gmidi.c

linux下面gadget设备驱动

		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)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	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)
{
	struct gmidi_device *dev = substream->rmidi->private_data;

	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",
			init_utsname()->sysname, init_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), GFP_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 = alloc_ep_req(gadget->ep0, USB_BUFSIZ);
	if (!dev->req) {
		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		= 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);