/*-
 * Copyright (c) 2014, 2015, 2019 Marcel Moolenaar
 * All rights reserved.
 *
 * 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/systm.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/cons.h>
#include <sys/fcntl.h>
#include <sys/interrupt.h>
#include <sys/kdb.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/proc.h>
#include <sys/queue.h>
#include <sys/reboot.h>
#include <sys/stdarg.h>
#include <machine/bus.h>
#include <sys/rman.h>
#include <sys/uio.h>
#include <machine/resource.h>

#include <dev/pci/pcivar.h>

#include <dev/proto/proto.h>
#include <dev/proto/proto_dev.h>
#include <dev/proto/proto_busdma.h>

CTASSERT(SYS_RES_IRQ != PROTO_RES_UNUSED &&
    SYS_RES_DRQ != PROTO_RES_UNUSED &&
    SYS_RES_MEMORY != PROTO_RES_UNUSED &&
    SYS_RES_IOPORT != PROTO_RES_UNUSED);
CTASSERT(SYS_RES_IRQ != PROTO_RES_PCICFG &&
    SYS_RES_DRQ != PROTO_RES_PCICFG &&
    SYS_RES_MEMORY != PROTO_RES_PCICFG &&
    SYS_RES_IOPORT != PROTO_RES_PCICFG);
CTASSERT(SYS_RES_IRQ != PROTO_RES_BUSDMA &&
    SYS_RES_DRQ != PROTO_RES_BUSDMA &&
    SYS_RES_MEMORY != PROTO_RES_BUSDMA &&
    SYS_RES_IOPORT != PROTO_RES_BUSDMA);

char proto_driver_name[] = "proto";

static d_open_t proto_open;
static d_close_t proto_close;
static d_read_t proto_read;
static d_write_t proto_write;
static d_ioctl_t proto_ioctl;
static d_mmap_t proto_mmap;

struct cdevsw proto_devsw = {
        .d_version = D_VERSION,
        .d_flags = 0,
        .d_name = proto_driver_name,
        .d_open = proto_open,
        .d_close = proto_close,
        .d_read = proto_read,
        .d_write = proto_write,
        .d_ioctl = proto_ioctl,
        .d_mmap = proto_mmap,
};

static MALLOC_DEFINE(M_PROTO, "PROTO", "PROTO driver");

int
proto_add_resource(struct proto_softc *sc, int type, int rid,
    struct resource *res)
{
        struct proto_res *r;

        if (type == PROTO_RES_UNUSED)
                return (EINVAL);
        if (sc->sc_rescnt == PROTO_RES_MAX)
                return (ENOSPC);

        r = sc->sc_res + sc->sc_rescnt++;
        r->r_type = type;
        r->r_rid = rid;
        r->r_d.res = res;
        return (0);
}

#ifdef notyet
static int
proto_intr(void *arg)
{
        struct proto_softc *sc = arg;

        /* XXX TODO */
        return (FILTER_HANDLED);
}
#endif

int
proto_probe(device_t dev, const char *prefix, char ***devnamesp)
{
        char **devnames = *devnamesp;
        const char *dn, *ep, *ev;
        size_t pfxlen;
        int idx, names;

        if (devnames == NULL) {
                pfxlen = strlen(prefix);
                names = 1;      /* NULL pointer */
                ev = kern_getenv("hw.proto.attach");
                if (ev != NULL) {
                        dn = ev;
                        while (*dn != '\0') {
                                ep = dn;
                                while (*ep != ',' && *ep != '\0')
                                        ep++;
                                if ((ep - dn) > pfxlen &&
                                    strncmp(dn, prefix, pfxlen) == 0)
                                        names++;
                                dn = (*ep == ',') ? ep + 1 : ep;
                        }
                }
                devnames = malloc(names * sizeof(caddr_t), M_DEVBUF,
                    M_WAITOK | M_ZERO);
                *devnamesp = devnames;
                if (ev != NULL) {
                        dn = ev;
                        idx = 0;
                        while (*dn != '\0') {
                                ep = dn;
                                while (*ep != ',' && *ep != '\0')
                                        ep++;
                                if ((ep - dn) > pfxlen &&
                                    strncmp(dn, prefix, pfxlen) == 0) {
                                        devnames[idx] = malloc(ep - dn + 1,
                                            M_DEVBUF, M_WAITOK | M_ZERO);
                                        memcpy(devnames[idx], dn, ep - dn);
                                        idx++;
                                }
                                dn = (*ep == ',') ? ep + 1 : ep;
                        }
                        freeenv(__DECONST(char *, ev));
                }
        }

        dn = device_get_desc(dev);
        while (*devnames != NULL) {
                if (strcmp(dn, *devnames) == 0)
                        return (BUS_PROBE_SPECIFIC);
                devnames++;
        }
        return (BUS_PROBE_HOOVER);
}

int
proto_attach(device_t dev)
{
        struct proto_softc *sc;
        struct proto_res *r;
        u_int res;

        sc = device_get_softc(dev);
        sc->sc_dev = dev;
        mtx_init(&sc->sc_mtx, "proto-softc", NULL, MTX_DEF);

        for (res = 0; res < sc->sc_rescnt; res++) {
                r = sc->sc_res + res;
                switch (r->r_type) {
                case SYS_RES_IRQ:
                        /* XXX TODO */
                        break;
                case SYS_RES_DRQ:
                        break;
                case SYS_RES_MEMORY:
                case SYS_RES_IOPORT:
                        r->r_size = rman_get_size(r->r_d.res);
                        r->r_u.cdev = make_dev(&proto_devsw, res, 0, 0, 0600,
                            "proto/%s/%02x.%s", device_get_desc(dev), r->r_rid,
                            (r->r_type == SYS_RES_IOPORT) ? "io" : "mem");
                        r->r_u.cdev->si_drv1 = sc;
                        r->r_u.cdev->si_drv2 = r;
                        break;
                case PROTO_RES_PCICFG:
                        r->r_size = 4096;
                        r->r_u.cdev = make_dev(&proto_devsw, res, 0, 0, 0600,
                            "proto/%s/pcicfg", device_get_desc(dev));
                        r->r_u.cdev->si_drv1 = sc;
                        r->r_u.cdev->si_drv2 = r;
                        break;
                case PROTO_RES_BUSDMA:
                        r->r_d.busdma = proto_busdma_attach(sc);
                        r->r_size = 0;  /* no read(2) nor write(2) */
                        r->r_u.cdev = make_dev(&proto_devsw, res, 0, 0, 0600,
                            "proto/%s/busdma", device_get_desc(dev));
                        r->r_u.cdev->si_drv1 = sc;
                        r->r_u.cdev->si_drv2 = r;
                        break;
                }
        }
        return (0);
}

int
proto_detach(device_t dev)
{
        struct proto_softc *sc;
        struct proto_res *r;
        u_int res;

        sc = device_get_softc(dev);

        mtx_lock(&sc->sc_mtx);
        if (sc->sc_opencnt == 0)
                sc->sc_opencnt = -1;
        mtx_unlock(&sc->sc_mtx);
        if (sc->sc_opencnt > 0)
                return (EBUSY);

        for (res = 0; res < sc->sc_rescnt; res++) {
                r = sc->sc_res + res;

                switch (r->r_type) {
                case SYS_RES_IRQ:
                        /* XXX TODO */
                        bus_release_resource(dev, r->r_type, r->r_rid,
                            r->r_d.res);
                        break;
                case SYS_RES_DRQ:
                        bus_release_resource(dev, r->r_type, r->r_rid,
                            r->r_d.res);
                        break;
                case SYS_RES_MEMORY:
                case SYS_RES_IOPORT:
                        destroy_dev(r->r_u.cdev);
                        bus_release_resource(dev, r->r_type, r->r_rid,
                            r->r_d.res);
                        break;
                case PROTO_RES_PCICFG:
                        destroy_dev(r->r_u.cdev);
                        break;
                case PROTO_RES_BUSDMA:
                        destroy_dev(r->r_u.cdev);
                        proto_busdma_detach(sc, r->r_d.busdma);
                        break;
                }
                r->r_type = PROTO_RES_UNUSED;
        }
        mtx_lock(&sc->sc_mtx);
        sc->sc_rescnt = 0;
        sc->sc_opencnt = 0;
        mtx_unlock(&sc->sc_mtx);
        mtx_destroy(&sc->sc_mtx);
        return (0);
}

/*
 * Device functions
 */

static int
proto_open(struct cdev *cdev, int oflags, int devtype, struct thread *td)
{
        struct proto_res *r;
        struct proto_softc *sc;
        int error;

        sc = cdev->si_drv1;
        mtx_lock(&sc->sc_mtx);
        if (sc->sc_opencnt >= 0) {
                r = cdev->si_drv2;
                if (!r->r_opened) {
                        r->r_opened = 1;
                        sc->sc_opencnt++;
                        error = 0;
                } else
                        error = EBUSY;
        } else
                error = ENXIO;
        mtx_unlock(&sc->sc_mtx);
        return (error);
}

static int
proto_close(struct cdev *cdev, int fflag, int devtype, struct thread *td)
{
        struct proto_res *r;
        struct proto_softc *sc;
        int error;

        sc = cdev->si_drv1;
        mtx_lock(&sc->sc_mtx);
        if (sc->sc_opencnt > 0) {
                r = cdev->si_drv2;
                if (r->r_opened) {
                        if (r->r_type == PROTO_RES_BUSDMA)
                                proto_busdma_cleanup(sc, r->r_d.busdma);
                        r->r_opened = 0;
                        sc->sc_opencnt--;
                        error = 0;
                } else
                        error = ENXIO;
        } else
                error = ENXIO;
        mtx_unlock(&sc->sc_mtx);
        return (error);
}

static int
proto_read(struct cdev *cdev, struct uio *uio, int ioflag)
{
        union {
                uint8_t x1[8];
                uint16_t x2[4];
                uint32_t x4[2];
                uint64_t x8[1];
        } buf;
        struct proto_softc *sc;
        struct proto_res *r;
        device_t dev;
        off_t ofs;
        u_long width;
        int error;

        sc = cdev->si_drv1;
        dev = sc->sc_dev;
        r = cdev->si_drv2;

        width = uio->uio_resid;
        if (width < 1 || width > 8 || bitcount16(width) > 1)
                return (EIO);
        ofs = uio->uio_offset;
        if (ofs + width > r->r_size)
                return (EIO);

        switch (width) {
        case 1:
                buf.x1[0] = (r->r_type == PROTO_RES_PCICFG) ?
                    pci_read_config(dev, ofs, 1) : bus_read_1(r->r_d.res, ofs);
                break;
        case 2:
                buf.x2[0] = (r->r_type == PROTO_RES_PCICFG) ?
                    pci_read_config(dev, ofs, 2) : bus_read_2(r->r_d.res, ofs);
                break;
        case 4:
                buf.x4[0] = (r->r_type == PROTO_RES_PCICFG) ?
                    pci_read_config(dev, ofs, 4) : bus_read_4(r->r_d.res, ofs);
                break;
#ifndef __i386__
        case 8:
                if (r->r_type == PROTO_RES_PCICFG)
                        return (EINVAL);
                buf.x8[0] = bus_read_8(r->r_d.res, ofs);
                break;
#endif
        default:
                return (EIO);
        }

        error = uiomove(&buf, width, uio);
        return (error);
}

static int
proto_write(struct cdev *cdev, struct uio *uio, int ioflag)
{
        union {
                uint8_t x1[8];
                uint16_t x2[4];
                uint32_t x4[2];
                uint64_t x8[1];
        } buf;
        struct proto_softc *sc;
        struct proto_res *r;
        device_t dev;
        off_t ofs;
        u_long width;
        int error;

        sc = cdev->si_drv1;
        dev = sc->sc_dev;
        r = cdev->si_drv2;

        width = uio->uio_resid;
        if (width < 1 || width > 8 || bitcount16(width) > 1)
                return (EIO);
        ofs = uio->uio_offset;
        if (ofs + width > r->r_size)
                return (EIO);

        error = uiomove(&buf, width, uio);
        if (error)
                return (error);

        switch (width) {
        case 1:
                if (r->r_type == PROTO_RES_PCICFG)
                        pci_write_config(dev, ofs, buf.x1[0], 1);
                else
                        bus_write_1(r->r_d.res, ofs, buf.x1[0]);
                break;
        case 2:
                if (r->r_type == PROTO_RES_PCICFG)
                        pci_write_config(dev, ofs, buf.x2[0], 2);
                else
                        bus_write_2(r->r_d.res, ofs, buf.x2[0]);
                break;
        case 4:
                if (r->r_type == PROTO_RES_PCICFG)
                        pci_write_config(dev, ofs, buf.x4[0], 4);
                else
                        bus_write_4(r->r_d.res, ofs, buf.x4[0]);
                break;
#ifndef __i386__
        case 8:
                if (r->r_type == PROTO_RES_PCICFG)
                        return (EINVAL);
                bus_write_8(r->r_d.res, ofs, buf.x8[0]);
                break;
#endif
        default:
                return (EIO);
        }

        return (0);
}

static int
proto_ioctl(struct cdev *cdev, u_long cmd, caddr_t data, int fflag,
    struct thread *td)
{
        struct proto_ioc_region *region;
        struct proto_ioc_busdma *busdma;
        struct proto_res *r;
        struct proto_softc *sc;
        int error;

        sc = cdev->si_drv1;
        r = cdev->si_drv2;

        error = 0;
        switch (cmd) {
        case PROTO_IOC_REGION:
                if (r->r_type == PROTO_RES_BUSDMA) {
                        error = EINVAL;
                        break;
                }
                region = (struct proto_ioc_region *)data;
                region->size = r->r_size;
                if (r->r_type == PROTO_RES_PCICFG)
                        region->address = 0;
                else
                        region->address = rman_get_start(r->r_d.res);
                break;
        case PROTO_IOC_BUSDMA:
                if (r->r_type != PROTO_RES_BUSDMA) {
                        error = EINVAL;
                        break;
                }
                busdma = (struct proto_ioc_busdma *)data;
                error = proto_busdma_ioctl(sc, r->r_d.busdma, busdma, td);
                break;
        default:
                error = ENOIOCTL;
                break;
        }
        return (error);
}

static int
proto_mmap(struct cdev *cdev, vm_ooffset_t offset, vm_paddr_t *paddr,
    int prot, vm_memattr_t *memattr)
{
        struct proto_res *r;

        if (offset & PAGE_MASK)
                return (EINVAL);
        if (prot & PROT_EXEC)
                return (EACCES);

        r = cdev->si_drv2;

        switch (r->r_type) {
        case SYS_RES_MEMORY:
                if (offset >= r->r_size)
                        return (EINVAL);
                *paddr = rman_get_start(r->r_d.res) + offset;
                *memattr = VM_MEMATTR_UNCACHEABLE;
                break;
        case PROTO_RES_BUSDMA:
                if (!proto_busdma_mmap_allowed(r->r_d.busdma, offset))
                        return (EINVAL);
                *paddr = offset;
                break;
        default:
                return (ENXIO);
        }
        return (0);
}