freebsd-dev/sys/dev/iicbus/iicbus.c
1999-08-28 01:08:13 +00:00

290 lines
7.0 KiB
C

/*-
* Copyright (c) 1998 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.
*
* $FreeBSD$
*
*/
/*
* 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 <machine/clock.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))
/*
* structure used to attach devices to the I2C bus
*/
struct iicbus_device {
const char *iicd_name; /* device name */
int iicd_class; /* driver or slave device class */
const char *iicd_desc; /* device descriptor */
u_char iicd_addr; /* address of the device */
int iicd_waitack; /* wait for ack timeout or delay */
int iicd_alive; /* 1 if device found */
};
/*
* Common I2C addresses
*/
#define I2C_GENERAL_CALL 0x0
#define PCF_MASTER_ADDRESS 0xaa
#define FIRST_SLAVE_ADDR 0x2
#define LAST_SLAVE_ADDR 255
#define IICBUS_UNKNOWN_CLASS 0
#define IICBUS_DEVICE_CLASS 1
#define IICBUS_DRIVER_CLASS 2
/*
* list of known devices
*
* XXX only one smb driver should exist for each I2C interface
*/
static struct iicbus_device iicbus_children[] = {
{ "iicsmb", IICBUS_DRIVER_CLASS, "I2C to SMB bridge" },
{ "iic", IICBUS_DRIVER_CLASS, "I2C general purpose I/O" },
#if 0
{ "ic", IICBUS_DEVICE_CLASS, "network interface", PCF_MASTER_ADDRESS },
#endif
{ NULL, 0 }
};
static devclass_t iicbus_devclass;
/*
* Device methods
*/
static int iicbus_probe(device_t);
static int iicbus_attach(device_t);
static int iicbus_print_child(device_t, device_t);
static int iicbus_read_ivar(device_t , device_t, int, u_long *);
static int iicbus_write_ivar(device_t , device_t, int, u_long);
static device_method_t iicbus_methods[] = {
/* device interface */
DEVMETHOD(device_probe, iicbus_probe),
DEVMETHOD(device_attach, iicbus_attach),
DEVMETHOD(device_detach, bus_generic_detach),
DEVMETHOD(device_shutdown, bus_generic_shutdown),
/* bus interface */
DEVMETHOD(bus_print_child, iicbus_print_child),
DEVMETHOD(bus_read_ivar, iicbus_read_ivar),
DEVMETHOD(bus_write_ivar, iicbus_write_ivar),
{ 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 0
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)
{
struct iicbus_device *iicdev;
device_t child;
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 0
printf("Probing for devices on iicbus%d:", device_get_unit(dev));
/* probe any devices */
for (addr = FIRST_SLAVE_ADDR; addr <= LAST_SLAVE_ADDR; addr++) {
if (iic_probe_device(dev, (u_char)addr)) {
printf(" <%x>", addr);
}
}
printf("\n");
#endif
/* attach known devices */
for (iicdev = iicbus_children; iicdev->iicd_name; iicdev++) {
switch (iicdev->iicd_class) {
case IICBUS_DEVICE_CLASS:
/* check if the devclass exists */
if (devclass_find(iicdev->iicd_name))
iicdev->iicd_alive = 1;
else if (bootverbose)
printf("iicbus: %s devclass not found\n",
iicdev->iicd_name);
break;
case IICBUS_DRIVER_CLASS:
/* check if the devclass exists */
if (devclass_find(iicdev->iicd_name))
iicdev->iicd_alive = 1;
else if (bootverbose)
printf("iicbus: %s devclass not found\n",
iicdev->iicd_name);
break;
default:
panic("%s: unknown class!", __FUNCTION__);
}
if (iicdev->iicd_alive) {
child = device_add_child(dev, iicdev->iicd_name,
-1, iicdev);
device_set_desc(child, iicdev->iicd_desc);
}
}
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);
}
static int
iicbus_print_child(device_t bus, device_t dev)
{
struct iicbus_device* iicdev = DEVTOIICBUS(dev);
int retval = 0;
retval += bus_print_child_header(bus, dev);
switch (iicdev->iicd_class) {
case IICBUS_DEVICE_CLASS:
retval += printf(" on %s addr 0x%x\n",
device_get_nameunit(bus), iicdev->iicd_addr);
break;
case IICBUS_DRIVER_CLASS:
retval += bus_print_child_footer(bus, dev);
break;
default:
panic("%s: unknown class!\n", __FUNCTION__);
}
return (retval);
}
static int
iicbus_read_ivar(device_t bus, device_t dev, int index, u_long* result)
{
struct iicbus_device* iicdev = DEVTOIICBUS(dev);
switch (index) {
case IICBUS_IVAR_ADDR:
*result = (u_long)iicdev->iicd_addr;
break;
default:
return (ENOENT);
}
return (0);
}
static int
iicbus_write_ivar(device_t bus, device_t dev, int index, u_long val)
{
switch (index) {
default:
return (ENOENT);
}
return (0);
}
DRIVER_MODULE(iicbus, pcf, 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);