usb: Missing dma_mask in uhci-platform.c when probed from device-tree

Device-tree probed devices don't get a dev.dma_mask set. This patch
sets a default 32bit mask on platforms using devicetree.

Without this patch, arch-vt8500 cannot detect uhci attached devices.
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/uhci-platform.c

@@ -60,6 +60,7 @@ static const struct hc_driver uhci_platform_hc_driver = {
 	.hub_control =		uhci_hub_control,
 };
 
+static u64 platform_uhci_dma_mask = DMA_BIT_MASK(32);
 
 static int __devinit uhci_hcd_platform_probe(struct platform_device *pdev)
 {
@@ -71,6 +72,14 @@ static int __devinit uhci_hcd_platform_probe(struct platform_device *pdev)
 	if (usb_disabled())
 		return -ENODEV;
 
+	/*
+	 * Right now device-tree probed devices don't get dma_mask set.
+	 * Since shared usb code relies on it, set it here for now.
+	 * Once we have dma capability bindings this can go away.
+	 */
+	if (!pdev->dev.dma_mask)
+		pdev->dev.dma_mask = &platform_uhci_dma_mask;
+
 	hcd = usb_create_hcd(&uhci_platform_hc_driver, &pdev->dev,
 			pdev->name);
 	if (!hcd)