/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright (c) 2011 Bayard G. Bell. All rights reserved.
 */


#include <sys/types.h>
#include <sys/conf.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/ddi_impldefs.h>
#include <sys/obpdefs.h>
#include <sys/cmn_err.h>
#include <sys/errno.h>
#include <sys/kmem.h>
#include <sys/debug.h>
#include <sys/sysmacros.h>
#include <sys/autoconf.h>
#include <sys/modctl.h>

#include <sys/fhc.h>
#include <sys/sram.h>
#include <sys/promif.h>

/* Useful debugging Stuff */
#include <sys/nexusdebug.h>

/*
 * Function protoypes
 */

static int sram_attach(dev_info_t *, ddi_attach_cmd_t);

static int sram_detach(dev_info_t *, ddi_detach_cmd_t);

static void sram_add_kstats(struct sram_soft_state *);

/*
 * Configuration data structures
 */
static struct cb_ops sram_cb_ops = {
        nulldev,                        /* open */
        nulldev,                        /* close */
        nulldev,                        /* strategy */
        nulldev,                        /* print */
        nodev,                          /* dump */
        nulldev,                        /* read */
        nulldev,                        /* write */
        nulldev,                        /* ioctl */
        nodev,                          /* devmap */
        nodev,                          /* mmap */
        nodev,                          /* segmap */
        nochpoll,                       /* poll */
        ddi_prop_op,                    /* cb_prop_op */
        0,                              /* streamtab */
        D_MP | D_NEW | D_HOTPLUG,       /* Driver compatibility flag */
        CB_REV,                         /* rev */
        nodev,                          /* cb_aread */
        nodev                           /* cb_awrite */
};

static struct dev_ops sram_ops = {
        DEVO_REV,                       /* rev */
        0,                              /* refcnt  */
        ddi_no_info,                    /* getinfo */
        nulldev,                        /* identify */
        nulldev,                        /* probe */
        sram_attach,                    /* attach */
        sram_detach,                    /* detach */
        nulldev,                        /* reset */
        &sram_cb_ops,                   /* cb_ops */
        (struct bus_ops *)0,            /* bus_ops */
        nulldev,                        /* power */
        ddi_quiesce_not_needed,                 /* quiesce */
};


/*
 * Driver globals
 */
void *sramp;                    /* sram soft state hook */
static struct kstat *resetinfo_ksp = NULL;
static int reset_info_created = 0;

extern struct mod_ops mod_driverops;

static struct modldrv modldrv = {
        &mod_driverops,         /* Type of module.  This one is a driver */
        "Sram Leaf",            /* name of module */
        &sram_ops,              /* driver ops */
};

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

/*
 * These are the module initialization routines.
 */

int
_init(void)
{
        int error;

        if ((error = ddi_soft_state_init(&sramp,
            sizeof (struct sram_soft_state), 1)) == 0 &&
            (error = mod_install(&modlinkage)) != 0)
                ddi_soft_state_fini(&sramp);
        return (error);
}

int
_fini(void)
{
        int error;

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

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

static int
sram_attach(dev_info_t *devi, ddi_attach_cmd_t cmd)
{
        int instance;
        struct sram_soft_state *softsp;

        switch (cmd) {
        case DDI_ATTACH:
                break;

        case DDI_RESUME:
                return (DDI_SUCCESS);

        default:
                return (DDI_FAILURE);
        }

        instance = ddi_get_instance(devi);

        if (ddi_soft_state_zalloc(sramp, instance) != DDI_SUCCESS)
                return (DDI_FAILURE);

        softsp = ddi_get_soft_state(sramp, instance);

        /* Set the dip in the soft state */
        softsp->dip = devi;

        /* get the board number from this devices parent. */
        softsp->pdip = ddi_get_parent(softsp->dip);
        if ((softsp->board = (int)ddi_getprop(DDI_DEV_T_ANY, softsp->pdip,
            DDI_PROP_DONTPASS, OBP_BOARDNUM, -1)) == -1) {
                cmn_err(CE_WARN, "sram%d: unable to retrieve %s property",
                    instance, OBP_BOARDNUM);
                goto bad;
        }

        DPRINTF(SRAM_ATTACH_DEBUG, ("sram%d: devi= 0x%p\n, "
            " softsp=0x%p\n", instance, (void *)devi, (void *)softsp));

        /* map in the registers for this device. */
        if (ddi_map_regs(softsp->dip, 0,
            (caddr_t *)&softsp->sram_base, 0, 0)) {
                cmn_err(CE_WARN, "sram%d: unable to map registers",
                    instance);
                goto bad;
        }

        /* nothing to suspend/resume here */
        (void) ddi_prop_update_string(DDI_DEV_T_NONE, devi,
            "pm-hardware-state", "no-suspend-resume");

        /* create the kstats for this device. */
        sram_add_kstats(softsp);

        ddi_report_dev(devi);

        return (DDI_SUCCESS);

bad:
        ddi_soft_state_free(sramp, instance);
        return (DDI_FAILURE);
}

/* ARGSUSED */
static int
sram_detach(dev_info_t *devi, ddi_detach_cmd_t cmd)
{
        int instance;
        struct sram_soft_state *softsp;

        /* get the instance of this devi */
        instance = ddi_get_instance(devi);

        /* get the soft state pointer for this device node */
        softsp = ddi_get_soft_state(sramp, instance);

        switch (cmd) {
        case DDI_SUSPEND:
                return (DDI_SUCCESS);

        case DDI_DETACH:
                (void) fhc_bdlist_lock(softsp->board);
                if (fhc_bd_detachable(softsp->board))
                        break;
                else
                        fhc_bdlist_unlock();
                /* FALLTHROUGH */

        default:
                return (DDI_FAILURE);
        }

        fhc_bdlist_unlock();

        /*
         * We do not remove the kstat here. There is only one instance for
         * the whole machine, and it must remain in existence while the
         * system is running.
         */


        /* unmap the registers */
        ddi_unmap_regs(softsp->dip, 0,
            (caddr_t *)&softsp->sram_base, 0, 0);

        /* free the soft state structure */
        ddi_soft_state_free(sramp, instance);

        ddi_prop_remove_all(devi);

        return (DDI_SUCCESS);
}

/*
 * The Reset-info structure passed up by POST has it's own kstat.
 * It only needs to get created once. So the first sram instance
 * that gets created will check for the OBP property 'reset-info'
 * in the root node of the OBP device tree. If this property exists,
 * then the reset-info kstat will get created. Otherwise it will
 * not get created. This will inform users whether or not a fatal
 * hardware reset has recently occurred.
 */
static void
sram_add_kstats(struct sram_soft_state *softsp)
{
        int reset_size;         /* size of data collected by POST */
        char *ksptr;            /* memory pointer for byte copy */
        char *srptr;            /* pointer to sram for byte copy */
        int i;
        union  {
                char size[4];   /* copy in word byte-by-byte */
                uint_t len;
        } rst_size;

        /*
         * only one reset_info kstat per system, so don't create it if
         * it exists already.
         */
        if (reset_info_created) {
                return;
        }

        /* mark that this code has been run. */
        reset_info_created = 1;

        /* does the root node have a 'fatal-reset-info' property? */
        if (prom_getprop(prom_rootnode(), "fatal-reset-info",
            (caddr_t)&softsp->offset) == -1) {
                return;
        }

        /* XXX - workaround for OBP bug */
        softsp->reset_info = softsp->sram_base + softsp->offset;

        /*
         * First read size. In case FW has not word aligned structure,
         * copy the unsigned int into a 4 byte union, then read it out as
         * an inteeger.
         */
        for (i = 0, srptr = softsp->reset_info; i < 4; i++) {
                rst_size.size[i] = *srptr++;
        }
        reset_size = rst_size.len;

        /*
         * If the reset size is zero, then POST did not
         * record any info.
         */
        if ((uint_t)reset_size == 0) {
                return;
        }

        /* Check for illegal size values. */
        if ((uint_t)reset_size > MX_RSTINFO_SZ) {
                cmn_err(CE_NOTE, "sram%d: illegal "
                    "reset_size: 0x%x",
                    ddi_get_instance(softsp->dip),
                    reset_size);
                return;
        }

        /* create the reset-info kstat */
        resetinfo_ksp = kstat_create("unix", 0,
            RESETINFO_KSTAT_NAME, "misc", KSTAT_TYPE_RAW,
            reset_size, KSTAT_FLAG_PERSISTENT);

        if (resetinfo_ksp == NULL) {
                cmn_err(CE_WARN, "sram%d: kstat_create failed",
                    ddi_get_instance(softsp->dip));
                return;
        }

        /*
         * now copy the data into kstat. Don't use block
         * copy, the local space sram does not support this.
         */
        srptr = softsp->reset_info;

        ksptr = (char *)resetinfo_ksp->ks_data;

        for (i = 0; i < reset_size; i++) {
                *ksptr++ = *srptr++;
        }

        kstat_install(resetinfo_ksp);
}