drivers/usb/host/xhci-mtk-sch.c - arm/linux - Git at Google

 /*
  * 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/module.h>
 #include <linux/slab.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)

 static int is_fs_or_ls(enum usb_device_speed speed)
 {
 	return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
 }

 /*
 * get the index of bandwidth domains array which @ep belongs to.
 *
 * the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
 * each HS root port is treated as a single bandwidth domain,
 * but each SS root port is treated as two bandwidth domains, one for IN eps,
 * one for OUT eps.
 * @real_port value is defined as follow according to xHCI spec:
 * 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
 * so the bandwidth domain array is organized as follow for simplification:
 * SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
 */
 static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
 	struct usb_host_endpoint *ep)
 {
 	struct xhci_virt_device *virt_dev;
 	int bw_index;

 	virt_dev = xhci->devs[udev->slot_id];

 	if (udev->speed == USB_SPEED_SUPER) {
 		if (usb_endpoint_dir_out(&ep->desc))
 			bw_index = (virt_dev->real_port - 1) * 2;
 		else
 			bw_index = (virt_dev->real_port - 1) * 2 + 1;
 	} else {
 		/* add one more for each SS port */
 		bw_index = virt_dev->real_port + 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));

 	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_burst 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) {

 			/*
 			 * the best case FS budget assumes that 188 FS bytes
 			 * occur in each microframe
 			 */
 			sch_ep->num_budget_microframes = DIV_ROUND_UP(
 				max_packet_size, FS_PAYLOAD_MAX);
 			sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
 			sch_ep->cs_count = sch_ep->num_budget_microframes;
 		}
 		if (ep_type == ISOC_IN_EP) {
 			/* at most need additional two CS. */
 			sch_ep->cs_count = DIV_ROUND_UP(
 				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 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;

 	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 -ERANGE;

 	/* update bus bandwidth info */
 	update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);

 	return 0;
 }

 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 is not behind
 	 * a TT are also ignored, root-hub will schedule them directly,
 	 * but need set @bpkts field of endpoint context to 1.
 	 */
 	if (is_fs_or_ls(speed) && !has_tt)
 		return false;

 	return true;
 }

 int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
 {
 	struct mu3h_sch_bw_info *sch_array;
 	int num_usb_bus;
 	int i;

 	/* ss IN and OUT are separated */
 	num_usb_bus = mtk->num_u3_ports * 2 + mtk->num_u2_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;
 }
 EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);

 void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
 {
 	kfree(mtk->sch_array);
 }
 EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);

 int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
 		struct usb_host_endpoint *ep)
 {
 	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
 	struct xhci_hcd *xhci;
 	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;
 	unsigned int ep_index;
 	int bw_index;
 	int ret = 0;

 	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;

 	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
 		__func__, usb_endpoint_type(&ep->desc), udev->speed,
 		usb_endpoint_maxp(&ep->desc),
 		usb_endpoint_dir_in(&ep->desc), ep);

 	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
 		/*
 		 * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
 		 * device does not connected through an external HS hub
 		 */
 		if (usb_endpoint_xfer_int(&ep->desc)
 			|| usb_endpoint_xfer_isoc(&ep->desc))
 			ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(1));

 		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));

 	xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
 			sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
 			sch_ep->offset, sch_ep->repeat);

 	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 xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
 	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;
 	int bw_index;

 	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() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
 		__func__, usb_endpoint_type(&ep->desc), udev->speed,
 		usb_endpoint_maxp(&ep->desc),
 		usb_endpoint_dir_in(&ep->desc), 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;
 		}
 	}
 }
 EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);
	/*
	* 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/module.h>
	#include <linux/slab.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)

	static int is_fs_or_ls(enum usb_device_speed speed)
	{
	return speed == USB_SPEED_FULL \|\| speed == USB_SPEED_LOW;
	}

	/*
	* get the index of bandwidth domains array which @ep belongs to.
	*
	* the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
	* each HS root port is treated as a single bandwidth domain,
	* but each SS root port is treated as two bandwidth domains, one for IN eps,
	* one for OUT eps.
	* @real_port value is defined as follow according to xHCI spec:
	* 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
	* so the bandwidth domain array is organized as follow for simplification:
	* SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
	*/
	static int get_bw_index(struct xhci_hcd xhci, struct usb_device udev,
	struct usb_host_endpoint *ep)
	{
	struct xhci_virt_device *virt_dev;
	int bw_index;

	virt_dev = xhci->devs[udev->slot_id];

	if (udev->speed == USB_SPEED_SUPER) {
	if (usb_endpoint_dir_out(&ep->desc))
	bw_index = (virt_dev->real_port - 1) * 2;
	else
	bw_index = (virt_dev->real_port - 1) * 2 + 1;
	} else {
	/* add one more for each SS port */
	bw_index = virt_dev->real_port + 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));

	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_burst 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) {

	/*
	* the best case FS budget assumes that 188 FS bytes
	* occur in each microframe
	*/
	sch_ep->num_budget_microframes = DIV_ROUND_UP(
	max_packet_size, FS_PAYLOAD_MAX);
	sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
	sch_ep->cs_count = sch_ep->num_budget_microframes;
	}
	if (ep_type == ISOC_IN_EP) {
	/* at most need additional two CS. */
	sch_ep->cs_count = DIV_ROUND_UP(
	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 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;

	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 -ERANGE;

	/* update bus bandwidth info */
	update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);

	return 0;
	}

	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 is not behind
	* a TT are also ignored, root-hub will schedule them directly,
	* but need set @bpkts field of endpoint context to 1.
	*/
	if (is_fs_or_ls(speed) && !has_tt)
	return false;

	return true;
	}

	int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
	{
	struct mu3h_sch_bw_info *sch_array;
	int num_usb_bus;
	int i;

	/* ss IN and OUT are separated */
	num_usb_bus = mtk->num_u3_ports * 2 + mtk->num_u2_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;
	}
	EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);

	void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
	{
	kfree(mtk->sch_array);
	}
	EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);

	int xhci_mtk_add_ep_quirk(struct usb_hcd hcd, struct usb_device udev,
	struct usb_host_endpoint *ep)
	{
	struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
	struct xhci_hcd *xhci;
	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;
	unsigned int ep_index;
	int bw_index;
	int ret = 0;

	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;

	xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
	__func__, usb_endpoint_type(&ep->desc), udev->speed,
	usb_endpoint_maxp(&ep->desc),
	usb_endpoint_dir_in(&ep->desc), ep);

	if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
	/*
	* set @bpkts to 1 if it is LS or FS periodic endpoint, and its
	* device does not connected through an external HS hub
	*/
	if (usb_endpoint_xfer_int(&ep->desc)
	\|\| usb_endpoint_xfer_isoc(&ep->desc))
	ep_ctx->reserved[0] \|= cpu_to_le32(EP_BPKTS(1));

	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));

	xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
	sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
	sch_ep->offset, sch_ep->repeat);

	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 xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
	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;
	int bw_index;

	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() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
	__func__, usb_endpoint_type(&ep->desc), udev->speed,
	usb_endpoint_maxp(&ep->desc),
	usb_endpoint_dir_in(&ep->desc), 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;
	}
	}
	}
	EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);