freebsd-skq/sys/dev/iicbus/ds1672.c
nwhitehorn 4d7a485a52 Change the way I2C bus attachment works to allow firmware-assisted bus
subclasses as are available with PCI. Changes I2C device drivers without
real probe logic to return BUS_PROBE_NOWILDWARD to avoid interference with
firmware bus enumeration, and reduces the probe priority of the iicbus
base driver to allow subclass attachment at higher priority.

Discussed on:	freebsd-arch
2009-01-06 17:23:37 +00:00

136 lines
3.7 KiB
C

/*-
* Copyright (c) 2006 Sam Leffler. 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 ``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 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("$FreeBSD$");
/*
* Dallas Semiconductor DS1672 RTC sitting on the I2C bus.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/clock.h>
#include <sys/time.h>
#include <sys/bus.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <dev/iicbus/iiconf.h>
#include "iicbus_if.h"
#include "clock_if.h"
#define IIC_M_WR 0 /* write operation */
#define DS1672_ADDR 0xd0 /* slave address */
#define DS1672_COUNTER 0 /* counter (bytes 0-3) */
#define DS1672_CTRL 4 /* control (1 byte) */
#define DS1672_TRICKLE 5 /* trickle charger (1 byte) */
#define NANOSEC 1000000000
struct ds1672_softc {
device_t sc_dev;
};
static int
ds1672_probe(device_t dev)
{
/* XXX really probe? */
device_set_desc(dev, "Dallas Semiconductor DS1672 RTC");
return (BUS_PROBE_NOWILDCARD);
}
static int
ds1672_attach(device_t dev)
{
struct ds1672_softc *sc = device_get_softc(dev);
sc->sc_dev = dev;
clock_register(dev, 1000);
return (0);
}
static int
ds1672_gettime(device_t dev, struct timespec *ts)
{
uint8_t addr[1] = { DS1672_COUNTER };
uint8_t secs[4];
struct iic_msg msgs[2] = {
{ DS1672_ADDR, IIC_M_WR, 1, addr },
{ DS1672_ADDR, IIC_M_RD, 4, secs },
};
int error;
error = iicbus_transfer(dev, msgs, 2);
if (error == 0) {
/* counter has seconds since epoch */
ts->tv_sec = (secs[3] << 24) | (secs[2] << 16)
| (secs[1] << 8) | (secs[0] << 0);
ts->tv_nsec = NANOSEC / 2;
}
return error;
}
static int
ds1672_settime(device_t dev, struct timespec *ts)
{
/* NB: register pointer precedes actual data */
uint8_t data[5] = { DS1672_COUNTER };
struct iic_msg msgs[1] = {
{ DS1672_ADDR, IIC_M_WR, 5, data },
};
data[1] = (ts->tv_sec >> 0) & 0xff;
data[2] = (ts->tv_sec >> 8) & 0xff;
data[3] = (ts->tv_sec >> 16) & 0xff;
data[4] = (ts->tv_sec >> 24) & 0xff;
return iicbus_transfer(dev, msgs, 1);
}
static device_method_t ds1672_methods[] = {
DEVMETHOD(device_probe, ds1672_probe),
DEVMETHOD(device_attach, ds1672_attach),
DEVMETHOD(clock_gettime, ds1672_gettime),
DEVMETHOD(clock_settime, ds1672_settime),
{0, 0},
};
static driver_t ds1672_driver = {
"ds1672",
ds1672_methods,
sizeof(struct ds1672_softc),
};
static devclass_t ds1672_devclass;
DRIVER_MODULE(ds1672, iicbus, ds1672_driver, ds1672_devclass, 0, 0);
MODULE_VERSION(ds1672, 1);
MODULE_DEPEND(ds1672, iicbus, 1, 1, 1);