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freebsd/sys/dev/iicbus/s35390a.c
2012-09-29 16:15:27 +00:00

330 lines
8.9 KiB
C

/*-
* Copyright (c) 2012 Yusuke Tanaka
* 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.
*/
/*-
* 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>
__FBSDID("$FreeBSD$");
/*
* Driver for Seiko Instruments S-35390A Real-time Clock
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#include "clock_if.h"
#include "iicbus_if.h"
#define S390_DEVNAME "s35390a_rtc"
#define S390_DEVCODE 0x6 /* 0110 */
/*
* S-35390A uses 4-bit device code + 3-bit command in the slave address
* field. The possible combination is 0x60-0x6f including the R/W bit.
* 0x60 means an write access to status register 1.
*/
#define S390_ADDR (S390_DEVCODE << 4)
/* Registers are encoded into the slave address */
#define S390_STATUS1 (0 << 1)
#define S390_STATUS2 (1 << 1)
#define S390_REALTIME1 (2 << 1)
#define S390_REALTIME2 (3 << 1)
#define S390_INT1_1 (4 << 1)
#define S390_INT1_2 (5 << 1)
#define S390_CLOCKADJ (6 << 1)
#define S390_FREE (7 << 1)
/* Status1 bits */
#define S390_ST1_POC (1 << 7)
#define S390_ST1_BLD (1 << 6)
#define S390_ST1_24H (1 << 1)
#define S390_ST1_RESET (1 << 0)
/* Status2 bits */
#define S390_ST2_TEST (1 << 7)
/* Realtime1 data bytes */
#define S390_RT1_NBYTES 7
#define S390_RT1_YEAR 0
#define S390_RT1_MONTH 1
#define S390_RT1_DAY 2
#define S390_RT1_WDAY 3
#define S390_RT1_HOUR 4
#define S390_RT1_MINUTE 5
#define S390_RT1_SECOND 6
struct s390rtc_softc {
device_t sc_dev;
uint16_t sc_addr;
};
/*
* S-35390A interprets bits in each byte on SDA in reverse order.
* bitreverse() reverses the bits in uint8_t.
*/
static const uint8_t nibbletab[] = {
/* 0x0 0000 -> 0000 */ 0x0,
/* 0x1 0001 -> 1000 */ 0x8,
/* 0x2 0010 -> 0100 */ 0x4,
/* 0x3 0011 -> 1100 */ 0xc,
/* 0x4 0100 -> 0010 */ 0x2,
/* 0x5 0101 -> 1010 */ 0xa,
/* 0x6 0110 -> 0110 */ 0x6,
/* 0x7 0111 -> 1110 */ 0xe,
/* 0x8 1000 -> 0001 */ 0x1,
/* 0x9 1001 -> 1001 */ 0x9,
/* 0xa 1010 -> 0101 */ 0x5,
/* 0xb 1011 -> 1101 */ 0xd,
/* 0xc 1100 -> 0011 */ 0x3,
/* 0xd 1101 -> 1011 */ 0xb,
/* 0xe 1110 -> 0111 */ 0x7,
/* 0xf 1111 -> 1111 */ 0xf, };
static uint8_t
bitreverse(uint8_t x)
{
return (nibbletab[x & 0xf] << 4) | nibbletab[x >> 4];
}
static int
s390rtc_read(device_t dev, uint8_t reg, uint8_t *buf, size_t len)
{
struct s390rtc_softc *sc = device_get_softc(dev);
struct iic_msg msg[] = {
{
.slave = sc->sc_addr | reg,
.flags = IIC_M_RD,
.len = len,
.buf = buf,
},
};
int i;
int error;
error = iicbus_transfer(dev, msg, 1);
if (error)
return (error);
/* this chip returns each byte in reverse order */
for (i = 0; i < len; ++i)
buf[i] = bitreverse(buf[i]);
return (0);
}
static int
s390rtc_write(device_t dev, uint8_t reg, uint8_t *buf, size_t len)
{
struct s390rtc_softc *sc = device_get_softc(dev);
struct iic_msg msg[] = {
{
.slave = sc->sc_addr | reg,
.flags = IIC_M_WR,
.len = len,
.buf = buf,
},
};
int i;
/* this chip expects each byte in reverse order */
for (i = 0; i < len; ++i)
buf[i] = bitreverse(buf[i]);
return (iicbus_transfer(dev, msg, 1));
}
static int
s390rtc_probe(device_t dev)
{
if (iicbus_get_addr(dev) != S390_ADDR) {
if (bootverbose)
device_printf(dev, "slave address mismatch. "
"(%02x != %02x)\n", iicbus_get_addr(dev),
S390_ADDR);
return (ENXIO);
}
device_set_desc(dev, "Seiko Instruments S-35390A Real-time Clock");
return (BUS_PROBE_SPECIFIC);
}
static int
s390rtc_attach(device_t dev)
{
struct s390rtc_softc *sc;
uint8_t reg;
int error;
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->sc_addr = iicbus_get_addr(dev);
/* Reset the chip and turn on 24h mode, after power-off or battery. */
error = s390rtc_read(dev, S390_STATUS1, &reg, 1);
if (error) {
device_printf(dev, "%s: cannot read status1 register\n",
__func__);
return (error);
}
if (reg & (S390_ST1_POC | S390_ST1_BLD)) {
reg |= S390_ST1_24H | S390_ST1_RESET;
error = s390rtc_write(dev, S390_STATUS1, &reg, 1);
if (error) {
device_printf(dev, "%s: cannot initialize\n", __func__);
return (error);
}
}
/* Disable the test mode, when enabled. */
error = s390rtc_read(dev, S390_STATUS2, &reg, 1);
if (error) {
device_printf(dev, "%s: cannot read status2 register\n",
__func__);
return (error);
}
if (reg & S390_ST2_TEST) {
reg &= ~S390_ST2_TEST;
error = s390rtc_write(dev, S390_STATUS2, &reg, 1);
if (error) {
device_printf(dev,
"%s: cannot disable the test mode\n", __func__);
return (error);
}
}
clock_register(dev, 1000000); /* 1 second resolution */
return (0);
}
static int
s390rtc_gettime(device_t dev, struct timespec *ts)
{
uint8_t bcd[S390_RT1_NBYTES];
struct clocktime ct;
int error;
error = s390rtc_read(dev, S390_REALTIME1, bcd, S390_RT1_NBYTES);
if (error) {
device_printf(dev, "%s: cannot read realtime1 register\n",
__func__);
return (error);
}
/*
* Convert the register values into something useable.
*/
ct.nsec = 0;
ct.sec = FROMBCD(bcd[S390_RT1_SECOND]);
ct.min = FROMBCD(bcd[S390_RT1_MINUTE]);
ct.hour = FROMBCD(bcd[S390_RT1_HOUR] & 0x3f);
ct.day = FROMBCD(bcd[S390_RT1_DAY]);
ct.dow = bcd[S390_RT1_WDAY] & 0x07;
ct.mon = FROMBCD(bcd[S390_RT1_MONTH]);
ct.year = FROMBCD(bcd[S390_RT1_YEAR]) + 2000;
return (clock_ct_to_ts(&ct, ts));
}
static int
s390rtc_settime(device_t dev, struct timespec *ts)
{
uint8_t bcd[S390_RT1_NBYTES];
struct clocktime ct;
clock_ts_to_ct(ts, &ct);
/*
* Convert our time representation into something the S-xx390
* can understand.
*/
bcd[S390_RT1_SECOND] = TOBCD(ct.sec);
bcd[S390_RT1_MINUTE] = TOBCD(ct.min);
bcd[S390_RT1_HOUR] = TOBCD(ct.hour);
bcd[S390_RT1_DAY] = TOBCD(ct.day);
bcd[S390_RT1_WDAY] = ct.dow;
bcd[S390_RT1_MONTH] = TOBCD(ct.mon);
bcd[S390_RT1_YEAR] = TOBCD(ct.year % 100);
return (s390rtc_write(dev, S390_REALTIME1, bcd, S390_RT1_NBYTES));
}
static device_method_t s390rtc_methods[] = {
DEVMETHOD(device_probe, s390rtc_probe),
DEVMETHOD(device_attach, s390rtc_attach),
DEVMETHOD(clock_gettime, s390rtc_gettime),
DEVMETHOD(clock_settime, s390rtc_settime),
DEVMETHOD_END
};
static driver_t s390rtc_driver = {
S390_DEVNAME,
s390rtc_methods,
sizeof(struct s390rtc_softc),
};
static devclass_t s390rtc_devclass;
DRIVER_MODULE(s35390a, iicbus, s390rtc_driver, s390rtc_devclass, NULL, NULL);
MODULE_VERSION(s35390a, 1);
MODULE_DEPEND(s35390a, iicbus, 1, 1, 1);