/*
 * 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.
 * Copyright (c) 2011 Bayard G. Bell. All rights reserved.
 */

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/open.h>
#include <sys/modctl.h>
#include <sys/promif.h>
#include <sys/stat.h>
#include <sys/ddi_impldefs.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/epm.h>
#include <sys/acpi/acpi.h>
#include <sys/acpica.h>
#include <sys/psm_types.h>

/*
 *      ACPI Power Management Driver
 *
 *      acpippm deals with those bits of ppm functionality that
 *      must be mediated by ACPI
 *
 *      The routines in this driver is referenced by Platform
 *      Power Management driver of X86 workstation systems.
 *      acpippm driver is loaded because it is listed as a platform driver
 *      It is initially configured as a pseudo driver.
 */
extern void pc_tod_set_rtc_offsets(ACPI_TABLE_FADT *);
extern int acpica_use_safe_delay;

/*
 * Configuration Function prototypes and data structures
 */
static int      appm_attach(dev_info_t *, ddi_attach_cmd_t);
static int      appm_detach(dev_info_t *, ddi_detach_cmd_t);
static int      appm_getinfo(dev_info_t *, ddi_info_cmd_t, void *, void **);
static int      appm_open(dev_t *dev_p, int flag, int otyp, cred_t *cred_p);
static int      appm_close(dev_t dev, int flag, int otyp, cred_t *cred_p);
static int      appm_ioctl(dev_t, int, intptr_t, int, cred_t *, int *);

/*
 * Configuration data structures
 */
static struct cb_ops appm_cbops = {
        appm_open,              /* open */
        appm_close,             /* close */
        nodev,                  /* strategy */
        nodev,                  /* print */
        nodev,                  /* dump */
        nodev,                  /* read */
        nodev,                  /* write */
        appm_ioctl,             /* ioctl */
        nodev,                  /* devmap */
        nodev,                  /* mmap */
        nodev,                  /* segmap */
        nochpoll,               /* chpoll */
        ddi_prop_op,            /* prop_op */
        NULL,                   /* stream */
        D_MP | D_NEW,           /* flag */
        CB_REV,                 /* rev */
        nodev,                  /* aread */
        nodev,                  /* awrite */
};

static struct dev_ops appm_ops = {
        DEVO_REV,               /* devo_rev */
        0,                      /* refcnt */
        appm_getinfo,           /* getinfo */
        nulldev,                /* identify */
        nulldev,                /* probe */
        appm_attach,            /* attach */
        appm_detach,            /* detach */
        nodev,                  /* reset */
        &appm_cbops,            /* cb_ops */
        NULL,                   /* bus_ops */
        NULL,                   /* power */
        ddi_quiesce_not_needed,         /* quiesce */
};

extern struct mod_ops mod_driverops;

static struct modldrv modldrv = {
        &mod_driverops,
        "ACPI ppm driver",
        &appm_ops,
};

static struct modlinkage modlinkage = {
        MODREV_1,
        &modldrv,
        NULL
};

/*
 * Driver state structure
 */
typedef struct {
        dev_info_t              *dip;
        ddi_acc_handle_t        devid_hndl;
        ddi_acc_handle_t        estar_hndl;
        int                     lyropen;                /* ref count */
} appm_unit;

/*
 * Driver global variables
 *
 * appm_lock synchronize the access of lyr handle to each appm
 * minor device, therefore write to tomatillo device is
 * sequentialized.  Lyr protocol requires pairing up lyr open
 * and close, so only a single reference is allowed per minor node.
 */
static void     *appm_statep;
static kmutex_t  appm_lock;

/*
 * S3 stuff:
 */
extern int acpi_enter_sleepstate(s3a_t *);
extern int acpi_exit_sleepstate(s3a_t *);


int
_init(void)
{
        int     error;

        if ((error = ddi_soft_state_init(&appm_statep,
            sizeof (appm_unit), 0)) != DDI_SUCCESS) {
                return (error);
        }

        mutex_init(&appm_lock, NULL, MUTEX_DRIVER, NULL);

        if ((error = mod_install(&modlinkage)) != DDI_SUCCESS) {
                mutex_destroy(&appm_lock);
                ddi_soft_state_fini(&appm_statep);
                return (error);
        }

        return (error);
}

int
_fini(void)
{
        int     error;

        if ((error = mod_remove(&modlinkage)) == DDI_SUCCESS) {
                mutex_destroy(&appm_lock);
                ddi_soft_state_fini(&appm_statep);
        }

        return (error);

}

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



/*
 * Driver attach(9e) entry point
 */
static int
appm_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        char    *str = "appm_attach";
        int             instance;
        appm_unit       *unitp;
        ACPI_TABLE_FADT *fadt = NULL;
        int             rv = DDI_SUCCESS;

        switch (cmd) {
        case DDI_ATTACH:
                break;
        case DDI_RESUME:
                return (DDI_SUCCESS);
        default:
                cmn_err(CE_WARN, "%s: cmd %d unsupported.\n", str, cmd);
                return (DDI_FAILURE);
        }

        instance = ddi_get_instance(dip);
        rv = ddi_soft_state_zalloc(appm_statep, instance);
        if (rv != DDI_SUCCESS) {
                cmn_err(CE_WARN, "%s: failed alloc for dev(%s@%s)",
                    str, ddi_binding_name(dip),
                    ddi_get_name_addr(dip) ? ddi_get_name_addr(dip) : " ");
                return (rv);
        }

        if ((unitp = ddi_get_soft_state(appm_statep, instance)) == NULL) {
                rv = DDI_FAILURE;
                goto doerrs;
        }

        /*
         * Export "ddi-kernel-ioctl" property - prepared to support
         * kernel ioctls (driver layering).
         * XXX is this still needed?
         * XXXX (RSF) Not that I am aware of.
         */
        rv = ddi_prop_create(DDI_DEV_T_NONE, dip, DDI_PROP_CANSLEEP,
            DDI_KERNEL_IOCTL, NULL, 0);
        if (rv != DDI_PROP_SUCCESS)
                goto doerrs;

        ddi_report_dev(dip);
        unitp->dip = dip;

        /*
         * XXX here we would do whatever we need to to determine if the
         * XXX platform supports ACPI, and fail the attach if not.
         * XXX If it does, we do whatever setup is needed to get access to
         * XXX ACPI register space.
         */

        unitp->lyropen = 0;

        /*
         * create minor node for kernel_ioctl calls
         */
        rv = ddi_create_minor_node(dip, "acpi-ppm", S_IFCHR, instance, 0, 0);
        if (rv != DDI_SUCCESS)
                goto doerrs;

        /* Get the FADT */
        if (AcpiGetTable(ACPI_SIG_FADT, 1,
            (ACPI_TABLE_HEADER **)&fadt) != AE_OK)
                return (rv);

        /* Init the RTC offsets */
        if (fadt != NULL)
                pc_tod_set_rtc_offsets(fadt);

        return (rv);

doerrs:

        if (ddi_prop_exists(DDI_DEV_T_ANY, dip, DDI_PROP_DONTPASS |
            DDI_PROP_NOTPROM, DDI_KERNEL_IOCTL))
                ddi_prop_remove_all(dip);

        ddi_soft_state_free(appm_statep, instance);

        return (rv);
}


/*
 * Driver getinfo(9e) entry routine
 */
/* ARGSUSED */
static int
appm_getinfo(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg, void **result)
{
        appm_unit       *unitp;
        int             instance;

        switch (cmd) {
        case DDI_INFO_DEVT2DEVINFO:
                instance = getminor((dev_t)arg);
                unitp = ddi_get_soft_state(appm_statep, instance);
                if (unitp == NULL) {
                        return (DDI_FAILURE);
                }
                *result = (void *) unitp->dip;
                return (DDI_SUCCESS);

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

        default:
                return (DDI_FAILURE);
        }
}


/*
 * detach(9e)
 */
/* ARGSUSED */
static int
appm_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        char *str = "appm_detach";

        switch (cmd) {
        case DDI_DETACH:
                return (DDI_FAILURE);
        case DDI_SUSPEND:
                return (DDI_SUCCESS);
        default:
                cmn_err(CE_WARN, "%s: cmd %d unsupported", str, cmd);
                return (DDI_FAILURE);
        }
}


/* ARGSUSED */
static int
appm_open(dev_t *dev_p, int flag, int otyp, cred_t *cred_p)
{
        appm_unit       *unitp;

        /* not intended to allow sysadmin level root process to open it */
        if (drv_priv(cred_p) != DDI_SUCCESS)
                return (EPERM);

        if ((unitp = ddi_get_soft_state(
            appm_statep, getminor(*dev_p))) == NULL) {
                cmn_err(CE_WARN, "appm_open: failed to get soft state!");
                return (DDI_FAILURE);
        }

        mutex_enter(&appm_lock);
        if (unitp->lyropen != 0) {
                mutex_exit(&appm_lock);
                return (EBUSY);
        }
        unitp->lyropen++;
        mutex_exit(&appm_lock);

        return (DDI_SUCCESS);
}


/* ARGSUSED */
static int
appm_close(dev_t dev, int flag, int otyp, cred_t *cred_p)
{
        appm_unit       *unitp;

        if ((unitp =
            ddi_get_soft_state(appm_statep, getminor(dev))) == NULL)
                return (DDI_FAILURE);

        mutex_enter(&appm_lock);
        unitp->lyropen = 0;
        mutex_exit(&appm_lock);

        return (DDI_SUCCESS);
}


/*
 * must match ppm.conf
 */
#define APPMIOC                 ('A' << 8)
#define APPMIOC_ENTER_S3        (APPMIOC | 1)   /* arg *s3a_t */
#define APPMIOC_EXIT_S3         (APPMIOC | 2)   /* arg *s3a_t */

/* ARGSUSED3 */
static int
appm_ioctl(dev_t dev, int cmd, intptr_t arg, int flag,
    cred_t *cred_p, int *rval_p)
{
        static boolean_t        acpi_initted = B_FALSE;
        char                    *str = "appm_ioctl";
        int                     ret;
        s3a_t                   *s3ap = (s3a_t *)arg;

        PMD(PMD_SX, ("%s: called with %x\n", str, cmd))

        if (drv_priv(cred_p) != 0) {
                PMD(PMD_SX, ("%s: EPERM\n", str))
                return (EPERM);
        }

        if (ddi_get_soft_state(appm_statep, getminor(dev)) == NULL) {
                PMD(PMD_SX, ("%s: no soft state: EIO\n", str))
                return (EIO);
        }

        if (!acpi_initted) {
                PMD(PMD_SX, ("%s: !acpi_initted\n", str))
                if (acpica_init() == 0) {
                        acpi_initted = B_TRUE;
                } else {
                        if (rval_p != NULL) {
                                *rval_p = EINVAL;
                        }
                        PMD(PMD_SX, ("%s: EINVAL\n", str))
                        return (EINVAL);
                }
        }

        PMD(PMD_SX, ("%s: looking for cmd %x\n", str, cmd))
        switch (cmd) {
        case APPMIOC_ENTER_S3:
                /*
                 * suspend to RAM (ie S3)
                 */
                PMD(PMD_SX, ("%s: cmd %x, arg %p\n", str, cmd, (void *)arg))
                acpica_use_safe_delay = 1;
                ret = acpi_enter_sleepstate(s3ap);
                break;

        case APPMIOC_EXIT_S3:
                /*
                 * return from S3
                 */
                PMD(PMD_SX, ("%s: cmd %x, arg %p\n", str, cmd, (void *)arg))
                ret = acpi_exit_sleepstate(s3ap);
                acpica_use_safe_delay = 0;
                break;

        default:
                PMD(PMD_SX, ("%s: cmd %x unrecognized: ENOTTY\n", str, cmd))
                return (ENOTTY);
        }

        /*
         * upon failure return EINVAL
         */
        if (ret != 0) {
                if (rval_p != NULL) {
                        *rval_p = EINVAL;
                }
                return (EINVAL);
        }

        return (0);
}