/*-
* 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/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <sys/sysctl.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");
/* Allow other subclasses to override this driver. */
return (BUS_PROBE_GENERIC);
}
#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);
int strict;
sc->dev = dev;
mtx_init(&sc->lock, "iicbus", NULL, MTX_DEF);
iicbus_init_frequency(dev, 0);
iicbus_reset(dev, IIC_FASTEST, 0, NULL);
if (resource_int_value(device_get_name(dev),
device_get_unit(dev), "strict", &strict) == 0)
sc->strict = strict;
else
sc->strict = 1;
/* 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
bus_generic_probe(dev);
bus_enumerate_hinted_children(dev);
bus_generic_attach(dev);
return (0);
}
static int
iicbus_detach(device_t dev)
{
struct iicbus_softc *sc = IICBUS_SOFTC(dev);
iicbus_reset(dev, IIC_FASTEST, 0, NULL);
bus_generic_detach(dev);
device_delete_children(dev);
mtx_destroy(&sc->lock);
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);
resource_list_print_type(&devi->rl, "irq", SYS_RES_IRQ, "%ld");
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> at addr %#x\n", devi->addr);
}
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, uintptr_t *result)
{
struct iicbus_ivar *devi = IICBUS_IVAR(child);
switch (which) {
default:
return (EINVAL);
case IICBUS_IVAR_ADDR:
*result = devi->addr;
break;
}
return (0);
}
static device_t
iicbus_add_child(device_t dev, u_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);
}
resource_list_init(&devi->rl);
device_set_ivars(child, devi);
return (child);
}
static void
iicbus_hinted_child(device_t bus, const char *dname, int dunit)
{
device_t child;
int irq;
struct iicbus_ivar *devi;
child = BUS_ADD_CHILD(bus, 0, dname, dunit);
devi = IICBUS_IVAR(child);
resource_int_value(dname, dunit, "addr", &devi->addr);
if (resource_int_value(dname, dunit, "irq", &irq) == 0) {
if (bus_set_resource(child, SYS_RES_IRQ, 0, irq, 1) != 0)
device_printf(bus,
"warning: bus_set_resource() failed\n");
}
}
static struct resource_list *
iicbus_get_resource_list(device_t bus __unused, device_t child)
{
struct iicbus_ivar *devi;
devi = IICBUS_IVAR(child);
return (&devi->rl);
}
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);
}
void
iicbus_init_frequency(device_t dev, u_int bus_freq)
{
struct iicbus_softc *sc = IICBUS_SOFTC(dev);
/*
* If a bus frequency value was passed in, use it. Otherwise initialize
* it first to the standard i2c 100KHz frequency, then override that
* from a hint if one exists.
*/
if (bus_freq > 0)
sc->bus_freq = bus_freq;
else {
sc->bus_freq = 100000;
resource_int_value(device_get_name(dev), device_get_unit(dev),
"frequency", (int *)&sc->bus_freq);
}
/*
* Set up the sysctl that allows the bus frequency to be changed.
* It is flagged as a tunable so that the user can set the value in
* loader(8), and that will override any other setting from any source.
* The sysctl tunable/value is the one most directly controlled by the
* user and thus the one that always takes precedence.
*/
SYSCTL_ADD_UINT(device_get_sysctl_ctx(dev),
SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
OID_AUTO, "frequency", CTLFLAG_RW | CTLFLAG_TUN, &sc->bus_freq,
sc->bus_freq, "Bus frequency in Hz");
}
static u_int
iicbus_get_frequency(device_t dev, u_char speed)
{
struct iicbus_softc *sc = IICBUS_SOFTC(dev);
/*
* If the frequency has not been configured for the bus, or the request
* is specifically for SLOW speed, use the standard 100KHz rate, else
* use the configured bus speed.
*/
if (sc->bus_freq == 0 || speed == IIC_SLOW)
return (100000);
return (sc->bus_freq);
}
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_setup_intr, bus_generic_setup_intr),
DEVMETHOD(bus_teardown_intr, bus_generic_teardown_intr),
DEVMETHOD(bus_activate_resource, bus_generic_activate_resource),
DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
DEVMETHOD(bus_adjust_resource, bus_generic_adjust_resource),
DEVMETHOD(bus_alloc_resource, bus_generic_rl_alloc_resource),
DEVMETHOD(bus_get_resource, bus_generic_rl_get_resource),
DEVMETHOD(bus_release_resource, bus_generic_rl_release_resource),
DEVMETHOD(bus_set_resource, bus_generic_rl_set_resource),
DEVMETHOD(bus_get_resource_list, iicbus_get_resource_list),
DEVMETHOD(bus_add_child, iicbus_add_child),
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),
DEVMETHOD(iicbus_get_frequency, iicbus_get_frequency),
DEVMETHOD_END
};
driver_t iicbus_driver = {
"iicbus",
iicbus_methods,
sizeof(struct iicbus_softc),
};
devclass_t iicbus_devclass;
MODULE_VERSION(iicbus, IICBUS_MODVER);
DRIVER_MODULE(iicbus, iichb, iicbus_driver, iicbus_devclass, 0, 0);
