CS_ENDPOINT,
+       .bDescriptorSubtype =   USB_MS_GENERAL,
+       .bNumEmbMIDIJack =      1,
+       .baAssocJackID = {
+               [0] =           JACK_IN_EMB,
+       }
+};
+
+/* B.6.1  Standard Bulk IN Endpoint Descriptor */
+static struct usb_endpoint_descriptor bulk_in_desc = {
+       .bLength =              USB_DT_ENDPOINT_AUDIO_SIZE,
+       .bDescriptorType =      USB_DT_ENDPOINT,
+       .bEndpointAddress =     USB_DIR_IN,
+       .bmAttributes =         USB_ENDPOINT_XFER_BULK,
+};
+
+/* B.6.2  Class-specific MS Bulk IN Endpoint Descriptor */
+static const struct usb_ms_endpoint_descriptor_1 ms_in_desc = {
+       .bLength =              USB_DT_MS_ENDPOINT_SIZE(1),
+       .bDescriptorType =      USB_DT_CS_ENDPOINT,
+       .bDescriptorSubtype =   USB_MS_GENERAL,
+       .bNumEmbMIDIJack =      1,
+       .baAssocJackID = {
+               [0] =           JACK_OUT_EMB,
+       }
+};
+
+static const struct usb_descriptor_header *gmidi_function [] = {
+       (struct usb_descriptor_header *)&ac_interface_desc,
+       (struct usb_descriptor_header *)&ac_header_desc,
+       (struct usb_descriptor_header *)&ms_interface_desc,
+
+       (struct usb_descriptor_header *)&ms_header_desc,
+       (struct usb_descriptor_header *)&jack_in_emb_desc,
+       (struct usb_descriptor_header *)&jack_in_ext_desc,
+       (struct usb_descriptor_header *)&jack_out_emb_desc,
+       (struct usb_descriptor_header *)&jack_out_ext_desc,
+       /* If you add more jacks, update ms_header_desc.wTotalLength */
+
+       (struct usb_descriptor_header *)&bulk_out_desc,
+       (struct usb_descriptor_header *)&ms_out_desc,
+       (struct usb_descriptor_header *)&bulk_in_desc,
+       (struct usb_descriptor_header *)&ms_in_desc,
+       NULL,
+};
+
+static char manufacturer[50];
+static char product_desc[40] = "MIDI Gadget";
+static char serial_number[20];
+
+/* static strings, in UTF-8 */
+static struct usb_string strings [] = {
+       { STRING_MANUFACTURER, manufacturer, },
+       { STRING_PRODUCT, product_desc, },
+       { STRING_SERIAL, serial_number, },
+       { STRING_MIDI_GADGET, longname, },
+       {  }                    /* end of list */
+};
+
+static struct usb_gadget_strings stringtab = {
+       .language       = 0x0409,       /* en-us */
+       .strings        = strings,
+};
+
+static int config_buf(struct usb_gadget *gadget,
+               u8 *buf, u8 type, unsigned index)
+{
+       int len;
+
+       /* only one configuration */
+       if (index != 0) {
+               return -EINVAL;
+       }
+       len = usb_gadget_config_buf(&config_desc,
+                       buf, USB_BUFSIZ, gmidi_function);
+       if (len < 0) {
+               return len;
+       }
+       ((struct usb_config_descriptor *)buf)->bDescriptorType = type;
+       return len;
+}
+
+static struct usb_request* alloc_ep_req(struct usb_ep *ep, unsigned length)
+{
+       struct usb_request      *req;
+
+       req = usb_ep_alloc_request(ep, GFP_ATOMIC);
+       if (req) {
+               req->length = length;
+               req->buf = kmalloc(length, GFP_ATOMIC);
+               if (!req->buf) {
+                       usb_ep_free_request(ep, req);
+                       req = NULL;
+               }
+       }
+       return req;
+}
+
+static void free_ep_req(struct usb_ep *ep, struct usb_request *req)
+{
+       kfree(req->buf);
+       usb_ep_free_request(ep, req);
+}
+
+static const uint8_t gmidi_cin_length[] = {
+       0, 0, 2, 3, 3, 1, 2, 3, 3, 3, 3, 3, 2, 2, 3, 1
+};
+
+/*
+ * Receives a chunk of MIDI data.
+ */
+static void gmidi_read_data(struct usb_ep *ep, int cable,
+                                  uint8_t* data, int length)
+{
+       struct gmidi_device *dev = ep->driver_data;
+       /* cable is ignored, because for now we only have one. */
+
+       if (!dev->out_substream) {
+               /* Nobody is listening - throw it on the floor. */
+               return;
+       }
+       if (!test_bit(dev->out_substream->number, &dev->out_triggered)) {
+               return;
+       }
+       snd_rawmidi_receive(dev->out_substream, data, length);
+}
+
+static void gmidi_handle_out_data(struct usb_ep *ep, struct usb_request *req)
+{
+       unsigned i;
+       u8 *buf = req->buf;
+
+       for (i = 0; i + 3 < req->actual; i += 4) {
+               if (buf[i] != 0) {
+                       int cable = buf[i] >> 4;
+                       int length = gmidi_cin_length[buf[i] & 0x0f];
+                       gmidi_read_data(ep, cable, &buf[i + 1], length);
+               }
+       }
+}
+
+static void gmidi_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       struct gmidi_device *dev = ep->driver_data;
+       int status = req->status;
+
+       switch (status) {
+       case 0:                         /* normal completion */
+               if (ep == dev->out_ep) {
+                       /* we received stuff.
+                          req is queued again, below */
+                       gmidi_handle_out_data(ep, req);
+               } else if (ep == dev->in_ep) {
+                       /* our transmit completed.
+                          see if there's more to go.
+                          gmidi_transmit eats req, don't queue it again. */
+                       gmidi_transmit(dev, req);
+                       return;
+               }
+               break;
+
+       /* this endpoint is normally active while we're configured */
+       case -ECONNABORTED:             /* hardware forced ep reset */
+       case -ECONNRESET:               /* request dequeued */
+       case -ESHUTDOWN:                /* disconnect from host */
+               VDBG(dev, "%s gone (%d), %d/%d\n", ep->name, status,
+                               req->actual, req->length);
+               if (ep == dev->out_ep) {
+                       gmidi_handle_out_data(ep, req);
+               }
+               free_ep_req(ep, req);
+               return;
+
+       case -EOVERFLOW:                /* buffer overrun on read means that
+                                        * we didn't provide a big enough
+                                        * buffer.
+                                        */
+       default:
+               DBG(dev, "%s complete --> %d, %d/%d\n", ep->name,
+                               status, req->actual, req->length);
+               break;
+       case -EREMOTEIO:                /* short read */
+               break;
+       }
+
+       status = usb_ep_queue(ep, req, GFP_ATOMIC);
+       if (status) {
+               ERROR(dev, "kill %s:  resubmit %d bytes --> %d\n",
+                               ep->name, req->length, status);
+               usb_ep_set_halt(ep);
+               /* FIXME recover later ... somehow */
+       }
+}
+
+static int set_gmidi_config(struct gmidi_device *dev, gfp_t gfp_flags)
+{
+       int err = 0;
+       struct usb_request *req;
+       struct usb_ep* ep;
+       unsigned i;
+
+       err = usb_ep_enable(dev->in_ep, &bulk_in_desc);
+       if (err) {
+               ERROR(dev, "can't start %s: %d\n", dev->in_ep->name, err);
+               goto fail;
+       }
+       dev->in_ep->driver_data = dev;
+
+       err = usb_ep_enable(dev->out_ep, &bulk_out_desc);
+       if (err) {
+               ERROR(dev, "can't start %s: %d\n", dev->out_ep->name, err);
+               goto fail;
+       }
+       dev->out_ep->driver_data = dev;
+
+       /* allocate a bunch of read buffers and queue them all at once. */
+       ep = dev->out_ep;
+       for (i = 0; i < qlen && err == 0; i++) {
+               req = alloc_ep_req(ep, buflen);
+               if (req) {
+                       req->complete = gmidi_complete;
+                       err = usb_ep_queue(ep, req, GFP_ATOMIC);
+                       if (err) {
+                               DBG(dev, "%s queue req: %d\n", ep->name, err);
+                       }
+               } else {
+                       err = -ENOMEM;
+               }
+       }
+fail:
+       /* caller is responsible for cleanup on error */
+       return err;
+}
+
+
+static void gmidi_reset_config(struct gmidi_device *dev)
+{
+       if (dev->config == 0) {
+               return;
+       }
+
+       DBG(dev, "reset config\n");
+
+       /* just disable endpoints, forcing completion of pending i/o.
+        * all our completion handlers free their requests in this case.
+        */
+       usb_ep_disable(dev->in_ep);
+       usb_ep_disable(dev->out_ep);
+       dev->config = 0;
+}
+
+/* change our operational config.  this code must agree with the code
+ * that returns config descriptors, and altsetting code.
+ *
+ * it's also responsible for power management interactions. some
+ * configurations might not work with our current power sources.
+ *
+ * note that some device controller hardware will constrain what this
+ * code can do, perhaps by disallowing more than one configuration or
+ * by limiting configuration choices (like the pxa2xx).
+ */
+static int
+gmidi_set_config(struct gmidi_device *dev, unsigned number, gfp_t gfp_flags)
+{
+       int result = 0;
+       struct usb_gadget *gadget = dev->gadget;
+
+#if 0
+       /* FIXME */
+       /* Hacking this bit out fixes a bug where on receipt of two
+          USB_REQ_SET_CONFIGURATION messages, we end up with no
+          buffered OUT requests waiting for data. This is clearly
+          hiding a bug elsewhere, because if the config didn't
+          change then we really shouldn't do anything. */
+       /* Having said that, when we do "change" from config 1
+          to config 1, we at least gmidi_reset_config() which
+          clears out any requests on endpoints, so it's not like
+          we leak or anything. */
+       if (number == dev->config) {
+               return 0;
+       }
+#endif
+
+       if (gadget_is_sa1100(gadget) && dev->config) {
+               /* tx fifo is full, but we can't clear it...*/
+               INFO(dev, "can't change configurations\n");
+               return -ESPIPE;
+       }
+       gmidi_reset_config(dev);
+
+       switch (number) {
+       case GMIDI_CONFIG:
+               result = set_gmidi_config(dev, gfp_flags);
+               break;
+       default:
+               result = -EINVAL;
+               /* FALL THROUGH */
+       case 0:
+               return result;
+       }
+
+       if (!result && (!dev->in_ep || !dev->out_ep)) {
+               result = -ENODEV;
+       }
+       if (result) {
+               gmidi_reset_config(dev);
+       } else {
+               char *speed;
+
+               switch (gadget->speed) {
+               case USB_SPEED_LOW:     speed = "low"; break;
+               case USB_SPEED_FULL:    speed = "full"; break;
+               case USB_SPEED_HIGH:    speed = "high"; break;
+               default:                speed = "?"; break;
+               }
+
+               dev->config = number;
+               INFO(dev, "%s speed\n", speed);
+       }
+       return result;
+}
+
+
+static void gmidi_setup_complete(struct usb_ep *ep, struct usb_request *req)
+{
+       if (req->status || req->actual != req->length) {
+               DBG((struct gmidi_device *) ep->driver_data,
+                               "setup complete --> %d, %d/%d\n",
+                               req->status, req->actual, req->length);
+       }
+}
+
+/*
+ * The setup() callback implements all the ep0 functionality that's
+ * not handled lower down, in hardware or the hardware driver (like
+ * device and endpoint feature flags, and their status).  It's all
+ * housekeeping for the gadget function we're implementing.  Most of
+ * the work is in config-specific setup.
+ */
+static int gmidi_setup(struct usb_gadget *gadget,
+                       const struct usb_ctrlrequest *ctrl)
+{
+       struct gmidi_device *dev = get_gadget_data(gadget);
+       struct usb_request *req = dev->req;
+       int value = -EOPNOTSUPP;
+       u16 w_index = le16_to_cpu(ctrl->wIndex);
+       u16 w_value = le16_to_cpu(ctrl->wValue);
+       u16 w_length = le16_to_cpu(ctrl->wLength);
+
+       /* usually this stores reply data in the pre-allocated ep0 buffer,
+        * but config change events will reconfigure hardware.
+        */
+       req->zero = 0;
+       switch (ctrl->bRequest) {
+
+       case USB_REQ_GET_DESCRIPTOR:
+               if (ctrl->bRequestType != USB_DIR_IN) {
+                       goto unknown;
+               }
+               switch (w_value >> 8) {
+
+               case USB_DT_DEVICE:
+                       value = min(w_length, (u16) sizeof(device_desc));
+                       memcpy(req->buf, &device_desc, value);
+                       break;
+               case USB_DT_CONFIG:
+                       value = config_buf(gadget, req->buf,
+                                       w_value >> 8,
+                                       w_value & 0xff);
+                       if (value >= 0) {
+                               value = min(w_length, (u16)value);
+                       }
+                       break;
+
+               case USB_DT_STRING:
+                       /* wIndex == language code.
+                        * this driver only handles one language, you can
+                        * add string tables for other languages, using
+                        * any UTF-8 characters
+                        */
+                       value = usb_gadget_get_string(&stringtab,
+                                       w_value & 0xff, req->buf);
+                       if (value >= 0) {
+                               value = min(w_length, (u16)value);
+                       }
+                       break;
+               }
+               break;
+
+       /* currently two configs, two speeds */
+       case USB_REQ_SET_CONFIGURATION:
+               if (ctrl->bRequestType != 0) {
+                       goto unknown;
+               }
+               if (gadget->a_hnp_support) {
+                       DBG(dev, "HNP available\n");
+               } else if (gadget->a_alt_hnp_support) {
+                       DBG(dev, "HNP needs a different root port\n");
+               } else {
+                       VDBG(dev, "HNP inactive\n");
+               }
+               spin_lock(&dev->lock);
+               value = gmidi_set_config(dev, w_value, GFP_ATOMIC);
+               spin_unlock(&dev->lock);
+               break;
+       case USB_REQ_GET_CONFIGURATION:
+               if (ctrl->bRequestType != USB_DIR_IN) {
+                       goto unknown;
+               }
+               *(u8 *)req->buf = dev->config;
+               value = min(w_length, (u16)1);
+               break;
+
+       /* until we add altsetting support, or other interfaces,
+        * only 0/0 are possible.  pxa2xx only supports 0/0 (poorly)
+        * and already killed pending endpoint I/O.
+        */
+       case USB_REQ_SET_INTERFACE:
+               if (ctrl->bRequestType != USB_RECIP_INTERFACE) {
+                       goto unknown;
+               }
+               spin_lock(&dev->lock);
+               if (dev->config && w_index < GMIDI_NUM_INTERFACES
+                       && w_value == 0)
+               {
+                       u8 config = dev->config;
+
+                       /* resets interface configuration, forgets about
+                        * previous transaction state (queued bufs, etc)
+                        * and re-inits endpoint state (toggle etc)
+                        * no response queued, just zero status == success.
+                        * if we had more than one interface we couldn't
+                        * use this "reset the config" shortcut.
+                        */
+                       gmidi_reset_config(dev);
+                       gmidi_set_config(dev, config, GFP_ATOMIC);
+                       value = 0;
+               }
+               spin_unlock(&dev->lock);
+               break;
+       case USB_REQ_GET_INTERFACE:
+               if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE)) {
+                       goto unknown;
+               }
+               if (!dev->config) {
+                       break;
+               }
+               if (w_index >= GMIDI_NUM_INTERFACES) {
+                       value = -EDOM;
+                       break;
+               }
+               *(u8 *)req->buf = 0;
+               value = min(w_length, (u16)1);
+               break;
+
+       default:
+unknown:
+               VDBG(dev, "unknown control req%02x.%02x v%04x i%04x l%d\n",
+                       ctrl->bRequestType, ctrl->bRequest,
+                       w_value, w_index, w_length);
+       }
+
+       /* respond with data transfer before status phase? */
+       if (value >= 0) {
+               req->length = value;
+               req->zero = value < w_length;
+               value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
+               if (value < 0) {
+                       DBG(dev, "ep_queue --> %d\n", value);
+                       req->status = 0;
+                       gmidi_setup_complete(gadget->ep0, req);
+               }
+       }
+
+       /* device either stalls (value < 0) or reports success */
+       return value;
+}
+
+static void gmidi_disconnect(struct usb_gadget *gadget)
+{
+       struct gmidi_device *dev = get_gadget_data(gadget);
+       unsigned long flags;
+
+       spin_lock_irqsave(&dev->lock, flags);
+       gmidi_reset_config(dev);
+
+       /* a more significant application might have some non-usb
+        * activities to quiesce here, saving resources like power
+        * or pushing the notification up a network stack.
+        */
+       spin_unlock_irqrestore(&dev->lock, flags);
+
+       /* next we may get setup() calls to enumerate new connections;
+        * or an unbind() during shutdown (including removing module).
+        */
+}
+
+static void /* __init_or_exit */ gmidi_unbind(struct usb_gadget *gadget)
+{
+       struct gmidi_device *dev = get_gadget_data(gadget);
+       struct snd_card* card;
+
+       DBG(dev, "unbind\n");
+
+       card = dev->card;
+       dev->card = NULL;
+       if (card) {
+               snd_card_free(card);
+       }
+
+       /* we've already been disconnected ... no i/o is active */
+       if (dev->req) {
+               dev->req->length = USB_BUFSIZ;
+               free_ep_req(gadget->ep0, dev->req);
+       }
+       kfree(dev);
+       set_gadget_data(gadget, NULL);
+}
+
+static int gmidi_snd_free(struct snd_device *device)
+{
+       return 0;
+}
+
+static void gmidi_transmit_packet(struct usb_request* req, uint8_t p0,
+                                       uint8_t p1, uint8_t p2, uint8_t p3)
+{
+       unsigned length = req->length;
+
+       uint8_t* buf = (uint8_t*)req->buf + length;
+       buf[0] = p0;
+       buf[1] = p1;
+       buf[2] = p2;
+       buf[3] = p3;
+       req->length = length + 4;
+}
+
+/*
+ * Converts MIDI commands to USB MIDI packets.
+ */
+static void gmidi_transmit_byte(struct usb_request* req,
+                               struct gmidi_in_port* port, uint8_t b)
+{
+       uint8_t p0 = port->cable;
+
+       if (b >= 0xf8) {
+               gmidi_transmit_packet(req, p0 | 0x0f, b, 0, 0);
+       } else if (b >= 0xf0) {
+               switch (b) {
+               case 0xf0:
+                       port->data[0] = b;
+                       port->state = STATE_SYSEX_1;
+                       break;
+               case 0xf1:
+               case 0xf3:
+                       port->data[0] = b;
+                       port->state = STATE_1PARAM;
+                       break;
+               case 0xf2:
+                       port->data[0] = b;
+                       port->state = STATE_2PARAM_1;
+                       break;
+               case 0xf4:
+               case 0xf5:
+                       port->state = STATE_UNKNOWN;
+                       break;
+               case 0xf6:
+                       gmidi_transmit_packet(req, p0 | 0x05, 0xf6, 0, 0);
+                       port->state = STATE_UNKNOWN;
+                       break;
+               case 0xf7:
+                       switch (port->state) {
+                       case STATE_SYSEX_0:
+                               gmidi_transmit_packet(req,
+                                       p0 | 0x05, 0xf7, 0, 0);
+                               break;
+                       case STATE_SYSEX_1:
+                               gmidi_transmit_packet(req,
+                                       p0 | 0x06, port->data[0], 0xf7, 0);
+                               break;
+                       case STATE_SYSEX_2:
+                               gmidi_transmit_packet(req,
+                                       p0 | 0x07, port->data[0],
+                                       port->data[1], 0xf7);
+                               break;
+                       }
+                       port->state = STATE_UNKNOWN;
+                       break;
+               }
+       } else if (b >= 0x80) {
+               port->data[0] = b;
+               if (b >= 0xc0 && b <= 0xdf)
+                       port->state = STATE_1PARAM;
+               else
+                       port->state = STATE_2PARAM_1;
+       } else { /* b < 0x80 */
+               switch (port->state) {
+               case STATE_1PARAM:
+                       if (port->data[0] < 0xf0) {
+                               p0 |= port->data[0] >> 4;
+                       } else {
+                               p0 |= 0x02;
+                               port->state = STATE_UNKNOWN;
+                       }
+                       gmidi_transmit_packet(req, p0, port->data[0], b, 0);
+                       break;
+               case STATE_2PARAM_1:
+                       port->data[1] = b;
+                       port->state = STATE_2PARAM_2;
+                       break;
+               case STATE_2PARAM_2:
+                       if (port->data[0] < 0xf0) {
+                               p0 |= port->data[0] >> 4;
+                               port->state = STATE_2PARAM_1;
+                       } else {
+                               p0 |= 0x03;
+                               port->state = STATE_UNKNOWN;
+                       }
+                       gmidi_transmit_packet(req,
+                               p0, port->data[0], port->data[1], b);
+                       break;
+               case STATE_SYSEX_0:
+                       port->data[0] = b;
+                       port->state = STATE_SYSEX_1;
+                       break;
+               case STATE_SYSEX_1:
+                       port->data[1] = b;
+                       port->state = STATE_SYSEX_2;
+                       break;
+               case STATE_SYSEX_2:
+                       gmidi_transmit_packet(req,
+                               p0 | 0x04, port->data[0], port->data[1], b);
+                       port->state = STATE_SYSEX_0;
+                       break;
+               }
+       }
+}
+
+static void gmidi_transmit(struct gmidi_device* dev, struct usb_request* req)
+{
+       struct usb_ep* ep = dev->in_ep;
+       struct gmidi_in_port* port = &dev->in_port;
+
+       if (!ep) {
+               return;
+       }
+       if (!req) {
+               req = alloc_ep_req(ep, buflen);
+       }
+       if (!req) {
+               ERROR(dev, "gmidi_transmit: alloc_ep_request failed\n");
+               return;
+       }
+       req->length = 0;
+       req->complete = gmidi_complete;
+
+       if (port->active) {
+               while (req->length + 3 < buflen) {
+                       uint8_t b;
+                       if (snd_rawmidi_transmit(dev->in_substream, &b, 1)
+                               != 1)
+                       {
+                               port->active = 0;
+                               break;
+                       }
+                       gmidi_transmit_byte(req, port, b);
+               }
+       }
+       if (req->length > 0) {
+               usb_ep_queue(ep, req, GFP_ATOMIC);
+       } else {
+               free_ep_req(ep, req);
+       }
+}
+
+static void gmidi_in_tasklet(unsigned long data)
+{
+       struct gmidi_device* dev = (struct gmidi_device*)data;
+
+       gmidi_transmit(dev, NULL);
+}
+
+static int gmidi_in_open(struct snd_rawmidi_substream *substream)
+{
+       struct gmidi_device* dev = substream->rmidi->private_data;
+
+       VDBG(dev, "gmidi_in_open\n");
+       dev->in_substream = substream;
+       dev->in_port.state = STATE_UNKNOWN;
+       return 0;
+}
+
+static int gmidi_in_close(struct snd_rawmidi_substream *substream)
+{
+       VDBG(dev, "gmidi_in_close\n");
+       return 0;
+}
+
+static void gmidi_in_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+       struct gmidi_device* dev = substream->rmidi->private_data;
+
+       VDBG(dev, "gmidi_in_trigger %d\n", up);
+       dev->in_port.active = up;
+       if (up) {
+               tasklet_hi_schedule(&dev->tasklet);
+       }
+}
+
+static int gmidi_out_open(struct snd_rawmidi_substream *substream)
+{
+       struct gmidi_device* dev = substream->rmidi->private_data;
+
+       VDBG(dev, "gmidi_out_open\n");
+       dev->out_substream = substream;
+       return 0;
+}
+
+static int gmidi_out_close(struct snd_rawmidi_substream *substream)
+{
+       VDBG(dev, "gmidi_out_close\n");
+       return 0;
+}
+
+static void gmidi_out_trigger(struct snd_rawmidi_substream *substream, int up)
+{
+       struct gmidi_device* dev = substream->rmidi->private_data;
+
+       VDBG(dev, "gmidi_out_trigger %d\n", up);
+       if (up) {
+               set_bit(substream->number, &dev->out_triggered);
+       } else {
+               clear_bit(substream->number, &dev->out_triggered);
+       }
+}
+
+static struct snd_rawmidi_ops gmidi_in_ops = {
+       .open = gmidi_in_open,
+       .close = gmidi_in_close,
+       .trigger = gmidi_in_trigger,
+};
+
+static struct snd_rawmidi_ops gmidi_out_ops = {
+       .open = gmidi_out_open,
+       .close = gmidi_out_close,
+       .trigger = gmidi_out_trigger
+};
+
+/* register as a sound "card" */
+static int gmidi_register_card(struct gmidi_device *dev)
+{
+       struct snd_card *card;
+       struct snd_rawmidi *rmidi;
+       int err;
+       int out_ports = 1;
+       int in_ports = 1;
+       static struct snd_device_ops ops = {
+               .dev_free = gmidi_snd_free,
+       };
+
+       card = snd_card_new(index, id, THIS_MODULE, 0);
+       if (!card) {
+               ERROR(dev, "snd_card_new failed\n");
+               err = -ENOMEM;
+               goto fail;
+       }
+       dev->card = card;
+
+       err = snd_device_new(card, SNDRV_DEV_LOWLEVEL, dev, &ops);
+       if (err < 0) {
+               ERROR(dev, "snd_device_new failed: error %d\n", err);
+               goto fail;
+       }
+
+       strcpy(card->driver, longname);
+       strcpy(card->longname, longname);
+       strcpy(card->shortname, shortname);
+
+       /* Set up rawmidi */
+       dev->in_port.dev = dev;
+       dev->in_port.active = 0;
+       snd_component_add(card, "MIDI");
+       err = snd_rawmidi_new(card, "USB MIDI Gadget", 0,
+                             out_ports, in_ports, &rmidi);
+       if (err < 0) {
+               ERROR(dev, "snd_rawmidi_new failed: error %d\n", err);
+               goto fail;
+       }
+       dev->rmidi = rmidi;
+       strcpy(rmidi->name, card->shortname);
+       rmidi->info_flags = SNDRV_RAWMIDI_INFO_OUTPUT |
+                           SNDRV_RAWMIDI_INFO_INPUT |
+                           SNDRV_RAWMIDI_INFO_DUPLEX;
+       rmidi->private_data = dev;
+
+       /* Yes, rawmidi OUTPUT = USB IN, and rawmidi INPUT = USB OUT.
+          It's an upside-down world being a gadget. */
+       snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_OUTPUT, &gmidi_in_ops);
+       snd_rawmidi_set_ops(rmidi, SNDRV_RAWMIDI_STREAM_INPUT, &gmidi_out_ops);
+
+       snd_card_set_dev(card, &dev->gadget->dev);
+
+       /* register it - we're ready to go */
+       err = snd_card_register(card);
+       if (err < 0) {
+               ERROR(dev, "snd_card_register failed\n");
+               goto fail;
+       }
+
+       VDBG(dev, "gmidi_register_card finished ok\n");
+       return 0;
+
+fail:
+       if (dev->card) {
+               snd_card_free(dev->card);
+               dev->card = NULL;
+       }
+       return err;
+}
+
+/*
+ * Creates an output endpoint, and initializes output ports.
+ */
+static int __devinit gmidi_bind(struct usb_gadget *gadget)
+{
+       struct gmidi_device *dev;
+       struct usb_ep *in_ep, *out_ep;
+       int gcnum, err = 0;
+
+       /* support optional vendor/distro customization */
+       if (idVendor) {
+               if (!idProduct) {
+                       printk(KERN_ERR "idVendor needs idProduct!\n");
+                       return -ENODEV;
+               }
+               device_desc.idVendor = cpu_to_le16(idVendor);
+               device_desc.idProduct = cpu_to_le16(idProduct);
+               if (bcdDevice) {
+                       device_desc.bcdDevice = cpu_to_le16(bcdDevice);
+               }
+       }
+       if (iManufacturer) {
+               strlcpy(manufacturer, iManufacturer, sizeof(manufacturer));
+       } else {
+               snprintf(manufacturer, sizeof(manufacturer), "%s %s with %s",
+                       system_utsname.sysname, system_utsname.release,
+                       gadget->name);
+       }
+       if (iProduct) {
+               strlcpy(product_desc, iProduct, sizeof(product_desc));
+       }
+       if (iSerialNumber) {
+               device_desc.iSerialNumber = STRING_SERIAL,
+               strlcpy(serial_number, iSerialNumber, sizeof(serial_number));
+       }
+
+       /* Bulk-only drivers like this one SHOULD be able to
+        * autoconfigure on any sane usb controller driver,
+        * but there may also be important quirks to address.
+        */
+       usb_ep_autoconfig_reset(gadget);
+       in_ep = usb_ep_autoconfig(gadget, &bulk_in_desc);
+       if (!in_ep) {
+autoconf_fail:
+               printk(KERN_ERR "%s: can't autoconfigure on %s\n",
+                       shortname, gadget->name);
+               return -ENODEV;
+       }
+       EP_IN_NAME = in_ep->name;
+       in_ep->driver_data = in_ep;     /* claim */
+
+       out_ep = usb_ep_autoconfig(gadget, &bulk_out_desc);
+       if (!out_ep) {
+               goto autoconf_fail;
+       }
+       EP_OUT_NAME = out_ep->name;
+       out_ep->driver_data = out_ep;   /* claim */
+
+       gcnum = usb_gadget_controller_number(gadget);
+       if (gcnum >= 0) {
+               device_desc.bcdDevice = cpu_to_le16(0x0200 + gcnum);
+       } else {
+               /* gmidi is so simple (no altsettings) that
+                * it SHOULD NOT have problems with bulk-capable hardware.
+                * so warn about unrecognized controllers, don't panic.
+                */
+               printk(KERN_WARNING "%s: controller '%s' not recognized\n",
+                       shortname, gadget->name);
+               device_desc.bcdDevice = __constant_cpu_to_le16(0x9999);
+       }
+
+
+       /* ok, we made sense of the hardware ... */
+       dev = kzalloc(sizeof(*dev), SLAB_KERNEL);
+       if (!dev) {
+               return -ENOMEM;
+       }
+       spin_lock_init(&dev->lock);
+       dev->gadget = gadget;
+       dev->in_ep = in_ep;
+       dev->out_ep = out_ep;
+       set_gadget_data(gadget, dev);
+       tasklet_init(&dev->tasklet, gmidi_in_tasklet, (unsigned long)dev);
+
+       /* preallocate control response and buffer */
+       dev->req = usb_ep_alloc_request(gadget->ep0, GFP_KERNEL);
+       if (!dev->req) {
+               err = -ENOMEM;
+               goto fail;
+       }
+       dev->req->buf = usb_ep_alloc_buffer(gadget->ep0, USB_BUFSIZ,
+                               &dev->req->dma, GFP_KERNEL);
+       if (!dev->req->buf) {
+               err = -ENOMEM;
+               goto fail;
+       }
+
+       dev->req->complete = gmidi_setup_complete;
+
+       device_desc.bMaxPacketSize0 = gadget->ep0->maxpacket;
+
+       gadget->ep0->driver_data = dev;
+
+       INFO(dev, "%s, version: " DRIVER_VERSION "\n", longname);
+       INFO(dev, "using %s, OUT %s IN %s\n", gadget->name,
+               EP_OUT_NAME, EP_IN_NAME);
+
+       /* register as an ALSA sound card */
+       err = gmidi_register_card(dev);
+       if (err < 0) {
+               goto fail;
+       }
+
+       VDBG(dev, "gmidi_bind finished ok\n");
+       return 0;
+
+fail:
+       gmidi_unbind(gadget);
+       return err;
+}
+
+
+static void gmidi_suspend(struct usb_gadget *gadget)
+{
+       struct gmidi_device *dev = get_gadget_data(gadget);
+
+       if (gadget->speed == USB_SPEED_UNKNOWN) {
+               return;
+       }
+
+       DBG(dev, "suspend\n");
+}
+
+static void gmidi_resume(struct usb_gadget *gadget)
+{
+       struct gmidi_device *dev = get_gadget_data(gadget);
+
+       DBG(dev, "resume\n");
+}
+
+
+static struct usb_gadget_driver gmidi_driver = {
+       .speed          = USB_SPEED_FULL,
+       .function       = (char *)longname,
+       .bind           = gmidi_bind,
+       .unbind         = __exit_p(gmidi_unbind),
+
+       .setup          = gmidi_setup,
+       .disconnect     = gmidi_disconnect,
+
+       .suspend        = gmidi_suspend,
+       .resume         = gmidi_resume,
+
+       .driver         = {
+               .name           = (char *)shortname,
+               .owner          = THIS_MODULE,
+       },
+};
+
+static int __init gmidi_init(void)
+{
+       return usb_gadget_register_driver(&gmidi_driver);
+}
+module_init(gmidi_init);
+
+static void __exit gmidi_cleanup(void)
+{
+       usb_gadget_unregister_driver(&gmidi_driver);
+}
+module_exit(gmidi_cleanup);
+
diff --git a/include/linux/usb/audio.h b/include/linux/usb/audio.h
new file mode 100644 (file)
index 0000000..6bd2359
--- /dev/null
@@ -0,0 +1,53 @@
+/*
+ * <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
diff --git a/include/linux/usb/midi.h b/include/linux/usb/midi.h
new file mode 100644 (file)
index 0000000..11a97d5
--- /dev/null
@@ -0,0 +1,112 @@
+/*
+ * <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