gmidi.c

linux下面gadget设备驱动

/*
 * gmidi.c -- USB MIDI Gadget Driver
 *
 * Copyright (C) 2006 Thumtronics Pty Ltd.
 * Developed for Thumtronics by Grey Innovation
 * Ben Williamson <[e-mail]>
 *
 * 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 VERBOSE_DEBUG */

#include <linux/kernel.h>
#include <linux/utsname.h>
#include <linux/device.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 DBG(d, fmt, args...) \
	dev_dbg(&(d)->gadget->dev , fmt , ## args)
#define VDBG(d, fmt, args...) \
	dev_vdbg(&(d)->gadget->dev , fmt , ## args)
#define ERROR(d, fmt, args...) \
	dev_err(&(d)->gadget->dev , fmt , ## args)
#define WARN(d, fmt, args...) \
	dev_warn(&(d)->gadget->dev , fmt , ## args)
#define INFO(d, fmt, args...) \
	dev_info(&(d)->gadget->dev , 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)
{