path: root/drivers/usb/host/xhci-mtk-sch.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2015 MediaTek Inc.
 * Author:
 *  Zhigang.Wei <zhigang.wei@mediatek.com>
 *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include "xhci.h"
#include "xhci-mtk.h"

#define SSP_BW_BOUNDARY	130000
#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
#define LS_PAYLOAD_MAX 18
/* section 11.18.1, per fs frame */
#define FS_BW_BOUNDARY	1157
#define LS_BW_BOUNDARY	144

/*
 * max number of microframes for split transfer, assume extra-cs budget is 0
 * for fs isoc in : 1 ss + 1 idle + 6 cs (roundup(1023/188))
 */
#define TT_MICROFRAMES_MAX	8
/* offset from SS for fs/ls isoc/intr ep (ss + idle) */
#define CS_OFFSET	2

#define DBG_BUF_EN	64

/* schedule error type */
#define ESCH_SS_Y6		1001
#define ESCH_SS_OVERLAP		1002
#define ESCH_CS_OVERFLOW	1003
#define ESCH_BW_OVERFLOW	1004
#define ESCH_FIXME		1005

/* mtk scheduler bitmasks */
#define EP_BPKTS(p)	((p) & 0x7f)
#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 char *sch_error_string(int err_num)
{
	switch (err_num) {
	case ESCH_SS_Y6:
		return "Can't schedule Start-Split in Y6";
	case ESCH_SS_OVERLAP:
		return "Can't find a suitable Start-Split location";
	case ESCH_CS_OVERFLOW:
		return "The last Complete-Split is greater than 7";
	case ESCH_BW_OVERFLOW:
		return "Bandwidth exceeds the maximum limit";
	case ESCH_FIXME:
		return "FIXME, to be resolved";
	default:
		return "Unknown";
	}
}

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

static const char *
decode_ep(struct usb_host_endpoint *ep, enum usb_device_speed speed)
{
	static char buf[DBG_BUF_EN];
	struct usb_endpoint_descriptor *epd = &ep->desc;
	unsigned int interval;
	const char *unit;

	interval = usb_decode_interval(epd, speed);
	if (interval % 1000) {
		unit = "us";
	} else {
		unit = "ms";
		interval /= 1000;
	}

	snprintf(buf, DBG_BUF_EN, "%s ep%d%s %s, mpkt:%d, interval:%d/%d%s",
		 usb_speed_string(speed), usb_endpoint_num(epd),
		 usb_endpoint_dir_in(epd) ? "in" : "out",
		 usb_ep_type_string(usb_endpoint_type(epd)),
		 usb_endpoint_maxp(epd), epd->bInterval, interval, unit);

	return buf;
}

static u32 get_bw_boundary(enum usb_device_speed speed)
{
	u32 boundary;

	switch (speed) {
	case USB_SPEED_SUPER_PLUS:
		boundary = SSP_BW_BOUNDARY;
		break;
	case USB_SPEED_SUPER:
		boundary = SS_BW_BOUNDARY;
		break;
	default:
		boundary = HS_BW_BOUNDARY;
		break;
	}

	return boundary;
}

/*
* get the bandwidth domain 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.
*/
static struct mu3h_sch_bw_info *
get_bw_info(struct xhci_hcd_mtk *mtk, struct usb_device *udev,
	    struct usb_host_endpoint *ep)
{
	struct xhci_hcd *xhci = hcd_to_xhci(mtk->hcd);
	struct xhci_virt_device *virt_dev;
	int bw_index;

	virt_dev = xhci->devs[udev->slot_id];
	if (!virt_dev->rhub_port) {
		WARN_ONCE(1, "%s invalid rhub port\n", dev_name(&udev->dev));
		return NULL;
	}

	if (udev->speed >= USB_SPEED_SUPER) {
		if (usb_endpoint_dir_out(&ep->desc))
			bw_index = (virt_dev->rhub_port->hw_portnum) * 2;
		else
			bw_index = (virt_dev->rhub_port->hw_portnum) * 2 + 1;
	} else {
		/* add one more for each SS port */
		bw_index = virt_dev->rhub_port->hw_portnum + xhci->usb3_rhub.num_ports;
	}

	return &mtk->sch_array[bw_index];
}

static u32 get_esit(struct xhci_ep_ctx *ep_ctx)
{
	u32 esit;

	esit = 1 << CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
	if (esit > XHCI_MTK_MAX_ESIT)
		esit = XHCI_MTK_MAX_ESIT;

	return esit;
}

static struct mu3h_sch_tt *find_tt(struct usb_device *udev)
{
	struct usb_tt *utt = udev->tt;
	struct mu3h_sch_tt *tt, **tt_index, **ptt;
	bool allocated_index = false;

	if (!utt)
		return NULL;	/* Not below a TT */

	/*
	 * Find/create our data structure.
	 * For hubs with a single TT, we get it directly.
	 * For hubs with multiple TTs, there's an extra level of pointers.
	 */
	tt_index = NULL;
	if (utt->multi) {
		tt_index = utt->hcpriv;
		if (!tt_index) {	/* Create the index array */
			tt_index = kcalloc(utt->hub->maxchild,
					sizeof(*tt_index), GFP_KERNEL);
			if (!tt_index)
				return ERR_PTR(-ENOMEM);
			utt->hcpriv = tt_index;
			allocated_index = true;
		}
		ptt = &tt_index[udev->ttport - 1];
	} else {
		ptt = (struct mu3h_sch_tt **) &utt->hcpriv;
	}

	tt = *ptt;
	if (!tt) {	/* Create the mu3h_sch_tt */
		tt = kzalloc(sizeof(*tt), GFP_KERNEL);
		if (!tt) {
			if (allocated_index) {
				utt->hcpriv = NULL;
				kfree(