freebsd-skq/sys/dev/iicbus/iic.c
raj 65b10fa5be Teach iic(4) the 'repeated start' I2C condition. This will be used by the
upcoming i2c(8) diag utility.

Reviewed by:	bms, stas
Obtained from:	Semihalf
2009-01-26 13:53:39 +00:00

390 lines
8.9 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/bus.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/sx.h>
#include <sys/systm.h>
#include <sys/uio.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 {
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 */
struct cdev *sc_devnode;
struct sx sc_lock;
};
#define IIC_LOCK(sc) sx_xlock(&(sc)->sc_lock)
#define IIC_UNLOCK(sc) sx_xunlock(&(sc)->sc_lock)
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_TRACKCLOSE,
.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)
{
if (device_find_child(parent, "iic", -1) == NULL)
BUS_ADD_CHILD(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_dev = dev;
sx_init(&sc->sc_lock, "iic");
sc->sc_devnode = make_dev(&iic_cdevsw, 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");
sx_destroy(&sc->sc_lock);
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)
destroy_dev(sc->sc_devnode);
sx_destroy(&sc->sc_lock);
return (0);
}
static int
iicopen(struct cdev *dev, int flags, int fmt, struct thread *td)
{
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 cdev *dev, int flags, int fmt, struct thread *td)
{
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 cdev *dev, struct uio * uio, int ioflag)
{
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 = 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);
IIC_UNLOCK(sc);
return (error);
}
static int
iicread(struct cdev *dev, struct uio * uio, int ioflag)
{
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 = min(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, bufsize, uio);
IIC_UNLOCK(sc);
return (error);
}
static int
iicioctl(struct cdev *dev, u_long cmd, caddr_t data, int flags, struct thread *td)
{
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(parent, 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 = 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;
/* 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 = malloc(m->len, M_TEMP, M_WAITOK);
if (!(m->flags & IIC_M_RD))
copyin(usrbufs[i], m->buf, m->len);
}
error = iicbus_transfer(iicdev, (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;
case I2CRPTSTART:
error = iicbus_repeated_start(parent, s->slave, 0);
break;
default:
error = ENOTTY;
}
iicbus_release_bus(parent, 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);