/*
 * 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/stat.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/modctl.h>
#include <sys/open.h>
#include <sys/types.h>
#include <sys/kmem.h>
#include <sys/systm.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/conf.h>
#include <sys/mode.h>
#include <sys/note.h>
#include <sys/i2c/misc/i2c_svc.h>
#include <sys/i2c/clients/ics951601.h>
#include <sys/i2c/clients/ics951601_impl.h>

/*
 * This is the client driver for the ics951601 device which is a general
 * purpose clock generator.  Setting a clock to 1 enables the clock while
 * setting it to 0 disables it.  All clocks are enabled by default by
 * the driver.  The user can read a clock, enable it or disable it.
 * The command sent as an ioctl argument should be the bitwise OR of the
 * clock number and the action upon it.  The supported clock numbers and
 * actions are defined in ics951601.h.  A pointer to an integer is sent
 * as the third  ioctl argument.  If the clock is to be read the value of the
 * clock is copied into it and if it is to be modified the integer referred
 * to should have the appropriate value of either 1 or 0.
 */

/*
 * cb ops
 */
static int ics951601_open(dev_t *, int, int, cred_t *);
static int ics951601_close(dev_t, int, int, cred_t *);
static int ics951601_ioctl(dev_t, int, intptr_t, int, cred_t *, int *);

/*
 * dev ops
 */
static int ics951601_s_attach(dev_info_t *dip, ddi_attach_cmd_t cmd);
static int ics951601_s_detach(dev_info_t *dip, ddi_detach_cmd_t cmd);
static int ics951601_info(dev_info_t *, ddi_info_cmd_t, void *, void **);

static struct cb_ops ics951601_cb_ops = {
        ics951601_open,                 /* open */
        ics951601_close,                /* close */
        nodev,                          /* strategy */
        nodev,                          /* print */
        nodev,                          /* dump */
        nodev,                          /* read */
        nodev,                          /* write */
        ics951601_ioctl,                /* ioctl */
        nodev,                          /* devmap */
        nodev,                          /* mmap */
        nodev,                          /* segmap */
        nochpoll,                       /* poll */
        ddi_prop_op,                    /* cb_prop_op */
        NULL,                           /* streamtab */
        D_NEW | D_MP | D_HOTPLUG,       /* Driver compatibility flag */
};

static struct dev_ops ics951601_dev_ops = {
        DEVO_REV,
        0,
        ics951601_info,
        nulldev,
        nulldev,
        ics951601_s_attach,
        ics951601_s_detach,
        nodev,
        &ics951601_cb_ops,
        NULL,
        NULL,
        ddi_quiesce_not_needed,         /* quiesce */
};

static struct modldrv ics951601_modldrv = {
        &mod_driverops,         /* type of module - driver */
        "ics951601 device driver",
        &ics951601_dev_ops,
};

static struct modlinkage ics951601_modlinkage = {
        MODREV_1,
        &ics951601_modldrv,
        0
};

/*
 * Writes to the clock generator involve sending the dummy command code, the
 * dummy byte count followed by byte 0 through byte 5. The dummy command code
 * and the dummy byte count are ignored by the ICS clock but must be sent.
 *
 * On reading from the clock generator, the controller will first receive a
 * byte count followed by byte 0 through byte 5.
 */

/*
 * The array for initializing the internal registers at attach time.
 */
static uchar_t init_clock_regs[8] = {
        0x0,    /* Dummy command code */
        0x7,    /* Dummy byte count */
        0x0,    /* Initial value for functionality register */
        0xff,   /* Initial value for PCI1A stop clocks register */
        0xff,   /* Initial value for PCI2A stop clocks register */
        0xff,   /* Initial value for PCI2B stop clocks register */
        0xff,   /* Default value for reserved register */
        0xef    /* Default value for latched input read back register */
};

static void *ics951601_soft_statep;
int ics951601_debug = 0;

int
_init(void)
{
        int    err;

        err = mod_install(&ics951601_modlinkage);
        if (err == 0) {
                (void) ddi_soft_state_init(&ics951601_soft_statep,
                    sizeof (ics951601_unit_t), 1);
        }
        return (err);
}

int
_fini(void)
{
        int    err;

        err = mod_remove(&ics951601_modlinkage);
        if (err == 0) {
                ddi_soft_state_fini(&ics951601_soft_statep);
        }
        return (err);
}

int
_info(struct modinfo *modinfop)
{
        return (mod_info(&ics951601_modlinkage, modinfop));
}

static int
ics951601_open(dev_t *devp, int flags, int otyp, cred_t *credp)
{
        int                     instance;
        ics951601_unit_t        *icsp;
        int                     err = EBUSY;

        /*
         * Make sure the open is for the right file type
         */
        if (otyp != OTYP_CHR) {
                return (EINVAL);
        }

        instance = getminor(*devp);
        if (instance < 0) {
                return (ENXIO);
        }
        icsp = (ics951601_unit_t *)ddi_get_soft_state(ics951601_soft_statep,
            instance);
        if (icsp == NULL) {
                return (ENXIO);
        }

        /* must be privileged to access this device */
        if (drv_priv(credp) != 0) {
                return (EPERM);
        }

        /*
         * Enforce exclusive access if required
         */
        mutex_enter(&icsp->ics951601_mutex);
        if (flags & FEXCL) {
                if (icsp->ics951601_oflag == 0) {
                        icsp->ics951601_oflag = FEXCL;
                        err = DDI_SUCCESS;
                }
        } else if (icsp->ics951601_oflag != FEXCL) {
                icsp->ics951601_oflag = (uint16_t)FOPEN;
                err = DDI_SUCCESS;
        }
        mutex_exit(&icsp->ics951601_mutex);
        return (err);
}

static int
ics951601_close(dev_t dev, int flags, int otyp, cred_t *credp)
{
        _NOTE(ARGUNUSED(flags, credp))

        int             instance;
        ics951601_unit_t        *icsp;

        /*
         *      Make sure the close is for the right file type
         */
        if (otyp != OTYP_CHR) {
                return (EINVAL);
        }

        instance = getminor(dev);
        icsp = (ics951601_unit_t *)ddi_get_soft_state(ics951601_soft_statep,
            instance);
        if (icsp == NULL) {
                return (ENXIO);
        }

        mutex_enter(&icsp->ics951601_mutex);
        icsp->ics951601_oflag = 0;
        mutex_exit(&icsp->ics951601_mutex);
        return (DDI_SUCCESS);
}

static int
ics951601_attach(dev_info_t *dip)
{
        ics951601_unit_t        *icsp;
        int                     instance = ddi_get_instance(dip);

        if (ddi_soft_state_zalloc(ics951601_soft_statep, instance) != 0) {
                cmn_err(CE_WARN, "%s%d failed to zalloc softstate",
                    ddi_get_name(dip), instance);
                return (DDI_FAILURE);
        }

        icsp = ddi_get_soft_state(ics951601_soft_statep, instance);

        if (icsp == NULL) {
                return (DDI_FAILURE);
        }

        mutex_init(&icsp->ics951601_mutex, NULL, MUTEX_DRIVER, NULL);
        cv_init(&icsp->ics951601_cv, NULL, CV_DRIVER, NULL);

        (void) snprintf(icsp->ics951601_name, sizeof (icsp->ics951601_name),
            "%s_%d", ddi_driver_name(dip), instance);


        if (ddi_create_minor_node(dip, icsp->ics951601_name, S_IFCHR,
            instance, ICS951601_NODE_TYPE, 0) == DDI_FAILURE) {
                cmn_err(CE_WARN, "%s ddi_create_minor_node failed",
                    icsp->ics951601_name);
                goto ATTACH_ERR;
        }

        /*
         * preallocate a single buffer for all reads and writes
         */
        if (i2c_transfer_alloc(icsp->ics951601_hdl, &icsp->ics951601_transfer,
            0, 0, I2C_SLEEP) != I2C_SUCCESS) {
                cmn_err(CE_WARN, "%s i2c_transfer_alloc failed",
                    icsp->ics951601_name);
                goto CREATE_NODE_ERR;
        }
        icsp->ics951601_cpr_state[0] = 0x0;
        icsp->ics951601_transfer->i2c_version = I2C_XFER_REV;

        if (i2c_client_register(dip, &icsp->ics951601_hdl) != I2C_SUCCESS) {
                cmn_err(CE_WARN, "%s i2c_client_register failed",
                    icsp->ics951601_name);
                goto ALLOC_ERR;
        }

        /* Enable all clocks */
        icsp->ics951601_transfer->i2c_flags = I2C_WR;
        icsp->ics951601_transfer->i2c_wlen = ICS951601_I2C_WRITE_TRANS_SIZE;
        icsp->ics951601_transfer->i2c_rlen = 0;
        icsp->ics951601_transfer->i2c_wbuf = init_clock_regs;

        if (i2c_transfer(icsp->ics951601_hdl, icsp->ics951601_transfer)
            != I2C_SUCCESS) {
                goto REG_ERR;
        }

        /*
         * Store the dip for future use
         */
        icsp->ics951601_dip = dip;

        return (DDI_SUCCESS);
REG_ERR:
        i2c_client_unregister(icsp->ics951601_hdl);

ALLOC_ERR:
        i2c_transfer_free(icsp->ics951601_hdl, icsp->ics951601_transfer);

CREATE_NODE_ERR:
        ddi_remove_minor_node(dip, NULL);

ATTACH_ERR:
        cv_destroy(&icsp->ics951601_cv);
        mutex_destroy(&icsp->ics951601_mutex);
        ddi_soft_state_free(ics951601_soft_statep, instance);

        return (DDI_FAILURE);
}


static void
ics951601_detach(dev_info_t *dip)
{
        ics951601_unit_t *icsp;
        int             instance;

        instance = ddi_get_instance(dip);
        icsp = ddi_get_soft_state(ics951601_soft_statep, instance);
        cv_destroy(&icsp->ics951601_cv);
        mutex_destroy(&icsp->ics951601_mutex);
        i2c_client_unregister(icsp->ics951601_hdl);
        i2c_transfer_free(icsp->ics951601_hdl, icsp->ics951601_transfer);
        ddi_remove_minor_node(dip, NULL);
        ddi_soft_state_free(ics951601_soft_statep, instance);
}

static int
ics951601_info(dev_info_t *dip, ddi_info_cmd_t cmd, void *arg, void **result)
{
        _NOTE(ARGUNUSED(dip))

        ics951601_unit_t        *icsp;
        int                     instance = getminor((dev_t)arg);

        switch (cmd) {
        case DDI_INFO_DEVT2DEVINFO:
                icsp = ddi_get_soft_state(ics951601_soft_statep, instance);
                if (icsp == NULL) {
                        return (DDI_FAILURE);
                }
                *result = (void *)icsp->ics951601_dip;

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

                return (DDI_SUCCESS);
        default:
                return (DDI_FAILURE);
        }
}

static int
ics951601_suspend(dev_info_t *dip)
{
        ics951601_unit_t        *icsp;
        int             instance = ddi_get_instance(dip);

        icsp = ddi_get_soft_state(ics951601_soft_statep, instance);

        /*
         * Set the busy flag so that future transactions block
         * until resume.
         */
        mutex_enter(&icsp->ics951601_mutex);
        while ((icsp->ics951601_flags & ICS951601_BUSYFLAG) ==
            ICS951601_BUSYFLAG) {
                if (cv_wait_sig(&icsp->ics951601_cv,
                    &icsp->ics951601_mutex) <= 0) {
                        mutex_exit(&icsp->ics951601_mutex);
                        return (DDI_FAILURE);
                }
        }
        icsp->ics951601_flags |= ICS951601_BUSYFLAG;
        mutex_exit(&icsp->ics951601_mutex);

        icsp->ics951601_transfer->i2c_flags = I2C_RD;
        icsp->ics951601_transfer->i2c_wlen = 0;
        icsp->ics951601_transfer->i2c_rlen = ICS951601_I2C_READ_TRANS_SIZE;
        icsp->ics951601_transfer->i2c_rbuf = icsp->ics951601_cpr_state + 1;

        if (i2c_transfer(icsp->ics951601_hdl, icsp->ics951601_transfer)
            != I2C_SUCCESS) {
                cmn_err(CE_WARN, "%s Suspend failed, unable to save registers",
                    icsp->ics951601_name);
                return (EIO);
        }
        return (DDI_SUCCESS);
}


static int
ics951601_resume(dev_info_t *dip)
{
        int             instance = ddi_get_instance(dip);
        ics951601_unit_t        *icsp;
        int             err = DDI_SUCCESS;

        icsp = (ics951601_unit_t *)
            ddi_get_soft_state(ics951601_soft_statep, instance);

        if (icsp == NULL) {
                return (ENXIO);
        }

        /*
         * Restore registers to status existing before cpr
         */
        icsp->ics951601_transfer->i2c_flags = I2C_WR;
        icsp->ics951601_transfer->i2c_rlen = 0;
        icsp->ics951601_transfer->i2c_wlen = ICS951601_I2C_WRITE_TRANS_SIZE;

        icsp->ics951601_transfer->i2c_wbuf = icsp->ics951601_cpr_state;

        if (i2c_transfer(icsp->ics951601_hdl, icsp->ics951601_transfer)
            != I2C_SUCCESS) {
                err = EIO;
                cmn_err(CE_WARN, " %s Unable to restore registers",
                    icsp->ics951601_name);
        }

        /*
         * Clear busy flag so that transactions may continue
         */
        mutex_enter(&icsp->ics951601_mutex);
        icsp->ics951601_flags = icsp->ics951601_flags & ~ICS951601_BUSYFLAG;
        cv_signal(&icsp->ics951601_cv);
        mutex_exit(&icsp->ics951601_mutex);
        return (err);
}

static int
ics951601_s_attach(dev_info_t *dip, ddi_attach_cmd_t cmd)
{
        switch (cmd) {
        case DDI_ATTACH:
                return (ics951601_attach(dip));
        case DDI_RESUME:
                return (ics951601_resume(dip));
        default:
                return (DDI_FAILURE);
        }
}

static int
ics951601_s_detach(dev_info_t *dip, ddi_detach_cmd_t cmd)
{
        switch (cmd) {
        case DDI_DETACH:
                ics951601_detach(dip);
                return (DDI_SUCCESS);
        case DDI_SUSPEND:
                return (ics951601_suspend(dip));
        default:
                return (DDI_FAILURE);
        }
}

static int
ics951601_ioctl(dev_t dev, int cmd, intptr_t arg, int mode, cred_t *credp,
    int *rvalp)
{
        _NOTE(ARGUNUSED(credp, rvalp))

        ics951601_unit_t                *icsp;
        int                     err = 0;
        uchar_t                 temp_arr[ICS951601_I2C_WRITE_TRANS_SIZE];
        int                     reg_no;
        uint8_t                 clock_bit;
        int                     ics_temp;
        int                     instance = getminor(dev);

        temp_arr[0] = 0x0;

        icsp = (ics951601_unit_t *)
            ddi_get_soft_state(ics951601_soft_statep, instance);

        if (ics951601_debug) {
                printf("ics951601_ioctl: instance=%d\n", instance);
        }

        /*
         * We serialize here and  block if there are pending transacations .
         */
        mutex_enter(&icsp->ics951601_mutex);
        while ((icsp->ics951601_flags & ICS951601_BUSYFLAG) ==
            ICS951601_BUSYFLAG) {
                if (cv_wait_sig(&icsp->ics951601_cv,
                    &icsp->ics951601_mutex) <= 0) {
                        mutex_exit(&icsp->ics951601_mutex);
                        return (EINTR);
                }
        }
        icsp->ics951601_flags |= ICS951601_BUSYFLAG;
        mutex_exit(&icsp->ics951601_mutex);

        reg_no  = ICS951601_CMD_TO_CLOCKREG(cmd);
        clock_bit = ICS951601_CMD_TO_CLOCKBIT(cmd);

        icsp->ics951601_transfer->i2c_flags = I2C_RD;
        icsp->ics951601_transfer->i2c_wlen = 0;
        icsp->ics951601_transfer->i2c_rlen = ICS951601_I2C_READ_TRANS_SIZE;
        icsp->ics951601_transfer->i2c_rbuf = temp_arr + 1;

        if (i2c_transfer(icsp->ics951601_hdl, icsp->ics951601_transfer)
            != I2C_SUCCESS) {

                err = DDI_FAILURE;
                goto cleanup;
        }
        switch (ICS951601_CMD_TO_ACTION(cmd)) {
        case ICS951601_READ_CLOCK:
                temp_arr[reg_no] &= clock_bit;
                ics_temp = temp_arr[reg_no] ? ICS951601_CLOCK_SET:
                    ICS951601_CLOCK_CLEAR;
                err = ddi_copyout((caddr_t)&ics_temp, (caddr_t)arg,
                    sizeof (int), mode);
                goto cleanup;
        case ICS951601_MODIFY_CLOCK:
                if (ddi_copyin((caddr_t)arg, (caddr_t)&ics_temp,
                    sizeof (int), mode) != DDI_SUCCESS) {
                        err = EIO;
                        goto cleanup;
                }
                if (ics_temp == ICS951601_CLOCK_SET) {
                        temp_arr[reg_no] |= clock_bit;
                } else if (ics_temp == ICS951601_CLOCK_CLEAR) {
                        temp_arr[reg_no] &= ~clock_bit;
                } else {
                        cmn_err(CE_WARN, "%s Clock can only be set to 1 or 0",
                            icsp->ics951601_name);
                        err = EINVAL;
                        goto cleanup;
                }
                break;
        default:
                err = EINVAL;
                goto cleanup;
        }

        icsp->ics951601_transfer->i2c_flags = I2C_WR;
        icsp->ics951601_transfer->i2c_wlen = ICS951601_I2C_WRITE_TRANS_SIZE;
        icsp->ics951601_transfer->i2c_rlen = 0;
        icsp->ics951601_transfer->i2c_wbuf = temp_arr;

        if (i2c_transfer(icsp->ics951601_hdl, icsp->ics951601_transfer)
            != I2C_SUCCESS) {

                err = DDI_FAILURE;
                goto cleanup;
        }
cleanup:
        mutex_enter(&icsp->ics951601_mutex);
        icsp->ics951601_flags  = icsp->ics951601_flags & ~ICS951601_BUSYFLAG;
        cv_signal(&icsp->ics951601_cv);
        mutex_exit(&icsp->ics951601_mutex);
        return (err);
}