/*-
 * Copyright (c) 2017 Ilya Bakulin.  All rights reserved.
 * Copyright (c) 2018-2019 The FreeBSD Foundation
 *
 * Portions of this software were developed by Björn Zeeb
 * under sponsorship from the FreeBSD Foundation.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 * Portions of this software may have been developed with reference to
 * the SD Simplified Specification.  The following disclaimer may apply:
 *
 * The following conditions apply to the release of the simplified
 * specification ("Simplified Specification") by the SD Card Association and
 * the SD Group. The Simplified Specification is a subset of the complete SD
 * Specification which is owned by the SD Card Association and the SD
 * Group. This Simplified Specification is provided on a non-confidential
 * basis subject to the disclaimers below. Any implementation of the
 * Simplified Specification may require a license from the SD Card
 * Association, SD Group, SD-3C LLC or other third parties.
 *
 * Disclaimers:
 *
 * The information contained in the Simplified Specification is presented only
 * as a standard specification for SD Cards and SD Host/Ancillary products and
 * is provided "AS-IS" without any representations or warranties of any
 * kind. No responsibility is assumed by the SD Group, SD-3C LLC or the SD
 * Card Association for any damages, any infringements of patents or other
 * right of the SD Group, SD-3C LLC, the SD Card Association or any third
 * parties, which may result from its use. No license is granted by
 * implication, estoppel or otherwise under any patent or other rights of the
 * SD Group, SD-3C LLC, the SD Card Association or any third party. Nothing
 * herein shall be construed as an obligation by the SD Group, the SD-3C LLC
 * or the SD Card Association to disclose or distribute any technical
 * information, know-how or other confidential information to any third party.
 */
/*
 * Implements the (kernel specific) SDIO parts.
 * This will hide all cam(4) functionality from the SDIO driver implementations
 * which will just be newbus/device(9) and hence look like any other driver for,
 * e.g., PCI.
 * The sdiob(4) parts effetively "translate" between the two worlds "bridging"
 * messages from MMCCAM to newbus and back.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/types.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_queue.h>
#include <cam/cam_periph.h>
#include <cam/cam_xpt.h>
#include <cam/cam_xpt_periph.h>
#include <cam/cam_xpt_internal.h> /* for cam_path */
#include <cam/cam_debug.h>

#include <dev/mmc/mmcreg.h>

#include <dev/sdio/sdiob.h>
#include <dev/sdio/sdio_subr.h>

#include "sdio_if.h"

#ifdef DEBUG
#define DPRINTF(...)            printf(__VA_ARGS__)
#define DPRINTFDEV(_dev, ...)   device_printf((_dev), __VA_ARGS__)
#else
#define DPRINTF(...)
#define DPRINTFDEV(_dev, ...)
#endif

struct sdiob_softc {
        uint32_t                        sdio_state;
#define SDIO_STATE_DEAD                 0x0001
#define SDIO_STATE_INITIALIZING         0x0002
#define SDIO_STATE_READY                0x0004
        uint32_t                        nb_state;
#define NB_STATE_DEAD                   0x0001
#define NB_STATE_SIM_ADDED              0x0002
#define NB_STATE_READY                  0x0004

        /* CAM side. */
        struct card_info                cardinfo;
        struct cam_periph               *periph;
        union ccb                       *ccb;
        struct task                     discover_task;

        /* Newbus side. */
        device_t                        dev;    /* Ourselves. */
        device_t                        child[8];
};

/* -------------------------------------------------------------------------- */
/*
 * SDIO CMD52 and CM53 implementations along with wrapper functions for
 * read/write and a CAM periph helper function.
 * These are the backend implementations of the sdio_if.m framework talking
 * through CAM to sdhci.
 * Note: these functions are also called during early discovery stage when
 * we are not a device(9) yet. Hence they cannot always use device_printf()
 * to log errors and have to call CAM_DEBUG() during these early stages.
 */

static int
sdioerror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
{

        return (cam_periph_error(ccb, cam_flags, sense_flags));
}

/* CMD52: direct byte access. */
static int
sdiob_rw_direct_sc(struct sdiob_softc *sc, uint8_t fn, uint32_t addr, bool wr,
    uint8_t *val)
{
        uint32_t arg, flags;
        int error;

        KASSERT((val != NULL), ("%s val passed as NULL\n", __func__));

        if (sc->ccb == NULL)
                sc->ccb = xpt_alloc_ccb();
        else
                memset(sc->ccb, 0, sizeof(*sc->ccb));
        xpt_setup_ccb(&sc->ccb->ccb_h, sc->periph->path, CAM_PRIORITY_NORMAL);
        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_TRACE,
            ("%s(fn=%d, addr=%#02x, wr=%d, *val=%#02x)\n", __func__,
            fn, addr, wr, *val));

        flags = MMC_RSP_R5 | MMC_CMD_AC;
        arg = SD_IO_RW_FUNC(fn) | SD_IO_RW_ADR(addr);
        if (wr)
                arg |= SD_IO_RW_WR | SD_IO_RW_RAW | SD_IO_RW_DAT(*val);

        cam_fill_mmcio(&sc->ccb->mmcio,
                /*retries*/ 0,
                /*cbfcnp*/ NULL,
                /*flags*/ CAM_DIR_NONE,
                /*mmc_opcode*/ SD_IO_RW_DIRECT,
                /*mmc_arg*/ arg,
                /*mmc_flags*/ flags,
                /*mmc_data*/ 0,
                /*timeout*/ sc->cardinfo.f[fn].timeout);
        error = cam_periph_runccb(sc->ccb, sdioerror, CAM_FLAG_NONE, 0, NULL);
        if (error != 0) {
                if (sc->dev != NULL)
                        device_printf(sc->dev,
                            "%s: Failed to %s address %#10x error=%d\n",
                            __func__, (wr) ? "write" : "read", addr, error);
                else
                        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_INFO,
                            ("%s: Failed to %s address: %#10x error=%d\n",
                            __func__, (wr) ? "write" : "read", addr, error));
                return (error);
        }

        /* TODO: Add handling of MMC errors */
        /* ccb->mmcio.cmd.error ? */
        if (wr == false)
                *val = sc->ccb->mmcio.cmd.resp[0] & 0xff;

        return (0);
}

static int
sdio_rw_direct(device_t dev, uint8_t fn, uint32_t addr, bool wr,
    uint8_t *val)
{
        struct sdiob_softc *sc;
        int error;

        sc = device_get_softc(dev);
        cam_periph_lock(sc->periph);
        error = sdiob_rw_direct_sc(sc, fn, addr, wr, val);
        cam_periph_unlock(sc->periph);
        return (error);
}

static int
sdiob_read_direct(device_t dev, uint8_t fn, uint32_t addr, uint8_t *val)
{
        int error;
        uint8_t v;

        error = sdio_rw_direct(dev, fn, addr, false, &v);
        /* Be polite and do not touch the value on read error. */
        if (error == 0 && val != NULL)
                *val = v;
        return (error);
}

static int
sdiob_write_direct(device_t dev, uint8_t fn, uint32_t addr, uint8_t val)
{

        return (sdio_rw_direct(dev, fn, addr, true, &val));
}

/*
 * CMD53: IO_RW_EXTENDED, read and write multiple I/O registers.
 * Increment false gets FIFO mode (single register address).
 */
/*
 * A b_count of 0 means byte mode, b_count > 0 gets block mode.
 * A b_count of >= 512 would mean infinitive block transfer, which would become
 * b_count = 0, is not yet supported.
 * For b_count == 0, blksz is the len of bytes, otherwise it is the amount of
 * full sized blocks (you must not round the blocks up and leave the last one
 * partial!)
 * For byte mode, the maximum of blksz is the functions cur_blksize.
 * This function should ever only be called by sdio_rw_extended_sc()! 
 */
static int
sdiob_rw_extended_cam(struct sdiob_softc *sc, uint8_t fn, uint32_t addr,
    bool wr, uint8_t *buffer, bool incaddr, uint32_t b_count, uint16_t blksz)
{
        struct mmc_data mmcd;
        uint32_t arg, cam_flags, flags, len;
        int error;

        if (sc->ccb == NULL)
                sc->ccb = xpt_alloc_ccb();
        else
                memset(sc->ccb, 0, sizeof(*sc->ccb));
        xpt_setup_ccb(&sc->ccb->ccb_h, sc->periph->path, CAM_PRIORITY_NORMAL);
        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_TRACE,
            ("%s(fn=%d addr=%#0x wr=%d b_count=%u blksz=%u buf=%p incr=%d)\n",
            __func__, fn, addr, wr, b_count, blksz, buffer, incaddr));

        KASSERT((b_count <= 511), ("%s: infinitive block transfer not yet "
            "supported: b_count %u blksz %u, sc %p, fn %u, addr %#10x, %s, "
            "buffer %p, %s\n", __func__, b_count, blksz, sc, fn, addr,
            wr ? "wr" : "rd", buffer, incaddr ? "incaddr" : "fifo"));
        /* Blksz needs to be within bounds for both byte and block mode! */
        KASSERT((blksz <= sc->cardinfo.f[fn].cur_blksize), ("%s: blksz "
            "%u > bur_blksize %u, sc %p, fn %u, addr %#10x, %s, "
            "buffer %p, %s, b_count %u\n", __func__, blksz,
            sc->cardinfo.f[fn].cur_blksize, sc, fn, addr,
            wr ? "wr" : "rd", buffer, incaddr ? "incaddr" : "fifo",
            b_count));
        if (b_count == 0) {
                /* Byte mode */
                len = blksz;
                if (blksz == 512)
                        blksz = 0;
                arg = SD_IOE_RW_LEN(blksz);
        } else {
                /* Block mode. */
#ifdef __notyet__
                if (b_count > 511) {
                        /* Infinitive block transfer. */
                        b_count = 0;
                }
#endif
                len = b_count * blksz;
                arg = SD_IOE_RW_BLK | SD_IOE_RW_LEN(b_count);
        }

        flags = MMC_RSP_R5 | MMC_CMD_ADTC;
        arg |= SD_IOE_RW_FUNC(fn) | SD_IOE_RW_ADR(addr);
        if (incaddr)
                arg |= SD_IOE_RW_INCR;

        memset(&mmcd, 0, sizeof(mmcd));
        mmcd.data = buffer;
        mmcd.len = len;
        if (arg & SD_IOE_RW_BLK) {
                /* XXX both should be known from elsewhere, aren't they? */
                mmcd.block_size = blksz;
                mmcd.block_count = b_count;
        }

        if (wr) {
                arg |= SD_IOE_RW_WR;
                cam_flags = CAM_DIR_OUT;
                mmcd.flags = MMC_DATA_WRITE;
        } else {
                cam_flags = CAM_DIR_IN;
                mmcd.flags = MMC_DATA_READ;
        }
#ifdef __notyet__
        if (b_count == 0) {
                /* XXX-BZ TODO FIXME.  Cancel I/O: CCCR -> ASx */
                /* Stop cmd. */
        }
#endif
        cam_fill_mmcio(&sc->ccb->mmcio,
                /*retries*/ 0,
                /*cbfcnp*/ NULL,
                /*flags*/ cam_flags,
                /*mmc_opcode*/ SD_IO_RW_EXTENDED,
                /*mmc_arg*/ arg,
                /*mmc_flags*/ flags,
                /*mmc_data*/ &mmcd,
                /*timeout*/ sc->cardinfo.f[fn].timeout);
        if (arg & SD_IOE_RW_BLK) {
                mmcd.flags |= MMC_DATA_BLOCK_SIZE;
                if (b_count != 1)
                        sc->ccb->mmcio.cmd.data->flags |= MMC_DATA_MULTI;
        }

        /* Execute. */
        error = cam_periph_runccb(sc->ccb, sdioerror, CAM_FLAG_NONE, 0, NULL);
        if (error != 0) {
                if (sc->dev != NULL)
                        device_printf(sc->dev,
                            "%s: Failed to %s address %#10x buffer %p size %u "
                            "%s b_count %u blksz %u error=%d\n",
                            __func__, (wr) ? "write to" : "read from", addr,
                            buffer, len, (incaddr) ? "incr" : "fifo",
                            b_count, blksz, error);
                else
                        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_INFO,
                            ("%s: Failed to %s address %#10x buffer %p size %u "
                            "%s b_count %u blksz %u error=%d\n",
                            __func__, (wr) ? "write to" : "read from", addr,
                            buffer, len, (incaddr) ? "incr" : "fifo",
                            b_count, blksz, error));
                return (error);
        }

        /* TODO: Add handling of MMC errors */
        /* ccb->mmcio.cmd.error ? */
        error = sc->ccb->mmcio.cmd.resp[0] & 0xff;
        if (error != 0) {
                if (sc->dev != NULL)
                        device_printf(sc->dev,
                            "%s: Failed to %s address %#10x buffer %p size %u "
                            "%s b_count %u blksz %u mmcio resp error=%d\n",
                            __func__, (wr) ? "write to" : "read from", addr,
                            buffer, len, (incaddr) ? "incr" : "fifo",
                            b_count, blksz, error);
                else
                        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_INFO,
                            ("%s: Failed to %s address %#10x buffer %p size %u "
                            "%s b_count %u blksz %u mmcio resp error=%d\n",
                            __func__, (wr) ? "write to" : "read from", addr,
                            buffer, len, (incaddr) ? "incr" : "fifo",
                            b_count, blksz, error));
        }
        return (error);
}

static int
sdiob_rw_extended_sc(struct sdiob_softc *sc, uint8_t fn, uint32_t addr,
    bool wr, uint32_t size, uint8_t *buffer, bool incaddr)
{
        int error;
        uint32_t len;
        uint32_t b_count;

        /*
         * If block mode is supported and we have at least 4 bytes to write and
         * the size is at least one block, then start doing blk transfers.
         */
        while (sc->cardinfo.support_multiblk &&
            size > 4 && size >= sc->cardinfo.f[fn].cur_blksize) {
                b_count = size / sc->cardinfo.f[fn].cur_blksize;
                KASSERT(b_count >= 1, ("%s: block count too small %u size %u "
                    "cur_blksize %u\n", __func__, b_count, size,
                    sc->cardinfo.f[fn].cur_blksize));

#ifdef __notyet__
                /* XXX support inifinite transfer with b_count = 0. */
#else
                if (b_count > 511)
                        b_count = 511;
#endif
                len = b_count * sc->cardinfo.f[fn].cur_blksize;
                error = sdiob_rw_extended_cam(sc, fn, addr, wr, buffer, incaddr,
                    b_count, sc->cardinfo.f[fn].cur_blksize);
                if (error != 0)
                        return (error);

                size -= len;
                buffer += len;
                if (incaddr)
                        addr += len;
        }

        while (size > 0) {
                len = MIN(size, sc->cardinfo.f[fn].cur_blksize);

                error = sdiob_rw_extended_cam(sc, fn, addr, wr, buffer, incaddr,
                    0, len);
                if (error != 0)
                        return (error);

                /* Prepare for next iteration. */
                size -= len;
                buffer += len;
                if (incaddr)
                        addr += len;
        }

        return (0);
}

static int
sdiob_rw_extended(device_t dev, uint8_t fn, uint32_t addr, bool wr,
    uint32_t size, uint8_t *buffer, bool incaddr)
{
        struct sdiob_softc *sc;
        int error;

        sc = device_get_softc(dev);
        cam_periph_lock(sc->periph);
        error = sdiob_rw_extended_sc(sc, fn, addr, wr, size, buffer, incaddr);
        cam_periph_unlock(sc->periph);
        return (error);
}

static int
sdiob_read_extended(device_t dev, uint8_t fn, uint32_t addr, uint32_t size,
    uint8_t *buffer, bool incaddr)
{

        return (sdiob_rw_extended(dev, fn, addr, false, size, buffer, incaddr));
}

static int
sdiob_write_extended(device_t dev, uint8_t fn, uint32_t addr, uint32_t size,
    uint8_t *buffer, bool incaddr)
{

        return (sdiob_rw_extended(dev, fn, addr, true, size, buffer, incaddr));
}

/* -------------------------------------------------------------------------- */
/* Bus interface, ivars handling. */

static int
sdiob_read_ivar(device_t dev, device_t child, int which, uintptr_t *result)
{
        struct sdiob_softc *sc;
        struct sdio_func *f;

        f = device_get_ivars(child);
        KASSERT(f != NULL, ("%s: dev %p child %p which %d, child ivars NULL\n",
            __func__, dev, child, which));

        switch (which) {
        case SDIOB_IVAR_SUPPORT_MULTIBLK:
                sc = device_get_softc(dev);
                KASSERT(sc != NULL, ("%s: dev %p child %p which %d, sc NULL\n",
                    __func__, dev, child, which));
                *result = sc->cardinfo.support_multiblk;
                break;
        case SDIOB_IVAR_FUNCTION:
                *result = (uintptr_t)f;
                break;
        case SDIOB_IVAR_FUNCNUM:
                *result = f->fn;
                break;
        case SDIOB_IVAR_CLASS:
                *result = f->class;
                break;
        case SDIOB_IVAR_VENDOR:
                *result = f->vendor;
                break;
        case SDIOB_IVAR_DEVICE:
                *result = f->device;
                break;
        case SDIOB_IVAR_DRVDATA:
                *result = f->drvdata;
                break;
        default:
                return (ENOENT);
        }
        return (0);
}

static int
sdiob_write_ivar(device_t dev, device_t child, int which, uintptr_t value)
{
        struct sdio_func *f;

        f = device_get_ivars(child);
        KASSERT(f != NULL, ("%s: dev %p child %p which %d, child ivars NULL\n",
            __func__, dev, child, which));

        switch (which) {
        case SDIOB_IVAR_SUPPORT_MULTIBLK:
        case SDIOB_IVAR_FUNCTION:
        case SDIOB_IVAR_FUNCNUM:
        case SDIOB_IVAR_CLASS:
        case SDIOB_IVAR_VENDOR:
        case SDIOB_IVAR_DEVICE:
                return (EINVAL);        /* Disallowed. */
        case SDIOB_IVAR_DRVDATA:
                f->drvdata = value;
                break;
        default:
                return (ENOENT);
        }

        return (0);
}

/* -------------------------------------------------------------------------- */
/*
 * Newbus functions for ourselves to probe/attach/detach and become a proper
 * device(9).  Attach will also probe for child devices (another driver
 * implementing SDIO).
 */

static int
sdiob_probe(device_t dev)
{

        device_set_desc(dev, "SDIO CAM-Newbus bridge");
        return (BUS_PROBE_DEFAULT);
}

static int
sdiob_attach(device_t dev)
{
        struct sdiob_softc *sc;
        int error, i;

        sc = device_get_softc(dev);
        if (sc == NULL)
                return (ENXIO);

        /*
         * Now that we are a dev, create one child device per function,
         * initialize the backpointer, so we can pass them around and
         * call CAM operations on the parent, and also set the function
         * itself as ivars, so that we can query/update them.
         * Do this before any child gets a chance to attach.
         */
        for (i = 0; i < sc->cardinfo.num_funcs; i++) {
                sc->child[i] = device_add_child(dev, NULL, DEVICE_UNIT_ANY);
                if (sc->child[i] == NULL) {
                        device_printf(dev, "%s: failed to add child\n", __func__);
                        return (ENXIO);
                }
                sc->cardinfo.f[i].dev = sc->child[i];

                /* Set the function as ivar to the child device. */
                device_set_ivars(sc->child[i], &sc->cardinfo.f[i]);
        }

        /*
         * No one will ever attach to F0; we do the above to have a "device"
         * to talk to in a general way in the code.
         * Also do the probe/attach in a 2nd loop, so that all devices are
         * present as we do have drivers consuming more than one device/func
         * and might play "tricks" in order to do that assuming devices and
         * ivars are available for all.
         */
        for (i = 1; i < sc->cardinfo.num_funcs; i++) {
                error = device_probe_and_attach(sc->child[i]);
                if (error != 0 && bootverbose)
                        device_printf(dev, "%s: device_probe_and_attach(%p %s) "
                            "failed %d for function %d, no child yet\n",
                             __func__,
                             sc->child, device_get_nameunit(sc->child[i]),
                             error, i);
        }

        sc->nb_state = NB_STATE_READY;

        cam_periph_lock(sc->periph);
        xpt_announce_periph(sc->periph, NULL);
        cam_periph_unlock(sc->periph);

        return (0);
}

static int
sdiob_detach(device_t dev)
{

        /* XXX TODO? */
        return (EOPNOTSUPP);
}

/* -------------------------------------------------------------------------- */
/*
 * driver(9) and device(9) "control plane".
 * This is what we use when we are making ourselves a device(9) in order to
 * provide a newbus interface again, as well as the implementation of the
 * SDIO interface.
 */

static device_method_t sdiob_methods[] = {
        /* Device interface. */
        DEVMETHOD(device_probe,         sdiob_probe),
        DEVMETHOD(device_attach,        sdiob_attach),
        DEVMETHOD(device_detach,        sdiob_detach),

        /* Bus interface. */
        DEVMETHOD(bus_add_child,        bus_generic_add_child),
        DEVMETHOD(bus_driver_added,     bus_generic_driver_added),
        DEVMETHOD(bus_read_ivar,        sdiob_read_ivar),
        DEVMETHOD(bus_write_ivar,       sdiob_write_ivar),

        /* SDIO interface. */
        DEVMETHOD(sdio_read_direct,     sdiob_read_direct),
        DEVMETHOD(sdio_write_direct,    sdiob_write_direct),
        DEVMETHOD(sdio_read_extended,   sdiob_read_extended),
        DEVMETHOD(sdio_write_extended,  sdiob_write_extended),

        DEVMETHOD_END
};

static driver_t sdiob_driver = {
        SDIOB_NAME_S,
        sdiob_methods,
        0
};

/* -------------------------------------------------------------------------- */
/*
 * CIS related.
 * Read card and function information and populate the cardinfo structure.
 */

static int
sdio_read_direct_sc(struct sdiob_softc *sc, uint8_t fn, uint32_t addr,
    uint8_t *val)
{
        int error;
        uint8_t v;

        error = sdiob_rw_direct_sc(sc, fn, addr, false, &v);
        if (error == 0 && val != NULL)
                *val = v;
        return (error);
}

static int
sdio_func_read_cis(struct sdiob_softc *sc, uint8_t fn, uint32_t cis_addr)
{
        char cis1_info_buf[256];
        char *cis1_info[4];
        int start, i, count, ret;
        uint32_t addr;
        uint8_t ch, tuple_id, tuple_len, tuple_count, v;

        /* If we encounter any read errors, abort and return. */
#define ERR_OUT(ret)                                                    \
        if (ret != 0)                                                   \
                goto err;
        ret = 0;
        /* Use to prevent infinite loop in case of parse errors. */
        tuple_count = 0;
        memset(cis1_info_buf, 0, 256);
        do {
                addr = cis_addr;
                ret = sdio_read_direct_sc(sc, 0, addr++, &tuple_id);
                ERR_OUT(ret);
                if (tuple_id == SD_IO_CISTPL_END)
                        break;
                if (tuple_id == 0) {
                        cis_addr++;
                        continue;
                }
                ret = sdio_read_direct_sc(sc, 0, addr++, &tuple_len);
                ERR_OUT(ret);
                if (tuple_len == 0) {
                        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_PERIPH,
                            ("%s: parse error: 0-length tuple %#02x\n",
                            __func__, tuple_id));
                        return (EIO);
                }

                switch (tuple_id) {
                case SD_IO_CISTPL_VERS_1:
                        addr += 2;
                        for (count = 0, start = 0, i = 0;
                             (count < 4) && ((i + 4) < 256); i++) {
                                ret = sdio_read_direct_sc(sc, 0, addr + i, &ch);
                                ERR_OUT(ret);
                                DPRINTF("%s: count=%d, start=%d, i=%d, got "
                                    "(%#02x)\n", __func__, count, start, i, ch);
                                if (ch == 0xff)
                                        break;
                                cis1_info_buf[i] = ch;
                                if (ch == 0) {
                                        cis1_info[count] =
                                            cis1_info_buf + start;
                                        start = i + 1;
                                        count++;
                                }
                        }
                        DPRINTF("Card info: ");
                        for (i=0; i < 4; i++)
                                if (cis1_info[i])
                                        DPRINTF(" %s", cis1_info[i]);
                        DPRINTF("\n");
                        break;
                case SD_IO_CISTPL_MANFID:
                        /* TPLMID_MANF */
                        ret = sdio_read_direct_sc(sc, 0, addr++, &v);
                        ERR_OUT(ret);
                        sc->cardinfo.f[fn].vendor = v;
                        ret = sdio_read_direct_sc(sc, 0, addr++, &v);
                        ERR_OUT(ret);
                        sc->cardinfo.f[fn].vendor |= (v << 8);
                        /* TPLMID_CARD */
                        ret = sdio_read_direct_sc(sc, 0, addr++, &v);
                        ERR_OUT(ret);
                        sc->cardinfo.f[fn].device = v;
                        ret = sdio_read_direct_sc(sc, 0, addr, &v);
                        ERR_OUT(ret);
                        sc->cardinfo.f[fn].device |= (v << 8);
                        break;
                case SD_IO_CISTPL_FUNCID:
                        /* Not sure if we need to parse it? */
                        break;
                case SD_IO_CISTPL_FUNCE:
                        if (tuple_len < 4) {
                                printf("%s: FUNCE is too short: %d\n",
                                    __func__, tuple_len);
                                break;
                        }
                        /* TPLFE_TYPE (Extended Data) */
                        ret = sdio_read_direct_sc(sc, 0, addr++, &v);
                        ERR_OUT(ret);
                        if (fn == 0) {
                                if (v != 0x00)
                                        break;
                        } else {
                                if (v != 0x01)
                                        break;
                                addr += 0x0b;
                        }
                        ret = sdio_read_direct_sc(sc, 0, addr, &v);
                        ERR_OUT(ret);
                        sc->cardinfo.f[fn].max_blksize = v;
                        ret = sdio_read_direct_sc(sc, 0, addr+1, &v);
                        ERR_OUT(ret);
                        sc->cardinfo.f[fn].max_blksize |= (v << 8);
                        break;
                default:
                        CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_PERIPH,
                            ("%s: Skipping fn %d tuple %d ID %#02x "
                            "len %#02x\n", __func__, fn, tuple_count,
                            tuple_id, tuple_len));
                }
                if (tuple_len == 0xff) {
                        /* Also marks the end of a tuple chain (E1 16.2) */
                        /* The tuple is valid, hence this going at the end. */
                        break;
                }
                cis_addr += 2 + tuple_len;
                tuple_count++;
        } while (tuple_count < 20);
err:
#undef ERR_OUT
        return (ret);
}

static int
sdio_get_common_cis_addr(struct sdiob_softc *sc, uint32_t *addr)
{
        int error;
        uint32_t a;
        uint8_t val;

        error = sdio_read_direct_sc(sc, 0, SD_IO_CCCR_CISPTR + 0, &val);
        if (error != 0)
                goto err;
        a = val;
        error = sdio_read_direct_sc(sc, 0, SD_IO_CCCR_CISPTR + 1, &val);
        if (error != 0)
                goto err;
        a |= (val << 8);
        error = sdio_read_direct_sc(sc, 0, SD_IO_CCCR_CISPTR + 2, &val);
        if (error != 0)
                goto err;
        a |= (val << 16);

        if (a < SD_IO_CIS_START || a > SD_IO_CIS_START + SD_IO_CIS_SIZE) {
err:
                CAM_DEBUG(sc->ccb->ccb_h.path, CAM_DEBUG_PERIPH,
                    ("%s: bad CIS address: %#04x, error %d\n", __func__, a,
                    error));
        } else if (error == 0 && addr != NULL)
                *addr = a;

        return (error);
}

static int
sdiob_get_card_info(struct sdiob_softc *sc)
{
        struct mmc_params *mmcp;
        uint32_t cis_addr, fbr_addr;
        int fn, error;
        uint8_t fn_max, val;

        error = sdio_get_common_cis_addr(sc, &cis_addr);
        if (error != 0)
                return (-1);

        memset(&sc->cardinfo, 0, sizeof(sc->cardinfo));

        /* F0 must always be present. */
        fn = 0;
        error = sdio_func_read_cis(sc, fn, cis_addr);
        if (error != 0)
                return (error);
        sc->cardinfo.num_funcs++;
        /* Read CCCR Card Capability. */
        error = sdio_read_direct_sc(sc, 0, SD_IO_CCCR_CARDCAP, &val);
        if (error != 0)
                return (error);
        sc->cardinfo.support_multiblk = (val & CCCR_CC_SMB) ? true : false;
        DPRINTF("%s: F%d: Vendor %#04x product %#04x max block size %d bytes "
            "support_multiblk %s\n",
            __func__, fn, sc->cardinfo.f[fn].vendor, sc->cardinfo.f[fn].device,
            sc->cardinfo.f[fn].max_blksize,
            sc->cardinfo.support_multiblk ? "yes" : "no");

        /* mmcp->sdio_func_count contains the number of functions w/o F0. */
        mmcp = &sc->ccb->ccb_h.path->device->mmc_ident_data;
        fn_max = MIN(mmcp->sdio_func_count + 1, nitems(sc->cardinfo.f));
        for (fn = 1; fn < fn_max; fn++) {
                fbr_addr = SD_IO_FBR_START * fn + SD_IO_FBR_CIS_OFFSET;

                error = sdio_read_direct_sc(sc, 0, fbr_addr++, &val);
                if (error != 0)
                        break;
                cis_addr = val;
                error = sdio_read_direct_sc(sc, 0, fbr_addr++, &val);
                if (error != 0)
                        break;
                cis_addr |= (val << 8);
                error = sdio_read_direct_sc(sc, 0, fbr_addr++, &val);
                if (error != 0)
                        break;
                cis_addr |= (val << 16);

                error = sdio_func_read_cis(sc, fn, cis_addr);
                if (error != 0)
                        break;

                /* Read the Standard SDIO Function Interface Code. */
                fbr_addr = SD_IO_FBR_START * fn;
                error = sdio_read_direct_sc(sc, 0, fbr_addr++, &val);
                if (error != 0)
                        break;
                sc->cardinfo.f[fn].class = (val & 0x0f);
                if (sc->cardinfo.f[fn].class == 0x0f) {
                        error = sdio_read_direct_sc(sc, 0, fbr_addr, &val);
                        if (error != 0)
                                break;
                        sc->cardinfo.f[fn].class = val;
                }

                sc->cardinfo.f[fn].fn = fn;
                sc->cardinfo.f[fn].cur_blksize = sc->cardinfo.f[fn].max_blksize;
                sc->cardinfo.f[fn].retries = 0;
                sc->cardinfo.f[fn].timeout = 5000;

                DPRINTF("%s: F%d: Class %d Vendor %#04x product %#04x "
                    "max_blksize %d bytes\n", __func__, fn,
                    sc->cardinfo.f[fn].class,
                    sc->cardinfo.f[fn].vendor, sc->cardinfo.f[fn].device,
                    sc->cardinfo.f[fn].max_blksize);
                if (sc->cardinfo.f[fn].vendor == 0) {
                        DPRINTF("%s: F%d doesn't exist\n", __func__, fn);
                        break;
                }
                sc->cardinfo.num_funcs++;
        }
        return (error);
}

/* -------------------------------------------------------------------------- */
/*
 * CAM periph registration, allocation, and detached from that a discovery
 * task, which goes off reads cardinfo, and then adds ourselves to our SIM's
 * device adding the devclass and registering the driver.  This keeps the
 * newbus chain connected though we will talk CAM in the middle (until one
 * day CAM might be newbusyfied).
 */

static int
sdio_newbus_sim_add(struct sdiob_softc *sc)
{
        device_t pdev;
        devclass_t bus_devclass;
        int error;

        /* Add ourselves to our parent (SIM) device. */

        /* Add ourselves to our parent. That way we can become a parent. */
        pdev = xpt_path_sim_device(sc->periph->path);
        KASSERT(pdev != NULL,
            ("%s: pdev is NULL, sc %p periph %p sim %p\n",
            __func__, sc, sc->periph, sc->periph->sim));

        if (sc->dev == NULL)
                sc->dev = BUS_ADD_CHILD(pdev, 0, SDIOB_NAME_S, DEVICE_UNIT_ANY);
        if (sc->dev == NULL)
                return (ENXIO);
        device_set_softc(sc->dev, sc);

        /*
         * Don't set description here; devclass_add_driver() ->
         * device_probe_child() -> device_set_driver() will nuke it again.
         */
        bus_devclass = device_get_devclass(pdev);
        if (bus_devclass == NULL) {
                printf("%s: Failed to get devclass from %s.\n", __func__,
                    device_get_nameunit(pdev));
                return (ENXIO);
        }

        bus_topo_lock();
        error = devclass_add_driver(bus_devclass, &sdiob_driver,
            BUS_PASS_DEFAULT, NULL);
        bus_topo_unlock();
        if (error != 0) {
                printf("%s: Failed to add driver to devclass: %d.\n",
                    __func__, error);
                return (error);
        }

        /* Done. */
        sc->nb_state = NB_STATE_SIM_ADDED;

        return (0);
}

static void
sdiobdiscover(void *context, int pending)
{
        struct cam_periph *periph;
        struct sdiob_softc *sc;
        int error;

        KASSERT(context != NULL, ("%s: context is NULL\n", __func__));
        periph = (struct cam_periph *)context;
        CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("%s\n", __func__));

        /* Periph was held for us when this task was enqueued. */
        if ((periph->flags & CAM_PERIPH_INVALID) != 0) {
                cam_periph_release(periph);
                return;
        }

        sc = periph->softc;
        sc->sdio_state = SDIO_STATE_INITIALIZING;

        if (sc->ccb == NULL)
                sc->ccb = xpt_alloc_ccb();

        /*
         * Read CCCR and FBR of each function, get manufacturer and device IDs,
         * max block size, and whatever else we deem necessary.
         */
        cam_periph_lock(periph);
        error = sdiob_get_card_info(sc);
        if  (error == 0)
                sc->sdio_state = SDIO_STATE_READY;
        else
                sc->sdio_state = SDIO_STATE_DEAD;
        cam_periph_unlock(periph);

        if (error)
                return;

        CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("%s: num_func %d\n",
            __func__, sc->cardinfo.num_funcs));

        /*
         * Now CAM portion of the driver has been initialized and
         * we know VID/PID of all the functions on the card.
         * Time to hook into the newbus.
         */
        error = sdio_newbus_sim_add(sc);
        if (error != 0)
                sc->nb_state = NB_STATE_DEAD;

        return;
}

/* Called at the end of cam_periph_alloc() for us to finish allocation. */
static cam_status
sdiobregister(struct cam_periph *periph, void *arg)
{
        struct sdiob_softc *sc;
        int error;

        CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("%s: arg %p\n", __func__, arg));
        if (arg == NULL) {
                printf("%s: no getdev CCB, can't register device pariph %p\n",
                    __func__, periph);
                return(CAM_REQ_CMP_ERR);
        }
        if (xpt_path_sim_device(periph->path) == NULL) {
                printf("%s: no device_t for sim %p\n", __func__, periph->sim);
                return(CAM_REQ_CMP_ERR);
        }

        sc = (struct sdiob_softc *) malloc(sizeof(*sc), M_DEVBUF,
            M_NOWAIT|M_ZERO);
        if (sc == NULL) {
                printf("%s: unable to allocate sc\n", __func__);
                return (CAM_REQ_CMP_ERR);
        }
        sc->sdio_state = SDIO_STATE_DEAD;
        sc->nb_state = NB_STATE_DEAD;
        TASK_INIT(&sc->discover_task, 0, sdiobdiscover, periph);

        /* Refcount until we are setup.  Can't block. */
        error = cam_periph_hold(periph, PRIBIO);
        if (error != 0) {
                printf("%s: lost periph during registration!\n", __func__);
                free(sc, M_DEVBUF);
                return(CAM_REQ_CMP_ERR);
        }
        periph->softc = sc;
        sc->periph = periph;
        cam_periph_unlock(periph);

        error = taskqueue_enqueue(taskqueue_thread, &sc->discover_task);

        cam_periph_lock(periph);
        /* We will continue to hold a refcount for discover_task. */
        /* cam_periph_unhold(periph); */

        xpt_schedule(periph, CAM_PRIORITY_XPT);

        return (CAM_REQ_CMP);
}

static void
sdioboninvalidate(struct cam_periph *periph)
{

        CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("%s:\n", __func__));

        return;
}

static void
sdiobcleanup(struct cam_periph *periph)
{

        CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("%s:\n", __func__));

        return;
}

static void
sdiobstart(struct cam_periph *periph, union ccb *ccb)
{

        CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("%s: ccb %p\n", __func__, ccb));

        return;
}

static void
sdiobasync(void *softc, uint32_t code, struct cam_path *path, void *arg)
{
        struct cam_periph *periph;
        struct ccb_getdev *cgd;
        cam_status status;

        periph = (struct cam_periph *)softc;

        CAM_DEBUG(path, CAM_DEBUG_TRACE, ("%s(code=%d)\n", __func__, code));
        switch (code) {
        case AC_FOUND_DEVICE:
                if (arg == NULL)
                        break;
                cgd = (struct ccb_getdev *)arg;
                if (cgd->protocol != PROTO_MMCSD)
                        break;

                /* We do not support SD memory (Combo) Cards. */
                if ((path->device->mmc_ident_data.card_features &
                    CARD_FEATURE_MEMORY)) {
                        CAM_DEBUG(path, CAM_DEBUG_TRACE,
                             ("Memory card, not interested\n"));
                        break;
                }

                /*
                 * Allocate a peripheral instance for this device which starts
                 * the probe process.
                 */
                status = cam_periph_alloc(sdiobregister, sdioboninvalidate,
                    sdiobcleanup, sdiobstart, SDIOB_NAME_S, CAM_PERIPH_BIO, path,
                    sdiobasync, AC_FOUND_DEVICE, cgd);
                if (status != CAM_REQ_CMP && status != CAM_REQ_INPROG)
                        CAM_DEBUG(path, CAM_DEBUG_PERIPH,
                             ("%s: Unable to attach to new device due to "
                             "status %#02x\n", __func__, status));
                break;
        default:
                CAM_DEBUG(path, CAM_DEBUG_PERIPH,
                     ("%s: cannot handle async code %#02x\n", __func__, code));
                cam_periph_async(periph, code, path, arg);
                break;
        }
}

static void
sdiobinit(void)
{
        cam_status status;

        /*
         * Register for new device notification.  We will be notified for all
         * already existing ones.
         */
        status = xpt_register_async(AC_FOUND_DEVICE, sdiobasync, NULL, NULL);
        if (status != CAM_REQ_CMP)
                printf("%s: Failed to attach async callback, statux %#02x",
                    __func__, status);
}

/* This function will allow unloading the KLD. */
static int
sdiobdeinit(void)
{

        return (EOPNOTSUPP);
}

static struct periph_driver sdiobdriver =
{
        .init =         sdiobinit,
        .driver_name =  SDIOB_NAME_S,
        .units =        TAILQ_HEAD_INITIALIZER(sdiobdriver.units),
        .generation =   0,
        .flags =        0,
        .deinit =       sdiobdeinit,
};

PERIPHDRIVER_DECLARE(SDIOB_NAME, sdiobdriver);
MODULE_VERSION(SDIOB_NAME, 1);