1 #include <linux/usb.h> 2 #include <linux/usb/hcd.h> 3 #include "usb.h" 4 5 static int uas_is_interface(struct usb_host_interface *intf) 6 { 7 return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE && 8 intf->desc.bInterfaceSubClass == USB_SC_SCSI && 9 intf->desc.bInterfaceProtocol == USB_PR_UAS); 10 } 11 12 static int uas_find_uas_alt_setting(struct usb_interface *intf) 13 { 14 int i; 15 16 for (i = 0; i < intf->num_altsetting; i++) { 17 struct usb_host_interface *alt = &intf->altsetting[i]; 18 19 if (uas_is_interface(alt)) 20 return alt->desc.bAlternateSetting; 21 } 22 23 return -ENODEV; 24 } 25 26 static int uas_find_endpoints(struct usb_host_interface *alt, 27 struct usb_host_endpoint *eps[]) 28 { 29 struct usb_host_endpoint *endpoint = alt->endpoint; 30 unsigned i, n_endpoints = alt->desc.bNumEndpoints; 31 32 for (i = 0; i < n_endpoints; i++) { 33 unsigned char *extra = endpoint[i].extra; 34 int len = endpoint[i].extralen; 35 while (len >= 3) { 36 if (extra[1] == USB_DT_PIPE_USAGE) { 37 unsigned pipe_id = extra[2]; 38 if (pipe_id > 0 && pipe_id < 5) 39 eps[pipe_id - 1] = &endpoint[i]; 40 break; 41 } 42 len -= extra[0]; 43 extra += extra[0]; 44 } 45 } 46 47 if (!eps[0] || !eps[1] || !eps[2] || !eps[3]) 48 return -ENODEV; 49 50 return 0; 51 } 52 53 static int uas_use_uas_driver(struct usb_interface *intf, 54 const struct usb_device_id *id) 55 { 56 struct usb_host_endpoint *eps[4] = { }; 57 struct usb_device *udev = interface_to_usbdev(intf); 58 struct usb_hcd *hcd = bus_to_hcd(udev->bus); 59 unsigned long flags = id->driver_info; 60 int r, alt; 61 62 usb_stor_adjust_quirks(udev, &flags); 63 64 if (flags & US_FL_IGNORE_UAS) 65 return 0; 66 67 alt = uas_find_uas_alt_setting(intf); 68 if (alt < 0) 69 return 0; 70 71 r = uas_find_endpoints(&intf->altsetting[alt], eps); 72 if (r < 0) 73 return 0; 74 75 if (udev->bus->sg_tablesize == 0) { 76 dev_warn(&udev->dev, 77 "The driver for the USB controller %s does not support scatter-gather which is\n", 78 hcd->driver->description); 79 dev_warn(&udev->dev, 80 "required by the UAS driver. Please try an other USB controller if you wish to use UAS.\n"); 81 return 0; 82 } 83 84 if (udev->speed >= USB_SPEED_SUPER && !hcd->can_do_streams) { 85 dev_warn(&udev->dev, 86 "USB controller %s does not support streams, which are required by the UAS driver.\n", 87 hcd_to_bus(hcd)->bus_name); 88 dev_warn(&udev->dev, 89 "Please try an other USB controller if you wish to use UAS.\n"); 90 return 0; 91 } 92 93 return 1; 94 } 95