usb: ehci: Add Renesas RCar M3/H3 EHCI support

Add a USB controller driver for the EHCI block in R8A7795/R8A7796 SoC.
This is a stopgap measure until we have proper DT support, clock and
reset framework in place, at which point we can switch to ehci-generic.

Signed-off-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
Reviewed-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 9a67e43..b824eec 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -133,6 +133,14 @@
 	  This driver supports combination of Chipidea USB controller
 	  and Synapsys USB PHY in host mode only.
 
+config USB_EHCI_RCAR_GEN3
+	bool "Support for Renesas RCar M3/H3 EHCI USB controller"
+	depends on RCAR_GEN3
+	default y
+	---help---
+	  Enables support for the on-chip EHCI controller on Renesas
+	  R8A7795 and R8A7796 SoCs.
+
 config USB_EHCI_ZYNQ
 	bool "Support for Xilinx Zynq on-chip EHCI USB controller"
 	depends on ARCH_ZYNQ
diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
index bf354fe..4ece0a2 100644
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -51,6 +51,7 @@
 obj-$(CONFIG_USB_EHCI_VCT) += ehci-vct.o
 obj-$(CONFIG_USB_EHCI_VF) += ehci-vf.o
 obj-$(CONFIG_USB_EHCI_RMOBILE) += ehci-rmobile.o
+obj-$(CONFIG_USB_EHCI_RCAR_GEN3) += ehci-rcar_gen3.o
 obj-$(CONFIG_USB_EHCI_ZYNQ) += ehci-zynq.o
 
 # xhci
diff --git a/drivers/usb/host/ehci-rcar_gen3.c b/drivers/usb/host/ehci-rcar_gen3.c
new file mode 100644
index 0000000..525e7f3
--- /dev/null
+++ b/drivers/usb/host/ehci-rcar_gen3.c
@@ -0,0 +1,106 @@
+/*
+ * drivers/usb/host/ehci-rcar_gen3.
+ *	This file is EHCI HCD (Host Controller Driver) for USB.
+ *
+ * Copyright (C) 2015-2017 Renesas Electronics Corporation
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <wait_bit.h>
+#include <asm/io.h>
+#include <usb/ehci-ci.h>
+#include "ehci.h"
+
+#define RCAR_GEN3_USB_BASE(n)	(0xEE080000 + ((n) * 0x20000))
+
+#define EHCI_USBCMD		0x120
+
+#define CORE_SPD_RSM_TIMSET	0x30c
+#define CORE_OC_TIMSET		0x310
+
+/* Register offset */
+#define AHB_OFFSET		0x200
+
+#define BASE_HSUSB		0xE6590000
+#define REG_LPSTS		(BASE_HSUSB + 0x0102)	/* 16bit */
+#define SUSPM			0x4000
+#define SUSPM_NORMAL		BIT(14)
+#define REG_UGCTRL2		(BASE_HSUSB + 0x0184)	/* 32bit */
+#define USB0SEL			0x00000030
+#define USB0SEL_EHCI		0x00000010
+
+#define SMSTPCR7		0xE615014C
+#define SMSTPCR700		BIT(0)	/* EHCI3 */
+#define SMSTPCR701		BIT(1)	/* EHCI2 */
+#define SMSTPCR702		BIT(2)	/* EHCI1 */
+#define SMSTPCR703		BIT(3)	/* EHCI0 */
+#define SMSTPCR704		BIT(4)	/* HSUSB */
+
+#define AHB_PLL_RST		BIT(1)
+
+#define USBH_INTBEN		BIT(2)
+#define USBH_INTAEN		BIT(1)
+
+#define AHB_INT_ENABLE		0x200
+#define AHB_USBCTR		0x20c
+
+int ehci_hcd_stop(int index)
+{
+#if defined(CONFIG_R8A7795)
+	const u32 mask = SMSTPCR703 | SMSTPCR702 | SMSTPCR701 | SMSTPCR700;
+#else
+	const u32 mask = SMSTPCR703 | SMSTPCR702;
+#endif
+	const u32 base = RCAR_GEN3_USB_BASE(index);
+	int ret;
+
+	/* Reset EHCI */
+	setbits_le32((uintptr_t)(base + EHCI_USBCMD), CMD_RESET);
+	ret = wait_for_bit("ehci-rcar", (void *)(uintptr_t)base + EHCI_USBCMD,
+			   CMD_RESET, false, 10, true);
+	if (ret) {
+		printf("ehci-rcar: reset failed (index=%i, ret=%i).\n",
+		       index, ret);
+	}
+
+	setbits_le32(SMSTPCR7, BIT(3 - index));
+
+	if ((readl(SMSTPCR7) & mask) == mask)
+		setbits_le32(SMSTPCR7, SMSTPCR704);
+
+	return 0;
+}
+
+int ehci_hcd_init(int index, enum usb_init_type init,
+		  struct ehci_hccr **hccr, struct ehci_hcor **hcor)
+{
+	const void __iomem *base =
+		(void __iomem *)(uintptr_t)RCAR_GEN3_USB_BASE(index);
+	struct usb_ehci *ehci = (struct usb_ehci *)(uintptr_t)base;
+
+	clrbits_le32(SMSTPCR7, BIT(3 - index));
+	clrbits_le32(SMSTPCR7, SMSTPCR704);
+
+	*hccr = (struct ehci_hccr *)((uintptr_t)&ehci->caplength);
+	*hcor = (struct ehci_hcor *)((uintptr_t)*hccr +
+			HC_LENGTH(ehci_readl(&(*hccr)->cr_capbase)));
+
+	/* Enable interrupt */
+	setbits_le32(base + AHB_INT_ENABLE, USBH_INTBEN | USBH_INTAEN);
+	writel(0x014e029b, base + CORE_SPD_RSM_TIMSET);
+	writel(0x000209ab, base + CORE_OC_TIMSET);
+
+	/* Choice USB0SEL */
+	clrsetbits_le32(REG_UGCTRL2, USB0SEL, USB0SEL_EHCI);
+
+	/* Clock & Reset */
+	clrbits_le32(base + AHB_USBCTR, AHB_PLL_RST);
+
+	/* low power status */
+	clrsetbits_le16(REG_LPSTS, SUSPM, SUSPM_NORMAL);
+
+	return 0;
+}