freebsd-skq/sys/dev/iicbus/iic.c
Warner Losh d7fac9732b Allow iic bridges to support a generalized transfer, rather than
forcing all transfers to do the start read/write stop by hand.  Some
smart bridges prefer this sort of operation, and this allows us to
support their features more easily.  When bridges don't support it, we
fall back to using the old-style opertaions.  Expand the ioctl
interface to expose this function.  Unlike the old-style interface,
this interface is thread safe, even on old bridges.
2006-07-14 23:15:06 +00:00

341 lines
8.2 KiB
C

/*-
* 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.
*
* $FreeBSD$
*
*/
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/uio.h>
#include <sys/fcntl.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iic.h>
#include "iicbus_if.h"
#define BUFSIZE 1024
struct iic_softc {
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 */
struct cdev *sc_devnode;
};
#define IIC_SOFTC(unit) \
((struct iic_softc *)devclass_get_softc(iic_devclass, (unit)))
#define IIC_DEVICE(unit) \
(devclass_get_device(iic_devclass, (unit)))
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),
{ 0, 0 }
};
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 cdevsw iic_cdevsw = {
.d_version = D_VERSION,
.d_flags = D_NEEDGIANT,
.d_open = iicopen,
.d_close = iicclose,
.d_read = iicread,
.d_write = iicwrite,
.d_ioctl = iicioctl,
.d_name = "iic",
};
static void
iic_identify(driver_t *driver, device_t parent)
{
BUS_ADD_CHILD(parent, 0, "iic", -1);
}
static int
iic_probe(device_t dev)
{
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_cdevsw, device_get_unit(dev),
UID_ROOT, GID_WHEEL,
0600, "iic%d", device_get_unit(dev));
return (0);
}
static int
iic_detach(device_t dev)
{
struct iic_softc *sc = (struct iic_softc *)device_get_softc(dev);
if (sc->sc_devnode)
destroy_dev(sc->sc_devnode);
return (0);
}
static int
iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct iic_softc *sc = IIC_SOFTC(minor(dev));
if (!sc)
return (EINVAL);
if (sc->sc_count > 0)
return (EBUSY);
sc->sc_count++;
return (0);
}
static int
iicclose(struct cdev *dev, int flags, int fmt, struct thread *td)
{
struct iic_softc *sc = IIC_SOFTC(minor(dev));
if (!sc)
return (EINVAL);
if (!sc->sc_count)
return (EINVAL);
sc->sc_count--;
if (sc->sc_count < 0)
panic("%s: iic_count < 0!", __func__);
return (0);
}
static int
iicwrite(struct cdev *dev, struct uio * uio, int ioflag)
{
device_t iicdev = IIC_DEVICE(minor(dev));
struct iic_softc *sc = IIC_SOFTC(minor(dev));
int sent, error, count;
if (!sc || !iicdev || !sc->sc_addr)
return (EINVAL);
if (sc->sc_count == 0)
return (EINVAL);
if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
return (error);
count = min(uio->uio_resid, BUFSIZE);
uiomove(sc->sc_buffer, 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);
return(error);
}
static int
iicread(struct cdev *dev, struct uio * uio, int ioflag)
{
device_t iicdev = IIC_DEVICE(minor(dev));
struct iic_softc *sc = IIC_SOFTC(minor(dev));
int len, error = 0;
int bufsize;
if (!sc || !iicdev || !sc->sc_addr)
return (EINVAL);
if (sc->sc_count == 0)
return (EINVAL);
if ((error = iicbus_request_bus(device_get_parent(iicdev), iicdev, IIC_DONTWAIT)))
return (error);
/* max amount of data to read */
len = min(uio->uio_resid, BUFSIZE);
if ((error = iicbus_block_read(device_get_parent(iicdev), sc->sc_addr,
sc->sc_inbuf, len, &bufsize)))
return (error);
if (bufsize > uio->uio_resid)
panic("%s: too much data read!", __func__);
iicbus_release_bus(device_get_parent(iicdev), iicdev);
return (uiomove(sc->sc_inbuf, bufsize, uio));
}
static int
iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
{
device_t iicdev = IIC_DEVICE(minor(dev));
struct iic_softc *sc = IIC_SOFTC(minor(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 (!sc)
return (EINVAL);
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:
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;
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 = malloc((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 = malloc((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 = malloc(sizeof(*d->msgs) * d->nmsgs, M_TEMP, M_WAITOK);
usrbufs = malloc(sizeof(void *) * d->nmsgs, M_TEMP, M_ZERO | M_WAITOK);
error = copyin(d->msgs, buf, sizeof(*d->msgs) * d->nmsgs);
if (error)
break;
/* Allocate 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 = malloc(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);
free(m->buf, M_TEMP);
}
free(usrbufs, M_TEMP);
break;
default:
error = ENOTTY;
}
iicbus_release_bus(device_get_parent(iicdev), iicdev);
if (buf != NULL)
free(buf, M_TEMP);
return (error);
}
DRIVER_MODULE(iic, iicbus, iic_driver, iic_devclass, 0, 0);
MODULE_DEPEND(iic, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);
MODULE_VERSION(iic, 1);