/*-
 * Copyright (c) 2020-2021 Emmanuel Vadot <manu@FreeBSD.org>
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mutex.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>
#include <cam/cam_debug.h>
#include <cam/cam_sim.h>
#include <cam/cam_xpt_sim.h>
#include <cam/mmc/mmc_sim.h>

#include "mmc_sim_if.h"

static void
mmc_cam_default_poll(struct cam_sim *sim)
{
        struct mmc_sim *mmc_sim;

        mmc_sim = cam_sim_softc(sim);
        MMC_SIM_CAM_POLL(mmc_sim->dev);
}

static void
mmc_sim_task(void *arg, int pending)
{
        struct mmc_sim *mmc_sim;
        struct ccb_trans_settings *cts;
        int rv;

        mmc_sim = arg;

        if (mmc_sim->ccb == NULL)
                return;

        cts = &mmc_sim->ccb->cts;
        switch (mmc_sim->ccb->ccb_h.func_code) {
        case XPT_MMC_GET_TRAN_SETTINGS:
                rv = MMC_SIM_GET_TRAN_SETTINGS(mmc_sim->dev, &cts->proto_specific.mmc);
                if (rv != 0)
                        mmc_sim->ccb->ccb_h.status = CAM_REQ_INVALID;
                else
                        mmc_sim->ccb->ccb_h.status = CAM_REQ_CMP;
                break;
        case XPT_MMC_SET_TRAN_SETTINGS:
                rv = MMC_SIM_SET_TRAN_SETTINGS(mmc_sim->dev, &cts->proto_specific.mmc);
                if (rv != 0)
                        mmc_sim->ccb->ccb_h.status = CAM_REQ_INVALID;
                else
                        mmc_sim->ccb->ccb_h.status = CAM_REQ_CMP;
                break;
        default:
                panic("Unsupported ccb func %x\n", mmc_sim->ccb->ccb_h.func_code);
                break;
        }

        xpt_done(mmc_sim->ccb);
        mmc_sim->ccb = NULL;
}


static void
mmc_cam_sim_default_action(struct cam_sim *sim, union ccb *ccb)
{
        struct mmc_sim *mmc_sim;
        struct ccb_trans_settings_mmc mmc;
        int rv;

        mmc_sim = cam_sim_softc(sim);

        mtx_assert(&mmc_sim->mtx, MA_OWNED);

        if (mmc_sim->ccb != NULL) {
                ccb->ccb_h.status = CAM_BUSY;
                xpt_done(ccb);
                return;
        }

        switch (ccb->ccb_h.func_code) {
        case XPT_PATH_INQ:
                rv = MMC_SIM_GET_TRAN_SETTINGS(mmc_sim->dev, &mmc);
                if (rv != 0) {
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                } else {
                        mmc_path_inq(&ccb->cpi, "Deglitch Networks",
                            sim, mmc.host_max_data * MMC_SECTOR_SIZE);
                }
                break;
        case XPT_GET_TRAN_SETTINGS:
        {
                struct ccb_trans_settings *cts = &ccb->cts;

                rv = MMC_SIM_GET_TRAN_SETTINGS(mmc_sim->dev, &cts->proto_specific.mmc);
                if (rv != 0)
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                else {
                        cts->protocol = PROTO_MMCSD;
                        cts->protocol_version = 1;
                        cts->transport = XPORT_MMCSD;
                        cts->transport_version = 1;
                        cts->xport_specific.valid = 0;
                        ccb->ccb_h.status = CAM_REQ_CMP;
                }
                break;
        }
        case XPT_MMC_GET_TRAN_SETTINGS:
        {
                ccb->ccb_h.status = CAM_SIM_QUEUED;
                mmc_sim->ccb = ccb;
                taskqueue_enqueue(taskqueue_thread, &mmc_sim->sim_task);
                return;
                /* NOTREACHED */
                break;
        }
        case XPT_SET_TRAN_SETTINGS:
        {
                struct ccb_trans_settings *cts = &ccb->cts;

                rv = MMC_SIM_SET_TRAN_SETTINGS(mmc_sim->dev, &cts->proto_specific.mmc);
                if (rv != 0)
                        ccb->ccb_h.status = CAM_REQ_INVALID;
                else
                        ccb->ccb_h.status = CAM_REQ_CMP;
                break;
        }
        case XPT_MMC_SET_TRAN_SETTINGS:
        {
                ccb->ccb_h.status = CAM_SIM_QUEUED;
                mmc_sim->ccb = ccb;
                taskqueue_enqueue(taskqueue_thread, &mmc_sim->sim_task);
                return;
                /* NOTREACHED */
                break;
        }
        case XPT_RESET_BUS:
                ccb->ccb_h.status = CAM_REQ_CMP;
                break;
        case XPT_MMC_IO:
        {
                rv = MMC_SIM_CAM_REQUEST(mmc_sim->dev, ccb);
                if (rv != 0)
                        ccb->ccb_h.status = CAM_SIM_QUEUED;
                return;
                /* NOTREACHED */
                break;
        }
        default:
                ccb->ccb_h.status = CAM_REQ_INVALID;
                break;
        }
        xpt_done(ccb);
        return;
}

int
mmc_cam_sim_alloc(device_t dev, const char *name, struct mmc_sim *mmc_sim)
{
        kobjop_desc_t kobj_desc;
        kobj_method_t *kobj_method;

        mmc_sim->dev = dev;

        if ((mmc_sim->devq = cam_simq_alloc(1)) == NULL) {
                goto fail;
        }

        snprintf(mmc_sim->name, sizeof(mmc_sim->name), "%s_sim", name);
        mtx_init(&mmc_sim->mtx, mmc_sim->name, NULL, MTX_DEF);

        /* Provide sim_poll hook only if the device has the poll method. */
        kobj_desc = &mmc_sim_cam_poll_desc;
        kobj_method = kobj_lookup_method(((kobj_t)dev)->ops->cls, NULL,
            kobj_desc);
        mmc_sim->sim = cam_sim_alloc(mmc_cam_sim_default_action,
            kobj_method == &kobj_desc->deflt ? NULL : mmc_cam_default_poll,
            mmc_sim->name, mmc_sim, device_get_unit(dev),
            &mmc_sim->mtx, 1, 1, mmc_sim->devq);

        if (mmc_sim->sim == NULL) {
                cam_simq_free(mmc_sim->devq);
                device_printf(dev, "cannot allocate CAM SIM\n");
                goto fail;
        }

        mtx_lock(&mmc_sim->mtx);
        if (xpt_bus_register(mmc_sim->sim, dev, 0) != 0) {
                device_printf(dev, "cannot register SCSI pass-through bus\n");
                cam_sim_free(mmc_sim->sim, FALSE);
                cam_simq_free(mmc_sim->devq);
                mtx_unlock(&mmc_sim->mtx);
                goto fail;
        }

        mtx_unlock(&mmc_sim->mtx);
        TASK_INIT(&mmc_sim->sim_task, 0, mmc_sim_task, mmc_sim);

        return (0);

fail:
        mmc_cam_sim_free(mmc_sim);
        return (1);
}

void
mmc_cam_sim_free(struct mmc_sim *mmc_sim)
{

        if (mmc_sim->sim != NULL) {
                mtx_lock(&mmc_sim->mtx);
                xpt_bus_deregister(cam_sim_path(mmc_sim->sim));
                cam_sim_free(mmc_sim->sim, FALSE);
                mtx_unlock(&mmc_sim->mtx);
        }

        if (mmc_sim->devq != NULL)
                cam_simq_free(mmc_sim->devq);
}

void
mmc_cam_sim_discover(struct mmc_sim *mmc_sim)
{

        mmccam_start_discovery(mmc_sim->sim);
}