// SPDX-License-Identifier: GPL-2.0+
/* Faraday FOTG210 EHCI-like driver
 *
 * Copyright (c) 2013 Faraday Technology Corporation
 *
 * Author: Yuan-Hsin Chen <yhchen@faraday-tech.com>
 *         Feng-Hsin Chiang <john453@faraday-tech.com>
 *         Po-Yu Chuang <ratbert.chuang@gmail.com>
 *
 * Most of code borrowed from the Linux-3.7 EHCI driver
 */
#include <linux/module.h>
#include <linux/of.h>
#include <linux/device.h>
#include <linux/dmapool.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/hrtimer.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/usb.h>
#include <linux/usb/hcd.h>
#include <linux/moduleparam.h>
#include <linux/dma-mapping.h>
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/clk.h>

#include <asm/byteorder.h>
#include <asm/irq.h>
#include <asm/unaligned.h>

#define DRIVER_AUTHOR "Yuan-Hsin Chen"
#define DRIVER_DESC "FOTG210 Host Controller (EHCI) Driver"
static const char hcd_name[] = "fotg210_hcd";

#undef FOTG210_URB_TRACE
#define FOTG210_STATS

/* magic numbers that can affect system performance */
#define FOTG210_TUNE_CERR       3 /* 0-3 qtd retries; 0 == don't stop */
#define FOTG210_TUNE_RL_HS      4 /* nak throttle; see 4.9 */
#define FOTG210_TUNE_RL_TT      0
#define FOTG210_TUNE_MULT_HS    1 /* 1-3 transactions/uframe; 4.10.3 */
#define FOTG210_TUNE_MULT_TT    1

/* Some drivers think it's safe to schedule isochronous transfers more than 256
 * ms into the future (partly as a result of an old bug in the scheduling
 * code).  In an attempt to avoid trouble, we will use a minimum scheduling
 * length of 512 frames instead of 256.
 */
#define FOTG210_TUNE_FLS 1 /* (medium) 512-frame schedule */

/* Initial IRQ latency:  faster than hw default */
static int log2_irq_thresh; /* 0 to 6 */
module_param(log2_irq_thresh, int, S_IRUGO);
MODULE_PARM_DESC(log2_irq_thresh, "log2 IRQ latency, 1-64 microframes");

/* initial park setting:  slower than hw default */
static unsigned park;
module_param(park, uint, S_IRUGO);
MODULE_PARM_DESC(park, "park setting; 1-3 back-to-back async packets");

/* for link power management(LPM) feature */
static unsigned int hird;
module_param(hird, int, S_IRUGO);
MODULE_PARM_DESC(hird, "host initiated resume duration, +1 for each 75us");

#define INTR_MASK (STS_IAA | STS_FATAL | STS_PCD | STS_ERR | STS_INT)

#include "fotg210.h"

#define fotg210_dbg(fotg210, fmt, args...) \
        dev_dbg(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
#define fotg210_err(fotg210, fmt, args...) \
        dev_err(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
#define fotg210_info(fotg210, fmt, args...) \
        dev_info(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)
#define fotg210_warn(fotg210, fmt, args...) \
        dev_warn(fotg210_to_hcd(fotg210)->self.controller, fmt, ## args)

/* check the values in the HCSPARAMS register (host controller _Structural_
 * parameters) see EHCI spec, Table 2-4 for each value
 */
static void dbg_hcs_params(struct fotg210_hcd *fotg210, char *label)
{
        u32 params = fotg210_readl(fotg210, &fotg210->caps->hcs_params);

        fotg210_dbg(fotg210, "%s hcs_params 0x%x ports=%d\n", label, params,
                        HCS_N_PORTS(params));
}

/* check the values in the HCCPARAMS register (host controller _Capability_
 * parameters) see EHCI Spec, Table 2-5 for each value
 */
static void dbg_hcc_params(struct fotg210_hcd *fotg210, char *label)
{
        u32 params = fotg210_readl(fotg210, &fotg210->caps->hcc_params);

        fotg210_dbg(fotg210, "%s hcc_params %04x uframes %s%s\n", label,
                        params,
                        HCC_PGM_FRAMELISTLEN(params) ? "256/512/1024" : "1024",
                        HCC_CANPARK(params) ? " park" : "");
}

static void __maybe_unused
dbg_qtd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd)
{
        fotg210_dbg(fotg210, "%s td %p n%08x %08x t%08x p0=%08x\n", label, qtd,
                        hc32_to_cpup(fotg210, &qtd->hw_next),
                        hc32_to_cpup(fotg210, &qtd->hw_alt_next),
                        hc32_to_cpup(fotg210, &qtd->hw_token),
                        hc32_to_cpup(fotg210, &qtd->hw_buf[0]));
        if (qtd->hw_buf[1])
                fotg210_dbg(fotg210, "  p1=%08x p2=%08x p3=%08x p4=%08x\n",
                                hc32_to_cpup(fotg210, &qtd->hw_buf[1]),
                                hc32_to_cpup(fotg210, &qtd->hw_buf[2]),
                                hc32_to_cpup(fotg210, &qtd->hw_buf[3]),
                                hc32_to_cpup(fotg210, &qtd->hw_buf[4]));
}

static void __maybe_unused
dbg_qh(const char *label, struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
{
        struct fotg210_qh_hw *hw = qh->hw;

        fotg210_dbg(fotg210, "%s qh %p n%08x info %x %x qtd %x\n", label, qh,
                        hw->hw_next, hw->hw_info1, hw->hw_info2,
                        hw->hw_current);

        dbg_qtd("overlay", fotg210, (struct fotg210_qtd *) &hw->hw_qtd_next);
}

static void __maybe_unused
dbg_itd(const char *label, struct fotg210_hcd *fotg210, struct fotg210_itd *itd)
{
        fotg210_dbg(fotg210, "%s[%d] itd %p, next %08x, urb %p\n", label,
                        itd->frame, itd, hc32_to_cpu(fotg210, itd->hw_next),
                        itd->urb);

        fotg210_dbg(fotg210,
                        "  trans: %08x %08x %08x %08x %08x %08x %08x %08x\n",
                        hc32_to_cpu(fotg210, itd->hw_transaction[0]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[1]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[2]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[3]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[4]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[5]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[6]),
                        hc32_to_cpu(fotg210, itd->hw_transaction[7]));

        fotg210_dbg(fotg210,
                        "  buf:   %08x %08x %08x %08x %08x %08x %08x\n",
                        hc32_to_cpu(fotg210, itd->hw_bufp[0]),
                        hc32_to_cpu(fotg210, itd->hw_bufp[1]),
                        hc32_to_cpu(fotg210, itd->hw_bufp[2]),
                        hc32_to_cpu(fotg210, itd->hw_bufp[3]),
                        hc32_to_cpu(fotg210, itd->hw_bufp[4]),
                        hc32_to_cpu(fotg210, itd->hw_bufp[5]),
                        hc32_to_cpu(fotg210, itd->hw_bufp[6]));

        fotg210_dbg(fotg210, "  index: %d %d %d %d %d %d %d %d\n",
                        itd->index[0], itd->index[1], itd->index[2],
                        itd->index[3], itd->index[4], itd->index[5],
                        itd->index[6], itd->index[7]);
}

static int __maybe_unused
dbg_status_buf(char *buf, unsigned len, const char *label, u32 status)
{
        return scnprintf(buf, len, "%s%sstatus %04x%s%s%s%s%s%s%s%s%s%s",
                        label, label[0] ? " " : "", status,
                        (status & STS_ASS) ? " Async" : "",
                        (status & STS_PSS) ? " Periodic" : "",
                        (status & STS_RECL) ? " Recl" : "",
                        (status & STS_HALT) ? " Halt" : "",
                        (status & STS_IAA) ? " IAA" : "",
                        (status & STS_FATAL) ? " FATAL" : "",
                        (status & STS_FLR) ? " FLR" : "",
                        (status & STS_PCD) ? " PCD" : "",
                        (status & STS_ERR) ? " ERR" : "",
                        (status & STS_INT) ? " INT" : "");
}

static int __maybe_unused
dbg_intr_buf(char *buf, unsigned len, const char *label, u32 enable)
{
        return scnprintf(buf, len, "%s%sintrenable %02x%s%s%s%s%s%s",
                        label, label[0] ? " " : "", enable,
                        (enable & STS_IAA) ? " IAA" : "",
                        (enable & STS_FATAL) ? " FATAL" : "",
                        (enable & STS_FLR) ? " FLR" : "",
                        (enable & STS_PCD) ? " PCD" : "",
                        (enable & STS_ERR) ? " ERR" : "",
                        (enable & STS_INT) ? " INT" : "");
}

static const char *const fls_strings[] = { "1024", "512", "256", "??" };

static int dbg_command_buf(char *buf, unsigned len, const char *label,
                u32 command)
{
        return scnprintf(buf, len,
                        "%s%scommand %07x %s=%d ithresh=%d%s%s%s period=%s%s %s",
                        label, label[0] ? " " : "", command,
                        (command & CMD_PARK) ? " park" : "(park)",
                        CMD_PARK_CNT(command),
                        (command >> 16) & 0x3f,
                        (command & CMD_IAAD) ? " IAAD" : "",
                        (command & CMD_ASE) ? " Async" : "",
                        (command & CMD_PSE) ? " Periodic" : "",
                        fls_strings[(command >> 2) & 0x3],
                        (command & CMD_RESET) ? " Reset" : "",
                        (command & CMD_RUN) ? "RUN" : "HALT");
}

static char *dbg_port_buf(char *buf, unsigned len, const char *label, int port,
                u32 status)
{
        char *sig;

        /* signaling state */
        switch (status & (3 << 10)) {
        case 0 << 10:
                sig = "se0";
                break;
        case 1 << 10:
                sig = "k";
                break; /* low speed */
        case 2 << 10:
                sig = "j";
                break;
        default:
                sig = "?";
                break;
        }

        scnprintf(buf, len, "%s%sport:%d status %06x %d sig=%s%s%s%s%s%s%s%s",
                        label, label[0] ? " " : "", port, status,
                        status >> 25, /*device address */
                        sig,
                        (status & PORT_RESET) ? " RESET" : "",
                        (status & PORT_SUSPEND) ? " SUSPEND" : "",
                        (status & PORT_RESUME) ? " RESUME" : "",
                        (status & PORT_PEC) ? " PEC" : "",
                        (status & PORT_PE) ? " PE" : "",
                        (status & PORT_CSC) ? " CSC" : "",
                        (status & PORT_CONNECT) ? " CONNECT" : "");

        return buf;
}

/* functions have the "wrong" filename when they're output... */
#define dbg_status(fotg210, label, status) {                    \
        char _buf[80];                                          \
        dbg_status_buf(_buf, sizeof(_buf), label, status);      \
        fotg210_dbg(fotg210, "%s\n", _buf);                     \
}

#define dbg_cmd(fotg210, label, command) {                      \
        char _buf[80];                                          \
        dbg_command_buf(_buf, sizeof(_buf), label, command);    \
        fotg210_dbg(fotg210, "%s\n", _buf);                     \
}

#define dbg_port(fotg210, label, port, status) {                               \
        char _buf[80];                                                         \
        fotg210_dbg(fotg210, "%s\n",                                           \
                        dbg_port_buf(_buf, sizeof(_buf), label, port, status));\
}

/* troubleshooting help: expose state in debugfs */
static int debug_async_open(struct inode *, struct file *);
static int debug_periodic_open(struct inode *, struct file *);
static int debug_registers_open(struct inode *, struct file *);
static int debug_async_open(struct inode *, struct file *);

static ssize_t debug_output(struct file*, char __user*, size_t, loff_t*);
static int debug_close(struct inode *, struct file *);

static const struct file_operations debug_async_fops = {
        .owner          = THIS_MODULE,
        .open           = debug_async_open,
        .read           = debug_output,
        .release        = debug_close,
        .llseek         = default_llseek,
};
static const struct file_operations debug_periodic_fops = {
        .owner          = THIS_MODULE,
        .open           = debug_periodic_open,
        .read           = debug_output,
        .release        = debug_close,
        .llseek         = default_llseek,
};
static const struct file_operations debug_registers_fops = {
        .owner          = THIS_MODULE,
        .open           = debug_registers_open,
        .read           = debug_output,
        .release        = debug_close,
        .llseek         = default_llseek,
};

static struct dentry *fotg210_debug_root;

struct debug_buffer {
        ssize_t (*fill_func)(struct debug_buffer *);    /* fill method */
        struct usb_bus *bus;
        struct mutex mutex;     /* protect filling of buffer */
        size_t count;           /* number of characters filled into buffer */
        char *output_buf;
        size_t alloc_size;
};

static inline char speed_char(u32 scratch)
{
        switch (scratch & (3 << 12)) {
        case QH_FULL_SPEED:
                return 'f';

        case QH_LOW_SPEED:
                return 'l';

        case QH_HIGH_SPEED:
                return 'h';

        default:
                return '?';
        }
}

static inline char token_mark(struct fotg210_hcd *fotg210, __hc32 token)
{
        __u32 v = hc32_to_cpu(fotg210, token);

        if (v & QTD_STS_ACTIVE)
                return '*';
        if (v & QTD_STS_HALT)
                return '-';
        if (!IS_SHORT_READ(v))
                return ' ';
        /* tries to advance through hw_alt_next */
        return '/';
}

static void qh_lines(struct fotg210_hcd *fotg210, struct fotg210_qh *qh,
                char **nextp, unsigned *sizep)
{
        u32 scratch;
        u32 hw_curr;
        struct fotg210_qtd *td;
        unsigned temp;
        unsigned size = *sizep;
        char *next = *nextp;
        char mark;
        __le32 list_end = FOTG210_LIST_END(fotg210);
        struct fotg210_qh_hw *hw = qh->hw;

        if (hw->hw_qtd_next == list_end) /* NEC does this */
                mark = '@';
        else
                mark = token_mark(fotg210, hw->hw_token);
        if (mark == '/') { /* qh_alt_next controls qh advance? */
                if ((hw->hw_alt_next & QTD_MASK(fotg210)) ==
                    fotg210->async->hw->hw_alt_next)
                        mark = '#'; /* blocked */
                else if (hw->hw_alt_next == list_end)
                        mark = '.'; /* use hw_qtd_next */
                /* else alt_next points to some other qtd */
        }
        scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
        hw_curr = (mark == '*') ? hc32_to_cpup(fotg210, &hw->hw_current) : 0;
        temp = scnprintf(next, size,
                        "qh/%p dev%d %cs ep%d %08x %08x(%08x%c %s nak%d)",
                        qh, scratch & 0x007f,
                        speed_char(scratch),
                        (scratch >> 8) & 0x000f,
                        scratch, hc32_to_cpup(fotg210, &hw->hw_info2),
                        hc32_to_cpup(fotg210, &hw->hw_token), mark,
                        (cpu_to_hc32(fotg210, QTD_TOGGLE) & hw->hw_token)
                                ? "data1" : "data0",
                        (hc32_to_cpup(fotg210, &hw->hw_alt_next) >> 1) & 0x0f);
        size -= temp;
        next += temp;

        /* hc may be modifying the list as we read it ... */
        list_for_each_entry(td, &qh->qtd_list, qtd_list) {
                scratch = hc32_to_cpup(fotg210, &td->hw_token);
                mark = ' ';
                if (hw_curr == td->qtd_dma)
                        mark = '*';
                else if (hw->hw_qtd_next == cpu_to_hc32(fotg210, td->qtd_dma))
                        mark = '+';
                else if (QTD_LENGTH(scratch)) {
                        if (td->hw_alt_next == fotg210->async->hw->hw_alt_next)
                                mark = '#';
                        else if (td->hw_alt_next != list_end)
                                mark = '/';
                }
                temp = snprintf(next, size,
                                "\n\t%p%c%s len=%d %08x urb %p",
                                td, mark, ({ char *tmp;
                                switch ((scratch>>8)&0x03) {
                                case 0:
                                        tmp = "out";
                                        break;
                                case 1:
                                        tmp = "in";
                                        break;
                                case 2:
                                        tmp = "setup";
                                        break;
                                default:
                                        tmp = "?";
                                        break;
                                 } tmp; }),
                                (scratch >> 16) & 0x7fff,
                                scratch,
                                td->urb);
                if (size < temp)
                        temp = size;
                size -= temp;
                next += temp;
                if (temp == size)
                        goto done;
        }

        temp = snprintf(next, size, "\n");
        if (size < temp)
                temp = size;

        size -= temp;
        next += temp;

done:
        *sizep = size;
        *nextp = next;
}

static ssize_t fill_async_buffer(struct debug_buffer *buf)
{
        struct usb_hcd *hcd;
        struct fotg210_hcd *fotg210;
        unsigned long flags;
        unsigned temp, size;
        char *next;
        struct fotg210_qh *qh;

        hcd = bus_to_hcd(buf->bus);
        fotg210 = hcd_to_fotg210(hcd);
        next = buf->output_buf;
        size = buf->alloc_size;

        *next = 0;

        /* dumps a snapshot of the async schedule.
         * usually empty except for long-term bulk reads, or head.
         * one QH per line, and TDs we know about
         */
        spin_lock_irqsave(&fotg210->lock, flags);
        for (qh = fotg210->async->qh_next.qh; size > 0 && qh;
                        qh = qh->qh_next.qh)
                qh_lines(fotg210, qh, &next, &size);
        if (fotg210->async_unlink && size > 0) {
                temp = scnprintf(next, size, "\nunlink =\n");
                size -= temp;
                next += temp;

                for (qh = fotg210->async_unlink; size > 0 && qh;
                                qh = qh->unlink_next)
                        qh_lines(fotg210, qh, &next, &size);
        }
        spin_unlock_irqrestore(&fotg210->lock, flags);

        return strlen(buf->output_buf);
}

/* count tds, get ep direction */
static unsigned output_buf_tds_dir(char *buf, struct fotg210_hcd *fotg210,
                struct fotg210_qh_hw *hw, struct fotg210_qh *qh, unsigned size)
{
        u32 scratch = hc32_to_cpup(fotg210, &hw->hw_info1);
        struct fotg210_qtd *qtd;
        char *type = "";
        unsigned temp = 0;

        /* count tds, get ep direction */
        list_for_each_entry(qtd, &qh->qtd_list, qtd_list) {
                temp++;
                switch ((hc32_to_cpu(fotg210, qtd->hw_token) >> 8) & 0x03) {
                case 0:
                        type = "out";
                        continue;
                case 1:
                        type = "in";
                        continue;
                }
        }

        return scnprintf(buf, size, "(%c%d ep%d%s [%d/%d] q%d p%d)",
                        speed_char(scratch), scratch & 0x007f,
                        (scratch >> 8) & 0x000f, type, qh->usecs,
                        qh->c_usecs, temp, (scratch >> 16) & 0x7ff);
}

#define DBG_SCHED_LIMIT 64
static ssize_t fill_periodic_buffer(struct debug_buffer *buf)
{
        struct usb_hcd *hcd;
        struct fotg210_hcd *fotg210;
        unsigned long flags;
        union fotg210_shadow p, *seen;
        unsigned temp, size, seen_count;
        char *next;
        unsigned i;
        __hc32 tag;

        seen = kmalloc_array(DBG_SCHED_LIMIT, sizeof(*seen), GFP_ATOMIC);
        if (!seen)
                return 0;

        seen_count = 0;

        hcd = bus_to_hcd(buf->bus);
        fotg210 = hcd_to_fotg210(hcd);
        next = buf->output_buf;
        size = buf->alloc_size;

        temp = scnprintf(next, size, "size = %d\n", fotg210->periodic_size);
        size -= temp;
        next += temp;

        /* dump a snapshot of the periodic schedule.
         * iso changes, interrupt usually doesn't.
         */
        spin_lock_irqsave(&fotg210->lock, flags);
        for (i = 0; i < fotg210->periodic_size; i++) {
                p = fotg210->pshadow[i];
                if (likely(!p.ptr))
                        continue;

                tag = Q_NEXT_TYPE(fotg210, fotg210->periodic[i]);

                temp = scnprintf(next, size, "%4d: ", i);
                size -= temp;
                next += temp;

                do {
                        struct fotg210_qh_hw *hw;

                        switch (hc32_to_cpu(fotg210, tag)) {
                        case Q_TYPE_QH:
                                hw = p.qh->hw;
                                temp = scnprintf(next, size, " qh%d-%04x/%p",
                                                p.qh->period,
                                                hc32_to_cpup(fotg210,
                                                        &hw->hw_info2)
                                                        /* uframe masks */
                                                        & (QH_CMASK | QH_SMASK),
                                                p.qh);
                                size -= temp;
                                next += temp;
                                /* don't repeat what follows this qh */
                                for (temp = 0; temp < seen_count; temp++) {
                                        if (seen[temp].ptr != p.ptr)
                                                continue;
                                        if (p.qh->qh_next.ptr) {
                                                temp = scnprintf(next, size,
                                                                " ...");
                                                size -= temp;
                                                next += temp;
                                        }
                                        break;
                                }
                                /* show more info the first time around */
                                if (temp == seen_count) {
                                        temp = output_buf_tds_dir(next,
                                                        fotg210, hw,
                                                        p.qh, size);

                                        if (seen_count < DBG_SCHED_LIMIT)
                                                seen[seen_count++].qh = p.qh;
                                } else
                                        temp = 0;
                                tag = Q_NEXT_TYPE(fotg210, hw->hw_next);
                                p = p.qh->qh_next;
                                break;
                        case Q_TYPE_FSTN:
                                temp = scnprintf(next, size,
                                                " fstn-%8x/%p",
                                                p.fstn->hw_prev, p.fstn);
                                tag = Q_NEXT_TYPE(fotg210, p.fstn->hw_next);
                                p = p.fstn->fstn_next;
                                break;
                        case Q_TYPE_ITD:
                                temp = scnprintf(next, size,
                                                " itd/%p", p.itd);
                                tag = Q_NEXT_TYPE(fotg210, p.itd->hw_next);
                                p = p.itd->itd_next;
                                break;
                        }
                        size -= temp;
                        next += temp;
                } while (p.ptr);

                temp = scnprintf(next, size, "\n");
                size -= temp;
                next += temp;
        }
        spin_unlock_irqrestore(&fotg210->lock, flags);
        kfree(seen);

        return buf->alloc_size - size;
}
#undef DBG_SCHED_LIMIT

static const char *rh_state_string(struct fotg210_hcd *fotg210)
{
        switch (fotg210->rh_state) {
        case FOTG210_RH_HALTED:
                return "halted";
        case FOTG210_RH_SUSPENDED:
                return "suspended";
        case FOTG210_RH_RUNNING:
                return "running";
        case FOTG210_RH_STOPPING:
                return "stopping";
        }
        return "?";
}

static ssize_t fill_registers_buffer(struct debug_buffer *buf)
{
        struct usb_hcd *hcd;
        struct fotg210_hcd *fotg210;
        unsigned long flags;
        unsigned temp, size, i;
        char *next, scratch[80];
        static const char fmt[] = "%*s\n";
        static const char label[] = "";

        hcd = bus_to_hcd(buf->bus);
        fotg210 = hcd_to_fotg210(hcd);
        next = buf->output_buf;
        size = buf->alloc_size;

        spin_lock_irqsave(&fotg210->lock, flags);

        if (!HCD_HW_ACCESSIBLE(hcd)) {
                size = scnprintf(next, size,
                                "bus %s, device %s\n"
                                "%s\n"
                                "SUSPENDED(no register access)\n",
                                hcd->self.controller->bus->name,
                                dev_name(hcd->self.controller),
                                hcd->product_desc);
                goto done;
        }

        /* Capability Registers */
        i = HC_VERSION(fotg210, fotg210_readl(fotg210,
                        &fotg210->caps->hc_capbase));
        temp = scnprintf(next, size,
                        "bus %s, device %s\n"
                        "%s\n"
                        "EHCI %x.%02x, rh state %s\n",
                        hcd->self.controller->bus->name,
                        dev_name(hcd->self.controller),
                        hcd->product_desc,
                        i >> 8, i & 0x0ff, rh_state_string(fotg210));
        size -= temp;
        next += temp;

        /* FIXME interpret both types of params */
        i = fotg210_readl(fotg210, &fotg210->caps->hcs_params);
        temp = scnprintf(next, size, "structural params 0x%08x\n", i);
        size -= temp;
        next += temp;

        i = fotg210_readl(fotg210, &fotg210->caps->hcc_params);
        temp = scnprintf(next, size, "capability params 0x%08x\n", i);
        size -= temp;
        next += temp;

        /* Operational Registers */
        temp = dbg_status_buf(scratch, sizeof(scratch), label,
                        fotg210_readl(fotg210, &fotg210->regs->status));
        temp = scnprintf(next, size, fmt, temp, scratch);
        size -= temp;
        next += temp;

        temp = dbg_command_buf(scratch, sizeof(scratch), label,
                        fotg210_readl(fotg210, &fotg210->regs->command));
        temp = scnprintf(next, size, fmt, temp, scratch);
        size -= temp;
        next += temp;

        temp = dbg_intr_buf(scratch, sizeof(scratch), label,
                        fotg210_readl(fotg210, &fotg210->regs->intr_enable));
        temp = scnprintf(next, size, fmt, temp, scratch);
        size -= temp;
        next += temp;

        temp = scnprintf(next, size, "uframe %04x\n",
                        fotg210_read_frame_index(fotg210));
        size -= temp;
        next += temp;

        if (fotg210->async_unlink) {
                temp = scnprintf(next, size, "async unlink qh %p\n",
                                fotg210->async_unlink);
                size -= temp;
                next += temp;
        }

#ifdef FOTG210_STATS
        temp = scnprintf(next, size,
                        "irq normal %ld err %ld iaa %ld(lost %ld)\n",
                        fotg210->stats.normal, fotg210->stats.error,
                        fotg210->stats.iaa, fotg210->stats.lost_iaa);
        size -= temp;
        next += temp;

        temp = scnprintf(next, size, "complete %ld unlink %ld\n",
                        fotg210->stats.complete, fotg210->stats.unlink);
        size -= temp;
        next += temp;
#endif

done:
        spin_unlock_irqrestore(&fotg210->lock, flags);

        return buf->alloc_size - size;
}

static struct debug_buffer
*alloc_buffer(struct usb_bus *bus, ssize_t (*fill_func)(struct debug_buffer *))
{
        struct debug_buffer *buf;

        buf = kzalloc(sizeof(struct debug_buffer), GFP_KERNEL);

        if (buf) {
                buf->bus = bus;
                buf->fill_func = fill_func;
                mutex_init(&buf->mutex);
                buf->alloc_size = PAGE_SIZE;
        }

        return buf;
}

static int fill_buffer(struct debug_buffer *buf)
{
        int ret = 0;

        if (!buf->output_buf)
                buf->output_buf = vmalloc(buf->alloc_size);

        if (!buf->output_buf) {
                ret = -ENOMEM;
                goto out;
        }

        ret = buf->fill_func(buf);

        if (ret >= 0) {
                buf->count = ret;
                ret = 0;
        }

out:
        return ret;
}

static ssize_t debug_output(struct file *file, char __user *user_buf,
                size_t len, loff_t *offset)
{
        struct debug_buffer *buf = file->private_data;
        int ret = 0;

        mutex_lock(&buf->mutex);
        if (buf->count == 0) {
                ret = fill_buffer(buf);
                if (ret != 0) {
                        mutex_unlock(&buf->mutex);
                        goto out;
                }
        }
        mutex_unlock(&buf->mutex);

        ret = simple_read_from_buffer(user_buf, len, offset,
                        buf->output_buf, buf->count);

out:
        return ret;

}

static int debug_close(struct inode *inode, struct file *file)
{
        struct debug_buffer *buf = file->private_data;

        if (buf) {
                vfree(buf->output_buf);
                kfree(buf);
        }

        return 0;
}
static int debug_async_open(struct inode *inode, struct file *file)
{
        file->private_data = alloc_buffer(inode->i_private, fill_async_buffer);

        return file->private_data ? 0 : -ENOMEM;
}

static int debug_periodic_open(struct inode *inode, struct file *file)
{
        struct debug_buffer *buf;

        buf = alloc_buffer(inode->i_private, fill_periodic_buffer);
        if (!buf)
                return -ENOMEM;

        buf->alloc_size = (sizeof(void *) == 4 ? 6 : 8)*PAGE_SIZE;
        file->private_data = buf;
        return 0;
}

static int debug_registers_open(struct inode *inode, struct file *file)
{
        file->private_data = alloc_buffer(inode->i_private,
                        fill_registers_buffer);

        return file->private_data ? 0 : -ENOMEM;
}

static inline void create_debug_files(struct fotg210_hcd *fotg210)
{
        struct usb_bus *bus = &fotg210_to_hcd(fotg210)->self;
        struct dentry *root;

        root = debugfs_create_dir(bus->bus_name, fotg210_debug_root);
        fotg210->debug_dir = root;

        debugfs_create_file("async", S_IRUGO, root, bus, &debug_async_fops);
        debugfs_create_file("periodic", S_IRUGO, root, bus,
                            &debug_periodic_fops);
        debugfs_create_file("registers", S_IRUGO, root, bus,
                            &debug_registers_fops);
}

static inline void remove_debug_files(struct fotg210_hcd *fotg210)
{
        debugfs_remove_recursive(fotg210->debug_dir);
}

/* handshake - spin reading hc until handshake completes or fails
 * @ptr: address of hc register to be read
 * @mask: bits to look at in result of read
 * @done: value of those bits when handshake succeeds
 * @usec: timeout in microseconds
 *
 * Returns negative errno, or zero on success
 *
 * Success happens when the "mask" bits have the specified value (hardware
 * handshake done).  There are two failure modes:  "usec" have passed (major
 * hardware flakeout), or the register reads as all-ones (hardware removed).
 *
 * That last failure should_only happen in cases like physical cardbus eject
 * before driver shutdown. But it also seems to be caused by bugs in cardbus
 * bridge shutdown:  shutting down the bridge before the devices using it.
 */
static int handshake(struct fotg210_hcd *fotg210, void __iomem *ptr,
                u32 mask, u32 done, int usec)
{
        u32 result;
        int ret;

        ret = readl_poll_timeout_atomic(ptr, result,
                                        ((result & mask) == done ||
                                         result == U32_MAX), 1, usec);
        if (result == U32_MAX)          /* card removed */
                return -ENODEV;

        return ret;
}

/* Force HC to halt state from unknown (EHCI spec section 2.3).
 * Must be called with interrupts enabled and the lock not held.
 */
static int fotg210_halt(struct fotg210_hcd *fotg210)
{
        u32 temp;

        spin_lock_irq(&fotg210->lock);

        /* disable any irqs left enabled by previous code */
        fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);

        /*
         * This routine gets called during probe before fotg210->command
         * has been initialized, so we can't rely on its value.
         */
        fotg210->command &= ~CMD_RUN;
        temp = fotg210_readl(fotg210, &fotg210->regs->command);
        temp &= ~(CMD_RUN | CMD_IAAD);
        fotg210_writel(fotg210, temp, &fotg210->regs->command);

        spin_unlock_irq(&fotg210->lock);
        synchronize_irq(fotg210_to_hcd(fotg210)->irq);

        return handshake(fotg210, &fotg210->regs->status,
                        STS_HALT, STS_HALT, 16 * 125);
}

/* Reset a non-running (STS_HALT == 1) controller.
 * Must be called with interrupts enabled and the lock not held.
 */
static int fotg210_reset(struct fotg210_hcd *fotg210)
{
        int retval;
        u32 command = fotg210_readl(fotg210, &fotg210->regs->command);

        /* If the EHCI debug controller is active, special care must be
         * taken before and after a host controller reset
         */
        if (fotg210->debug && !dbgp_reset_prep(fotg210_to_hcd(fotg210)))
                fotg210->debug = NULL;

        command |= CMD_RESET;
        dbg_cmd(fotg210, "reset", command);
        fotg210_writel(fotg210, command, &fotg210->regs->command);
        fotg210->rh_state = FOTG210_RH_HALTED;
        fotg210->next_statechange = jiffies;
        retval = handshake(fotg210, &fotg210->regs->command,
                        CMD_RESET, 0, 250 * 1000);

        if (retval)
                return retval;

        if (fotg210->debug)
                dbgp_external_startup(fotg210_to_hcd(fotg210));

        fotg210->port_c_suspend = fotg210->suspended_ports =
                        fotg210->resuming_ports = 0;
        return retval;
}

/* Idle the controller (turn off the schedules).
 * Must be called with interrupts enabled and the lock not held.
 */
static void fotg210_quiesce(struct fotg210_hcd *fotg210)
{
        u32 temp;

        if (fotg210->rh_state != FOTG210_RH_RUNNING)
                return;

        /* wait for any schedule enables/disables to take effect */
        temp = (fotg210->command << 10) & (STS_ASS | STS_PSS);
        handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, temp,
                        16 * 125);

        /* then disable anything that's still active */
        spin_lock_irq(&fotg210->lock);
        fotg210->command &= ~(CMD_ASE | CMD_PSE);
        fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
        spin_unlock_irq(&fotg210->lock);

        /* hardware can take 16 microframes to turn off ... */
        handshake(fotg210, &fotg210->regs->status, STS_ASS | STS_PSS, 0,
                        16 * 125);
}

static void end_unlink_async(struct fotg210_hcd *fotg210);
static void unlink_empty_async(struct fotg210_hcd *fotg210);
static void fotg210_work(struct fotg210_hcd *fotg210);
static void start_unlink_intr(struct fotg210_hcd *fotg210,
                              struct fotg210_qh *qh);
static void end_unlink_intr(struct fotg210_hcd *fotg210, struct fotg210_qh *qh);

/* Set a bit in the USBCMD register */
static void fotg210_set_command_bit(struct fotg210_hcd *fotg210, u32 bit)
{
        fotg210->command |= bit;
        fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);

        /* unblock posted write */
        fotg210_readl(fotg210, &fotg210->regs->command);
}

/* Clear a bit in the USBCMD register */
static void fotg210_clear_command_bit(struct fotg210_hcd *fotg210, u32 bit)
{
        fotg210->command &= ~bit;
        fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);

        /* unblock posted write */
        fotg210_readl(fotg210, &fotg210->regs->command);
}

/* EHCI timer support...  Now using hrtimers.
 *
 * Lots of different events are triggered from fotg210->hrtimer.  Whenever
 * the timer routine runs, it checks each possible event; events that are
 * currently enabled and whose expiration time has passed get handled.
 * The set of enabled events is stored as a collection of bitflags in
 * fotg210->enabled_hrtimer_events, and they are numbered in order of
 * increasing delay values (ranging between 1 ms and 100 ms).
 *
 * Rather than implementing a sorted list or tree of all pending events,
 * we keep track only of the lowest-numbered pending event, in
 * fotg210->next_hrtimer_event.  Whenever fotg210->hrtimer gets restarted, its
 * expiration time is set to the timeout value for this event.
 *
 * As a result, events might not get handled right away; the actual delay
 * could be anywhere up to twice the requested delay.  This doesn't
 * matter, because none of the events are especially time-critical.  The
 * ones that matter most all have a delay of 1 ms, so they will be
 * handled after 2 ms at most, which is okay.  In addition to this, we
 * allow for an expiration range of 1 ms.
 */

/* Delay lengths for the hrtimer event types.
 * Keep this list sorted by delay length, in the same order as
 * the event types indexed by enum fotg210_hrtimer_event in fotg210.h.
 */
static unsigned event_delays_ns[] = {
        1 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_POLL_ASS */
        1 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_POLL_PSS */
        1 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_POLL_DEAD */
        1125 * NSEC_PER_USEC,   /* FOTG210_HRTIMER_UNLINK_INTR */
        2 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_FREE_ITDS */
        6 * NSEC_PER_MSEC,      /* FOTG210_HRTIMER_ASYNC_UNLINKS */
        10 * NSEC_PER_MSEC,     /* FOTG210_HRTIMER_IAA_WATCHDOG */
        10 * NSEC_PER_MSEC,     /* FOTG210_HRTIMER_DISABLE_PERIODIC */
        15 * NSEC_PER_MSEC,     /* FOTG210_HRTIMER_DISABLE_ASYNC */
        100 * NSEC_PER_MSEC,    /* FOTG210_HRTIMER_IO_WATCHDOG */
};

/* Enable a pending hrtimer event */
static void fotg210_enable_event(struct fotg210_hcd *fotg210, unsigned event,
                bool resched)
{
        ktime_t *timeout = &fotg210->hr_timeouts[event];

        if (resched)
                *timeout = ktime_add(ktime_get(), event_delays_ns[event]);
        fotg210->enabled_hrtimer_events |= (1 << event);

        /* Track only the lowest-numbered pending event */
        if (event < fotg210->next_hrtimer_event) {
                fotg210->next_hrtimer_event = event;
                hrtimer_start_range_ns(&fotg210->hrtimer, *timeout,
                                NSEC_PER_MSEC, HRTIMER_MODE_ABS);
        }
}


/* Poll the STS_ASS status bit; see when it agrees with CMD_ASE */
static void fotg210_poll_ASS(struct fotg210_hcd *fotg210)
{
        unsigned actual, want;

        /* Don't enable anything if the controller isn't running (e.g., died) */
        if (fotg210->rh_state != FOTG210_RH_RUNNING)
                return;

        want = (fotg210->command & CMD_ASE) ? STS_ASS : 0;
        actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_ASS;

        if (want != actual) {

                /* Poll again later, but give up after about 20 ms */
                if (fotg210->ASS_poll_count++ < 20) {
                        fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_ASS,
                                        true);
                        return;
                }
                fotg210_dbg(fotg210, "Waited too long for the async schedule status (%x/%x), giving up\n",
                                want, actual);
        }
        fotg210->ASS_poll_count = 0;

        /* The status is up-to-date; restart or stop the schedule as needed */
        if (want == 0) {        /* Stopped */
                if (fotg210->async_count > 0)
                        fotg210_set_command_bit(fotg210, CMD_ASE);

        } else {                /* Running */
                if (fotg210->async_count == 0) {

                        /* Turn off the schedule after a while */
                        fotg210_enable_event(fotg210,
                                        FOTG210_HRTIMER_DISABLE_ASYNC,
                                        true);
                }
        }
}

/* Turn off the async schedule after a brief delay */
static void fotg210_disable_ASE(struct fotg210_hcd *fotg210)
{
        fotg210_clear_command_bit(fotg210, CMD_ASE);
}


/* Poll the STS_PSS status bit; see when it agrees with CMD_PSE */
static void fotg210_poll_PSS(struct fotg210_hcd *fotg210)
{
        unsigned actual, want;

        /* Don't do anything if the controller isn't running (e.g., died) */
        if (fotg210->rh_state != FOTG210_RH_RUNNING)
                return;

        want = (fotg210->command & CMD_PSE) ? STS_PSS : 0;
        actual = fotg210_readl(fotg210, &fotg210->regs->status) & STS_PSS;

        if (want != actual) {

                /* Poll again later, but give up after about 20 ms */
                if (fotg210->PSS_poll_count++ < 20) {
                        fotg210_enable_event(fotg210, FOTG210_HRTIMER_POLL_PSS,
                                        true);
                        return;
                }
                fotg210_dbg(fotg210, "Waited too long for the periodic schedule status (%x/%x), giving up\n",
                                want, actual);
        }
        fotg210->PSS_poll_count = 0;

        /* The status is up-to-date; restart or stop the schedule as needed */
        if (want == 0) {        /* Stopped */
                if (fotg210->periodic_count > 0)
                        fotg210_set_command_bit(fotg210, CMD_PSE);

        } else {                /* Running */
                if (fotg210->periodic_count == 0) {

                        /* Turn off the schedule after a while */
                        fotg210_enable_event(fotg210,
                                        FOTG210_HRTIMER_DISABLE_PERIODIC,
                                        true);
                }
        }
}

/* Turn off the periodic schedule after a brief delay */
static void fotg210_disable_PSE(struct fotg210_hcd *fotg210)
{
        fotg210_clear_command_bit(fotg210, CMD_PSE);
}


/* Poll the STS_HALT status bit; see when a dead controller stops */
static void fotg210_handle_controller_death(struct fotg210_hcd *fotg210)
{
        if (!(fotg210_readl(fotg210, &fotg210->regs->status) & STS_HALT)) {

                /* Give up after a few milliseconds */
                if (fotg210->died_poll_count++ < 5) {
                        /* Try again later */
                        fotg210_enable_event(fotg210,
                                        FOTG210_HRTIMER_POLL_DEAD, true);
                        return;
                }
                fotg210_warn(fotg210, "Waited too long for the controller to stop, giving up\n");
        }

        /* Clean up the mess */
        fotg210->rh_state = FOTG210_RH_HALTED;
        fotg210_writel(fotg210, 0, &fotg210->regs->intr_enable);
        fotg210_work(fotg210);
        end_unlink_async(fotg210);

        /* Not in process context, so don't try to reset the controller */
}


/* Handle unlinked interrupt QHs once they are gone from the hardware */
static void fotg210_handle_intr_unlinks(struct fotg210_hcd *fotg210)
{
        bool stopped = (fotg210->rh_state < FOTG210_RH_RUNNING);

        /*
         * Process all the QHs on the intr_unlink list that were added
         * before the current unlink cycle began.  The list is in
         * temporal order, so stop when we reach the first entry in the
         * current cycle.  But if the root hub isn't running then
         * process all the QHs on the list.
         */
        fotg210->intr_unlinking = true;
        while (fotg210->intr_unlink) {
                struct fotg210_qh *qh = fotg210->intr_unlink;

                if (!stopped && qh->unlink_cycle == fotg210->intr_unlink_cycle)
                        break;
                fotg210->intr_unlink = qh->unlink_next;
                qh->unlink_next = NULL;
                end_unlink_intr(fotg210, qh);
        }

        /* Handle remaining entries later */
        if (fotg210->intr_unlink) {
                fotg210_enable_event(fotg210, FOTG210_HRTIMER_UNLINK_INTR,
                                true);
                ++fotg210->intr_unlink_cycle;
        }
        fotg210->intr_unlinking = false;
}


/* Start another free-iTDs/siTDs cycle */
static void start_free_itds(struct fotg210_hcd *fotg210)
{
        if (!(fotg210->enabled_hrtimer_events &
                        BIT(FOTG210_HRTIMER_FREE_ITDS))) {
                fotg210->last_itd_to_free = list_entry(
                                fotg210->cached_itd_list.prev,
                                struct fotg210_itd, itd_list);
                fotg210_enable_event(fotg210, FOTG210_HRTIMER_FREE_ITDS, true);
        }
}

/* Wait for controller to stop using old iTDs and siTDs */
static void end_free_itds(struct fotg210_hcd *fotg210)
{
        struct fotg210_itd *itd, *n;

        if (fotg210->rh_state < FOTG210_RH_RUNNING)
                fotg210->last_itd_to_free = NULL;

        list_for_each_entry_safe(itd, n, &fotg210->cached_itd_list, itd_list) {
                list_del(&itd->itd_list);
                dma_pool_free(fotg210->itd_pool, itd, itd->itd_dma);
                if (itd == fotg210->last_itd_to_free)
                        break;
        }

        if (!list_empty(&fotg210->cached_itd_list))
                start_free_itds(fotg210);
}


/* Handle lost (or very late) IAA interrupts */
static void fotg210_iaa_watchdog(struct fotg210_hcd *fotg210)
{
        if (fotg210->rh_state != FOTG210_RH_RUNNING)
                return;

        /*
         * Lost IAA irqs wedge things badly; seen first with a vt8235.
         * So we need this watchdog, but must protect it against both
         * (a) SMP races against real IAA firing and retriggering, and
         * (b) clean HC shutdown, when IAA watchdog was pending.
         */
        if (fotg210->async_iaa) {
                u32 cmd, status;

                /* If we get here, IAA is *REALLY* late.  It's barely
                 * conceivable that the system is so busy that CMD_IAAD
                 * is still legitimately set, so let's be sure it's
                 * clear before we read STS_IAA.  (The HC should clear
                 * CMD_IAAD when it sets STS_IAA.)
                 */
                cmd = fotg210_readl(fotg210, &fotg210->regs->command);

                /*
                 * If IAA is set here it either legitimately triggered
                 * after the watchdog timer expired (_way_ late, so we'll
                 * still count it as lost) ... or a silicon erratum:
                 * - VIA seems to set IAA without triggering the IRQ;
                 * - IAAD potentially cleared without setting IAA.
                 */
                status = fotg210_readl(fotg210, &fotg210->regs->status);
                if ((status & STS_IAA) || !(cmd & CMD_IAAD)) {
                        INCR(fotg210->stats.lost_iaa);
                        fotg210_writel(fotg210, STS_IAA,
                                        &fotg210->regs->status);
                }

                fotg210_dbg(fotg210, "IAA watchdog: status %x cmd %x\n",
                                status, cmd);
                end_unlink_async(fotg210);
        }
}


/* Enable the I/O watchdog, if appropriate */
static void turn_on_io_watchdog(struct fotg210_hcd *fotg210)
{
        /* Not needed if the controller isn't running or it's already enabled */
        if (fotg210->rh_state != FOTG210_RH_RUNNING ||
                        (fotg210->enabled_hrtimer_events &
                        BIT(FOTG210_HRTIMER_IO_WATCHDOG)))
                return;

        /*
         * Isochronous transfers always need the watchdog.
         * For other sorts we use it only if the flag is set.
         */
        if (fotg210->isoc_count > 0 || (fotg210->need_io_watchdog &&
                        fotg210->async_count + fotg210->intr_count > 0))
                fotg210_enable_event(fotg210, FOTG210_HRTIMER_IO_WATCHDOG,
                                true);
}


/* Handler functions for the hrtimer event types.
 * Keep this array in the same order as the event types indexed by
 * enum fotg210_hrtimer_event in fotg210.h.
 */
static void (*event_handlers[])(struct fotg210_hcd *) = {
        fotg210_poll_ASS,                       /* FOTG210_HRTIMER_POLL_ASS */
        fotg210_poll_PSS,                       /* FOTG210_HRTIMER_POLL_PSS */
        fotg210_handle_controller_death,        /* FOTG210_HRTIMER_POLL_DEAD */
        fotg210_handle_intr_unlinks,    /* FOTG210_HRTIMER_UNLINK_INTR */
        end_free_itds,                  /* FOTG210_HRTIMER_FREE_ITDS */
        unlink_empty_async,             /* FOTG210_HRTIMER_ASYNC_UNLINKS */
        fotg210_iaa_watchdog,           /* FOTG210_HRTIMER_IAA_WATCHDOG */
        fotg210_disable_PSE,            /* FOTG210_HRTIMER_DISABLE_PERIODIC */
        fotg210_disable_ASE,            /* FOTG210_HRTIMER_DISABLE_ASYNC */
        fotg210_work,                   /* FOTG210_HRTIMER_IO_WATCHDOG */
};

static enum hrtimer_restart fotg210_hrtimer_func(struct hrtimer *t)
{
        struct fotg210_hcd *fotg210 =
                        container_of(t, struct fotg210_hcd, hrtimer);
        ktime_t now;
        unsigned long events;
        unsigned long flags;
        unsigned e;

        spin_lock_irqsave(&fotg210->lock, flags);

        events = fotg210->enabled_hrtimer_events;
        fotg210->enabled_hrtimer_events = 0;
        fotg210->next_hrtimer_event = FOTG210_HRTIMER_NO_EVENT;

        /*
         * Check each pending event.  If its time has expired, handle
         * the event; otherwise re-enable it.
         */
        now = ktime_get();
        for_each_set_bit(e, &events, FOTG210_HRTIMER_NUM_EVENTS) {
                if (ktime_compare(now, fotg210->hr_timeouts[e]) >= 0)
                        event_handlers[e](fotg210);
                else
                        fotg210_enable_event(fotg210, e, false);
        }

        spin_unlock_irqrestore(&fotg210->lock, flags);
        return HRTIMER_NORESTART;
}

#define fotg210_bus_suspend NULL
#define fotg210_bus_resume NULL

static int check_reset_complete(struct fotg210_hcd *fotg210, int index,
                u32 __iomem *status_reg, int port_status)
{
        if (!(port_status & PORT_CONNECT))
                return port_status;

        /* if reset finished and it's still not enabled -- handoff */
        if (!(port_status & PORT_PE))
                /* with integrated TT, there's nobody to hand it to! */
                fotg210_dbg(fotg210, "Failed to enable port %d on root hub TT\n",
                                index + 1);
        else
                fotg210_dbg(fotg210, "port %d reset complete, port enabled\n",
                                index + 1);

        return port_status;
}


/* build "status change" packet (one or two bytes) from HC registers */

static int fotg210_hub_status_data(struct usb_hcd *hcd, char *buf)
{
        struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
        u32 temp, status;
        u32 mask;
        int retval = 1;
        unsigned long flags;

        /* init status to no-changes */
        buf[0] = 0;

        /* Inform the core about resumes-in-progress by returning
         * a non-zero value even if there are no status changes.
         */
        status = fotg210->resuming_ports;

        mask = PORT_CSC | PORT_PEC;
        /* PORT_RESUME from hardware ~= PORT_STAT_C_SUSPEND */

        /* no hub change reports (bit 0) for now (power, ...) */

        /* port N changes (bit N)? */
        spin_lock_irqsave(&fotg210->lock, flags);

        temp = fotg210_readl(fotg210, &fotg210->regs->port_status);

        /*
         * Return status information even for ports with OWNER set.
         * Otherwise hub_wq wouldn't see the disconnect event when a
         * high-speed device is switched over to the companion
         * controller by the user.
         */

        if ((temp & mask) != 0 || test_bit(0, &fotg210->port_c_suspend) ||
                        (fotg210->reset_done[0] &&
                        time_after_eq(jiffies, fotg210->reset_done[0]))) {
                buf[0] |= 1 << 1;
                status = STS_PCD;
        }
        /* FIXME autosuspend idle root hubs */
        spin_unlock_irqrestore(&fotg210->lock, flags);
        return status ? retval : 0;
}

static void fotg210_hub_descriptor(struct fotg210_hcd *fotg210,
                struct usb_hub_descriptor *desc)
{
        int ports = HCS_N_PORTS(fotg210->hcs_params);
        u16 temp;

        desc->bDescriptorType = USB_DT_HUB;
        desc->bPwrOn2PwrGood = 10;      /* fotg210 1.0, 2.3.9 says 20ms max */
        desc->bHubContrCurrent = 0;

        desc->bNbrPorts = ports;
        temp = 1 + (ports / 8);
        desc->bDescLength = 7 + 2 * temp;

        /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
        memset(&desc->u.hs.DeviceRemovable[0], 0, temp);
        memset(&desc->u.hs.DeviceRemovable[temp], 0xff, temp);

        temp = HUB_CHAR_INDV_PORT_OCPM; /* per-port overcurrent reporting */
        temp |= HUB_CHAR_NO_LPSM;       /* no power switching */
        desc->wHubCharacteristics = cpu_to_le16(temp);
}

static int fotg210_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
                u16 wIndex, char *buf, u16 wLength)
{
        struct fotg210_hcd *fotg210 = hcd_to_fotg210(hcd);
        int ports = HCS_N_PORTS(fotg210->hcs_params);
        u32 __iomem *status_reg = &fotg210->regs->port_status;
        u32 temp, temp1, status;
        unsigned long flags;
        int retval = 0;
        unsigned selector;

        /*
         * FIXME:  support SetPortFeatures USB_PORT_FEAT_INDICATOR.
         * HCS_INDICATOR may say we can change LEDs to off/amber/green.
         * (track current state ourselves) ... blink for diagnostics,
         * power, "this is the one", etc.  EHCI spec supports this.
         */

        spin_lock_irqsave(&fotg210->lock, flags);
        switch (typeReq) {
        case ClearHubFeature:
                switch (wValue) {
                case C_HUB_LOCAL_POWER:
                case C_HUB_OVER_CURRENT:
                        /* no hub-wide feature/status flags */
                        break;
                default:
                        goto error;
                }
                break;
        case ClearPortFeature:
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
                temp = fotg210_readl(fotg210, status_reg);
                temp &= ~PORT_RWC_BITS;

                /*
                 * Even if OWNER is set, so the port is owned by the
                 * companion controller, hub_wq needs to be able to clear
                 * the port-change status bits (especially
                 * USB_PORT_STAT_C_CONNECTION).
                 */

                switch (wValue) {
                case USB_PORT_FEAT_ENABLE:
                        fotg210_writel(fotg210, temp & ~PORT_PE, status_reg);
                        break;
                case USB_PORT_FEAT_C_ENABLE:
                        fotg210_writel(fotg210, temp | PORT_PEC, status_reg);
                        break;
                case USB_PORT_FEAT_SUSPEND:
                        if (temp & PORT_RESET)
                                goto error;
                        if (!(temp & PORT_SUSPEND))
                                break;
                        if ((temp & PORT_PE) == 0)
                                goto error;

                        /* resume signaling for 20 msec */
                        fotg210_writel(fotg210, temp | PORT_RESUME, status_reg);
                        fotg210->reset_done[wIndex] = jiffies
                                        + msecs_to_jiffies(USB_RESUME_TIMEOUT);
                        break;
                case USB_PORT_FEAT_C_SUSPEND:
                        clear_bit(wIndex, &fotg210->port_c_suspend);
                        break;
                case USB_PORT_FEAT_C_CONNECTION:
                        fotg210_writel(fotg210, temp | PORT_CSC, status_reg);
                        break;
                case USB_PORT_FEAT_C_OVER_CURRENT:
                        fotg210_writel(fotg210, temp | OTGISR_OVC,
                                        &fotg210->regs->otgisr);
                        break;
                case USB_PORT_FEAT_C_RESET:
                        /* GetPortStatus clears reset */
                        break;
                default:
                        goto error;
                }
                fotg210_readl(fotg210, &fotg210->regs->command);
                break;
        case GetHubDescriptor:
                fotg210_hub_descriptor(fotg210, (struct usb_hub_descriptor *)
                                buf);
                break;
        case GetHubStatus:
                /* no hub-wide feature/status flags */
                memset(buf, 0, 4);
                /*cpu_to_le32s ((u32 *) buf); */
                break;
        case GetPortStatus:
                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
                status = 0;
                temp = fotg210_readl(fotg210, status_reg);

                /* wPortChange bits */
                if (temp & PORT_CSC)
                        status |= USB_PORT_STAT_C_CONNECTION << 16;
                if (temp & PORT_PEC)
                        status |= USB_PORT_STAT_C_ENABLE << 16;

                temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
                if (temp1 & OTGISR_OVC)
                        status |= USB_PORT_STAT_C_OVERCURRENT << 16;

                /* whoever resumes must GetPortStatus to complete it!! */
                if (temp & PORT_RESUME) {

                        /* Remote Wakeup received? */
                        if (!fotg210->reset_done[wIndex]) {
                                /* resume signaling for 20 msec */
                                fotg210->reset_done[wIndex] = jiffies
                                                + msecs_to_jiffies(20);
                                /* check the port again */
                                mod_timer(&fotg210_to_hcd(fotg210)->rh_timer,
                                                fotg210->reset_done[wIndex]);
                        }

                        /* resume completed? */
                        else if (time_after_eq(jiffies,
                                        fotg210->reset_done[wIndex])) {
                                clear_bit(wIndex, &fotg210->suspended_ports);
                                set_bit(wIndex, &fotg210->port_c_suspend);
                                fotg210->reset_done[wIndex] = 0;

                                /* stop resume signaling */
                                temp = fotg210_readl(fotg210, status_reg);
                                fotg210_writel(fotg210, temp &
                                                ~(PORT_RWC_BITS | PORT_RESUME),
                                                status_reg);
                                clear_bit(wIndex, &fotg210->resuming_ports);
                                retval = handshake(fotg210, status_reg,
                                                PORT_RESUME, 0, 2000);/* 2ms */
                                if (retval != 0) {
                                        fotg210_err(fotg210,
                                                        "port %d resume error %d\n",
                                                        wIndex + 1, retval);
                                        goto error;
                                }
                                temp &= ~(PORT_SUSPEND|PORT_RESUME|(3<<10));
                        }
                }

                /* whoever resets must GetPortStatus to complete it!! */
                if ((temp & PORT_RESET) && time_after_eq(jiffies,
                                fotg210->reset_done[wIndex])) {
                        status |= USB_PORT_STAT_C_RESET << 16;
                        fotg210->reset_done[wIndex] = 0;
                        clear_bit(wIndex, &fotg210->resuming_ports);

                        /* force reset to complete */
                        fotg210_writel(fotg210,
                                        temp & ~(PORT_RWC_BITS | PORT_RESET),
                                        status_reg);
                        /* REVISIT:  some hardware needs 550+ usec to clear
                         * this bit; seems too long to spin routinely...
                         */
                        retval = handshake(fotg210, status_reg,
                                        PORT_RESET, 0, 1000);
                        if (retval != 0) {
                                fotg210_err(fotg210, "port %d reset error %d\n",
                                                wIndex + 1, retval);
                                goto error;
                        }

                        /* see what we found out */
                        temp = check_reset_complete(fotg210, wIndex, status_reg,
                                        fotg210_readl(fotg210, status_reg));

                        /* restart schedule */
                        fotg210->command |= CMD_RUN;
                        fotg210_writel(fotg210, fotg210->command, &fotg210->regs->command);
                }

                if (!(temp & (PORT_RESUME|PORT_RESET))) {
                        fotg210->reset_done[wIndex] = 0;
                        clear_bit(wIndex, &fotg210->resuming_ports);
                }

                /* transfer dedicated ports to the companion hc */
                if ((temp & PORT_CONNECT) &&
                                test_bit(wIndex, &fotg210->companion_ports)) {
                        temp &= ~PORT_RWC_BITS;
                        fotg210_writel(fotg210, temp, status_reg);
                        fotg210_dbg(fotg210, "port %d --> companion\n",
                                        wIndex + 1);
                        temp = fotg210_readl(fotg210, status_reg);
                }

                /*
                 * Even if OWNER is set, there's no harm letting hub_wq
                 * see the wPortStatus values (they should all be 0 except
                 * for PORT_POWER anyway).
                 */

                if (temp & PORT_CONNECT) {
                        status |= USB_PORT_STAT_CONNECTION;
                        status |= fotg210_port_speed(fotg210, temp);
                }
                if (temp & PORT_PE)
                        status |= USB_PORT_STAT_ENABLE;

                /* maybe the port was unsuspended without our knowledge */
                if (temp & (PORT_SUSPEND|PORT_RESUME)) {
                        status |= USB_PORT_STAT_SUSPEND;
                } else if (test_bit(wIndex, &fotg210->suspended_ports)) {
                        clear_bit(wIndex, &fotg210->suspended_ports);
                        clear_bit(wIndex, &fotg210->resuming_ports);
                        fotg210->reset_done[wIndex] = 0;
                        if (temp & PORT_PE)
                                set_bit(wIndex, &fotg210->port_c_suspend);
                }

                temp1 = fotg210_readl(fotg210, &fotg210->regs->otgisr);
                if (temp1 & OTGISR_OVC)
                        status |= USB_PORT_STAT_OVERCURRENT;
                if (temp & PORT_RESET)
                        status |= USB_PORT_STAT_RESET;
                if (test_bit(wIndex, &fotg210->port_c_suspend))
                        status |= USB_PORT_STAT_C_SUSPEND << 16;

                if (status & ~0xffff)   /* only if wPortChange is interesting */
                        dbg_port(fotg210, "GetStatus", wIndex + 1, temp);
                put_unaligned_le32(status, buf);
                break;
        case SetHubFeature:
                switch (wValue) {
                case C_HUB_LOCAL_POWER:
                case C_HUB_OVER_CURRENT:
                        /* no hub-wide feature/status flags */
                        break;
                default:
                        goto error;
                }
                break;
        case SetPortFeature:
                selector = wIndex >> 8;
                wIndex &= 0xff;

                if (!wIndex || wIndex > ports)
                        goto error;
                wIndex--;
                temp = fotg210_readl(fotg210, status_reg);
                temp &= ~PORT_RWC_BITS;
                switch (wValue) {
                case USB_PORT_FEAT_SUSPEND:
                        if ((temp & PORT_PE) == 0
                                        || (temp & PORT_RESET) != 0)
                                goto error;

                        /* After above check the port must be connected.
                         * Set appropriate bit thus could put phy into low power
                         * mode if we have hostpc feature
                         */
                        fotg210_writel(fotg210, temp | PORT_SUSPEND,
                                        status_reg);
                        set_bit(wIndex, &fotg210->suspended_ports);
                        break;
                case USB_PORT_FEAT_RESET:
                        if (temp & PORT_RESUME)
                                goto error;
                        /* line status bits may report this as low speed,
                         * which can be fine if this root hub has a
                         * transaction translator built in.
                         */
                        fotg210_dbg(fotg210, "port %d reset\n", wIndex + 1);
                        temp |= PORT_RESET;
                        temp &= ~PORT_PE;

                        /*
                         * caller must wait, then call GetPortStatus
                         * usb 2.0 spec says 50 ms resets on root
                         */
                        fotg210->reset_done[wIndex] = jiffies
                                        + msecs_to_jiffies(50);
                        fotg210_writel(fotg210, temp, status_reg);
                        break;

                /* For downstream facing ports (these):  one hub port is put
                 * into test mode according to USB2 11.24.2.13, then the hub
                 * must be reset (which for root hub now means rmmod+modprobe,
                 * or else system reboot).  See EHCI 2.3.9 and 4.14 for info
                 * about the EHCI-specific stuff.
                 */
                case USB_PORT_FEAT_TEST:
                        if (!selector || selector > 5)
                                goto error;
                        spin_unlock_irqrestore(&fotg210->lock, flags);
                        fotg210_quiesce(fotg210);
                        spin_lock_irqsave(&fotg210->lock, flags);

                        /* Put all enabled ports into suspend */
                        temp = fotg210_readl(fotg210, status_reg) &
                                ~PORT_RWC_BITS;
                        if (temp & PORT_PE)
                                fotg210_writel(fotg210, temp | PORT_SUSPEND,
                                                status_reg);

                        spin_unlock_irqrestore(&fotg210->lock, flags);
                        fotg210_halt(fotg210);
                        spin_lock_irqsave(&fotg210->lock, flags);

                        temp = fotg210_readl(fotg210, status_reg);
                        temp |= selector << 16;
                        fotg210_writel(fotg210, temp, status_reg);
                        break;

                default:
                        goto error;
                }
                fotg210_readl(fotg210, &fotg210->regs->command);
                break;

        default:
error:
                /* "stall" on error */
                retval = -EPIPE;
        }
        spin_unlock_irqrestore(&fotg210->lock, flags);
        return retval;
}

static void __maybe_unused fotg210_relinquish_port(struct usb_hcd *hcd,
                int portnum)
{
        return;
}

static int __maybe_unused fotg210_port_handed_over(struct usb_hcd *hcd,
                int portnum)
{
        return 0;
}

/* There's basically three types of memory:
 *      - data used only by the HCD ... kmalloc is fine
 *      - async and periodic schedules, shared by HC and HCD ... these
 *        need to use dma_pool or dma_alloc_coherent
 *      - driver buffers, read/written by HC ... single shot DMA mapped
 *
 * There's also "register" data (e.g. PCI or SOC), which is memory mapped.
 * No memory seen by this driver is pageable.
 */

/* Allocate the key transfer structures from the previously allocated pool */
static inline void fotg210_qtd_init(struct fotg210_hcd *fotg210,
                struct fotg210_qtd *qtd, dma_addr_t dma)
{
        memset(qtd, 0, sizeof(*qtd));
        qtd->qtd_dma = dma;
        qtd->hw_token = cpu_to_hc32(fotg210, QTD_STS_HALT);
        qtd->hw_next = FOTG210_LIST_END(fotg210);
        qtd->hw_alt_next = FOTG210_LIST_END(fotg210);
        INIT_LIST_HEAD(&qtd->qtd_list);
}

static struct fotg210_qtd *fotg210_qtd_alloc(struct fotg210_hcd *fotg210,
                gfp_t flags)
{
        struct fotg210_qtd *qtd;
        dma_addr_t dma;

        qtd = dma_pool_alloc(fotg210->qtd_pool, flags, &dma);
        if (qtd != NULL)
                fotg210_qtd_init(fotg210, qtd, dma);

        return qtd;
}

static inline void fotg210_qtd_free(struct fotg210_hcd *fotg210,
                struct fotg210_qtd *qtd)
{
        dma_pool_free(fotg210->qtd_pool, qtd, qtd->qtd_dma);
}


static void qh_destroy(struct fotg210_hcd *fotg210, struct fotg210_qh *qh)
{
        /* clean qtds first, and know this is not linked */
        if (!list_empty(&qh->qtd_list) || qh->qh_next.ptr) {
                fotg210_dbg(fotg210, "unused qh not empty!\n");
                BUG();
        }
        if (qh->dummy)
                fotg210_qtd_free(fotg210, qh->dummy);
        dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
        kfree(qh);
}

static struct fotg210_qh *fotg210_qh_alloc(struct fotg210_hcd *fotg210,
                gfp_t flags)
{
        struct fotg210_qh *qh;
        dma_addr_t dma;

        qh = kzalloc(sizeof(*qh), GFP_ATOMIC);
        if (!qh)
                goto done;
        qh->hw = dma_pool_zalloc(fotg210->qh_pool, flags, &dma);
        if (!qh->hw)
                goto fail;
        qh->qh_dma = dma;
        INIT_LIST_HEAD(&qh->qtd_list);

        /* dummy td enables safe urb queuing */
        qh->dummy = fotg210_qtd_alloc(fotg210, flags);
        if (qh->dummy == NULL) {
                fotg210_dbg(fotg210, "no dummy td\n");
                goto fail1;
        }
done:
        return qh;
fail1:
        dma_pool_free(fotg210->qh_pool, qh->hw, qh->qh_dma);
fail:
        kfree(qh);
        return NULL;
}

/* The queue heads and transfer descriptors are managed from pools tied
 * to each of the "per device" structures.
 * This is the initialisation and cleanup code.
 */

static void fotg210_mem_cleanup(struct fotg210_hcd *fotg210)
{
        if (fotg210->async)
                qh_destroy(fotg210, fotg210->async);
        fotg210->async = NULL;

        if (fotg210->dummy)
                qh_destroy(fotg210, fotg210->dummy);
        fotg210->dummy = NULL;

        /* DMA consistent memory and pools */
        dma_pool_destroy(fotg210->qtd_pool);
        fotg210->qtd_pool = NULL;

        dma_pool_destroy(fotg210->qh_pool);
        fotg210->qh_pool = NULL;

        dma_pool_destroy(fotg210->itd_pool);
        fotg210->itd_pool = NULL;

        if (fotg210->periodic)
                dma_free_coherent(fotg210_to_hcd(fotg210)->self.controller,
                                fotg210->periodic_size * sizeof(u32),
                                fotg210->periodic, fotg210->periodic_dma);
        fotg210->periodic = NULL;

        /* shadow periodic table */
        kfree(fotg210->pshadow);
        fotg210->pshadow = NULL;
}

/* remember to add cleanup code (above) if you add anything here */
static int fotg210_mem_init(struct fotg210_hcd *fotg210, gfp_t flags)
{
        int i;

        /* QTDs for control/bulk/intr transfers */
        fotg210->qtd_pool = dma_pool_create("fotg210_qtd",
                        fotg210_to_hcd(fotg210)->self.controller,
                        sizeof(struct fotg210_qtd),
                        32 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!fotg210->qtd_pool)
                goto fail;

        /* QHs for control/bulk/intr transfers */
        fotg210->qh_pool = dma_pool_create("fotg210_qh",
                        fotg210_to_hcd(fotg210)->self.controller,
                        sizeof(struct fotg210_qh_hw),
                        32 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!fotg210->qh_pool)
                goto fail;

        fotg210->async = fotg210_qh_alloc(fotg210, flags);
        if (!fotg210->async)
                goto fail;

        /* ITD for high speed ISO transfers */
        fotg210->itd_pool = dma_pool_create("fotg210_itd",
                        fotg210_to_hcd(fotg210)->self.controller,
                        sizeof(struct fotg210_itd),
                        64 /* byte alignment (for hw parts) */,
                        4096 /* can't cross 4K */);
        if (!fotg210->itd_pool)
                goto fail;

        /* Hardware periodic table */
        fotg210->periodic =
                dma_alloc_coherent(fotg210_to_hcd(fotg210)->self.controller,
                                fotg210->periodic_size * sizeof(__le32),
                                &fotg210->periodic_dma, 0);
        if (fotg210->periodic == NULL)
                goto fail;

        for (i = 0; i < fotg210->periodic_size; i++)
                fotg210->periodic[i] = FOTG210_LIST_END(fotg210);

        /* software shadow of hardware table */
        fotg210->pshadow = kcalloc(fotg210->periodic_size, sizeof(void *),
                        flags);
        if (fotg210->pshadow != NULL)
                return 0;

fail:
        fotg210_dbg(fotg210, "couldn't init memory\n");
        fotg210_mem_cleanup(fotg210);
        return -ENOMEM;
}
/* EHCI hardware queue manipulation ... the core.  QH/QTD manipulation.
 *
 * Control, bulk, and interrupt traffic all use "qh" lists.  They list "qtd"
 * entries describing USB transactions, max 16-20kB/entry (with 4kB-aligned
 * buffers needed for the larger number).  We use one QH per endpoint, queue
 * multiple urbs (all three types) per endpoint.  URBs may need several qtds.
 *
 * ISO traffic uses "ISO TD" (itd) records, and (along with
 * interrupts) needs careful scheduling.  Performance improvements can be
 * an ongoing challenge.  That's in "ehci-sched.c".
 *
 * USB 1.1 devices are handled (a) by "companion" OHCI or UHCI root hubs,
 * or otherwise through transaction translators (TTs) in USB 2.0 hubs using
 * (b) special fields in qh entries or (c) split iso entries.  TTs will
 * buffer low/full speed data so the host collects it at high speed.
 */

/* fill a qtd, returning how much of the buffer we were able to queue up */
static int qtd_fill(struct fotg210_hcd *fotg210, struct fotg210_qtd *qtd,
                dma_addr_t buf, size_t len, int token, int maxpacket)
{
        int i, count;
        u64 addr = buf;

        /* one buffer entry per 4K ... first might be short or unaligned */
        qtd->hw_buf[0] = cpu_to_hc32(fotg210, (u32)addr);