NetBSD/sys/dev/i2c/ds1307.c
he aafdb08c5a Fix the various todr_gettime() and todr_settime() fallouts from
-Wcast-qual differently, by instead changing the signatore of those
"functions" to take a "volatile struct timeval*" instead of a
"struct timeval*".  Many places, these functions are called with
&time, and time is declared as volatile in <sys/kernel.h>.  This
way we can get rid of all the ugly casts which now also triggered
warnings, and caused more code to be added to work around the
problem.

Reviewed by thorpej.
2005-06-04 20:14:24 +00:00

390 lines
10 KiB
C

/* $NetBSD: ds1307.c,v 1.2 2005/06/04 20:14:25 he Exp $ */
/*
* Copyright (c) 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <sys/event.h>
#include <dev/clock_subr.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/ds1307reg.h>
struct dsrtc_softc {
struct device sc_dev;
i2c_tag_t sc_tag;
int sc_address;
int sc_open;
struct todr_chip_handle sc_todr;
};
static void dsrtc_attach(struct device *, struct device *, void *);
static int dsrtc_match(struct device *, struct cfdata *, void *);
CFATTACH_DECL(dsrtc, sizeof(struct dsrtc_softc),
dsrtc_match, dsrtc_attach, NULL, NULL);
extern struct cfdriver dsrtc_cd;
dev_type_open(dsrtc_open);
dev_type_close(dsrtc_close);
dev_type_read(dsrtc_read);
dev_type_write(dsrtc_write);
const struct cdevsw dsrtc_cdevsw = {
dsrtc_open, dsrtc_close, dsrtc_read, dsrtc_write, noioctl,
nostop, notty, nopoll, nommap, nokqfilter
};
static int dsrtc_clock_read(struct dsrtc_softc *, struct clock_ymdhms *);
static int dsrtc_clock_write(struct dsrtc_softc *, struct clock_ymdhms *);
static int dsrtc_gettime(struct todr_chip_handle *, volatile struct timeval *);
static int dsrtc_settime(struct todr_chip_handle *, volatile struct timeval *);
static int dsrtc_getcal(struct todr_chip_handle *, int *);
static int dsrtc_setcal(struct todr_chip_handle *, int);
static int
dsrtc_match(struct device *parent, struct cfdata *cf, void *arg)
{
struct i2c_attach_args *ia = arg;
if (ia->ia_addr == DS1307_ADDR)
return (1);
return (0);
}
static void
dsrtc_attach(struct device *parent, struct device *self, void *arg)
{
struct dsrtc_softc *sc = (struct dsrtc_softc *)self;
struct i2c_attach_args *ia = arg;
aprint_naive(": Real-time Clock/NVRAM\n");
aprint_normal(": DS1307 Real-time Clock/NVRAM\n");
sc->sc_tag = ia->ia_tag;
sc->sc_address = ia->ia_addr;
sc->sc_open = 0;
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = dsrtc_gettime;
sc->sc_todr.todr_settime = dsrtc_settime;
sc->sc_todr.todr_getcal = dsrtc_getcal;
sc->sc_todr.todr_setcal = dsrtc_setcal;
sc->sc_todr.todr_setwen = NULL;
todr_attach(&sc->sc_todr);
}
/*ARGSUSED*/
int
dsrtc_open(dev_t dev, int flag, int fmt, struct proc *p)
{
struct dsrtc_softc *sc;
if ((sc = device_lookup(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
/* XXX: Locking */
if (sc->sc_open)
return (EBUSY);
sc->sc_open = 1;
return (0);
}
/*ARGSUSED*/
int
dsrtc_close(dev_t dev, int flag, int fmt, struct proc *p)
{
struct dsrtc_softc *sc;
if ((sc = device_lookup(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
sc->sc_open = 0;
return (0);
}
/*ARGSUSED*/
int
dsrtc_read(dev_t dev, struct uio *uio, int flags)
{
struct dsrtc_softc *sc;
u_int8_t ch, cmdbuf[1];
int a, error;
if ((sc = device_lookup(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
if (uio->uio_offset >= DS1307_NVRAM_SIZE)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < DS1307_NVRAM_SIZE) {
a = (int)uio->uio_offset;
cmdbuf[0] = a + DS1307_NVRAM_START;
if ((error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1,
&ch, 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
printf("%s: dsrtc_read: read failed at 0x%x\n",
sc->sc_dev.dv_xname, a);
return (error);
}
if ((error = uiomove(&ch, 1, uio)) != 0) {
iic_release_bus(sc->sc_tag, 0);
return (error);
}
}
iic_release_bus(sc->sc_tag, 0);
return (0);
}
/*ARGSUSED*/
int
dsrtc_write(dev_t dev, struct uio *uio, int flags)
{
struct dsrtc_softc *sc;
u_int8_t cmdbuf[2];
int a, error;
if ((sc = device_lookup(&dsrtc_cd, minor(dev))) == NULL)
return (ENXIO);
if (uio->uio_offset >= DS1307_NVRAM_SIZE)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < DS1307_NVRAM_SIZE) {
a = (int)uio->uio_offset;
cmdbuf[0] = a + DS1307_NVRAM_START;
if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
break;
if ((error = iic_exec(sc->sc_tag,
uio->uio_resid ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
printf("%s: dsrtc_write: write failed at 0x%x\n",
sc->sc_dev.dv_xname, a);
break;
}
}
iic_release_bus(sc->sc_tag, 0);
return (error);
}
static int
dsrtc_gettime(struct todr_chip_handle *ch, volatile struct timeval *tv)
{
struct dsrtc_softc *sc = ch->cookie;
struct clock_ymdhms dt, check;
int retries;
memset(&dt, 0, sizeof(dt));
memset(&check, 0, sizeof(check));
/*
* Since we don't support Burst Read, we have to read the clock twice
* until we get two consecutive identical results.
*/
retries = 5;
do {
dsrtc_clock_read(sc, &dt);
dsrtc_clock_read(sc, &check);
} while (memcmp(&dt, &check, sizeof(check)) != 0 && --retries);
tv->tv_sec = clock_ymdhms_to_secs(&dt);
tv->tv_usec = 0;
return (0);
}
static int
dsrtc_settime(struct todr_chip_handle *ch, volatile struct timeval *tv)
{
struct dsrtc_softc *sc = ch->cookie;
struct clock_ymdhms dt;
clock_secs_to_ymdhms(tv->tv_sec, &dt);
if (dsrtc_clock_write(sc, &dt) == 0)
return (-1);
return (0);
}
static int
dsrtc_setcal(struct todr_chip_handle *ch, int cal)
{
return (EOPNOTSUPP);
}
static int
dsrtc_getcal(struct todr_chip_handle *ch, int *cal)
{
return (EOPNOTSUPP);
}
static int
dsrtc_clock_read(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
{
u_int8_t bcd[DS1307_NRTC_REGS], cmdbuf[1];
int i;
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
printf("%s: dsrtc_clock_read: failed to acquire I2C bus\n",
sc->sc_dev.dv_xname);
return (0);
}
/* Read each RTC register in order. */
for (i = DS1307_SECONDS; i < DS1307_NRTC_REGS; i++) {
cmdbuf[0] = i;
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1,
&bcd[i], 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
printf("%s: dsrtc_clock_read: failed to read rtc "
"at 0x%x\n", sc->sc_dev.dv_xname, i);
return (0);
}
}
/* Done with I2C */
iic_release_bus(sc->sc_tag, I2C_F_POLL);
/*
* Convert the DS1307's register values into something useable
*/
dt->dt_sec = FROMBCD(bcd[DS1307_SECONDS] & DS1307_SECONDS_MASK);
dt->dt_min = FROMBCD(bcd[DS1307_MINUTES] & DS1307_MINUTES_MASK);
if ((bcd[DS1307_HOURS] & DS1307_HOURS_24HRS) == 0) {
dt->dt_hour = FROMBCD(bcd[DS1307_HOURS] &
DS1307_HOURS_12MASK);
if (bcd[DS1307_HOURS] & DS1307_HOURS_12HRS_PM)
dt->dt_hour += 12;
} else {
dt->dt_hour = FROMBCD(bcd[DS1307_HOURS] &
DS1307_HOURS_24MASK);
}
dt->dt_day = FROMBCD(bcd[DS1307_DATE] & DS1307_DATE_MASK);
dt->dt_mon = FROMBCD(bcd[DS1307_MONTH] & DS1307_MONTH_MASK);
/* XXX: Should be an MD way to specify EPOCH used by BIOS/Firmware */
dt->dt_year = FROMBCD(bcd[DS1307_YEAR]) + POSIX_BASE_YEAR;
return (1);
}
static int
dsrtc_clock_write(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
{
uint8_t bcd[DS1307_NRTC_REGS], cmdbuf[2];
int i;
/*
* Convert our time representation into something the DS1307
* can understand.
*/
bcd[DS1307_SECONDS] = TOBCD(dt->dt_sec);
bcd[DS1307_MINUTES] = TOBCD(dt->dt_min);
bcd[DS1307_HOURS] = TOBCD(dt->dt_hour) | DS1307_HOURS_24HRS;
bcd[DS1307_DATE] = TOBCD(dt->dt_day);
bcd[DS1307_DAY] = TOBCD(dt->dt_wday);
bcd[DS1307_MONTH] = TOBCD(dt->dt_mon);
bcd[DS1307_YEAR] = TOBCD((dt->dt_year - POSIX_BASE_YEAR) % 100);
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
printf("%s: dsrtc_clock_write: failed to acquire I2C bus\n",
sc->sc_dev.dv_xname);
return (0);
}
/* Stop the clock */
cmdbuf[0] = DS1307_SECONDS;
cmdbuf[1] = DS1307_SECONDS_CH;
if (iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
printf("%s: dsrtc_clock_write: failed to Hold Clock\n",
sc->sc_dev.dv_xname);
return (0);
}
/*
* Write registers in reverse order. The last write (to the Seconds
* register) will undo the Clock Hold, above.
*/
for (i = DS1307_NRTC_REGS - 1; i >= 0; i--) {
cmdbuf[0] = i;
if (iic_exec(sc->sc_tag,
i ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &bcd[i], 1,
I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
printf("%s: dsrtc_clock_write: failed to write rtc "
" at 0x%x\n", sc->sc_dev.dv_xname, i);
/* XXX: Clock Hold is likely still asserted! */
return (0);
}
}
iic_release_bus(sc->sc_tag, I2C_F_POLL);
return (1);
}