path: root/target/linux/mediatek/patches/0047-xhci-mediatek-support-MTK-xHCI-host-controller.patch

From e604b6c864f2e3b6fe0706c4bef886533d92f67a Mon Sep 17 00:00:00 2001
From: Chunfeng Yun <chunfeng.yun@mediatek.com>
Date: Wed, 27 May 2015 19:48:02 +0800
Subject: [PATCH 47/76] xhci: mediatek: support MTK xHCI host controller

MTK xhci host controller defines some extra SW scheduling
parameters for HW to minimize the scheduling effort for
synchronous and interrupt endpoints. The parameters are
put into reseved DWs of slot context and endpoint context.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
 drivers/usb/host/Kconfig     |    9 +
 drivers/usb/host/Makefile    |    3 +
 drivers/usb/host/xhci-mtk.c  |  470 ++++++++++++++++++++++++++++++++++++++++++
 drivers/usb/host/xhci-mtk.h  |  119 +++++++++++
 drivers/usb/host/xhci-plat.c |   22 +-
 drivers/usb/host/xhci-ring.c |   35 +++-
 drivers/usb/host/xhci.c      |   16 +-
 drivers/usb/host/xhci.h      |    1 +
 8 files changed, 667 insertions(+), 8 deletions(-)
 create mode 100644 drivers/usb/host/xhci-mtk.c
 create mode 100644 drivers/usb/host/xhci-mtk.h

--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -41,6 +41,15 @@
 
 	  If unsure, say N.
 
+config USB_XHCI_MTK
+	tristate "xHCI support for Mediatek MT65xx"
+	select USB_XHCI_PLATFORM
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	---help---
+	  Say 'Y' to enable the support for the xHCI host controller
+	  found in Mediatek MT65xx SoCs.
+	  If unsure, say N.
+
 config USB_XHCI_MVEBU
 	tristate "xHCI support for Marvell Armada 375/38x"
 	select USB_XHCI_PLATFORM
--- a/drivers/usb/host/Makefile
+++ b/drivers/usb/host/Makefile
@@ -15,6 +15,9 @@
 xhci-hcd-y += xhci-trace.o
 
 xhci-plat-hcd-y := xhci-plat.o
+ifneq ($(CONFIG_USB_XHCI_MTK), )
+	xhci-plat-hcd-y		+= xhci-mtk.o
+endif
 ifneq ($(CONFIG_USB_XHCI_MVEBU), )
 	xhci-plat-hcd-y		+= xhci-mvebu.o
 endif
--- /dev/null
+++ b/drivers/usb/host/xhci-mtk.c
@@ -0,0 +1,470 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author:
+ *  Zhigang.Wei <zhigang.wei@mediatek.com>
+ *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include "xhci-mtk.h"
+
+
+#define SS_BW_BOUNDARY	51000
+/* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
+#define HS_BW_BOUNDARY	6144
+/* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
+#define FS_PAYLOAD_MAX 188
+
+/* mtk scheduler bitmasks */
+#define EP_BPKTS(p)	((p) & 0x3f)
+#define EP_BCSCOUNT(p)	(((p) & 0x7) << 8)
+#define EP_BBM(p)	((p) << 11)
+#define EP_BOFFSET(p)	((p) & 0x3fff)
+#define EP_BREPEAT(p)	(((p) & 0x7fff) << 16)
+
+static int is_fs_or_ls(enum usb_device_speed speed)
+{
+	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
+}
+
+static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
+	struct usb_host_endpoint *ep)
+{
+	int bw_index;
+	int port_id;
+	struct xhci_virt_device *virt_dev;
+
+	virt_dev = xhci->devs[udev->slot_id];
+	port_id = virt_dev->real_port;
+
+	if (udev->speed == USB_SPEED_SUPER) {
+		if (usb_endpoint_dir_out(&ep->desc))
+			bw_index = (port_id - 1) * 2;
+		else
+			bw_index = (port_id - 1) * 2 + 1;
+	} else {
+		bw_index = port_id + xhci->num_usb3_ports - 1;
+	}
+
+	return bw_index;
+}
+
+
+static void setup_sch_info(struct usb_device *udev,
+		struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
+{
+	u32 ep_type;
+	u32 ep_interval;
+	u32 max_packet_size;
+	u32 max_burst;
+	u32 mult;
+	u32 esit_pkts;
+
+	ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
+	ep_interval = CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
+	max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
+	max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
+	mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
+	pr_debug("%s: max_burst = %d, mult = %d\n", __func__, max_burst, mult);
+
+	sch_ep->ep_type = ep_type;
+	sch_ep->max_packet_size = max_packet_size;
+	sch_ep->esit = 1 << ep_interval;
+	sch_ep->offset = 0;
+	sch_ep->burst_mode = 0;
+
+	if (udev->speed == USB_SPEED_HIGH) {
+		sch_ep->cs_count = 0;
+		/*
+		 * usb_20 spec section5.9
+		 * a single microframe is enough for HS synchromous endpoints
+		 * in a interval
+		 */
+		sch_ep->num_budget_microframes = 1;
+		sch_ep->repeat = 0;
+		/*
+		 * xHCI spec section6.2.3.4
+		 * @max_busrt is the number of additional transactions opportunities
+		 * per microframe
+		 */
+		sch_ep->pkts = max_burst + 1;
+		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
+	} else if (udev->speed == USB_SPEED_SUPER) {
+		/* usb3_r1 spec section4.4.7 & 4.4.8 */
+		sch_ep->cs_count = 0;
+		esit_pkts = (mult + 1) * (max_burst + 1);
+		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
+			sch_ep->pkts = esit_pkts;
+			sch_ep->num_budget_microframes = 1;
+			sch_ep->repeat = 0;
+		}
+
+		if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
+			if (esit_pkts <= sch_ep->esit)
+				sch_ep->pkts = 1;
+			else
+				sch_ep->pkts = roundup_pow_of_two(esit_pkts)
+					/ sch_ep->esit;
+
+			sch_ep->num_budget_microframes =
+				DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
+
+			if (sch_ep->num_budget_microframes > 1)
+				sch_ep->repeat = 1;
+			else
+				sch_ep->repeat = 0;
+		}
+		sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
+	} else if (is_fs_or_ls(udev->speed)) {
+		/*
+		 * usb_20 spec section11.18.4
+		 * assume worst cases
+		 */
+		sch_ep->repeat = 0;
+		sch_ep->pkts = 1; /* at most one packet for each microframe */
+		if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
+			sch_ep->cs_count = 3; /* at most need 3 CS*/
+			/* one for SS and one for budgeted transaction */
+			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
+			sch_ep->bw_cost_per_microframe = max_packet_size;
+		}
+		if (ep_type == ISOC_OUT_EP) {
+			/* must never schedule a cs ISOC OUT ep */
+			sch_ep->cs_count = 0;
+			/*
+			 * the best case FS budget assumes that 188 FS bytes
+			 * occur in each microframe
+			 */
+			sch_ep->num_budget_microframes = DIV_ROUND_UP(
+				sch_ep->max_packet_size, FS_PAYLOAD_MAX);
+			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
+		}
+		if (ep_type == ISOC_IN_EP) {
+			/* at most need additional two CS. */
+			sch_ep->cs_count = DIV_ROUND_UP(
+				sch_ep->max_packet_size, FS_PAYLOAD_MAX) + 2;
+			sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
+			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
+		}
+	}
+}
+
+/* Get maximum bandwidth when we schedule at offset slot. */
+static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
+	struct mu3h_sch_ep_info *sch_ep, u32 offset)
+{
+	u32 num_esit;
+	u32 max_bw = 0;
+	int i;
+	int j;
+
+	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+	for (i = 0; i < num_esit; i++) {
+		u32 base = offset + i * sch_ep->esit;
+
+		for (j = 0; j < sch_ep->num_budget_microframes; j++) {
+			if (sch_bw->bus_bw[base + j] > max_bw)
+				max_bw = sch_bw->bus_bw[base + j];
+		}
+	}
+	return max_bw;
+}
+
+static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
+	struct mu3h_sch_ep_info *sch_ep, int bw_cost)
+{
+	u32 num_esit;
+	u32 base;
+	int i;
+	int j;
+
+	num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
+	for (i = 0; i < num_esit; i++) {
+		base = sch_ep->offset + i * sch_ep->esit;
+		for (j = 0; j < sch_ep->num_budget_microframes; j++)
+			sch_bw->bus_bw[base + j] += bw_cost;
+	}
+
+}
+
+static void debug_sch_ep(struct mu3h_sch_ep_info *sch_ep)
+{
+	pr_debug("sch_ep->ep_type = %d\n", sch_ep->ep_type);
+	pr_debug("sch_ep->max_packet_size = %d\n", sch_ep->max_packet_size);
+	pr_debug("sch_ep->esit = %d\n", sch_ep->esit);
+	pr_debug("sch_ep->num_budget_microframes = %d\n",
+			sch_ep->num_budget_microframes);
+	pr_debug("sch_ep->bw_cost_per_microframe = %d\n",
+			sch_ep->bw_cost_per_microframe);
+	pr_debug("sch_ep->ep = %p\n", sch_ep->ep);
+	pr_debug("sch_ep->offset = %d\n", sch_ep->offset);
+	pr_debug("sch_ep->repeat = %d\n", sch_ep->repeat);
+	pr_debug("sch_ep->pkts = %d\n", sch_ep->pkts);
+	pr_debug("sch_ep->cs_count = %d\n", sch_ep->cs_count);
+}
+
+static int check_sch_bw(struct usb_device *udev,
+	struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
+{
+	u32 offset;
+	u32 esit;
+	u32 num_budget_microframes;
+	u32 min_bw;
+	u32 min_index;
+	u32 worst_bw;
+	u32 bw_boundary;
+
+	if (sch_ep->esit > XHCI_MTK_MAX_ESIT)
+		sch_ep->esit = XHCI_MTK_MAX_ESIT;
+
+	esit = sch_ep->esit;
+	num_budget_microframes = sch_ep->num_budget_microframes;
+
+	/*
+	 * Search through all possible schedule microframes.
+	 * and find a microframe where its worst bandwidth is minimum.
+	 */
+	min_bw = ~0;
+	min_index = 0;
+	for (offset = 0; offset < esit; offset++) {
+		if ((offset + num_budget_microframes) > sch_ep->esit)
+			break;
+		/*
+		 * usb_20 spec section11.18:
+		 * must never schedule Start-Split in Y6
+		 */
+		if (is_fs_or_ls(udev->speed) && (offset % 8 == 6))
+			continue;
+
+		worst_bw = get_max_bw(sch_bw, sch_ep, offset);
+		if (min_bw > worst_bw) {
+			min_bw = worst_bw;
+			min_index = offset;
+		}
+		if (min_bw == 0)
+			break;
+	}
+	sch_ep->offset = min_index;
+
+	debug_sch_ep(sch_ep);
+
+	bw_boundary = (udev->speed == USB_SPEED_SUPER)
+				? SS_BW_BOUNDARY : HS_BW_BOUNDARY;
+
+	/* check bandwidth */
+	if (min_bw + sch_ep->bw_cost_per_microframe > bw_boundary)
+		return -1;
+
+	/* update bus bandwidth info */
+	update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);
+
+	return 0;
+}
+
+static void debug_sch_bw(struct mu3h_sch_bw_info *sch_bw)
+{
+	int i;
+
+	pr_debug("xhci_mtk_scheduler :bus_bw_info\n");
+	for (i = 0; i < XHCI_MTK_MAX_ESIT; i++)
+		pr_debug("%d  ", sch_bw->bus_bw[i]);
+
+	pr_debug("\n");
+}
+
+
+static int need_bw_sch(struct usb_host_endpoint *ep,
+	enum usb_device_speed speed, int has_tt)
+{
+	/* only for synchronous endpoints */
+	if (usb_endpoint_xfer_control(&ep->desc)
+		|| usb_endpoint_xfer_bulk(&ep->desc))
+		return 0;
+	/*
+	 * for LS & FS synchronous endpoints which its device don't attach
+	 * to TT are also ignored, root-hub will schedule them directly
+	 */
+	if (is_fs_or_ls(speed) && !has_tt)
+		return 0;
+
+	return 1;
+}
+
+int xhci_mtk_init_quirk(struct xhci_hcd *xhci)
+{
+	struct usb_hcd *hcd = xhci_to_hcd(xhci);
+	struct device *dev = hcd->self.controller;
+	struct mu3h_sch_bw_info *sch_array;
+	size_t array_size;
+	int num_usb_bus;
+	int i;
+
+	/* ss IN and OUT are separated */
+	num_usb_bus = xhci->num_usb3_ports * 2 + xhci->num_usb2_ports;
+	array_size = sizeof(*sch_array) * num_usb_bus;
+
+	sch_array = kzalloc(array_size, GFP_KERNEL);
+	if (sch_array == NULL)
+		return -ENOMEM;
+
+	for (i = 0; i < num_usb_bus; i++)
+		INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
+
+	dev->platform_data = sch_array;
+	xhci->quirks |= XHCI_MTK_HOST;
+	/*
+	 * MTK host controller gives a spurious successful event after a
+	 * short transfer. Ignore it.
+	 */
+	xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
+
+	return 0;
+}
+
+
+void xhci_mtk_exit_quirk(struct xhci_hcd *xhci)
+{
+	struct usb_hcd *hcd = xhci_to_hcd(xhci);
+	struct mu3h_sch_bw_info *sch_array;
+
+	sch_array = dev_get_platdata(hcd->self.controller);
+	kfree(sch_array);
+}
+
+
+int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep)
+{
+	int ret = 0;
+	int port_id;
+	int bw_index;
+	struct xhci_hcd *xhci;
+	unsigned int ep_index;
+	struct xhci_ep_ctx *ep_ctx;
+	struct xhci_slot_ctx *slot_ctx;
+	struct xhci_virt_device *virt_dev;
+	struct mu3h_sch_bw_info *sch_bw;
+	struct mu3h_sch_ep_info *sch_ep;
+	struct mu3h_sch_bw_info *sch_array;
+
+	xhci = hcd_to_xhci(hcd);
+	virt_dev = xhci->devs[udev->slot_id];
+	ep_index = xhci_get_endpoint_index(&ep->desc);
+	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
+	sch_array = dev_get_platdata(hcd->self.controller);
+
+	port_id = virt_dev->real_port;
+	xhci_dbg(xhci, "%s() xfer_type: %d, speed:%d, ep:%p\n", __func__,
+		usb_endpoint_type(&ep->desc), udev->speed, ep);
+
+	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
+		return 0;
+
+	bw_index = get_bw_index(xhci, udev, ep);
+	sch_bw = &sch_array[bw_index];
+
+	sch_ep = kzalloc(sizeof(struct mu3h_sch_ep_info), GFP_KERNEL);
+	if (!sch_ep)
+		return -ENOMEM;
+
+	setup_sch_info(udev, ep_ctx, sch_ep);
+
+	ret = check_sch_bw(udev, sch_bw, sch_ep);
+	if (ret) {
+		xhci_err(xhci, "Not enough bandwidth!\n");
+		kfree(sch_ep);
+		return -ENOSPC;
+	}
+
+	list_add_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);
+	sch_ep->ep = ep;
+
+	ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(sch_ep->pkts)
+		| EP_BCSCOUNT(sch_ep->cs_count) | EP_BBM(sch_ep->burst_mode));
+	ep_ctx->reserved[1] |= cpu_to_le32(EP_BOFFSET(sch_ep->offset)
+		| EP_BREPEAT(sch_ep->repeat));
+
+	debug_sch_bw(sch_bw);
+	return 0;
+}
+
+void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep)
+{
+	int bw_index;
+	struct xhci_hcd *xhci;
+	struct xhci_slot_ctx *slot_ctx;
+	struct xhci_virt_device *virt_dev;
+	struct mu3h_sch_bw_info *sch_array;
+	struct mu3h_sch_bw_info *sch_bw;
+	struct mu3h_sch_ep_info *sch_ep;
+
+	xhci = hcd_to_xhci(hcd);
+	virt_dev = xhci->devs[udev->slot_id];
+	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+	sch_array = dev_get_platdata(hcd->self.controller);
+
+	xhci_dbg(xhci, "%s() xfer_type: %d, speed:%d, ep:%p\n", __func__,
+		usb_endpoint_type(&ep->desc), udev->speed, ep);
+
+	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
+		return;
+
+	bw_index = get_bw_index(xhci, udev, ep);
+	sch_bw = &sch_array[bw_index];
+
+	list_for_each_entry(sch_ep, &sch_bw->bw_ep_list, endpoint) {
+		if (sch_ep->ep == ep) {
+			update_bus_bw(sch_bw, sch_ep,
+				-sch_ep->bw_cost_per_microframe);
+			list_del(&sch_ep->endpoint);
+			kfree(sch_ep);
+			break;
+		}
+	}
+	debug_sch_bw(sch_bw);
+}
+
+
+/*
+ * The TD size is the number of bytes remaining in the TD (including this TRB),
+ * right shifted by 10.
+ * It must fit in bits 21:17, so it can't be bigger than 31.
+ */
+u32 xhci_mtk_td_remainder_quirk(unsigned int td_running_total,
+	unsigned trb_buffer_length, struct urb *urb)
+{
+	u32 max = 31;
+	int remainder, td_packet_count, packet_transferred;
+	unsigned int td_transfer_size = urb->transfer_buffer_length;
+	unsigned int maxp;
+
+	maxp = GET_MAX_PACKET(usb_endpoint_maxp(&urb->ep->desc));
+
+	/* 0 for the last TRB */
+	if (td_running_total + trb_buffer_length == td_transfer_size)
+		return 0;
+
+	packet_transferred = td_running_total / maxp;
+	td_packet_count = DIV_ROUND_UP(td_transfer_size, maxp);
+	remainder = td_packet_count - packet_transferred;
+
+	if (remainder > max)
+		return max << 17;
+	else
+		return remainder << 17;
+}
+
+
--- /dev/null
+++ b/drivers/usb/host/xhci-mtk.h
@@ -0,0 +1,119 @@
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ * Author:
+ *  Zhigang.Wun <zhigang.wei@mediatek.com>
+ *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _XHCI_MTK_H_
+#define _XHCI_MTK_H_
+
+#include "xhci.h"
+
+/**
+ * To simplify scheduler algorithm, set a upper limit for ESIT,
+ * if a synchromous ep's ESIT is larger than @XHCI_MTK_MAX_ESIT,
+ * round down to the limit value, that means allocating more
+ * bandwidth to it.
+ */
+#define XHCI_MTK_MAX_ESIT	64
+
+/**
+ * struct mu3h_sch_bw_info
+ * @bus_bw: array to keep track of bandwidth already used at each uframes
+ * @bw_ep_list: eps in the bandwidth domain
+ *
+ * treat a HS root port as a bandwidth domain, but treat a SS root port as
+ * two bandwidth domains, one for IN eps and another for OUT eps.
+ */
+struct mu3h_sch_bw_info {
+	u32 bus_bw[XHCI_MTK_MAX_ESIT];
+	struct list_head bw_ep_list;
+};
+
+/**
+ * struct mu3h_sch_ep_info
+ * @esit: unit is 125us, equal to 2 << Interval field in ep-context
+ * @num_budget_microframes: number of continuous uframes
+ *		(@repeat==1) scheduled within the interval
+ * @ep: address of usb_host_endpoint
+ * @offset: which uframe of the interval that transfer should be
+ *		scheduled first time within the interval
+ * @repeat: the time gap between two uframes that transfers are
+ *		scheduled within a interval. in the simple algorithm, only
+ *		assign 0 or 1 to it; 0 means using only one uframe in a
+ *		interval, and1 means using @num_budget_microframes
+ *		continuous uframes
+ * @pkts: number of packets to be transferred in the scheduled uframes
+ * @cs_count: number of CS that host will trigger
+ */
+struct mu3h_sch_ep_info {
+	u32 ep_type;
+	u32 max_packet_size;
+	u32 esit;
+	u32 num_budget_microframes;
+	u32 bw_cost_per_microframe;
+	void *ep;
+	struct list_head endpoint;
+
+	/* mtk xhci scheduling info */
+	u32 offset;
+	u32 repeat;
+	u32 pkts;
+	u32 cs_count;
+	u32 burst_mode;
+};
+
+
+#if IS_ENABLED(CONFIG_USB_XHCI_MTK)
+
+int xhci_mtk_init_quirk(struct xhci_hcd *xhci);
+void xhci_mtk_exit_quirk(struct xhci_hcd *xhci);
+int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep);
+void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
+		struct usb_host_endpoint *ep);
+u32 xhci_mtk_td_remainder_quirk(unsigned int td_running_total,
+	unsigned trb_buffer_length, struct urb *urb);
+
+#else
+static inline int xhci_mtk_init_quirk(struct xhci_hcd *xhci)
+{
+	return 0;
+}
+
+static inline void xhci_mtk_exit_quirk(struct xhci_hcd *xhci)
+{
+}
+
+static inline int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd,
+	struct usb_device *udev, struct usb_host_endpoint *ep)
+{
+	return 0;
+}
+
+static inline void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd,
+	struct usb_device *udev, struct usb_host_endpoint *ep)
+{
+	return 0;
+}
+
+static inline u32 xhci_mtk_td_remainder_quirk(unsigned int td_running_total,
+	unsigned trb_buffer_length, struct urb *urb)
+{
+	return 0;
+}
+
+#endif
+
+#endif		/* _XHCI_MTK_H_ */
--- a/drivers/usb/host/xhci-plat.c
+++ b/drivers/usb/host/xhci-plat.c
@@ -23,6 +23,7 @@
 #include "xhci.h"
 #include "xhci-mvebu.h"
 #include "xhci-rcar.h"
+#include "xhci-mtk.h"
 
 static struct hc_driver __read_mostly xhci_plat_hc_driver;
 
@@ -49,7 +50,23 @@
 			return ret;
 	}
 
-	return xhci_gen_setup(hcd, xhci_plat_quirks);
+	ret = xhci_gen_setup(hcd, xhci_plat_quirks);
+	if (ret)
+		return ret;
+
+	if (of_device_is_compatible(of_node, "mediatek,mt8173-xhci")) {
+		struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+
+		if (!usb_hcd_is_primary_hcd(hcd))
+			return 0;
+		ret = xhci_mtk_init_quirk(xhci);
+		if (ret) {
+			kfree(xhci);
+			return ret;
+		}
+	}
+
+	return ret;
 }
 
 static int xhci_plat_start(struct usb_hcd *hcd)
@@ -207,6 +224,8 @@
 	if (!IS_ERR(clk))
 		clk_disable_unprepare(clk);
 	usb_put_hcd(hcd);
+	if (xhci->quirks & XHCI_MTK_HOST)
+		xhci_mtk_exit_quirk(xhci);
 	kfree(xhci);
 
 	return 0;
@@ -253,6 +272,7 @@
 	{ .compatible = "marvell,armada-380-xhci"},
 	{ .compatible = "renesas,xhci-r8a7790"},
 	{ .compatible = "renesas,xhci-r8a7791"},
+	{ .compatible = "mediatek,mt8173-xhci"},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, usb_xhci_of_match);
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -68,6 +68,7 @@
 #include <linux/slab.h>
 #include "xhci.h"
 #include "xhci-trace.h"
+#include "xhci-mtk.h"
 
 /*
  * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
@@ -3163,9 +3164,14 @@
 
 		/* Set the TRB length, TD size, and interrupter fields. */
 		if (xhci->hci_version < 0x100) {
-			remainder = xhci_td_remainder(
+			if (xhci->quirks & XHCI_MTK_HOST) {
+				remainder = xhci_mtk_td_remainder_quirk(
+					running_total, trb_buff_len, urb);
+			} else {
+				remainder = xhci_td_remainder(
 					urb->transfer_buffer_length -
 					running_total);
+			}
 		} else {
 			remainder = xhci_v1_0_td_remainder(running_total,
 					trb_buff_len, total_packet_count, urb,
@@ -3336,9 +3342,14 @@
 
 		/* Set the TRB length, TD size, and interrupter fields. */
 		if (xhci->hci_version < 0x100) {
-			remainder = xhci_td_remainder(
+			if (xhci->quirks & XHCI_MTK_HOST) {
+				remainder = xhci_mtk_td_remainder_quirk(
+					running_total, trb_buff_len, urb);
+			} else {
+				remainder = xhci_td_remainder(
 					urb->transfer_buffer_length -
 					running_total);
+			}
 		} else {
 			remainder = xhci_v1_0_td_remainder(running_total,
 					trb_buff_len, total_packet_count, urb,
@@ -3457,8 +3468,14 @@
 		field = TRB_TYPE(TRB_DATA);
 
 	length_field = TRB_LEN(urb->transfer_buffer_length) |
-		xhci_td_remainder(urb->transfer_buffer_length) |
 		TRB_INTR_TARGET(0);
+
+	if (xhci->quirks & XHCI_MTK_HOST)
+		length_field |= xhci_mtk_td_remainder_quirk(0,
+				urb->transfer_buffer_length, urb);
+	else
+		length_field |= xhci_td_remainder(urb->transfer_buffer_length);
+
 	if (urb->transfer_buffer_length > 0) {
 		if (setup->bRequestType & USB_DIR_IN)
 			field |= TRB_DIR_IN;
@@ -3682,8 +3699,14 @@
 
 			/* Set the TRB length, TD size, & interrupter fields. */
 			if (xhci->hci_version < 0x100) {
-				remainder = xhci_td_remainder(
-						td_len - running_total);
+				if (xhci->quirks & XHCI_MTK_HOST) {
+					remainder = xhci_mtk_td_remainder_quirk(
+						running_total, trb_buff_len,
+						urb);
+				} else {
+					remainder = xhci_td_remainder(
+							td_len - running_total);
+				}
 			} else {
 				remainder = xhci_v1_0_td_remainder(
 						running_total, trb_buff_len,
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -31,6 +31,7 @@
 
 #include "xhci.h"
 #include "xhci-trace.h"
+#include "xhci-mtk.h"
 
 #define DRIVER_AUTHOR "Sarah Sharp"
 #define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver"
@@ -624,7 +625,11 @@
 			"// Set the interrupt modulation register");
 	temp = readl(&xhci->ir_set->irq_control);
 	temp &= ~ER_IRQ_INTERVAL_MASK;
-	temp |= (u32) 160;
+	/*
+	 * the increment interval is 8 times as much as that defined
+	 * in xHCI spec on MTK's controller
+	 */
+	temp |= (u32) ((xhci->quirks & XHCI_MTK_HOST) ? 20 : 160);
 	writel(temp, &xhci->ir_set->irq_control);
 
 	/* Set the HCD state before we enable the irqs */
@@ -1698,6 +1703,9 @@
 
 	xhci_endpoint_zero(xhci, xhci->devs[udev->slot_id], ep);
 
+	if (xhci->quirks & XHCI_MTK_HOST)
+		xhci_mtk_drop_ep_quirk(hcd, udev, ep);
+
 	xhci_dbg(xhci, "drop ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x\n",
 			(unsigned int) ep->desc.bEndpointAddress,
 			udev->slot_id,
@@ -1793,6 +1801,12 @@
 		return -ENOMEM;
 	}
 
+	if (xhci->quirks & XHCI_MTK_HOST) {
+		ret = xhci_mtk_add_ep_quirk(hcd, udev, ep);
+		if (ret < 0)
+			return ret;
+	}
+
 	ctrl_ctx->add_flags |= cpu_to_le32(added_ctxs);
 	new_add_flags = le32_to_cpu(ctrl_ctx->add_flags);
 
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1568,6 +1568,7 @@
 /* For controllers with a broken beyond repair streams implementation */
 #define XHCI_BROKEN_STREAMS	(1 << 19)
 #define XHCI_PME_STUCK_QUIRK	(1 << 20)
+#define XHCI_MTK_HOST		(1 << 21)
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
 	/* There are two roothubs to keep track of bus suspend info for */