/*-
 * Copyright (c) 1998, 2001 Nicolas Souchu
 * 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 AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 *
 * $FreeBSD: src/sys/dev/iicbus/iic.c,v 1.43 2009/01/26 13:53:39 raj Exp $
 */

#include <sys/param.h>
#include <sys/buf.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <sys/uio.h>

#include <bus/iicbus/iiconf.h>
#include <bus/iicbus/iicbus.h>
#include <bus/iicbus/iic.h>

#include "iicbus_if.h"

#define BUFSIZE 1024

struct iic_softc {

        device_t sc_dev;
        u_char sc_addr;                 /* 7 bit address on iicbus */
        int sc_count;                   /* >0 if device opened */

        char sc_buffer[BUFSIZE];        /* output buffer */
        char sc_inbuf[BUFSIZE];         /* input buffer */

        cdev_t sc_devnode;
};

#define IIC_LOCK(sc)
#define IIC_UNLOCK(sc)

static int iic_probe(device_t);
static int iic_attach(device_t);
static int iic_detach(device_t);
static void iic_identify(driver_t *driver, device_t parent);

static devclass_t iic_devclass;

static device_method_t iic_methods[] = {
        /* device interface */
        DEVMETHOD(device_identify,      iic_identify),
        DEVMETHOD(device_probe,         iic_probe),
        DEVMETHOD(device_attach,        iic_attach),
        DEVMETHOD(device_detach,        iic_detach),

        /* iicbus interface */
        DEVMETHOD(iicbus_intr,          iicbus_generic_intr),

        DEVMETHOD_END
};

static driver_t iic_driver = {
        "iic",
        iic_methods,
        sizeof(struct iic_softc),
};

static  d_open_t        iicopen;
static  d_close_t       iicclose;
static  d_write_t       iicwrite;
static  d_read_t        iicread;
static  d_ioctl_t       iicioctl;

static struct dev_ops iic_ops = {
        { "iic", 0, 0 },
        .d_open =       iicopen,
        .d_close =      iicclose,
        .d_read =       iicread,
        .d_write =      iicwrite,
        .d_ioctl =      iicioctl,
};

static void
iic_identify(driver_t *driver, device_t parent)
{

        if (device_find_child(parent, "iic", -1) == NULL)
                BUS_ADD_CHILD(parent, parent, 0, "iic", -1);
}

static int
iic_probe(device_t dev)
{
        if (iicbus_get_addr(dev) > 0)
                return (ENXIO);

        device_set_desc(dev, "I2C generic I/O");

        return (0);
}
        
static int
iic_attach(device_t dev)
{
        struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);

        sc->sc_devnode = make_dev(&iic_ops, device_get_unit(dev),
                        UID_ROOT, GID_WHEEL,
                        0600, "iic%d", device_get_unit(dev));
        if (sc->sc_devnode == NULL) {
                device_printf(dev, "failed to create character device\n");
                return (ENXIO);
        }
        sc->sc_devnode->si_drv1 = sc;

        return (0);
}

static int
iic_detach(device_t dev)
{
        struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);

        if (sc->sc_devnode)
                dev_ops_remove_minor(&iic_ops, device_get_unit(dev));

        return (0);
}

static int
iicopen(struct dev_open_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct iic_softc *sc = dev->si_drv1;

        IIC_LOCK(sc);
        if (sc->sc_count > 0) {
                IIC_UNLOCK(sc);
                return (EBUSY);
        }

        sc->sc_count++;
        IIC_UNLOCK(sc);

        return (0);
}

static int
iicclose(struct dev_close_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct iic_softc *sc = dev->si_drv1;

        IIC_LOCK(sc);
        if (!sc->sc_count) {
                /* XXX: I don't think this can happen. */
                IIC_UNLOCK(sc);
                return (EINVAL);
        }

        sc->sc_count--;

        if (sc->sc_count < 0)
                panic("%s: iic_count < 0!", __func__);
        IIC_UNLOCK(sc);

        return (0);
}

static int
iicwrite(struct dev_write_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct uio *uio = ap->a_uio;
        struct iic_softc *sc = dev->si_drv1;
        device_t iicdev = sc->sc_dev;
        int sent, error, count;

        IIC_LOCK(sc);
        if (!sc->sc_addr) {
                IIC_UNLOCK(sc);
                return (EINVAL);
        }

        if (sc->sc_count == 0) {
                /* XXX: I don't think this can happen. */
                IIC_UNLOCK(sc);
                return (EINVAL);
        }

        error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
            IIC_DONTWAIT);
        if (error) {
                IIC_UNLOCK(sc);
                return (error);
        }

        count = (int)szmin(uio->uio_resid, BUFSIZE);
        uiomove(sc->sc_buffer, (size_t)count, uio);

        error = iicbus_block_write(device_get_parent(iicdev), sc->sc_addr,
                                        sc->sc_buffer, count, &sent);

        iicbus_release_bus(device_get_parent(iicdev), iicdev);
        IIC_UNLOCK(sc);

        return (error);
}

static int
iicread(struct dev_read_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        struct uio *uio = ap->a_uio;
        struct iic_softc *sc = dev->si_drv1;
        device_t iicdev = sc->sc_dev;
        int len, error = 0;
        int bufsize;

        IIC_LOCK(sc);
        if (!sc->sc_addr) {
                IIC_UNLOCK(sc);
                return (EINVAL);
        }

        if (sc->sc_count == 0) {
                /* XXX: I don't think this can happen. */
                IIC_UNLOCK(sc);
                return (EINVAL);
        }

        error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
            IIC_DONTWAIT);
        if (error) {
                IIC_UNLOCK(sc);
                return (error);
        }

        /* max amount of data to read */
        len = (int)szmin(uio->uio_resid, BUFSIZE);

        error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
            sc->sc_inbuf, len, &bufsize);
        if (error) {
                IIC_UNLOCK(sc);
                return (error);
        }

        if (bufsize > uio->uio_resid)
                panic("%s: too much data read!", __func__);

        iicbus_release_bus(device_get_parent(iicdev), iicdev);

        error = uiomove(sc->sc_inbuf, (size_t)bufsize, uio);
        IIC_UNLOCK(sc);
        return (error);
}

static int
iicioctl(struct dev_ioctl_args *ap)
{
        cdev_t dev = ap->a_head.a_dev;
        u_long cmd = ap->a_cmd;
        caddr_t data = ap->a_data;
        int flags = ap->a_fflag;
        struct iic_softc *sc = dev->si_drv1;
        device_t iicdev = sc->sc_dev;
        device_t parent = device_get_parent(iicdev);
        struct iiccmd *s = (struct iiccmd *)data;
        struct iic_rdwr_data *d = (struct iic_rdwr_data *)data;
        struct iic_msg *m;
        int error, count, i;
        char *buf = NULL;
        void **usrbufs = NULL;

        if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev,
                        (flags & O_NONBLOCK) ? IIC_DONTWAIT :
                                                (IIC_WAIT | IIC_INTR))))
                return (error);

        switch (cmd) {
        case I2CSTART:
                IIC_LOCK(sc);
                error = iicbus_start(parent, s->slave, 0);

                /*
                 * Implicitly set the chip addr to the slave addr passed as
                 * parameter. Consequently, start/stop shall be called before
                 * the read or the write of a block.
                 */
                if (!error)
                        sc->sc_addr = s->slave;
                IIC_UNLOCK(sc);

                break;

        case I2CSTOP:
                error = iicbus_stop(parent);
                break;

        case I2CRSTCARD:
                error = iicbus_reset(parent, IIC_UNKNOWN, 0, NULL);
                break;

        case I2CWRITE:
                if (s->count <= 0) {
                        error = EINVAL;
                        break;
                }
                buf = kmalloc((unsigned long)s->count, M_TEMP, M_WAITOK);
                error = copyin(s->buf, buf, s->count);
                if (error)
                        break;
                error = iicbus_write(parent, buf, s->count, &count, 10);
                break;

        case I2CREAD:
                if (s->count <= 0) {
                        error = EINVAL;
                        break;
                }
                buf = kmalloc((unsigned long)s->count, M_TEMP, M_WAITOK);
                error = iicbus_read(parent, buf, s->count, &count, s->last, 10);
                if (error)
                        break;
                error = copyout(buf, s->buf, s->count);
                break;

        case I2CRDWR:
                buf = kmalloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK);
                usrbufs = kmalloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK);
                error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
                if (error)
                        break;
                /* Alloc kernel buffers for userland data, copyin write data */
                for (i = 0; i < d->nmsgs; i++) {
                        m = &((struct iic_msg *)buf)[i];
                        usrbufs[i] = m->buf;
                        m->buf = kmalloc(m->len, M_TEMP, M_WAITOK);
                        if (!(m->flags & IIC_M_RD))
                                copyin(usrbufs[i], m->buf, m->len);
                }
                error = iicbus_transfer(parent, (struct iic_msg *)buf, d->nmsgs);
                /* Copyout all read segments, free up kernel buffers */
                for (i = 0; i < d->nmsgs; i++) {
                        m = &((struct iic_msg *)buf)[i];
                        if (m->flags & IIC_M_RD)
                                copyout(m->buf, usrbufs[i], m->len);
                        kfree(m->buf, M_TEMP);
                }
                kfree(usrbufs, M_TEMP);
                break;

        case I2CRPTSTART:
                error = iicbus_repeated_start(parent, s->slave, 0);
                break;

        default:
                error = ENOTTY;
        }

        iicbus_release_bus(device_get_parent(iicdev), iicdev);

        if (buf != NULL)
                kfree(buf, M_TEMP);
        return (error);
}

DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, NULL, NULL);
MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_VERSION(iic, 1);