usb: host: xhci-plat: add support for the R-Car H2 and M2 xHCI controllers

The R-Car H2 and M2 SoCs come with an xHCI controller that requires
some specific initializations related to the firmware downloading and
some specific registers. This patch adds the support for this special
configuration as an xHCI quirk executed during probe and start.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: "mathias.nyman@intel.com" <mathias.nyman@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/Kconfig

@@ -37,6 +37,14 @@ config USB_XHCI_MVEBU
 	  Say 'Y' to enable the support for the xHCI host controller
 	  found in Marvell Armada 375/38x ARM SOCs.
 
+config USB_XHCI_RCAR
+	tristate "xHCI support for Renesas R-Car SoCs"
+	select USB_XHCI_PLATFORM
+	depends on ARCH_SHMOBILE || COMPILE_TEST
+	---help---
+	  Say 'Y' to enable the support for the xHCI host controller
+	  found in Renesas R-Car ARM SoCs.
+
 endif # USB_XHCI_HCD
 
 config USB_EHCI_HCD

drivers/usb/host/Makefile

@@ -22,6 +22,9 @@ ifneq ($(CONFIG_USB_XHCI_PLATFORM), )
 ifneq ($(CONFIG_USB_XHCI_MVEBU), )
 	xhci-hcd-y		+= xhci-mvebu.o
 endif
+ifneq ($(CONFIG_USB_XHCI_RCAR), )
+	xhci-hcd-y		+= xhci-rcar.o
+endif
 endif
 
 obj-$(CONFIG_USB_WHCI_HCD)	+= whci/

drivers/usb/host/xhci-plat.c

@@ -21,6 +21,7 @@
 
 #include "xhci.h"
 #include "xhci-mvebu.h"
+#include "xhci-rcar.h"
 
 static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
 {
@@ -35,11 +36,27 @@ static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
 /* called during probe() after chip reset completes */
 static int xhci_plat_setup(struct usb_hcd *hcd)
 {
+	struct device_node *of_node = hcd->self.controller->of_node;
+	int ret;
+
+	if (of_device_is_compatible(of_node, "renesas,xhci-r8a7790") ||
+	    of_device_is_compatible(of_node, "renesas,xhci-r8a7791")) {
+		ret = xhci_rcar_init_quirk(hcd);
+		if (ret)
+			return ret;
+	}
+
 	return xhci_gen_setup(hcd, xhci_plat_quirks);
 }
 
 static int xhci_plat_start(struct usb_hcd *hcd)
 {
+	struct device_node *of_node = hcd->self.controller->of_node;
+
+	if (of_device_is_compatible(of_node, "renesas,xhci-r8a7790") ||
+	    of_device_is_compatible(of_node, "renesas,xhci-r8a7791"))
+		xhci_rcar_start(hcd);
+
 	return xhci_run(hcd);
 }
 
@@ -263,6 +280,8 @@ static const struct of_device_id usb_xhci_of_match[] = {
 	{ .compatible = "xhci-platform" },
 	{ .compatible = "marvell,armada-375-xhci"},
 	{ .compatible = "marvell,armada-380-xhci"},
+	{ .compatible = "renesas,xhci-r8a7790"},
+	{ .compatible = "renesas,xhci-r8a7791"},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, usb_xhci_of_match);

drivers/usb/host/xhci-rcar.c

+/*
+ * xHCI host controller driver for R-Car SoCs
+ *
+ * Copyright (C) 2014 Renesas Electronics Corporation
+ *
+ * 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/firmware.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/usb/phy.h>
+
+#include "xhci.h"
+#include "xhci-rcar.h"
+
+#define FIRMWARE_NAME		"r8a779x_usb3_v1.dlmem"
+MODULE_FIRMWARE(FIRMWARE_NAME);
+
+/*** Register Offset ***/
+#define RCAR_USB3_INT_ENA	0x224	/* Interrupt Enable */
+#define RCAR_USB3_DL_CTRL	0x250	/* FW Download Control & Status */
+#define RCAR_USB3_FW_DATA0	0x258	/* FW Data0 */
+
+#define RCAR_USB3_LCLK		0xa44	/* LCLK Select */
+#define RCAR_USB3_CONF1		0xa48	/* USB3.0 Configuration1 */
+#define RCAR_USB3_CONF2		0xa5c	/* USB3.0 Configuration2 */
+#define RCAR_USB3_CONF3		0xaa8	/* USB3.0 Configuration3 */
+#define RCAR_USB3_RX_POL	0xab0	/* USB3.0 RX Polarity */
+#define RCAR_USB3_TX_POL	0xab8	/* USB3.0 TX Polarity */
+
+/*** Register Settings ***/
+/* Interrupt Enable */
+#define RCAR_USB3_INT_XHC_ENA	0x00000001
+#define RCAR_USB3_INT_PME_ENA	0x00000002
+#define RCAR_USB3_INT_HSE_ENA	0x00000004
+#define RCAR_USB3_INT_ENA_VAL	(RCAR_USB3_INT_XHC_ENA | \
+				RCAR_USB3_INT_PME_ENA | RCAR_USB3_INT_HSE_ENA)
+
+/* FW Download Control & Status */
+#define RCAR_USB3_DL_CTRL_ENABLE	0x00000001
+#define RCAR_USB3_DL_CTRL_FW_SUCCESS	0x00000010
+#define RCAR_USB3_DL_CTRL_FW_SET_DATA0	0x00000100
+
+/* LCLK Select */
+#define RCAR_USB3_LCLK_ENA_VAL	0x01030001
+
+/* USB3.0 Configuration */
+#define RCAR_USB3_CONF1_VAL	0x00030204
+#define RCAR_USB3_CONF2_VAL	0x00030300
+#define RCAR_USB3_CONF3_VAL	0x13802007
+
+/* USB3.0 Polarity */
+#define RCAR_USB3_RX_POL_VAL	BIT(21)
+#define RCAR_USB3_TX_POL_VAL	BIT(4)
+
+void xhci_rcar_start(struct usb_hcd *hcd)
+{
+	u32 temp;
+
+	if (hcd->regs != NULL) {
+		/* Interrupt Enable */
+		temp = readl(hcd->regs + RCAR_USB3_INT_ENA);
+		temp |= RCAR_USB3_INT_ENA_VAL;
+		writel(temp, hcd->regs + RCAR_USB3_INT_ENA);
+		/* LCLK Select */
+		writel(RCAR_USB3_LCLK_ENA_VAL, hcd->regs + RCAR_USB3_LCLK);
+		/* USB3.0 Configuration */
+		writel(RCAR_USB3_CONF1_VAL, hcd->regs + RCAR_USB3_CONF1);
+		writel(RCAR_USB3_CONF2_VAL, hcd->regs + RCAR_USB3_CONF2);
+		writel(RCAR_USB3_CONF3_VAL, hcd->regs + RCAR_USB3_CONF3);
+		/* USB3.0 Polarity */
+		writel(RCAR_USB3_RX_POL_VAL, hcd->regs + RCAR_USB3_RX_POL);
+		writel(RCAR_USB3_TX_POL_VAL, hcd->regs + RCAR_USB3_TX_POL);
+	}
+}
+
+static int xhci_rcar_download_firmware(struct device *dev, void __iomem *regs)
+{
+	const struct firmware *fw;
+	int retval, index, j, time;
+	int timeout = 10000;
+	u32 data, val, temp;
+
+	/* request R-Car USB3.0 firmware */
+	retval = request_firmware(&fw, FIRMWARE_NAME, dev);
+	if (retval)
+		return retval;
+
+	/* download R-Car USB3.0 firmware */
+	temp = readl(regs + RCAR_USB3_DL_CTRL);
+	temp |= RCAR_USB3_DL_CTRL_ENABLE;
+	writel(temp, regs + RCAR_USB3_DL_CTRL);
+
+	for (index = 0; index < fw->size; index += 4) {
+		/* to avoid reading beyond the end of the buffer */
+		for (data = 0, j = 3; j >= 0; j--) {
+			if ((j + index) < fw->size)
+				data |= fw->data[index + j] << (8 * j);
+		}
+		writel(data, regs + RCAR_USB3_FW_DATA0);
+		temp = readl(regs + RCAR_USB3_DL_CTRL);
+		temp |= RCAR_USB3_DL_CTRL_FW_SET_DATA0;
+		writel(temp, regs + RCAR_USB3_DL_CTRL);
+
+		for (time = 0; time < timeout; time++) {
+			val = readl(regs + RCAR_USB3_DL_CTRL);
+			if ((val & RCAR_USB3_DL_CTRL_FW_SET_DATA0) == 0)
+				break;
+			udelay(1);
+		}
+		if (time == timeout) {
+			retval = -ETIMEDOUT;
+			break;
+		}
+	}
+
+	temp = readl(regs + RCAR_USB3_DL_CTRL);
+	temp &= ~RCAR_USB3_DL_CTRL_ENABLE;
+	writel(temp, regs + RCAR_USB3_DL_CTRL);
+
+	for (time = 0; time < timeout; time++) {
+		val = readl(regs + RCAR_USB3_DL_CTRL);
+		if (val & RCAR_USB3_DL_CTRL_FW_SUCCESS) {
+			retval = 0;
+			break;
+		}
+		udelay(1);
+	}
+	if (time == timeout)
+		retval = -ETIMEDOUT;
+
+	release_firmware(fw);
+
+	return retval;
+}
+
+/* This function needs to initialize a "phy" of usb before */
+int xhci_rcar_init_quirk(struct usb_hcd *hcd)
+{
+	/* If hcd->regs is NULL, we don't just call the following function */
+	if (!hcd->regs)
+		return 0;
+
+	return xhci_rcar_download_firmware(hcd->self.controller, hcd->regs);
+}

drivers/usb/host/xhci-rcar.h

+/*
+ * drivers/usb/host/xhci-rcar.h
+ *
+ * Copyright (C) 2014 Renesas Electronics Corporation
+ *
+ * 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.
+ */
+
+#ifndef _XHCI_RCAR_H
+#define _XHCI_RCAR_H
+
+#if IS_ENABLED(CONFIG_USB_XHCI_RCAR)
+void xhci_rcar_start(struct usb_hcd *hcd);
+int xhci_rcar_init_quirk(struct usb_hcd *hcd);
+#else
+static inline void xhci_rcar_start(struct usb_hcd *hcd)
+{
+}
+
+static inline int xhci_rcar_init_quirk(struct usb_hcd *hcd)
+{
+	return 0;
+}
+#endif
+#endif /* _XHCI_RCAR_H */