usb: dwc3: core: split host address space

This fix prevents a problem with dwc3 and host mode where
we were requesting the entire memory region in dwc3/core.c,
thus preventing xhci-plat from ever ioremapping its own address space.

Signed-off-by: Ido Shayevitz <[e-mail]>
Signed-off-by: Felipe Balbi <[e-mail]>

drivers/usb/dwc3/core.c

···
 	struct device		*dev = &pdev->dev;
 
 	int			ret = -ENOMEM;
-	int			irq;
 
 	void __iomem		*regs;
 	void			*mem;
···
 	dwc = PTR_ALIGN(mem, DWC3_ALIGN_MASK + 1);
 	dwc->mem = mem;
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 	if (!res) {
-		dev_err(dev, "missing resource\n");
+		dev_err(dev, "missing IRQ\n");
 		return -ENODEV;
 	}
+	dwc->xhci_resources[1] = *res;
 
-	dwc->res = res;
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "missing memory resource\n");
+		return -ENODEV;
+	}
+	dwc->xhci_resources[0] = *res;
+	dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
+					DWC3_XHCI_REGS_END;
 
-	res = devm_request_mem_region(dev, res->start, resource_size(res),
+	 /*
+	  * Request memory region but exclude xHCI regs,
+	  * since it will be requested by the xhci-plat driver.
+	  */
+	res = devm_request_mem_region(dev, res->start + DWC3_GLOBALS_REGS_START,
+			resource_size(res) - DWC3_GLOBALS_REGS_START,
 			dev_name(dev));
 	if (!res) {
 		dev_err(dev, "can't request mem region\n");
···
 		return -ENOMEM;
 	}
 
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0) {
-		dev_err(dev, "missing IRQ\n");
-		return -ENODEV;
-	}
-
 	spin_lock_init(&dwc->lock);
 	platform_set_drvdata(pdev, dwc);
 
 	dwc->regs	= regs;
 	dwc->regs_size	= resource_size(res);
 	dwc->dev	= dev;
-	dwc->irq	= irq;
 
 	if (!strncmp("super", maximum_speed, 5))
 		dwc->maximum_speed = DWC3_DCFG_SUPERSPEED;

drivers/usb/dwc3/core.h

···
 
 /* Global constants */
 #define DWC3_ENDPOINTS_NUM	32
+#define DWC3_XHCI_RESOURCES_NUM	2
 
 #define DWC3_EVENT_BUFFERS_SIZE	PAGE_SIZE
 #define DWC3_EVENT_TYPE_MASK	0xfe
···
 #define DWC3_GEVNTCOUNT_MASK	0xfffc
 #define DWC3_GSNPSID_MASK	0xffff0000
 #define DWC3_GSNPSREV_MASK	0xffff
+
+/* DWC3 registers memory space boundries */
+#define DWC3_XHCI_REGS_START		0x0
+#define DWC3_XHCI_REGS_END		0x7fff
+#define DWC3_GLOBALS_REGS_START		0xc100
+#define DWC3_GLOBALS_REGS_END		0xc6ff
+#define DWC3_DEVICE_REGS_START		0xc700
+#define DWC3_DEVICE_REGS_END		0xcbff
+#define DWC3_OTG_REGS_START		0xcc00
+#define DWC3_OTG_REGS_END		0xccff
 
 /* Global Registers */
 #define DWC3_GSBUSCFG0		0xc100
···
 	struct device		*dev;
 
 	struct platform_device	*xhci;
-	struct resource		*res;
+	struct resource		xhci_resources[DWC3_XHCI_RESOURCES_NUM];
 
 	struct dwc3_event_buffer **ev_buffs;
 	struct dwc3_ep		*eps[DWC3_ENDPOINTS_NUM];
···
 
 	void __iomem		*regs;
 	size_t			regs_size;
-
-	int			irq;
 
 	u32			num_event_buffers;
 	u32			u1u2;

drivers/usb/dwc3/host.c

···
 
 #include "core.h"
 
-static struct resource generic_resources[] = {
-	{
-		.flags = IORESOURCE_IRQ,
-	},
-	{
-		.flags = IORESOURCE_MEM,
-	},
-};
-
 int dwc3_host_init(struct dwc3 *dwc)
 {
 	struct platform_device	*xhci;
···
 
 	dwc->xhci = xhci;
 
-	/* setup resources */
-	generic_resources[0].start = dwc->irq;
-
-	generic_resources[1].start = dwc->res->start;
-	generic_resources[1].end = dwc->res->start + 0x7fff;
-
-	ret = platform_device_add_resources(xhci, generic_resources,
-			ARRAY_SIZE(generic_resources));
+	ret = platform_device_add_resources(xhci, dwc->xhci_resources,
+						DWC3_XHCI_RESOURCES_NUM);
 	if (ret) {
 		dev_err(dwc->dev, "couldn't add resources to xHCI device\n");
 		goto err1;

drivers/usb/dwc3/io.h

···
 
 #include <linux/io.h>
 
+#include "core.h"
+
 static inline u32 dwc3_readl(void __iomem *base, u32 offset)
 {
-	return readl(base + offset);
+	/*
+	 * We requested the mem region starting from the Globals address
+	 * space, see dwc3_probe in core.c.
+	 * However, the offsets are given starting from xHCI address space.
+	 */
+	return readl(base + (offset - DWC3_GLOBALS_REGS_START));
 }
 
 static inline void dwc3_writel(void __iomem *base, u32 offset, u32 value)
 {
-	writel(value, base + offset);
+	/*
+	 * We requested the mem region starting from the Globals address
+	 * space, see dwc3_probe in core.c.
+	 * However, the offsets are given starting from xHCI address space.
+	 */
+	writel(value, base + (offset - DWC3_GLOBALS_REGS_START));
 }
 
 #endif /* __DRIVERS_USB_DWC3_IO_H */