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Commit a2bfb4a3 authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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USB: support for cdc-acm of single interface devices 



This implement support in cdc-acm for acm devices another popular OS can handle

- adds support for autodetection of devices that use one interface
- autodetection of endpoints
- add a quirk for surpressing a setting that OS doesn't use
- autoassume that quirk for single interface devices

Signed-off-by: default avatarOliver Neukum <oliver@neukum.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0b10395a

drivers/usb/class/cdc-acm.c

+56 −12
Original line number Diff line number Diff line
@@ -937,9 +937,9 @@ static int acm_probe(struct usb_interface *intf, 
	int buflen = intf->altsetting->extralen;

	struct usb_interface *control_interface;

	struct usb_interface *data_interface;

	struct usb_endpoint_descriptor *epctrl;

	struct usb_endpoint_descriptor *epread;

	struct usb_endpoint_descriptor *epwrite;

	struct usb_endpoint_descriptor *epctrl = NULL;

	struct usb_endpoint_descriptor *epread = NULL;

	struct usb_endpoint_descriptor *epwrite = NULL;

	struct usb_device *usb_dev = interface_to_usbdev(intf);

	struct acm *acm;

	int minor;
@@ -952,6 +952,7 @@ static int acm_probe(struct usb_interface *intf, 
	unsigned long quirks;

	int num_rx_buf;

	int i;

	int combined_interfaces = 0;



	/* normal quirks */

	quirks = (unsigned long)id->driver_info;
@@ -1033,9 +1034,15 @@ static int acm_probe(struct usb_interface *intf, 
			data_interface = usb_ifnum_to_if(usb_dev, (data_interface_num = call_interface_num));

			control_interface = intf;

		} else {

			dev_dbg(&intf->dev,

					"No union descriptor, giving up\n");

			if (intf->cur_altsetting->desc.bNumEndpoints != 3) {

				dev_dbg(&intf->dev,"No union descriptor, giving up\n");

				return -ENODEV;

			} else {

				dev_warn(&intf->dev,"No union descriptor, testing for castrated device\n");

				combined_interfaces = 1;

				control_interface = data_interface = intf;

				goto look_for_collapsed_interface;

			}

		}

	} else {

		control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
@@ -1049,6 +1056,36 @@ static int acm_probe(struct usb_interface *intf, 
	if (data_interface_num != call_interface_num)

		dev_dbg(&intf->dev, "Separate call control interface. That is not fully supported.\n");



	if (control_interface == data_interface) {

		/* some broken devices designed for windows work this way */

		dev_warn(&intf->dev,"Control and data interfaces are not separated!\n");

		combined_interfaces = 1;

		/* a popular other OS doesn't use it */

		quirks |= NO_CAP_LINE;

		if (data_interface->cur_altsetting->desc.bNumEndpoints != 3) {

			dev_err(&intf->dev, "This needs exactly 3 endpoints\n");

			return -EINVAL;

		}

look_for_collapsed_interface:

		for (i = 0; i < 3; i++) {

			struct usb_endpoint_descriptor *ep;

			ep = &data_interface->cur_altsetting->endpoint[i].desc;



			if (usb_endpoint_is_int_in(ep))

				epctrl = ep;

			else if (usb_endpoint_is_bulk_out(ep))

				epwrite = ep;

			else if (usb_endpoint_is_bulk_in(ep))

				epread = ep;

			else

				return -EINVAL;

		}

		if (!epctrl || !epread || !epwrite)

			return -ENODEV;

		else

			goto made_compressed_probe;

	}



skip_normal_probe:



	/*workaround for switched interfaces */
@@ -1068,10 +1105,11 @@ static int acm_probe(struct usb_interface *intf, 
	}



	/* Accept probe requests only for the control interface */

	if (intf != control_interface)

	if (!combined_interfaces && intf != control_interface)

		return -ENODEV;



	if (usb_interface_claimed(data_interface)) { /* valid in this context */

	if (!combined_interfaces && usb_interface_claimed(data_interface)) {

		/* valid in this context */

		dev_dbg(&intf->dev, "The data interface isn't available\n");

		return -EBUSY;

	}
@@ -1095,6 +1133,7 @@ static int acm_probe(struct usb_interface *intf, 
		epread = epwrite;

		epwrite = t;

	}

made_compressed_probe:

	dbg("interfaces are valid");

	for (minor = 0; minor < ACM_TTY_MINORS && acm_table[minor]; minor++);
@@ -1112,12 +1151,15 @@ static int acm_probe(struct usb_interface *intf, 
	ctrlsize = le16_to_cpu(epctrl->wMaxPacketSize);

	readsize = le16_to_cpu(epread->wMaxPacketSize) *

				(quirks == SINGLE_RX_URB ? 1 : 2);

	acm->combined_interfaces = combined_interfaces;

	acm->writesize = le16_to_cpu(epwrite->wMaxPacketSize) * 20;

	acm->control = control_interface;

	acm->data = data_interface;

	acm->minor = minor;

	acm->dev = usb_dev;

	acm->ctrl_caps = ac_management_function;

	if (quirks & NO_CAP_LINE)

		acm->ctrl_caps &= ~USB_CDC_CAP_LINE;

	acm->ctrlsize = ctrlsize;

	acm->readsize = readsize;

	acm->rx_buflimit = num_rx_buf;
@@ -1225,7 +1267,8 @@ static int acm_probe(struct usb_interface *intf, 
	usb_fill_int_urb(acm->ctrlurb, usb_dev,

			 usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),

			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm,

			epctrl->bInterval);

			 /* works around buggy devices */

			 epctrl->bInterval ? epctrl->bInterval : 0xff);

	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;

	acm->ctrlurb->transfer_dma = acm->ctrl_dma;
@@ -1312,6 +1355,7 @@ static void acm_disconnect(struct usb_interface *intf) 
								acm->ctrl_dma);

	acm_read_buffers_free(acm);



	if (!acm->combined_interfaces)

		usb_driver_release_interface(&acm_driver, intf == acm->control ?

					acm->data : acm->control);

drivers/usb/class/cdc-acm.h

+2 −0
Original line number Diff line number Diff line
@@ -125,6 +125,7 @@ struct acm { 
	unsigned char clocal;				/* termios CLOCAL */

	unsigned int ctrl_caps;				/* control capabilities from the class specific header */

	unsigned int susp_count;			/* number of suspended interfaces */

	int combined_interfaces:1;			/* control and data collapsed */

	struct acm_wb *delayed_wb;			/* write queued for a device about to be woken */

};
@@ -133,3 +134,4 @@ struct acm { 
/* constants describing various quirks and errors */

#define NO_UNION_NORMAL			1

#define SINGLE_RX_URB			2

#define NO_CAP_LINE			4