[PATCH v3] Axi-usb: Add support for 64-bit addressing.

[nava.manne@xilinx.com (Nava kishore Manne)]

This patch updates the driver to support 64-bit DMA addressing.

Signed-off-by: Nava kishore Manne <navam@xilinx.com>
---
Changes for v3:
                -Added new compatable string for 5.00 IP version as suggested by
                 Arnd Bergmann.
                -Used write_fn() insted of lo_hi_writeq() as suggested by
                 Arnd Bergmann.

Changes for v2:
                -Added dma-ranges property in device tree as suggested by Arnd Bergmann.
                -Modified the driver code based on the xlnx,addrwidth.

 .../devicetree/bindings/usb/udc-xilinx.txt         | 21 +++++----
 drivers/usb/gadget/udc/udc-xilinx.c                | 53 ++++++++++++++++++++--
 2 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/usb/udc-xilinx.txt b/Documentation/devicetree/bindings/usb/udc-xilinx.txt
index 47b4e39..09df757 100644
--- a/Documentation/devicetree/bindings/usb/udc-xilinx.txt
+++ b/Documentation/devicetree/bindings/usb/udc-xilinx.txt
@@ -1,18 +1,23 @@
 Xilinx USB2 device controller
 
 Required properties:
-- compatible		: Should be "xlnx,usb2-device-4.00.a"
+- compatible		: Should be "xlnx,usb2-device-4.00.a" or
+			  "xlnx,usb2-device-5.00"
 - reg			: Physical base address and size of the USB2
 			  device registers map.
 - interrupts		: Should contain single irq line of USB2 device
 			  controller
 - xlnx,has-builtin-dma	: if DMA is included
+- dma-ranges		: Should be as the following
+			  <child-bus-address, parent-bus-address, length>
+- xlnx,addrwidth	: Should be the dma addressing size in bits(ex: 64 bits)
 
 Example:
- 		axi-usb2-device at 42e00000 {
-                        compatible = "xlnx,usb2-device-4.00.a";
-                        interrupts = <0x0 0x39 0x1>;
-                        reg = <0x42e00000 0x10000>;
-                        xlnx,has-builtin-dma;
-                };
-
+		axi-usb2-device at 42e00000 {
+			compatible = "xlnx,usb2-device-4.00.a";
+			interrupts = <0x0 0x39 0x1>;
+			reg = <0x42e00000 0x10000>;
+			dma-ranges = <0x00000000 0x00000000 0x40000000>;
+			xlnx,has-builtin-dma;
+			xlnx,addrwidth = <0x40>;
+		};
diff --git a/drivers/usb/gadget/udc/udc-xilinx.c b/drivers/usb/gadget/udc/udc-xilinx.c
index 1cbb0ac..112a6f3 100644
--- a/drivers/usb/gadget/udc/udc-xilinx.c
+++ b/drivers/usb/gadget/udc/udc-xilinx.c
@@ -47,6 +47,15 @@
 #define XUSB_DMA_LENGTH_OFFSET		0x0210	/* DMA Length Register */
 #define XUSB_DMA_STATUS_OFFSET		0x0214	/* DMA Status Register */
 
+/* DMA source Address Reg for LSB */
+#define XUSB_DMA_DSAR_ADDR_OFFSET_LSB   0x0308
+/* DMA source Address Reg for MSB */
+#define XUSB_DMA_DSAR_ADDR_OFFSET_MSB   0x030C
+/* DMA destination Addr Reg LSB */
+#define XUSB_DMA_DDAR_ADDR_OFFSET_LSB   0x0310
+/* DMA destination Addr Reg MSB */
+#define XUSB_DMA_DDAR_ADDR_OFFSET_MSB   0x0314
+
 /* Endpoint Configuration Space offsets */
 #define XUSB_EP_CFGSTATUS_OFFSET	0x00	/* Endpoint Config Status  */
 #define XUSB_EP_BUF0COUNT_OFFSET	0x08	/* Buffer 0 Count */
@@ -193,7 +202,7 @@ struct xusb_udc {
 	void __iomem *addr;
 	spinlock_t lock;
 	bool dma_enabled;
-
+	u32 dma_addrwidth;
 	unsigned int (*read_fn)(void __iomem *);
 	void (*write_fn)(void __iomem *, u32, u32);
 };
@@ -214,6 +223,20 @@ static const struct usb_endpoint_descriptor config_bulk_out_desc = {
 	.wMaxPacketSize		= cpu_to_le16(EP0_MAX_PACKET),
 };
 
+/**
+ * xudc_write64 - write 64bit value to device registers
+ * @addr: base addr of device registers
+ * @offset: register offset
+ * @val: data to be written
+ **/
+static void xudc_write64(struct xusb_ep *ep, u32 offset, u64 val)
+{
+	struct xusb_udc *udc = ep->udc;
+
+	udc->write_fn(udc->addr, offset, lower_32_bits(val));
+	udc->write_fn(udc->addr, offset+0x04, upper_32_bits(val));
+}
+
 /**
  * xudc_write32 - little endian write to device registers
  * @addr: base addr of device registers
@@ -330,8 +353,13 @@ static int xudc_start_dma(struct xusb_ep *ep, dma_addr_t src,
 	 * destination registers and then set the length
 	 * into the DMA length register.
 	 */
-	udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
-	udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
+	if (udc->dma_addrwidth > 32) {
+		xudc_write64(ep, XUSB_DMA_DSAR_ADDR_OFFSET_LSB, src);
+		xudc_write64(ep, XUSB_DMA_DDAR_ADDR_OFFSET_LSB, dst);
+	} else {
+		udc->write_fn(udc->addr, XUSB_DMA_DSAR_ADDR_OFFSET, src);
+		udc->write_fn(udc->addr, XUSB_DMA_DDAR_ADDR_OFFSET, dst);
+	}
 	udc->write_fn(udc->addr, XUSB_DMA_LENGTH_OFFSET, length);
 
 	/*
@@ -2097,6 +2125,24 @@ static int xudc_probe(struct platform_device *pdev)
 
 	udc->dma_enabled = of_property_read_bool(np, "xlnx,has-builtin-dma");
 
+	if (of_device_is_compatible(np, "xlnx,usb2-device-5.00")) {
+		ret = of_property_read_u32(np, "xlnx,addrwidth",
+						&udc->dma_addrwidth);
+		if (ret < 0)
+			dev_warn(&pdev->dev,
+				"missing xlnx,addrwidth property\n");
+	} else {
+		udc->dma_addrwidth = 32;
+	}
+
+	/* Set the dma mask bits */
+	ret = dma_set_mask_and_coherent(&pdev->dev,
+					DMA_BIT_MASK(udc->dma_addrwidth));
+	if (ret < 0) {
+		dev_dbg(&pdev->dev, "no usable DMA configuration");
+		goto fail;
+	}
+
 	/* Setup gadget structure */
 	udc->gadget.ops = &xusb_udc_ops;
 	udc->gadget.max_speed = USB_SPEED_HIGH;
@@ -2168,6 +2214,7 @@ static int xudc_remove(struct platform_device *pdev)
 /* Match table for of_platform binding */
 static const struct of_device_id usb_of_match[] = {
 	{ .compatible = "xlnx,usb2-device-4.00.a", },
+	{ .compatible = "xlnx,usb2-device-5.00", },
 	{ /* end of list */ },
 };
 MODULE_DEVICE_TABLE(of, usb_of_match);
-- 
2.8.3.394.g3916adf