USB: cdc-acm: export parsed capabilities through sysfs

this patch exports the attributes cdc-acm knows about a device through sysfs.

Signed-off-by: Oliver Neukum <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/class/cdc-acm.c

···
 	}
 	return rc;
 }
+/*
+ * attributes exported through sysfs
+ */
+static ssize_t show_caps
+(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct acm *acm = usb_get_intfdata(intf);
 
+	return sprintf(buf, "%d", acm->ctrl_caps);
+}
+static DEVICE_ATTR(bmCapabilities, S_IRUGO, show_caps, NULL);
+
+static ssize_t show_country_codes
+(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct acm *acm = usb_get_intfdata(intf);
+
+	memcpy(buf, acm->country_codes, acm->country_code_size);
+	return acm->country_code_size;
+}
+
+static DEVICE_ATTR(wCountryCodes, S_IRUGO, show_country_codes, NULL);
+
+static ssize_t show_country_rel_date
+(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct acm *acm = usb_get_intfdata(intf);
+
+	return sprintf(buf, "%d", acm->country_rel_date);
+}
+
+static DEVICE_ATTR(iCountryCodeRelDate, S_IRUGO, show_country_rel_date, NULL);
 /*
  * Interrupt handlers for various ACM device responses
  */
···
 	usb_free_urb(acm->writeurb);
 	for (i = 0; i < nr; i++)
 		usb_free_urb(acm->ru[i].urb);
+	kfree(acm->country_codes);
 	kfree(acm);
 }
 
···
 		      const struct usb_device_id *id)
 {
 	struct usb_cdc_union_desc *union_header = NULL;
+	struct usb_cdc_country_functional_desc *cfd = NULL;
 	char *buffer = intf->altsetting->extra;
 	int buflen = intf->altsetting->extralen;
 	struct usb_interface *control_interface;
···
 				union_header = (struct usb_cdc_union_desc *)
 							buffer;
 				break;
-			case USB_CDC_COUNTRY_TYPE: /* maybe somehow export */
-				break; /* for now we ignore it */
+			case USB_CDC_COUNTRY_TYPE: /* export through sysfs*/
+				cfd = (struct usb_cdc_country_functional_desc *)buffer;
+				break;
 			case USB_CDC_HEADER_TYPE: /* maybe check version */ 
 				break; /* for now we ignore it */ 
 			case USB_CDC_ACM_TYPE:
···
 		goto alloc_fail7;
 	}
 
+	usb_set_intfdata (intf, acm);
+
+	i = device_create_file(&intf->dev, &dev_attr_bmCapabilities);
+	if (i < 0)
+		goto alloc_fail8;
+
+	if (cfd) { /* export the country data */
+		acm->country_codes = kmalloc(cfd->bLength - 4, GFP_KERNEL);
+		if (!acm->country_codes)
+			goto skip_countries;
+		acm->country_code_size = cfd->bLength - 4;
+		memcpy(acm->country_codes, (u8 *)&cfd->wCountyCode0, cfd->bLength - 4);
+		acm->country_rel_date = cfd->iCountryCodeRelDate;
+
+		i = device_create_file(&intf->dev, &dev_attr_wCountryCodes);
+		if (i < 0) {
+			kfree(acm->country_codes);
+			goto skip_countries;
+		}
+
+		i = device_create_file(&intf->dev, &dev_attr_iCountryCodeRelDate);
+		if (i < 0) {
+			kfree(acm->country_codes);
+			goto skip_countries;
+		}
+	}
+
+skip_countries:
 	usb_fill_int_urb(acm->ctrlurb, usb_dev, usb_rcvintpipe(usb_dev, epctrl->bEndpointAddress),
 			 acm->ctrl_buffer, ctrlsize, acm_ctrl_irq, acm, epctrl->bInterval);
 	acm->ctrlurb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
···
 	tty_register_device(acm_tty_driver, minor, &control_interface->dev);
 
 	acm_table[minor] = acm;
-	usb_set_intfdata (intf, acm);
-	return 0;
 
+	return 0;
+alloc_fail8:
+	usb_free_urb(acm->writeurb);
 alloc_fail7:
 	for (i = 0; i < num_rx_buf; i++)
 		usb_buffer_free(usb_dev, acm->readsize, acm->rb[i].base, acm->rb[i].dma);
···
 
 static void acm_disconnect(struct usb_interface *intf)
 {
-	struct acm *acm = usb_get_intfdata (intf);
+	struct acm *acm = usb_get_intfdata(intf);
 	struct usb_device *usb_dev = interface_to_usbdev(intf);
 	int i;
 
···
 		mutex_unlock(&open_mutex);
 		return;
 	}
+	if (acm->country_codes){
+		device_remove_file(&intf->dev, &dev_attr_wCountryCodes);
+		device_remove_file(&intf->dev, &dev_attr_iCountryCodeRelDate);
+	}
+	device_remove_file(&intf->dev, &dev_attr_bmCapabilities);
 	acm->dev = NULL;
 	usb_set_intfdata(acm->control, NULL);
 	usb_set_intfdata(acm->data, NULL);

drivers/usb/class/cdc-acm.h

···
 	struct urb *ctrlurb, *writeurb;			/* urbs */
 	u8 *ctrl_buffer;				/* buffers of urbs */
 	dma_addr_t ctrl_dma;				/* dma handles of buffers */
+	u8 *country_codes;				/* country codes from device */
+	unsigned int country_code_size;			/* size of this buffer */
+	unsigned int country_rel_date;			/* release date of version */
 	struct acm_wb wb[ACM_NW];
 	struct acm_ru ru[ACM_NR];
 	struct acm_rb rb[ACM_NR];