/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */


#include <sys/types.h>
#include <sys/conf.h>
#include <sys/cmn_err.h>
#include <sys/kmem.h>
#include <sys/open.h>
#include <sys/stat.h>
#include <sys/modctl.h>
#include <sys/errno.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>

/* #define SBUSMEM_DEBUG */

#ifdef SBUSMEM_DEBUG
#include <sys/ddi_impldefs.h>

int sbusmem_debug_flag;
#define sbusmem_debug   if (sbusmem_debug_flag) printf
#endif /* SBUSMEM_DEBUG */

static void *sbusmem_state_head;

struct sbusmem_unit {
        uint_t size;
        uint_t pagesize;
        dev_info_t *dip;
};

static int sbmem_open(dev_t *, int, int, cred_t *);
static int sbmem_close(dev_t, int, int, struct cred *);
static int sbmem_read(dev_t, struct uio *, cred_t *);
static int sbmem_write(dev_t, struct uio *, cred_t *);
static int sbmem_devmap(dev_t, devmap_cookie_t, offset_t, size_t,
                size_t *, uint_t);

static struct cb_ops sbmem_cb_ops = {
        sbmem_open,             /* open */
        sbmem_close,            /* close */
        nodev,                  /* strategy */
        nodev,                  /* print */
        nodev,                  /* dump */
        sbmem_read,             /* read */
        sbmem_write,            /* write */
        nodev,                  /* ioctl */
        sbmem_devmap,           /* devmap */
        nodev,                  /* mmap */
        ddi_devmap_segmap,      /* segmap */
        nochpoll,               /* poll */
        ddi_prop_op,            /* cb_prop_op */
        0,                      /* streamtab  */
        D_NEW|D_MP|D_DEVMAP|D_HOTPLUG,  /* Driver compatibility flag */
        CB_REV,                 /* rev */
        nodev,                  /* int (*cb_aread)() */
        nodev                   /* int (*cb_awrite)() */
};

static int sbmem_attach(dev_info_t *, ddi_attach_cmd_t);
static int sbmem_detach(dev_info_t *, ddi_detach_cmd_t);
static int sbmem_info(dev_info_t *, ddi_info_cmd_t, void *, void **);

static struct dev_ops sbmem_ops = {
        DEVO_REV,               /* devo_rev, */
        0,                      /* refcnt  */
        sbmem_info,             /* get_dev_info */
        nulldev,                /* identify */
        nulldev,                /* probe */
        sbmem_attach,           /* attach */
        sbmem_detach,           /* detach */
        nodev,                  /* reset */
        &sbmem_cb_ops,          /* driver operations */
        (struct bus_ops *)0,    /* bus operations */
        nulldev,                /* power */
        ddi_quiesce_not_needed,         /* quiesce */
};

static struct modldrv modldrv = {
        &mod_driverops, /* Type of module.  This one is a driver */
        "SBus memory driver", /* Name of module. */
        &sbmem_ops,     /* driver ops */
};

static struct modlinkage modlinkage = {
        MODREV_1, (void *)&modldrv, NULL
};

static int sbmem_rw(dev_t, struct uio *, enum uio_rw, cred_t *);

int
_init(void)
{
        int error;

        if ((error = ddi_soft_state_init(&sbusmem_state_head,
            sizeof (struct sbusmem_unit), 1)) != 0) {
                return (error);
        }
        if ((error = mod_install(&modlinkage)) != 0) {
                ddi_soft_state_fini(&sbusmem_state_head);
        }
        return (error);
}

int
_fini(void)
{
        int error;

        if ((error = mod_remove(&modlinkage)) == 0) {
                ddi_soft_state_fini(&sbusmem_state_head);
        }
        return (error);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&modlinkage, modinfop));
}

static int
sbmem_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
        struct sbusmem_unit *un;
        int error = DDI_FAILURE;
        int instance, ilen;
        uint_t size;
        char *ident;

        switch (cmd) {
        case DDI_ATTACH:
                instance = ddi_get_instance(devi);

                size = ddi_getprop(DDI_DEV_T_NONE, devi,
                    DDI_PROP_DONTPASS | DDI_PROP_CANSLEEP, "size", -1);
                if (size == (uint_t)-1) {
#ifdef SBUSMEM_DEBUG
                        sbusmem_debug(
                            "sbmem_attach%d: No size property\n", instance);
#endif /* SBUSMEM_DEBUG */
                        break;
                }

#ifdef SBUSMEM_DEBUG
                {
                        struct regspec *rp = ddi_rnumber_to_regspec(devi, 0);

                        if (rp == NULL) {
                                sbusmem_debug(
                            "sbmem_attach%d: No reg property\n", instance);
                        } else {
                                sbusmem_debug(
                            "sbmem_attach%d: slot 0x%x size 0x%x\n", instance,
                                    rp->regspec_bustype, rp->regspec_size);
                        }
                }
#endif /* SBUSMEM_DEBUG */

                if (ddi_getlongprop(DDI_DEV_T_ANY, devi,
                    DDI_PROP_DONTPASS | DDI_PROP_CANSLEEP, "ident",
                    (caddr_t)&ident, &ilen) != DDI_PROP_SUCCESS) {
#ifdef SBUSMEM_DEBUG
                        sbusmem_debug(
                            "sbmem_attach%d: No ident property\n", instance);
#endif /* SBUSMEM_DEBUG */
                        break;
                }

                if (ddi_soft_state_zalloc(sbusmem_state_head,
                    instance) != DDI_SUCCESS)
                        break;

                if ((un = ddi_get_soft_state(sbusmem_state_head,
                    instance)) == NULL) {
                        ddi_soft_state_free(sbusmem_state_head, instance);
                        break;
                }

                if (ddi_create_minor_node(devi, ident, S_IFCHR, instance,
                    DDI_PSEUDO, 0) == DDI_FAILURE) {
                        kmem_free(ident, ilen);
                        ddi_remove_minor_node(devi, NULL);
                        ddi_soft_state_free(sbusmem_state_head, instance);
                        break;
                }
                kmem_free(ident, ilen);
                un->dip = devi;
                un->size = size;
                un->pagesize = ddi_ptob(devi, 1);

#ifdef SBUSMEM_DEBUG
                sbusmem_debug("sbmem_attach%d: dip 0x%p size 0x%x\n",
                    instance, devi, size);
#endif /* SBUSMEM_DEBUG */

                ddi_report_dev(devi);
                error = DDI_SUCCESS;
                break;
        case DDI_RESUME:
                error = DDI_SUCCESS;
                break;
        default:
                break;
        }
        return (error);
}

static int
sbmem_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
        int instance;

        switch (cmd) {
        case DDI_DETACH:
                instance = ddi_get_instance(devi);
                ddi_remove_minor_node(devi, NULL);
                ddi_soft_state_free(sbusmem_state_head, instance);
                return (DDI_SUCCESS);

        case DDI_SUSPEND:
                return (DDI_SUCCESS);
        }
        return (DDI_FAILURE);
}

/*ARGSUSED1*/
static int
sbmem_open(dev_t *devp, int flag, int typ, cred_t *cred)
{
        int instance;

        if (typ != OTYP_CHR)
                return (EINVAL);

        instance = getminor(*devp);
        if (ddi_get_soft_state(sbusmem_state_head, instance) == NULL) {
                return (ENXIO);
        }
        return (0);
}

/*ARGSUSED*/
static int
sbmem_close(dev_t dev, int flag, int otyp, struct cred *cred)
{
        if (otyp != OTYP_CHR)
                return (EINVAL);

        return (0);
}

static int
sbmem_info(dev_info_t *dip __unused, ddi_info_cmd_t infocmd, void *arg,
    void **result)
{
        int instance, error = DDI_FAILURE;
        struct sbusmem_unit *un;

        switch (infocmd) {
        case DDI_INFO_DEVT2DEVINFO:
                instance = getminor((dev_t)arg);
                if ((un = ddi_get_soft_state(sbusmem_state_head,
                    instance)) != NULL) {
                        *result = (void *)un->dip;
                        error = DDI_SUCCESS;
#ifdef SBUSMEM_DEBUG
                sbusmem_debug(
                    "sbmem_info%d: returning dip 0x%p\n", instance, un->dip);
#endif /* SBUSMEM_DEBUG */

                }
                break;

        case DDI_INFO_DEVT2INSTANCE:
                instance = getminor((dev_t)arg);
                *result = (void *)(uintptr_t)instance;
                error = DDI_SUCCESS;
                break;

        default:
                break;
        }
        return (error);
}

static int
sbmem_read(dev_t dev, struct uio *uio, cred_t *cred)
{
        return (sbmem_rw(dev, uio, UIO_READ, cred));
}

static int
sbmem_write(dev_t dev, struct uio *uio, cred_t *cred)
{
        return (sbmem_rw(dev, uio, UIO_WRITE, cred));
}

static int
sbmem_rw(dev_t dev, struct uio *uio, enum uio_rw rw, cred_t *cred __unused)
{
        uint_t c;
        struct iovec *iov;
        struct sbusmem_unit *un;
        uint_t pagesize, msize;
        int instance, error = 0;
        dev_info_t *dip;
        caddr_t reg;

        instance = getminor(dev);
        if ((un = ddi_get_soft_state(sbusmem_state_head, instance)) == NULL) {
                return (ENXIO);
        }
        dip = un->dip;
        pagesize = un->pagesize;

        while (uio->uio_resid > 0 && error == 0) {
                iov = uio->uio_iov;
                if (iov->iov_len == 0) {
                        uio->uio_iov++;
                        uio->uio_iovcnt--;
                        if (uio->uio_iovcnt < 0)
                                cmn_err(CE_PANIC, "sbmem_rw");
                        continue;
                }

                if (uio->uio_offset > un->size) {
                        return (EFAULT);
                }

                if (uio->uio_offset == un->size) {
                        return (0);             /* EOF */
                }
                msize = pagesize - (uio->uio_offset & (pagesize - 1));
                if (ddi_map_regs(dip, 0, &reg, uio->uio_offset,
                    (off_t)msize) != DDI_SUCCESS) {
                        return (EFAULT);
                }
                c = min(msize, (uint_t)iov->iov_len);
                if (ddi_peekpokeio(dip, uio, rw, reg, (int)c,
                    sizeof (int)) != DDI_SUCCESS)
                        error = EFAULT;

                ddi_unmap_regs(dip, 0, &reg, uio->uio_offset, (off_t)msize);
        }
        return (error);
}

static int
sbmem_devmap(dev_t dev, devmap_cookie_t dhp, offset_t off, size_t len,
    size_t *maplen, uint_t model __unused)
{
        struct sbusmem_unit *un;
        int instance, error;

        instance = getminor(dev);
        if ((un = ddi_get_soft_state(sbusmem_state_head, instance)) == NULL) {
                return (ENXIO);
        }
        if (off + len > un->size) {
                return (ENXIO);
        }
        if ((error = devmap_devmem_setup(dhp, un->dip, NULL, 0,
            off, len, PROT_ALL, DEVMAP_DEFAULTS, NULL)) < 0) {
                return (error);
        }
        *maplen = ptob(btopr(len));
        return (0);
}