freebsd-skq/sys/dev/iicbus/iicbus.c
imp 88cdc2595d MFp4: Make the iicbus fully hinted. We no longer automatically add
some devices (and not others).  To get instances onto the iicbus, one
now needs hints or an identify routine.  We also do not probe the bus
for devices because many iic devices cannot be safely probed (and when
they can, the probe order turns out to be somewhat difficult to get
right).

# I'm not 100% sure that the iicsmb removal is right.  Please contact me if
# this causes difficulty.
2007-03-23 23:08:28 +00:00

271 lines
6.5 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/malloc.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbus_if.h"
/* See comments below for why auto-scanning is a bad idea. */
#define SCAN_IICBUS 0
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
struct iicbus_softc *sc = IICBUS_SOFTC(dev);
sc->dev = dev;
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
/* Always attach the iicsmb children */
BUS_ADD_CHILD(dev, 0, "iicsmb", -1);
/* attach any known device */
BUS_ADD_CHILD(dev, 0, "iic", -1);
/* Attach the wired devices via hints */
bus_enumerate_hinted_children(dev);
/* Now probe and attach them */
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_print_child(device_t dev, device_t child)
{
struct iicbus_ivar *devi = IICBUS_IVAR(child);
int retval = 0;
retval += bus_print_child_header(dev, child);
if (devi->addr != 0)
retval += printf(" at addr %#x", devi->addr);
retval += bus_print_child_footer(dev, child);
return (retval);
}
static void
iicbus_probe_nomatch(device_t bus, device_t child)
{
struct iicbus_ivar *devi = IICBUS_IVAR(child);
device_printf(bus, "<unknown card>");
printf(" at addr %#x\n", devi->addr);
return;
}
static int
iicbus_child_location_str(device_t bus, device_t child, char *buf,
size_t buflen)
{
struct iicbus_ivar *devi = IICBUS_IVAR(child);
snprintf(buf, buflen, "addr=%#x", devi->addr);
return (0);
}
static int
iicbus_child_pnpinfo_str(device_t bus, device_t child, char *buf,
size_t buflen)
{
*buf = '\0';
return (0);
}
static int
iicbus_read_ivar(device_t bus, device_t child, int which, u_char *result)
{
struct iicbus_ivar *devi = IICBUS_IVAR(child);
switch (which) {
default:
return (EINVAL);
case IICBUS_IVAR_ADDR:
*(uint32_t *)result = devi->addr;
break;
}
return (0);
}
static device_t
iicbus_add_child(device_t dev, int order, const char *name, int unit)
{
device_t child;
struct iicbus_ivar *devi;
child = device_add_child_ordered(dev, order, name, unit);
if (child == NULL)
return (child);
devi = malloc(sizeof(struct iicbus_ivar), M_DEVBUF, M_NOWAIT | M_ZERO);
if (devi == NULL) {
device_delete_child(dev, child);
return (0);
}
device_set_ivars(child, devi);
return (child);
}
static void
iicbus_hinted_child(device_t bus, const char *dname, int dunit)
{
device_t child;
struct iicbus_ivar *devi;
child = BUS_ADD_CHILD(bus, 0, dname, dunit);
devi = IICBUS_IVAR(child);
resource_int_value(dname, dunit, "addr", &devi->addr);
}
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 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, iicbus_print_child),
DEVMETHOD(bus_probe_nomatch, iicbus_probe_nomatch),
DEVMETHOD(bus_read_ivar, iicbus_read_ivar),
DEVMETHOD(bus_child_pnpinfo_str, iicbus_child_pnpinfo_str),
DEVMETHOD(bus_child_location_str, iicbus_child_location_str),
DEVMETHOD(bus_hinted_child, iicbus_hinted_child),
/* iicbus interface */
DEVMETHOD(iicbus_transfer, iicbus_transfer),
{ 0, 0 }
};
driver_t iicbus_driver = {
"iicbus",
iicbus_methods,
sizeof(struct iicbus_softc),
};
devclass_t iicbus_devclass;
DRIVER_MODULE(iicbus, envctrl, iicbus_driver, iicbus_devclass, 0, 0);
DRIVER_MODULE(iicbus, iicbb, iicbus_driver, iicbus_devclass, 0, 0);
MODULE_VERSION(iicbus, IICBUS_MODVER);