usb: host: xhci-plat: add support for the Armada 375/38x XHCI controllers

The Armada 375 and 38x SoCs come with an XHCI controller that requires
some specific initialization related to the MBus windows
configuration. This patch adds the support for this special
configuration as an XHCI quirk executed during probe.

Two new compatible strings are added to identify the Armada 375 and
Armada 38x XHCI controllers, and therefore enable the relevant quirk.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/Kconfig

@@ -29,6 +29,14 @@ if USB_XHCI_HCD
 config USB_XHCI_PLATFORM
 	tristate
 
+config USB_XHCI_MVEBU
+	tristate "xHCI support for Marvell Armada 375/38x"
+	select USB_XHCI_PLATFORM
+	depends on ARCH_MVEBU || COMPILE_TEST
+	---help---
+	  Say 'Y' to enable the support for the xHCI host controller
+	  found in Marvell Armada 375/38x ARM SOCs.
+
 endif # USB_XHCI_HCD
 
 config USB_EHCI_HCD

drivers/usb/host/Makefile

@@ -19,6 +19,9 @@ xhci-hcd-$(CONFIG_PCI)	+= xhci-pci.o
 
 ifneq ($(CONFIG_USB_XHCI_PLATFORM), )
 	xhci-hcd-y		+= xhci-plat.o
+ifneq ($(CONFIG_USB_XHCI_MVEBU), )
+	xhci-hcd-y		+= xhci-mvebu.o
+endif
 endif
 
 obj-$(CONFIG_USB_WHCI_HCD)	+= whci/

drivers/usb/host/xhci-mvebu.c

@@ -0,0 +1,72 @@
+/*
+ * Copyright (C) 2014 Marvell
+ * Author: Gregory CLEMENT <gregory.clement@free-electrons.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/io.h>
+#include <linux/mbus.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+#include "xhci-mvebu.h"
+
+#define USB3_MAX_WINDOWS	4
+#define USB3_WIN_CTRL(w)	(0x0 + ((w) * 8))
+#define USB3_WIN_BASE(w)	(0x4 + ((w) * 8))
+
+static void xhci_mvebu_mbus_config(void __iomem *base,
+			const struct mbus_dram_target_info *dram)
+{
+	int win;
+
+	/* Clear all existing windows */
+	for (win = 0; win < USB3_MAX_WINDOWS; win++) {
+		writel(0, base + USB3_WIN_CTRL(win));
+		writel(0, base + USB3_WIN_BASE(win));
+	}
+
+	/* Program each DRAM CS in a seperate window */
+	for (win = 0; win < dram->num_cs; win++) {
+		const struct mbus_dram_window *cs = dram->cs + win;
+
+		writel(((cs->size - 1) & 0xffff0000) | (cs->mbus_attr << 8) |
+		       (dram->mbus_dram_target_id << 4) | 1,
+		       base + USB3_WIN_CTRL(win));
+
+		writel((cs->base & 0xffff0000), base + USB3_WIN_BASE(win));
+	}
+}
+
+int xhci_mvebu_mbus_init_quirk(struct platform_device *pdev)
+{
+	struct resource	*res;
+	void __iomem *base;
+	const struct mbus_dram_target_info *dram;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res)
+		return -ENODEV;
+
+	/*
+	 * We don't use devm_ioremap() because this mapping should
+	 * only exists for the duration of this probe function.
+	 */
+	base = ioremap(res->start, resource_size(res));
+	if (!base)
+		return -ENODEV;
+
+	dram = mv_mbus_dram_info();
+	xhci_mvebu_mbus_config(base, dram);
+
+	/*
+	 * This memory area was only needed to configure the MBus
+	 * windows, and is therefore no longer useful.
+	 */
+	iounmap(base);
+
+	return 0;
+}

drivers/usb/host/xhci-mvebu.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (C) 2014 Marvell
+ *
+ * Gregory Clement <gregory.clement@free-electrons.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __LINUX_XHCI_MVEBU_H
+#define __LINUX_XHCI_MVEBU_H
+#if IS_ENABLED(CONFIG_USB_XHCI_MVEBU)
+int xhci_mvebu_mbus_init_quirk(struct platform_device *pdev);
+#else
+static inline int xhci_mvebu_mbus_init_quirk(struct platform_device *pdev)
+{
+	return 0;
+}
+#endif
+#endif /* __LINUX_XHCI_MVEBU_H */

drivers/usb/host/xhci-plat.c

@@ -19,6 +19,7 @@
 #include <linux/slab.h>
 
 #include "xhci.h"
+#include "xhci-mvebu.h"
 
 static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
 {
@@ -109,6 +110,15 @@ static int xhci_plat_probe(struct platform_device *pdev)
 	if (!res)
 		return -ENODEV;
 
+	if (of_device_is_compatible(pdev->dev.of_node,
+				    "marvell,armada-375-xhci") ||
+	    of_device_is_compatible(pdev->dev.of_node,
+				    "marvell,armada-380-xhci")) {
+		ret = xhci_mvebu_mbus_init_quirk(pdev);
+		if (ret)
+			return ret;
+	}
+
 	/* Initialize dma_mask and coherent_dma_mask to 32-bits */
 	ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
 	if (ret)
@@ -253,6 +263,8 @@ static const struct dev_pm_ops xhci_plat_pm_ops = {
 static const struct of_device_id usb_xhci_of_match[] = {
 	{ .compatible = "generic-xhci" },
 	{ .compatible = "xhci-platform" },
+	{ .compatible = "marvell,armada-375-xhci"},
+	{ .compatible = "marvell,armada-380-xhci"},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, usb_xhci_of_match);