drivers: USB Blaster II: claim interface before using it

If not, multiple instances of OOCD can concurrently use it.

Change-Id: I48cc9d90521d1dcc7720c6e8bec74f45972d16f7
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-on: http://openocd.zylin.com/4589
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

diff --git a/src/jtag/drivers/usb_blaster/ublast2_access_libusb.c b/src/jtag/drivers/usb_blaster/ublast2_access_libusb.c
index 6f15fa70a280115bdba86857924522859a257795..82dc95071f625fa7a1d05933eacb1f45cd2121eb 100644 (file)
--- a/src/jtag/drivers/usb_blaster/ublast2_access_libusb.c
+++ b/src/jtag/drivers/usb_blaster/ublast2_access_libusb.c
@@ -133,6 +133,11 @@ static int load_usb_blaster_firmware(struct libusb_device_handle *libusb_dev,
                return ERROR_FAIL;
        }
 
+       if (libusb_claim_interface(libusb_dev, 0)) {
+               LOG_ERROR("unable to claim interface");
+               return ERROR_JTAG_INIT_FAILED;
+       }
+
        ublast2_firmware_image.base_address = 0;
        ublast2_firmware_image.base_address_set = false;
 
@@ -184,6 +189,13 @@ static int load_usb_blaster_firmware(struct libusb_device_handle *libusb_dev,
 
        image_close(&ublast2_firmware_image);
 
+       /*
+        * Release claimed interface. Most probably it is already disconnected
+        * and re-enumerated as new devices after firmware upload, so we do
+        * not need to care about errors.
+        */
+       libusb_release_interface(libusb_dev, 0);
+
        return ERROR_OK;
 }
 
@@ -228,6 +240,12 @@ static int ublast2_libusb_init(struct ublast_lowlevel *low)
                }
        }
 
+       if (libusb_claim_interface(low->libusb_dev, 0)) {
+               LOG_ERROR("unable to claim interface");
+               jtag_libusb_close(low->libusb_dev);
+               return ERROR_JTAG_INIT_FAILED;
+       }
+
        char buffer[5];
        jtag_libusb_control_transfer(low->libusb_dev,
                                     LIBUSB_REQUEST_TYPE_VENDOR |
@@ -246,6 +264,9 @@ static int ublast2_libusb_init(struct ublast_lowlevel *low)
 
 static int ublast2_libusb_quit(struct ublast_lowlevel *low)
 {
+       if (libusb_release_interface(low->libusb_dev, 0))
+               LOG_ERROR("usb release interface failed");
+
        jtag_libusb_close(low->libusb_dev);
        return ERROR_OK;
 };