USB: ohci-omap3: Add device tree support and binding information

Allows the OHCI controller found in OMAP3 and later chips to
be specified via device tree.
Signed-off-by: NRoger Quadros <rogerq@ti.com>
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/ohci-omap3.txt

+OMAP HS USB OHCI controller (OMAP3 and later)
+
+Required properties:
+
+- compatible: should be "ti,ohci-omap3"
+- reg: should contain one register range i.e. start and length
+- interrupts: description of the interrupt line
+
+Example for OMAP4:
+
+usbhsohci: ohci@4a064800 {
+	compatible = "ti,ohci-omap3", "usb-ohci";
+	reg = <0x4a064800 0x400>;
+	interrupts = <0 76 0x4>;
+};

drivers/usb/host/ohci-omap3.c

@@ -31,6 +31,8 @@
 
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/dma-mapping.h>
 
 /*-------------------------------------------------------------------------*/
 
@@ -112,6 +114,8 @@ static const struct hc_driver ohci_omap3_hc_driver = {
 
 /*-------------------------------------------------------------------------*/
 
+static u64 omap_ohci_dma_mask = DMA_BIT_MASK(32);
+
 /*
  * configure so an HC device and id are always provided
  * always called with process context; sleeping is OK
@@ -159,6 +163,13 @@ static int ohci_hcd_omap3_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	/*
+	 * 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 = &omap_ohci_dma_mask;
 
 	hcd = usb_create_hcd(&ohci_omap3_hc_driver, dev,
 			dev_name(dev));
@@ -228,12 +239,20 @@ static void ohci_hcd_omap3_shutdown(struct platform_device *pdev)
 		hcd->driver->shutdown(hcd);
 }
 
+static const struct of_device_id omap_ohci_dt_ids[] = {
+	{ .compatible = "ti,ohci-omap3" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, omap_ohci_dt_ids);
+
 static struct platform_driver ohci_hcd_omap3_driver = {
 	.probe		= ohci_hcd_omap3_probe,
 	.remove		= ohci_hcd_omap3_remove,
 	.shutdown	= ohci_hcd_omap3_shutdown,
 	.driver		= {
 		.name	= "ohci-omap3",
+		.of_match_table = of_match_ptr(omap_ohci_dt_ids),
 	},
 };