diff --git a/media/mtp/MtpDevice.cpp b/media/mtp/MtpDevice.cpp
index d22c72f..d02ed90 100644
--- a/media/mtp/MtpDevice.cpp
+++ b/media/mtp/MtpDevice.cpp
@@ -38,6 +38,121 @@
 
 namespace android {
 
+static bool isMtpDevice(uint16_t vendor, uint16_t product) {
+    // Sandisk Sansa Fuze
+    if (vendor == 0x0781 && product == 0x74c2)
+        return true;
+    // Samsung YP-Z5
+    if (vendor == 0x04e8 && product == 0x503c)
+        return true;
+    return false;
+}
+
+MtpDevice* MtpDevice::open(const char* deviceName, int fd) {
+    struct usb_device *device = usb_device_new(deviceName, fd);
+    if (!device) {
+        LOGE("usb_device_new failed for %s", deviceName);
+        return NULL;
+    }
+
+    struct usb_descriptor_header* desc;
+    struct usb_descriptor_iter iter;
+
+    usb_descriptor_iter_init(device, &iter);
+
+    while ((desc = usb_descriptor_iter_next(&iter)) != NULL) {
+        if (desc->bDescriptorType == USB_DT_INTERFACE) {
+            struct usb_interface_descriptor *interface = (struct usb_interface_descriptor *)desc;
+
+            if (interface->bInterfaceClass == USB_CLASS_STILL_IMAGE &&
+                interface->bInterfaceSubClass == 1 && // Still Image Capture
+                interface->bInterfaceProtocol == 1)     // Picture Transfer Protocol (PIMA 15470)
+            {
+                LOGD("Found camera: \"%s\" \"%s\"\n", usb_device_get_manufacturer_name(device),
+                        usb_device_get_product_name(device));
+            } else if (interface->bInterfaceClass == 0xFF &&
+                    interface->bInterfaceSubClass == 0xFF &&
+                    interface->bInterfaceProtocol == 0) {
+                char* interfaceName = usb_device_get_string(device, interface->iInterface);
+                if (!interfaceName || strcmp(interfaceName, "MTP"))
+                    continue;
+                // Looks like an android style MTP device
+                LOGD("Found MTP device: \"%s\" \"%s\"\n", usb_device_get_manufacturer_name(device),
+                        usb_device_get_product_name(device));
+            } else {
+                // look for special cased devices based on vendor/product ID
+                // we are doing this mainly for testing purposes
+                uint16_t vendor = usb_device_get_vendor_id(device);
+                uint16_t product = usb_device_get_product_id(device);
+                if (!isMtpDevice(vendor, product)) {
+                    // not an MTP or PTP device
+                    continue;
+                }
+                // request MTP OS string and descriptor
+                // some music players need to see this before entering MTP mode.
+                char buffer[256];
+                memset(buffer, 0, sizeof(buffer));
+                int ret = usb_device_send_control(device,
+                        USB_DIR_IN|USB_RECIP_DEVICE|USB_TYPE_STANDARD,
+                        USB_REQ_GET_DESCRIPTOR, (USB_DT_STRING << 8) | 0xEE,
+                        0, sizeof(buffer), buffer);
+                printf("usb_device_send_control returned %d errno: %d\n", ret, errno);
+                if (ret > 0) {
+                    printf("got MTP string %s\n", buffer);
+                    ret = usb_device_send_control(device,
+                            USB_DIR_IN|USB_RECIP_DEVICE|USB_TYPE_VENDOR, 1,
+                            0, 4, sizeof(buffer), buffer);
+                    printf("OS descriptor got %d\n", ret);
+                } else {
+                    printf("no MTP string\n");
+                }
+            }
+
+            // if we got here, then we have a likely MTP or PTP device
+
+            // interface should be followed by three endpoints
+            struct usb_endpoint_descriptor *ep;
+            struct usb_endpoint_descriptor *ep_in_desc = NULL;
+            struct usb_endpoint_descriptor *ep_out_desc = NULL;
+            struct usb_endpoint_descriptor *ep_intr_desc = NULL;
+            for (int i = 0; i < 3; i++) {
+                ep = (struct usb_endpoint_descriptor *)usb_descriptor_iter_next(&iter);
+                if (!ep || ep->bDescriptorType != USB_DT_ENDPOINT) {
+                    LOGE("endpoints not found\n");
+                    return NULL;
+                }
+                if (ep->bmAttributes == USB_ENDPOINT_XFER_BULK) {
+                    if (ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK)
+                        ep_in_desc = ep;
+                    else
+                        ep_out_desc = ep;
+                } else if (ep->bmAttributes == USB_ENDPOINT_XFER_INT &&
+                    ep->bEndpointAddress & USB_ENDPOINT_DIR_MASK) {
+                    ep_intr_desc = ep;
+                }
+            }
+            if (!ep_in_desc || !ep_out_desc || !ep_intr_desc) {
+                LOGE("endpoints not found\n");
+                return NULL;
+            }
+
+            if (usb_device_claim_interface(device, interface->bInterfaceNumber)) {
+                LOGE("usb_device_claim_interface failed errno: %d\n", errno);
+                return NULL;
+            }
+
+            MtpDevice* mtpDevice = new MtpDevice(device, interface->bInterfaceNumber,
+                        ep_in_desc, ep_out_desc, ep_intr_desc);
+            mtpDevice->initialize();
+            return mtpDevice;
+        }
+    }
+
+    usb_device_close(device);
+    LOGE("device not found");
+    return NULL;
+}
+
 MtpDevice::MtpDevice(struct usb_device* device, int interface,
             const struct usb_endpoint_descriptor *ep_in,
             const struct usb_endpoint_descriptor *ep_out,
@@ -49,7 +164,6 @@
         mRequestOut(NULL),
         mRequestIntr(NULL),
         mDeviceInfo(NULL),
-        mID(usb_device_get_unique_id(device)),
         mSessionID(0),
         mTransactionID(0),
         mReceivedResponse(false)
@@ -430,6 +544,98 @@
     return NULL;
 }
 
+bool MtpDevice::readObject(MtpObjectHandle handle,
+        bool (* callback)(void* data, int offset, int length, void* clientData),
+        int objectSize, void* clientData) {
+    Mutex::Autolock autoLock(mMutex);
+    bool result = false;
+
+    mRequest.reset();
+    mRequest.setParameter(1, handle);
+    if (sendRequest(MTP_OPERATION_GET_OBJECT)
+            && mData.readDataHeader(mRequestIn1)) {
+        uint32_t length = mData.getContainerLength();
+        if (length - MTP_CONTAINER_HEADER_SIZE != objectSize) {
+            LOGE("readObject error objectSize: %d, length: %d",
+                    objectSize, length);
+            goto fail;
+        }
+        length -= MTP_CONTAINER_HEADER_SIZE;
+        uint32_t remaining = length;
+        int offset = 0;
+
+        int initialDataLength = 0;
+        void* initialData = mData.getData(initialDataLength);
+        if (initialData) {
+            if (initialDataLength > 0) {
+                if (!callback(initialData, 0, initialDataLength, clientData))
+                    goto fail;
+                remaining -= initialDataLength;
+                offset += initialDataLength;
+            }
+            free(initialData);
+        }
+
+        // USB reads greater than 16K don't work
+        char buffer1[16384], buffer2[16384];
+        mRequestIn1->buffer = buffer1;
+        mRequestIn2->buffer = buffer2;
+        struct usb_request* req = mRequestIn1;
+        void* writeBuffer = NULL;
+        int writeLength = 0;
+
+        while (remaining > 0 || writeBuffer) {
+            if (remaining > 0) {
+                // queue up a read request
+                req->buffer_length = (remaining > sizeof(buffer1) ? sizeof(buffer1) : remaining);
+                if (mData.readDataAsync(req)) {
+                    LOGE("readDataAsync failed");
+                    goto fail;
+                }
+            } else {
+                req = NULL;
+            }
+
+            if (writeBuffer) {
+                // write previous buffer
+                if (!callback(writeBuffer, offset, writeLength, clientData)) {
+                    LOGE("write failed");
+                    // wait for pending read before failing
+                    if (req)
+                        mData.readDataWait(mDevice);
+                    goto fail;
+                }
+                offset += writeLength;
+                writeBuffer = NULL;
+            }
+
+            // wait for read to complete
+            if (req) {
+                int read = mData.readDataWait(mDevice);
+                if (read < 0)
+                    goto fail;
+
+                if (read > 0) {
+                    writeBuffer = req->buffer;
+                    writeLength = read;
+                    remaining -= read;
+                    req = (req == mRequestIn1 ? mRequestIn2 : mRequestIn1);
+                } else {
+                    writeBuffer = NULL;
+                }
+            }
+        }
+
+        MtpResponseCode response = readResponse();
+        if (response == MTP_RESPONSE_OK)
+            result = true;
+    }
+
+fail:
+    return result;
+}
+
+
 // reads the object's data and writes it to the specified file path
 bool MtpDevice::readObject(MtpObjectHandle handle, const char* destPath, int group, int perm) {
     LOGD("readObject: %s", destPath);
@@ -507,10 +713,14 @@
                 if (read < 0)
                     goto fail;
 
-                writeBuffer = req->buffer;
-                writeLength = read;
-                remaining -= read;
-                req = (req == mRequestIn1 ? mRequestIn2 : mRequestIn1);
+                if (read > 0) {
+                    writeBuffer = req->buffer;
+                    writeLength = read;
+                    remaining -= read;
+                    req = (req == mRequestIn1 ? mRequestIn2 : mRequestIn1);
+                } else {
+                    writeBuffer = NULL;
+                }
             }
         }