NetBSD/sys/dev/ic/rs5c313.c

340 lines
8.0 KiB
C

/* $NetBSD: rs5c313.c,v 1.1 2006/09/07 01:12:00 uwe Exp $ */
/*-
* Copyright (c) 2006 The NetBSD Foundation, Inc.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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>
__KERNEL_RCSID(0, "$NetBSD: rs5c313.c,v 1.1 2006/09/07 01:12:00 uwe Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <dev/clock_subr.h>
#include <dev/ic/rs5c313reg.h>
#include <dev/ic/rs5c313var.h>
/* todr(9) methods */
static int rs5c313_todr_gettime(todr_chip_handle_t, volatile struct timeval *);
static int rs5c313_todr_settime(todr_chip_handle_t, volatile struct timeval *);
/* sugar for chip access */
#define rtc_begin(sc) ((*sc->sc_ops->rs5c313_op_begin)(sc))
#define rtc_ce(sc, onoff) ((*sc->sc_ops->rs5c313_op_ce)(sc, onoff))
#define rtc_clk(sc, onoff) ((*sc->sc_ops->rs5c313_op_clk)(sc, onoff))
#define rtc_dir(sc, output) ((*sc->sc_ops->rs5c313_op_dir)(sc, output))
#define rtc_di(sc) ((*sc->sc_ops->rs5c313_op_read)(sc))
#define rtc_do(sc, bit) ((*sc->sc_ops->rs5c313_op_write)(sc, bit))
static int rs5c313_init(struct rs5c313_softc *);
static int rs5c313_read_reg(struct rs5c313_softc *, int);
static void rs5c313_write_reg(struct rs5c313_softc *, int, int);
void
rs5c313_attach(struct rs5c313_softc *sc)
{
printf(": RS5C313 real time clock\n");
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = rs5c313_todr_gettime;
sc->sc_todr.todr_settime = rs5c313_todr_settime;
sc->sc_todr.todr_setwen = NULL;
if (rs5c313_init(sc) != 0) {
printf("%s: init failed\n", sc->sc_dev.dv_xname);
return;
}
todr_attach(&sc->sc_todr);
}
static int
rs5c313_init(struct rs5c313_softc *sc)
{
int status = 0;
int retry;
rtc_ce(sc, 0);
rtc_begin(sc);
rtc_ce(sc, 1);
if ((rs5c313_read_reg(sc, RS5C313_CTRL) & CTRL_XSTP) == 0) {
sc->sc_valid = 1;
goto done;
}
sc->sc_valid = 0;
printf("%s: time not valid\n", sc->sc_dev.dv_xname);
rs5c313_write_reg(sc, RS5C313_TINT, 0);
rs5c313_write_reg(sc, RS5C313_CTRL, (CTRL_BASE | CTRL_ADJ));
for (retry = 1000; retry > 0; --retry) {
if (rs5c313_read_reg(sc, RS5C313_CTRL) & CTRL_BSY)
delay(1);
else
break;
}
if (retry == 0) {
status = EIO;
goto done;
}
rs5c313_write_reg(sc, RS5C313_CTRL, CTRL_BASE);
done:
rtc_ce(sc, 0);
return status;
}
static int
rs5c313_todr_gettime(todr_chip_handle_t todr, volatile struct timeval *tv)
{
struct rs5c313_softc *sc = todr->cookie;
struct clock_ymdhms dt;
int retry;
int s;
/*
* If chip had invalid data on init, don't bother reading
* bogus values, let todr(9) cope.
*/
if (sc->sc_valid == 0)
return EIO;
s = splhigh();
rtc_begin(sc);
for (retry = 10; retry > 0; --retry) {
rtc_ce(sc, 1);
rs5c313_write_reg(sc, RS5C313_CTRL, CTRL_BASE);
if ((rs5c313_read_reg(sc, RS5C313_CTRL) & CTRL_BSY) == 0)
break;
rtc_ce(sc, 0);
delay(1);
}
if (retry == 0) {
splx(s);
return EIO;
}
#define RTCGET(x, y) \
do { \
int ones = rs5c313_read_reg(sc, RS5C313_ ## y ## 1); \
int tens = rs5c313_read_reg(sc, RS5C313_ ## y ## 10); \
dt.dt_ ## x = tens * 10 + ones; \
} while (/* CONSTCOND */0)
RTCGET(sec, SEC);
RTCGET(min, MIN);
RTCGET(hour, HOUR);
RTCGET(day, DAY);
RTCGET(mon, MON);
RTCGET(year, YEAR);
#undef RTCGET
dt.dt_wday = rs5c313_read_reg(sc, RS5C313_WDAY);
rtc_ce(sc, 0);
splx(s);
dt.dt_year = (dt.dt_year % 100) + 1900;
if (dt.dt_year < 1970) {
dt.dt_year += 100;
}
/*
* If time_t is 32 bits, then the "End of Time" is
* Mon Jan 18 22:14:07 2038 (US/Eastern)
* This code copes with RTC's past the end of time if time_t
* is an int32 or less. Needed because sometimes RTCs screw
* up or are badly set, and that would cause the time to go
* negative in the calculation below, which causes Very Bad
* Mojo. This at least lets the user boot and fix the problem.
* Note the code is self eliminating once time_t goes to 64 bits.
*/
if (/* CONSTCOND */ sizeof(time_t) <= sizeof(int32_t)) {
if (dt.dt_year >= 2038) {
return -1;
}
}
tv->tv_sec = clock_ymdhms_to_secs(&dt) + rtc_offset * 60;
tv->tv_usec = 0;
return 0;
}
static int
rs5c313_todr_settime(todr_chip_handle_t todr, volatile struct timeval *tv)
{
struct rs5c313_softc *sc = todr->cookie;
struct clock_ymdhms dt;
int retry;
int t;
int s;
clock_secs_to_ymdhms(tv->tv_sec - rtc_offset * 60, &dt);
s = splhigh();
rtc_begin(sc);
for (retry = 10; retry > 0; --retry) {
rtc_ce(sc, 1);
rs5c313_write_reg(sc, RS5C313_CTRL, CTRL_BASE);
if ((rs5c313_read_reg(sc, RS5C313_CTRL) & CTRL_BSY) == 0)
break;
rtc_ce(sc, 0);
delay(1);
}
if (retry == 0) {
splx(s);
return EIO;
}
#define RTCSET(x, y) \
do { \
t = TOBCD(dt.dt_ ## y) & 0xff; \
rs5c313_write_reg(sc, RS5C313_ ## x ## 1, t & 0x0f); \
rs5c313_write_reg(sc, RS5C313_ ## x ## 10, (t >> 4) & 0x0f); \
} while (/* CONSTCOND */0)
RTCSET(SEC, sec);
RTCSET(MIN, min);
RTCSET(HOUR, hour);
RTCSET(DAY, day);
RTCSET(MON, mon);
#undef RTCSET
t = dt.dt_year % 100;
t = TOBCD(t);
rs5c313_write_reg(sc, RS5C313_YEAR1, t & 0x0f);
rs5c313_write_reg(sc, RS5C313_YEAR10, (t >> 4) & 0x0f);
rs5c313_write_reg(sc, RS5C313_WDAY, dt.dt_wday);
rtc_ce(sc, 0);
splx(s);
sc->sc_valid = 1;
return 0;
}
static int
rs5c313_read_reg(struct rs5c313_softc *sc, int addr)
{
int data;
/* output */
rtc_dir(sc, 1);
/* control */
rtc_do(sc, 1); /* ignored */
rtc_do(sc, 1); /* R/#W = 1(READ) */
rtc_do(sc, 1); /* AD = 1 */
rtc_do(sc, 0); /* DT = 0 */
/* address */
rtc_do(sc, addr & 0x8); /* A3 */
rtc_do(sc, addr & 0x4); /* A2 */
rtc_do(sc, addr & 0x2); /* A1 */
rtc_do(sc, addr & 0x1); /* A0 */
/* input */
rtc_dir(sc, 0);
/* ignore */
(void)rtc_di(sc);
(void)rtc_di(sc);
(void)rtc_di(sc);
(void)rtc_di(sc);
/* data */
data = rtc_di(sc); /* D3 */
data <<= 1;
data |= rtc_di(sc); /* D2 */
data <<= 1;
data |= rtc_di(sc); /* D1 */
data <<= 1;
data |= rtc_di(sc); /* D0 */
return data;
}
static void
rs5c313_write_reg(struct rs5c313_softc *sc, int addr, int data)
{
/* output */
rtc_dir(sc, 1);
/* control */
rtc_do(sc, 1); /* ignored */
rtc_do(sc, 0); /* R/#W = 0 (WRITE) */
rtc_do(sc, 1); /* AD = 1 */
rtc_do(sc, 0); /* DT = 0 */
/* address */
rtc_do(sc, addr & 0x8); /* A3 */
rtc_do(sc, addr & 0x4); /* A2 */
rtc_do(sc, addr & 0x2); /* A1 */
rtc_do(sc, addr & 0x1); /* A0 */
/* control */
rtc_do(sc, 1); /* ignored */
rtc_do(sc, 0); /* R/#W = 0(WRITE) */
rtc_do(sc, 0); /* AD = 0 */
rtc_do(sc, 1); /* DT = 1 */
/* data */
rtc_do(sc, data & 0x8); /* D3 */
rtc_do(sc, data & 0x4); /* D2 */
rtc_do(sc, data & 0x2); /* D1 */
rtc_do(sc, data & 0x1); /* D0 */
}