/* $NetBSD: s390.c,v 1.4 2018/06/16 21:22:13 thorpej Exp $ */
/*-
* Copyright (c) 2011 Frank Wille.
* All rights reserved.
*
* Written by Frank Wille for The NetBSD Project.
*
* 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 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: s390.c,v 1.4 2018/06/16 21:22:13 thorpej Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/conf.h>
#include <dev/clock_subr.h>
#include <dev/i2c/i2cvar.h>
#include <dev/i2c/s390reg.h>
struct s390rtc_softc {
device_t sc_dev;
i2c_tag_t sc_tag;
i2c_addr_t sc_addr;
struct todr_chip_handle sc_todr;
};
static int s390rtc_match(device_t, cfdata_t, void *);
static void s390rtc_attach(device_t, device_t, void *);
CFATTACH_DECL_NEW(s390rtc, sizeof(struct s390rtc_softc),
s390rtc_match, s390rtc_attach, NULL, NULL);
static int s390rtc_gettime(struct todr_chip_handle *, struct timeval *);
static int s390rtc_settime(struct todr_chip_handle *, struct timeval *);
static int s390rtc_clock_read(struct s390rtc_softc *, struct clock_ymdhms *);
static int s390rtc_clock_write(struct s390rtc_softc *, struct clock_ymdhms *);
static int s390rtc_read(struct s390rtc_softc *, int, uint8_t *, size_t);
static int s390rtc_write(struct s390rtc_softc *, int, uint8_t *, size_t);
static uint8_t bitreverse(uint8_t);
static int
s390rtc_match(device_t parent, cfdata_t cf, void *arg)
{
struct i2c_attach_args *ia = arg;
int match_result;
if (iic_use_direct_match(ia, cf, NULL, &match_result))
return match_result;
/* indirect config - check typical address */
if (ia->ia_addr == S390_ADDR)
return I2C_MATCH_ADDRESS_ONLY;
return 0;
}
static void
s390rtc_attach(device_t parent, device_t self, void *arg)
{
struct s390rtc_softc *sc = device_private(self);
struct i2c_attach_args *ia = arg;
uint8_t reg[1];
aprint_naive(": Real-time Clock\n");
aprint_normal(": Seiko Instruments 35390A Real-time Clock\n");
sc->sc_tag = ia->ia_tag;
sc->sc_addr = ia->ia_addr;
sc->sc_dev = self;
/* Reset the chip and turn on 24h mode, after power-off or battery. */
if (!s390rtc_read(sc, S390_STATUS1, reg, sizeof(reg)))
return;
if (reg[0] & (S390_ST1_POC | S390_ST1_BLD)) {
reg[0] |= S390_ST1_24H | S390_ST1_RESET;
if (!s390rtc_write(sc, S390_STATUS1, reg, sizeof(reg)))
return;
}
/* Disable the test mode, when enabled. */
if (!s390rtc_read(sc, S390_STATUS2, reg, sizeof(reg)))
return;
if ((reg[0] & S390_ST2_TEST)) {
reg[0] &= ~S390_ST2_TEST;
if (!s390rtc_write(sc, S390_STATUS2, reg, sizeof(reg)))
return;
}
sc->sc_todr.cookie = sc;
sc->sc_todr.todr_gettime = s390rtc_gettime;
sc->sc_todr.todr_settime = s390rtc_settime;
sc->sc_todr.todr_setwen = NULL;
todr_attach(&sc->sc_todr);
}
static int
s390rtc_gettime(struct todr_chip_handle *ch, struct timeval *tv)
{
struct s390rtc_softc *sc = ch->cookie;
struct clock_ymdhms dt;
memset(&dt, 0, sizeof(dt));
if (!s390rtc_clock_read(sc, &dt))
return -1;
tv->tv_sec = clock_ymdhms_to_secs(&dt);
tv->tv_usec = 0;
return 0;
}
static int
s390rtc_settime(struct todr_chip_handle *ch, struct timeval *tv)
{
struct s390rtc_softc *sc = ch->cookie;
struct clock_ymdhms dt;
clock_secs_to_ymdhms(tv->tv_sec, &dt);
if (!s390rtc_clock_write(sc, &dt))
return -1;
return 0;
}
static int
s390rtc_clock_read(struct s390rtc_softc *sc, struct clock_ymdhms *dt)
{
uint8_t bcd[S390_RT1_NBYTES];
if (!s390rtc_read(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES))
return 0;
/*
* Convert the register values into something useable.
*/
dt->dt_sec = bcdtobin(bcd[S390_RT1_SECOND]);
dt->dt_min = bcdtobin(bcd[S390_RT1_MINUTE]);
dt->dt_hour = bcdtobin(bcd[S390_RT1_HOUR] & 0x3f);
dt->dt_day = bcdtobin(bcd[S390_RT1_DAY]);
dt->dt_mon = bcdtobin(bcd[S390_RT1_MONTH]);
dt->dt_year = bcdtobin(bcd[S390_RT1_YEAR]) + 2000;
return 1;
}
static int
s390rtc_clock_write(struct s390rtc_softc *sc, struct clock_ymdhms *dt)
{
uint8_t bcd[S390_RT1_NBYTES];
/*
* Convert our time representation into something the S-xx390
* can understand.
*/
bcd[S390_RT1_SECOND] = bintobcd(dt->dt_sec);
bcd[S390_RT1_MINUTE] = bintobcd(dt->dt_min);
bcd[S390_RT1_HOUR] = bintobcd(dt->dt_hour);
bcd[S390_RT1_DAY] = bintobcd(dt->dt_day);
bcd[S390_RT1_WDAY] = bintobcd(dt->dt_wday);
bcd[S390_RT1_MONTH] = bintobcd(dt->dt_mon);
bcd[S390_RT1_YEAR] = bintobcd(dt->dt_year % 100);
return s390rtc_write(sc, S390_REALTIME1, bcd, S390_RT1_NBYTES);
}
static int
s390rtc_read(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len)
{
int i;
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus\n", __func__);
return 0;
}
if (iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr + reg,
NULL, 0, buf, len, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
aprint_error_dev(sc->sc_dev,
"%s: failed to read reg%d\n", __func__, reg);
return 0;
}
iic_release_bus(sc->sc_tag, I2C_F_POLL);
/* this chip returns each byte in reverse order */
for (i = 0; i < len; i++)
buf[i] = bitreverse(buf[i]);
return 1;
}
static int
s390rtc_write(struct s390rtc_softc *sc, int reg, uint8_t *buf, size_t len)
{
int i;
if (iic_acquire_bus(sc->sc_tag, I2C_F_POLL)) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus\n", __func__);
return 0;
}
/* this chip expects each byte in reverse order */
for (i = 0; i < len; i++)
buf[i] = bitreverse(buf[i]);
if (iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr + reg,
NULL, 0, buf, len, I2C_F_POLL)) {
iic_release_bus(sc->sc_tag, I2C_F_POLL);
aprint_error_dev(sc->sc_dev,
"%s: failed to write reg%d\n", __func__, reg);
return 0;
}
iic_release_bus(sc->sc_tag, I2C_F_POLL);
return 1;
}
static uint8_t
bitreverse(uint8_t x)
{
static unsigned char nibbletab[16] = {
0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15
};
return (nibbletab[x & 15] << 4) | nibbletab[x >> 4];
}