Subject: [PATCH v2 4/5] xhci: mediatek: support MTK xHCI host controller

From: [email-masked] (John Crispin)
Date: Mon, 13 Jul 2015 16:52:20 +0200

Hi

there is a cross dependency between the modules. xhci-mtk.ko requires
xhci.ko to be loaded. however this will look for xhci_mtk_add_ep_quirk()
which is part of xhci-mtk. the modules will build but are not run time
loadable.

	John

On 08/07/2015 11:41, Chunfeng Yun wrote:
> 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 <[email-masked]>
> ---
>  drivers/usb/host/Kconfig     |   9 +
>  drivers/usb/host/Makefile    |   1 +
>  drivers/usb/host/xhci-mtk.c  | 814 +++++++++++++++++++++++++++++++++++++++++++
>  drivers/usb/host/xhci-mtk.h  | 108 ++++++
>  drivers/usb/host/xhci-ring.c |  35 +-
>  drivers/usb/host/xhci.c      |  19 +-
>  drivers/usb/host/xhci.h      |   1 +
>  7 files changed, 980 insertions(+), 7 deletions(-)
>  create mode 100644 drivers/usb/host/xhci-mtk.c
>  create mode 100644 drivers/usb/host/xhci-mtk.h
> 
> diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
> index 8afc3c1..2202c68 100644
> --- a/drivers/usb/host/Kconfig
> +++ b/drivers/usb/host/Kconfig
> @@ -34,6 +34,15 @@ config USB_XHCI_PCI
>  config USB_XHCI_PLATFORM
>  	tristate
>  
> +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
> diff --git a/drivers/usb/host/Makefile b/drivers/usb/host/Makefile
> index 754efaa..90c6eb2 100644
> --- a/drivers/usb/host/Makefile
> +++ b/drivers/usb/host/Makefile
> @@ -30,6 +30,7 @@ endif
>  
>  obj-$(CONFIG_USB_XHCI_PCI)	+= xhci-pci.o
>  obj-$(CONFIG_USB_XHCI_PLATFORM) += xhci-plat-hcd.o
> +obj-$(CONFIG_USB_XHCI_MTK)	+= xhci-mtk.o
>  
>  obj-$(CONFIG_USB_EHCI_HCD)	+= ehci-hcd.o
>  obj-$(CONFIG_USB_EHCI_PCI)	+= ehci-pci.o
> diff --git a/drivers/usb/host/xhci-mtk.c b/drivers/usb/host/xhci-mtk.c
> new file mode 100644
> index 0000000..45f0606
> --- /dev/null
> +++ b/drivers/usb/host/xhci-mtk.c
> @@ -0,0 +1,814 @@
> +/*
> + * Copyright (c) 2015 MediaTek Inc.
> + * Author:
> + *  Zhigang.Wei <[email-masked]>
> + *  Chunfeng.Yun <[email-masked]>
> + *
> + * 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/clk.h>
> +#include <linux/dma-mapping.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/usb/phy.h>
> +#include <linux/slab.h>
> +#include <linux/usb/xhci_pdriver.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "xhci.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)
> +
> +
> +struct xhci_hcd_mtk {
> +	struct device *dev;
> +	struct usb_hcd *hcd;
> +	struct mu3h_sch_bw_info *sch_array;
> +	struct regulator *vusb33;
> +	struct regulator *vbus;
> +	struct clk *sys_mac;	/* sys and mac clock */
> +};
> +
> +
> +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("%s:\n", __func__);
> +	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("%s: bus_bw_info\n", __func__);
> +	for (i = 0; i < XHCI_MTK_MAX_ESIT; i++)
> +		pr_debug("%d  ", sch_bw->bus_bw[i]);
> +
> +	pr_debug("\n");
> +}
> +
> +
> +static bool need_bw_sch(struct usb_host_endpoint *ep,
> +	enum usb_device_speed speed, int has_tt)
> +{
> +	/* only for periodic endpoints */
> +	if (usb_endpoint_xfer_control(&ep->desc)
> +		|| usb_endpoint_xfer_bulk(&ep->desc))
> +		return false;
> +	/*
> +	 * for LS & FS periodic 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 false;
> +
> +	return true;
> +}
> +
> +static int xhci_mtk_sch_init(struct xhci_hcd *xhci)
> +{
> +	struct usb_hcd *hcd = xhci_to_hcd(xhci);
> +	struct device *dev = hcd->self.controller;
> +	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
> +	struct mu3h_sch_bw_info *sch_array;
> +	int num_usb_bus;
> +	int i;
> +
> +	/* ss IN and OUT are separated */
> +	num_usb_bus = xhci->num_usb3_ports * 2 + xhci->num_usb2_ports;
> +
> +	sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), 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);
> +
> +	mtk->sch_array = sch_array;
> +
> +	return 0;
> +}
> +
> +
> +static void xhci_mtk_sch_exit(struct xhci_hcd *xhci)
> +{
> +	struct usb_hcd *hcd = xhci_to_hcd(xhci);
> +	struct device *dev = hcd->self.controller;
> +	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
> +
> +	kfree(mtk->sch_array);
> +}
> +
> +
> +int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
> +		struct usb_host_endpoint *ep)
> +{
> +	struct device *dev = hcd->self.controller;
> +	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
> +
> +	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 = mtk->sch_array;
> +
> +	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_NOIO);
> +	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;
> +}
> +EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);
> +
> +
> +void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
> +		struct usb_host_endpoint *ep)
> +{
> +	struct device *dev = hcd->self.controller;
> +	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
> +
> +	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 = mtk->sch_array;
> +
> +	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);
> +}
> +EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);
> +
> +
> +/*
> + * The TD size is the number of max packet sized packets 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;
> +}
> +EXPORT_SYMBOL_GPL(xhci_mtk_td_remainder_quirk);
> +
> +
> +static int xhci_mtk_setup(struct usb_hcd *hcd);
> +static const struct xhci_driver_overrides xhci_mtk_overrides __initconst = {
> +	.extra_priv_size = sizeof(struct xhci_hcd),
> +	.reset = xhci_mtk_setup,
> +};
> +
> +static struct hc_driver __read_mostly xhci_mtk_hc_driver;
> +
> +
> +static int xhci_mtk_ldos_enable(struct xhci_hcd_mtk *mtk)
> +{
> +	int ret;
> +
> +	ret = regulator_enable(mtk->vbus);
> +	if (ret) {
> +		dev_err(mtk->dev, "failed to enable vbus\n");
> +		return ret;
> +	}
> +
> +	ret = regulator_enable(mtk->vusb33);
> +	if (ret) {
> +		dev_err(mtk->dev, "failed to enable vusb33\n");
> +		regulator_disable(mtk->vbus);
> +		return ret;
> +	}
> +	return 0;
> +}
> +
> +static void xhci_mtk_ldos_disable(struct xhci_hcd_mtk *mtk)
> +{
> +	regulator_disable(mtk->vbus);
> +	regulator_disable(mtk->vusb33);
> +}
> +
> +static void xhci_mtk_quirks(struct device *dev, struct xhci_hcd *xhci)
> +{
> +	/*
> +	 * As of now platform drivers don't provide MSI support so we ensure
> +	 * here that the generic code does not try to make a pci_dev from our
> +	 * dev struct in order to setup MSI
> +	 */
> +	xhci->quirks |= XHCI_PLAT;
> +	xhci->quirks |= XHCI_MTK_HOST;
> +	/*
> +	 * MTK host controller gives a spurious successful event after a
> +	 * short transfer. Ignore it.
> +	 */
> +	xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
> +}
> +
> +/* called during probe() after chip reset completes */
> +static int xhci_mtk_setup(struct usb_hcd *hcd)
> +{
> +	struct xhci_hcd *xhci;
> +	int ret;
> +
> +	ret = xhci_gen_setup(hcd, xhci_mtk_quirks);
> +	if (ret)
> +		return ret;
> +
> +	if (!usb_hcd_is_primary_hcd(hcd))
> +		return 0;
> +
> +	xhci = hcd_to_xhci(hcd);
> +	ret = xhci_mtk_sch_init(xhci);
> +	if (ret) {
> +		kfree(xhci);
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +
> +static int xhci_mtk_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = pdev->dev.of_node;
> +	struct usb_xhci_pdata *pdata = dev_get_platdata(dev);
> +	struct xhci_hcd_mtk *mtk;
> +	const struct hc_driver *driver;
> +	struct xhci_hcd *xhci;
> +	struct resource *res;
> +	struct usb_hcd *hcd;
> +	int ret = -ENODEV;
> +	int irq;
> +
> +	if (usb_disabled())
> +		return -ENODEV;
> +
> +	driver = &xhci_mtk_hc_driver;
> +	mtk = devm_kzalloc(dev, sizeof(*mtk), GFP_KERNEL);
> +	if (!mtk)
> +		return -ENOMEM;
> +	mtk->dev = dev;
> +
> +	mtk->sys_mac = devm_clk_get(dev, "sys_mac");
> +	if (IS_ERR(mtk->sys_mac)) {
> +		dev_err(dev, "error to get sys_mac\n");
> +		ret = PTR_ERR(mtk->sys_mac);
> +		goto err;
> +	}
> +
> +	mtk->vbus = devm_regulator_get(dev, "reg-vbus");
> +	if (IS_ERR(mtk->vbus)) {
> +		dev_err(dev, "fail to get vbus\n");
> +		ret = PTR_ERR(mtk->vbus);
> +		goto err;
> +	}
> +
> +	mtk->vusb33 = devm_regulator_get(dev, "reg-vusb33");
> +	if (IS_ERR(mtk->vusb33)) {
> +		dev_err(dev, "fail to get vusb33\n");
> +		ret = PTR_ERR(mtk->vusb33);
> +		goto err;
> +	}
> +	pm_runtime_enable(dev);
> +	pm_runtime_get_sync(dev);
> +
> +	ret = xhci_mtk_ldos_enable(mtk);
> +	if (ret)
> +		goto disable_pm;
> +
> +	ret = clk_prepare_enable(mtk->sys_mac);
> +	if (ret)
> +		goto disable_ldos;
> +
> +	irq = platform_get_irq(pdev, 0);
> +	if (irq < 0)
> +		goto disable_clk;
> +
> +	/* Initialize dma_mask and coherent_dma_mask to 32-bits */
> +	ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
> +	if (ret)
> +		goto disable_clk;
> +
> +	if (!dev->dma_mask)
> +		dev->dma_mask = &dev->coherent_dma_mask;
> +	else
> +		dma_set_mask(dev, DMA_BIT_MASK(32));
> +
> +	hcd = usb_create_hcd(driver, dev, dev_name(dev));
> +	if (!hcd) {
> +		ret = -ENOMEM;
> +		goto disable_clk;
> +	}
> +
> +	/*
> +	 * USB 2.0 roothub is stored in the platform_device.
> +	 * Swap it with mtk HCD.
> +	 */
> +	mtk->hcd = platform_get_drvdata(pdev);
> +	platform_set_drvdata(pdev, mtk);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	hcd->regs = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(hcd->regs)) {
> +		ret = PTR_ERR(hcd->regs);
> +		goto put_usb2_hcd;
> +	}
> +	hcd->rsrc_start = res->start;
> +	hcd->rsrc_len = resource_size(res);
> +
> +	hcd->usb_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
> +	if (IS_ERR(hcd->usb_phy)) {
> +		ret = PTR_ERR(hcd->usb_phy);
> +		if (ret == -EPROBE_DEFER)
> +			goto put_usb2_hcd;
> +		hcd->usb_phy = NULL;
> +	} else {
> +		ret = usb_phy_init(hcd->usb_phy);
> +		if (ret)
> +			goto put_usb2_hcd;
> +	}
> +
> +	device_wakeup_enable(hcd->self.controller);
> +
> +	xhci = hcd_to_xhci(hcd);
> +	xhci->main_hcd = hcd;
> +	xhci->shared_hcd = usb_create_shared_hcd(driver, dev,
> +			dev_name(dev), hcd);
> +	if (!xhci->shared_hcd) {
> +		ret = -ENOMEM;
> +		goto disable_usb_phy;
> +	}
> +
> +	if ((node && of_property_read_bool(node, "usb3-lpm-capable")) ||
> +			(pdata && pdata->usb3_lpm_capable))
> +		xhci->quirks |= XHCI_LPM_SUPPORT;
> +
> +	if (HCC_MAX_PSA(xhci->hcc_params) >= 4)
> +		xhci->shared_hcd->can_do_streams = 1;
> +
> +	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
> +	if (ret)
> +		goto put_usb3_hcd;
> +
> +	ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
> +	if (ret)
> +		goto dealloc_usb2_hcd;
> +
> +	return 0;
> +
> +
> +dealloc_usb2_hcd:
> +	usb_remove_hcd(hcd);
> +
> +put_usb3_hcd:
> +	usb_put_hcd(xhci->shared_hcd);
> +
> +disable_usb_phy:
> +	usb_phy_shutdown(hcd->usb_phy);
> +
> +put_usb2_hcd:
> +	usb_put_hcd(hcd);
> +
> +disable_clk:
> +	clk_disable_unprepare(mtk->sys_mac);
> +
> +disable_ldos:
> +	xhci_mtk_ldos_disable(mtk);
> +
> +disable_pm:
> +	pm_runtime_put_sync(dev);
> +	pm_runtime_disable(dev);
> +
> +err:
> +	return ret;
> +}
> +
> +static int xhci_mtk_remove(struct platform_device *dev)
> +{
> +	struct xhci_hcd_mtk *mtk = platform_get_drvdata(dev);
> +	struct usb_hcd	*hcd = mtk->hcd;
> +	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
> +
> +	usb_remove_hcd(xhci->shared_hcd);
> +	usb_phy_shutdown(hcd->usb_phy);
> +
> +	usb_remove_hcd(hcd);
> +	usb_put_hcd(xhci->shared_hcd);
> +	usb_put_hcd(hcd);
> +	xhci_mtk_sch_exit(xhci);
> +	clk_disable_unprepare(mtk->sys_mac);
> +	xhci_mtk_ldos_disable(mtk);
> +	pm_runtime_put_sync(&dev->dev);
> +	pm_runtime_disable(&dev->dev);
> +
> +	return 0;
> +}
> +
> +#ifdef CONFIG_PM_SLEEP
> +static int xhci_mtk_suspend(struct device *dev)
> +{
> +	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
> +	struct usb_hcd	*hcd = mtk->hcd;
> +	int ret;
> +
> +	ret = usb_phy_set_suspend(hcd->usb_phy, 1);
> +	/* keep on power of mac to maintain register, and only close clock */
> +	clk_disable_unprepare(mtk->sys_mac);
> +	return ret;
> +}
> +
> +static int xhci_mtk_resume(struct device *dev)
> +{
> +	struct xhci_hcd_mtk *mtk = dev_get_drvdata(dev);
> +	struct usb_hcd	*hcd = mtk->hcd;
> +	int ret;
> +
> +	clk_prepare_enable(mtk->sys_mac);
> +	ret = usb_phy_set_suspend(hcd->usb_phy, 0);
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops xhci_mtk_pm_ops = {
> +	SET_SYSTEM_SLEEP_PM_OPS(xhci_mtk_suspend, xhci_mtk_resume)
> +};
> +#define DEV_PM_OPS	(&xhci_mtk_pm_ops)
> +#else
> +#define DEV_PM_OPS	NULL
> +#endif /* CONFIG_PM */
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id mtk_xhci_of_match[] = {
> +	{ .compatible = "mediatek,mt8173-xhci"},
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, mtk_xhci_of_match);
> +#endif
> +
> +static struct platform_driver mtk_xhci_driver = {
> +	.probe	= xhci_mtk_probe,
> +	.remove	= xhci_mtk_remove,
> +	.driver	= {
> +		.name = "xhci-mtk",
> +		.pm = DEV_PM_OPS,
> +		.of_match_table = of_match_ptr(mtk_xhci_of_match),
> +	},
> +};
> +
> +static int __init xhci_mtk_init(void)
> +{
> +	xhci_init_driver(&xhci_mtk_hc_driver, &xhci_mtk_overrides);
> +	return platform_driver_register(&mtk_xhci_driver);
> +}
> +module_init(xhci_mtk_init);
> +
> +static void __exit xhci_mtk_exit(void)
> +{
> +	platform_driver_unregister(&mtk_xhci_driver);
> +}
> +module_exit(xhci_mtk_exit);
> +
> +MODULE_DESCRIPTION("MediaTek xHCI Host Controller Driver");
> +MODULE_LICENSE("GPL v2");
> +
> diff --git a/drivers/usb/host/xhci-mtk.h b/drivers/usb/host/xhci-mtk.h
> new file mode 100644
> index 0000000..e0fdd19
> --- /dev/null
> +++ b/drivers/usb/host/xhci-mtk.h
> @@ -0,0 +1,108 @@
> +/*
> + * Copyright (c) 2015 MediaTek Inc.
> + * Author:
> + *  Zhigang.Wei <[email-masked]>
> + *  Chunfeng.Yun <[email-masked]>
> + *
> + * 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_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_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_ */
> diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
> index 94416ff..73997a0 100644
> --- 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
> @@ -3131,9 +3132,14 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
>  
>  		/* 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,
> @@ -3286,9 +3292,14 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
>  
>  		/* 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,
> @@ -3383,7 +3394,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
>  		field |= 0x1;
>  
>  	/* xHCI 1.0 6.4.1.2.1: Transfer Type field */
> -	if (xhci->hci_version == 0x100) {
> +	if ((xhci->hci_version == 0x100) || (xhci->quirks & XHCI_MTK_HOST)) {
>  		if (urb->transfer_buffer_length > 0) {
>  			if (setup->bRequestType & USB_DIR_IN)
>  				field |= TRB_TX_TYPE(TRB_DATA_IN);
> @@ -3407,8 +3418,14 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
>  		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;
> @@ -3632,8 +3649,14 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
>  
>  			/* 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,
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 7da0d60..209fc8a 100644
> --- 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"
> @@ -623,7 +624,11 @@ int xhci_run(struct usb_hcd *hcd)
>  			"// 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 */
> @@ -1688,6 +1693,9 @@ int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
>  
>  	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,
> @@ -1783,6 +1791,15 @@ int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
>  		return -ENOMEM;
>  	}
>  
> +	if (xhci->quirks & XHCI_MTK_HOST) {
> +		ret = xhci_mtk_add_ep_quirk(hcd, udev, ep);
> +		if (ret < 0) {
> +			xhci_free_or_cache_endpoint_ring(xhci,
> +				virt_dev, ep_index);
> +			return ret;
> +		}
> +	}
> +
>  	ctrl_ctx->add_flags |= cpu_to_le32(added_ctxs);
>  	new_add_flags = le32_to_cpu(ctrl_ctx->add_flags);
>  
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 31e46cc..d257ce3 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1567,6 +1567,7 @@ struct xhci_hcd {
>  /* 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 */
>