NetBSD/sys/dev/i2c/m41t00.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

429 lines
11 KiB
C

/* $NetBSD: m41t00.c,v 1.4 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/proc.h>
#include <sys/event.h>
#include <machine/bus.h>
#include <dev/clock_subr.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/m41t00reg.h>
struct m41t00_softc {
struct device sc_dev;
i2c_tag_t sc_tag;
int sc_address;
int sc_open;
struct todr_chip_handle sc_todr;
};
static int m41t00_match(struct device *, struct cfdata *, void *);
static void m41t00_attach(struct device *, struct device *, void *);
CFATTACH_DECL(m41trtc, sizeof(struct m41t00_softc),
m41t00_match, m41t00_attach, NULL, NULL);
extern struct cfdriver m41trtc_cd;
dev_type_open(m41t00_open);
dev_type_close(m41t00_close);
dev_type_read(m41t00_read);
dev_type_write(m41t00_write);
const struct cdevsw m41t00_cdevsw = {
m41t00_open, m41t00_close, m41t00_read, m41t00_write, noioctl,
nostop, notty, nopoll, nommap, nokqfilter,
};
static int m41t00_clock_read(struct m41t00_softc *, struct clock_ymdhms *);
static int m41t00_clock_write(struct m41t00_softc *, struct clock_ymdhms *);
static int m41t00_gettime(struct todr_chip_handle *, volatile struct timeval *);
static int m41t00_settime(struct todr_chip_handle *, volatile struct timeval *);
static int m41t00_getcal(struct todr_chip_handle *, int *);
static int m41t00_setcal(struct todr_chip_handle *, int);
int
m41t00_match(struct device *parent, struct cfdata *cf, void *aux)
{
struct i2c_attach_args *ia = aux;
if (ia->ia_addr == M41T00_ADDR) {
return 1;
}
return 0;
}
void
m41t00_attach(struct device *parent, struct device *self, void *aux)
{
struct m41t00_softc *sc = (struct m41t00_softc *)self;
struct i2c_attach_args *ia = aux;
sc->sc_tag = ia->ia_tag;
sc->sc_address = ia->ia_addr;
aprint_naive(": Real-time Clock\n");
aprint_normal(": M41T00 Real-time Clock\n");
sc->sc_open = 0;
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = m41t00_gettime;
sc->sc_todr.todr_settime = m41t00_settime;
sc->sc_todr.todr_getcal = m41t00_getcal;
sc->sc_todr.todr_setcal = m41t00_setcal;
sc->sc_todr.todr_setwen = NULL;
todr_attach(&sc->sc_todr);
}
/*ARGSUSED*/
int
m41t00_open(dev_t dev, int flag, int fmt, struct proc *p)
{
struct m41t00_softc *sc;
if ((sc = device_lookup(&m41trtc_cd, minor(dev))) == NULL)
return ENXIO;
/* XXX: Locking */
if (sc->sc_open)
return EBUSY;
sc->sc_open = 1;
return 0;
}
/*ARGSUSED*/
int
m41t00_close(dev_t dev, int flag, int fmt, struct proc *p)
{
struct m41t00_softc *sc;
if ((sc = device_lookup(&m41trtc_cd, minor(dev))) == NULL)
return ENXIO;
sc->sc_open = 0;
return 0;
}
/*ARGSUSED*/
int
m41t00_read(dev_t dev, struct uio *uio, int flags)
{
struct m41t00_softc *sc;
u_int8_t ch, cmdbuf[1];
int a, error;
if ((sc = device_lookup(&m41trtc_cd, minor(dev))) == NULL)
return (ENXIO);
if (uio->uio_offset >= M41T00_NBYTES)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < M41T00_NBYTES) {
a = (int)uio->uio_offset;
cmdbuf[0] = a;
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: m41t00_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
m41t00_write(dev_t dev, struct uio *uio, int flags)
{
struct m41t00_softc *sc;
u_int8_t cmdbuf[2];
int a, error;
if ((sc = device_lookup(&m41trtc_cd, minor(dev))) == NULL)
return (ENXIO);
if (uio->uio_offset >= M41T00_NBYTES)
return (EINVAL);
if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return (error);
while (uio->uio_resid && uio->uio_offset < M41T00_NBYTES) {
a = (int)uio->uio_offset;
cmdbuf[0] = a;
if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
break;
if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
printf("%s: m41t00_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
m41t00_gettime(struct todr_chip_handle *ch, volatile struct timeval *tv)
{
struct m41t00_softc *sc = ch->cookie;
struct clock_ymdhms dt;
if (m41t00_clock_read(sc, &dt) == 0)
return (-1);
tv->tv_sec = clock_ymdhms_to_secs(&dt);
tv->tv_usec = 0;
return (0);
}
static int
m41t00_settime(struct todr_chip_handle *ch, volatile struct timeval *tv)
{
struct m41t00_softc *sc = ch->cookie;
struct clock_ymdhms dt;
clock_secs_to_ymdhms(tv->tv_sec, &dt);
if (m41t00_clock_write(sc, &dt) == 0)
return (-1);
return (0);
}
static int
m41t00_setcal(struct todr_chip_handle *ch, int cal)
{
return (EOPNOTSUPP);
}
static int
m41t00_getcal(struct todr_chip_handle *ch, int *cal)
{
return (EOPNOTSUPP);
}
static int m41t00_rtc_offset[] = {
M41T00_SEC,
M41T00_MIN,
M41T00_CENHR,
M41T00_DAY,
M41T00_DATE,
M41T00_MONTH,
M41T00_YEAR,
};
static int
m41t00_clock_read(struct m41t00_softc *sc, struct clock_ymdhms *dt)
{
u_int8_t bcd[M41T00_NBYTES], cmdbuf[1];
int i, n;
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
printf("%s: m41t00_clock_read: failed to acquire I2C bus\n",
sc->sc_dev.dv_xname);
return (0);
}
/* Read each timekeeping register in order. */
n = sizeof(m41t00_rtc_offset) / sizeof(m41t00_rtc_offset[0]);
for (i = 0; i < n ; i++) {
cmdbuf[0] = m41t00_rtc_offset[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: m41t00_clock_read: failed to read rtc "
"at 0x%x\n", sc->sc_dev.dv_xname,
m41t00_rtc_offset[i]);
return (0);
}
}
/* Done with I2C */
iic_release_bus(sc->sc_tag, I2C_F_POLL);
/*
* Convert the M41T00's register values into something useable
*/
dt->dt_sec = FROMBCD(bcd[M41T00_SEC] & M41T00_SEC_MASK);
dt->dt_min = FROMBCD(bcd[M41T00_MIN] & M41T00_MIN_MASK);
dt->dt_hour = FROMBCD(bcd[M41T00_CENHR] & M41T00_HOUR_MASK);
dt->dt_day = FROMBCD(bcd[M41T00_DATE] & M41T00_DATE_MASK);
dt->dt_wday = FROMBCD(bcd[M41T00_DAY] & M41T00_DAY_MASK);
dt->dt_mon = FROMBCD(bcd[M41T00_MONTH] & M41T00_MONTH_MASK);
dt->dt_year = FROMBCD(bcd[M41T00_YEAR] & M41T00_YEAR_MASK);
/*
* Since the m41t00 just stores 00-99, and this is 2003 as I write
* this comment, use 2000 as a base year
*/
dt->dt_year += 2000;
return (1);
}
static int
m41t00_clock_write(struct m41t00_softc *sc, struct clock_ymdhms *dt)
{
uint8_t bcd[M41T00_DATE_BYTES], cmdbuf[2];
uint8_t init_seconds, final_seconds;
int i;
/*
* Convert our time representation into something the MAX6900
* can understand.
*/
bcd[M41T00_SEC] = TOBCD(dt->dt_sec);
bcd[M41T00_MIN] = TOBCD(dt->dt_min);
bcd[M41T00_CENHR] = TOBCD(dt->dt_hour);
bcd[M41T00_DATE] = TOBCD(dt->dt_day);
bcd[M41T00_DAY] = TOBCD(dt->dt_wday);
bcd[M41T00_MONTH] = TOBCD(dt->dt_mon);
bcd[M41T00_YEAR] = TOBCD(dt->dt_year % 100);
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
printf("%s: m41t00_clock_write: failed to acquire I2C bus\n",
sc->sc_dev.dv_xname);
return (0);
}
/*
* The MAX6900 RTC manual recommends ensuring "atomicity" of
* a non-burst write by:
*
* - writing SECONDS
* - reading back SECONDS, remembering it as "initial seconds"
* - write the remaing RTC registers
* - read back SECONDS as "final seconds"
* - if "initial seconds" == 59, ensure "final seconds" == 59
* - else, ensure "final seconds" is no more than one second
* beyond "initial seconds".
*
* This sounds reasonable for the M41T00, too.
*/
again:
cmdbuf[0] = M41T00_SEC;
if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
cmdbuf, 1, &bcd[M41T00_SEC], 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
printf("%s: m41t00_clock_write: failed to write SECONDS\n",
sc->sc_dev.dv_xname);
return (0);
}
cmdbuf[0] = M41T00_SEC;
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
cmdbuf, 1, &init_seconds, 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
printf("%s: m41t00_clock_write: failed to read "
"INITIAL SECONDS\n", sc->sc_dev.dv_xname);
return (0);
}
init_seconds = FROMBCD(init_seconds & M41T00_SEC_MASK);
for (i = 1; i < M41T00_DATE_BYTES; i++) {
cmdbuf[0] = m41t00_rtc_offset[i];
if (iic_exec(sc->sc_tag,
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: m41t00_clock_write: failed to write rtc "
" at 0x%x\n", sc->sc_dev.dv_xname,
m41t00_rtc_offset[i]);
return (0);
}
}
cmdbuf[0] = M41T00_SEC;
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
cmdbuf, 1, &final_seconds, 1, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
printf("%s: m41t00_clock_write: failed to read "
"FINAL SECONDS\n", sc->sc_dev.dv_xname);
return (0);
}
final_seconds = FROMBCD(final_seconds & M41T00_SEC_MASK);
if ((init_seconds != final_seconds) &&
(((init_seconds + 1) % 60) != final_seconds)) {
#if 1
printf("%s: m41t00_clock_write: init %d, final %d, try again\n",
sc->sc_dev.dv_xname, init_seconds, final_seconds);
#endif
goto again;
}
iic_release_bus(sc->sc_tag, I2C_F_POLL);
return (1);
}