freebsd-nq/sys/dev/iicbus/iicbus.c
2004-05-27 13:29:09 +00:00

195 lines
4.8 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Autoconfiguration and support routines for the Philips serial I2C bus
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbus_if.h"
#define DEVTOIICBUS(dev) ((struct iicbus_device*)device_get_ivars(dev))
static devclass_t iicbus_devclass;
/* See comments below for why auto-scanning is a bad idea. */
#define SCAN_IICBUS 0
/*
* Device methods
*/
static int iicbus_probe(device_t);
static int iicbus_attach(device_t);
static int iicbus_detach(device_t);
static int iicbus_add_child(device_t dev, int order, const char *name, int unit);
static device_method_t iicbus_methods[] = {
/* device interface */
DEVMETHOD(device_probe, iicbus_probe),
DEVMETHOD(device_attach, iicbus_attach),
DEVMETHOD(device_detach, iicbus_detach),
/* bus interface */
DEVMETHOD(bus_add_child, iicbus_add_child),
DEVMETHOD(bus_driver_added, bus_generic_driver_added),
DEVMETHOD(bus_print_child, bus_generic_print_child),
{ 0, 0 }
};
static driver_t iicbus_driver = {
"iicbus",
iicbus_methods,
sizeof(struct iicbus_softc),
};
static int
iicbus_probe(device_t dev)
{
device_set_desc(dev, "Philips I2C bus");
return (0);
}
#if SCAN_IICBUS
static int
iic_probe_device(device_t dev, u_char addr)
{
int count;
char byte;
if ((addr & 1) == 0) {
/* is device writable? */
if (!iicbus_start(dev, (u_char)addr, 0)) {
iicbus_stop(dev);
return (1);
}
} else {
/* is device readable? */
if (!iicbus_block_read(dev, (u_char)addr, &byte, 1, &count))
return (1);
}
return (0);
}
#endif
/*
* We add all the devices which we know about.
* The generic attach routine will attach them if they are alive.
*/
static int
iicbus_attach(device_t dev)
{
#if SCAN_IICBUS
unsigned char addr;
#endif
iicbus_reset(dev, IIC_FASTEST, 0, NULL);
/* device probing is meaningless since the bus is supposed to be
* hot-plug. Moreover, some I2C chips do not appreciate random
* accesses like stop after start to fast, reads for less than
* x bytes...
*/
#if SCAN_IICBUS
printf("Probing for devices on iicbus%d:", device_get_unit(dev));
/* probe any devices */
for (addr = 16; addr < 240; addr++) {
if (iic_probe_device(dev, (u_char)addr)) {
printf(" <%x>", addr);
}
}
printf("\n");
#endif
/* attach any known device */
device_add_child(dev, "ic", -1);
device_add_child(dev, "iic", -1);
device_add_child(dev, "iicsmb", -1);
bus_generic_attach(dev);
return (0);
}
static int
iicbus_detach(device_t dev)
{
iicbus_reset(dev, IIC_FASTEST, 0, NULL);
bus_generic_detach(dev);
return (0);
}
static int
iicbus_add_child(device_t dev, int order, const char *name, int unit)
{
device_add_child_ordered(dev, order, name, unit);
bus_generic_attach(dev);
return (0);
}
int
iicbus_generic_intr(device_t dev, int event, char *buf)
{
return (0);
}
int
iicbus_null_callback(device_t dev, int index, caddr_t data)
{
return (0);
}
int
iicbus_null_repeated_start(device_t dev, u_char addr)
{
return (IIC_ENOTSUPP);
}
DRIVER_MODULE(iicbus, pcf, iicbus_driver, iicbus_devclass, 0, 0);
DRIVER_MODULE(iicbus, envctrl, iicbus_driver, iicbus_devclass, 0, 0);
DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
DRIVER_MODULE(iicbus, bti2c, iicbus_driver, iicbus_devclass, 0, 0);
MODULE_VERSION(iicbus, IICBUS_MODVER);