freebsd-skq/sys/dev/iicbus/rtc8583.c
Ian Lepore 89ba361fcc The year is stored in a single byte in sram, in binary format, as a count
of years since the century, so strip the century out when converting to or
from bcd_clocktime format (the conversion routines will infer century by
pivoting on 70).
2018-03-04 21:58:32 +00:00

303 lines
7.6 KiB
C

/*-
* Copyright (c) 2017 Hiroki Mori. All rights reserved.
* Copyright (c) 2017 Ian Lepore. 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.
*
* This code base on isl12xx.c
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Driver for realtime clock EPSON RTC-8583
*/
#include "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/clock.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/module.h>
#ifdef FDT
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "clock_if.h"
#include "iicbus_if.h"
#define RTC8583_SC_REG 0x01 /* RTC Seconds */
#define RTC8583_USERSRAM_REG 0x10 /* User SRAM register (first) */
#define MAX_TRANSFER 16
/*
* A struct laid out in the same order as the time registers in the chip.
*/
struct time_regs {
uint8_t msec, sec, min, hour, day, month;
};
struct rtc8583_softc {
device_t dev;
device_t busdev;
struct intr_config_hook
init_hook;
};
#ifdef FDT
static struct ofw_compat_data compat_data[] = {
{"epson,rtc8583", 1},
{NULL, 0},
};
#endif
static void rtc8583_init(void *arg);
static int rtc8583_probe(device_t dev);
static int rtc8583_attach(device_t dev);
static int rtc8583_detach(device_t dev);
static int rtc8583_gettime(device_t dev, struct timespec *ts);
static int rtc8583_settime(device_t dev, struct timespec *ts);
static int rtc8583_writeto(device_t slavedev, uint8_t regaddr,
void *buffer, uint16_t buflen, int waithow);
/* Implementation */
static int
rtc8583_writeto(device_t slavedev, uint8_t regaddr, void *buffer,
uint16_t buflen, int waithow)
{
struct iic_msg msgs;
uint8_t slaveaddr;
uint8_t newbuf[MAX_TRANSFER];
slaveaddr = iicbus_get_addr(slavedev);
newbuf[0] = regaddr;
memcpy(newbuf + 1, buffer, buflen);
msgs.slave = slaveaddr;
msgs.flags = IIC_M_WR;
msgs.len = 1 + buflen;
msgs.buf = newbuf;
return (iicbus_transfer_excl(slavedev, &msgs, 1, waithow));
}
static inline int
rtc8583_read1(struct rtc8583_softc *sc, uint8_t reg, uint8_t *data)
{
return (iicdev_readfrom(sc->dev, reg, data, 1, IIC_WAIT));
}
static inline int
rtc8583_write1(struct rtc8583_softc *sc, uint8_t reg, uint8_t val)
{
return (rtc8583_writeto(sc->dev, reg, &val, 1, IIC_WAIT));
}
static void
rtc8583_init(void *arg)
{
struct rtc8583_softc *sc;
sc = (struct rtc8583_softc*)arg;
config_intrhook_disestablish(&sc->init_hook);
/*
* Register as a system realtime clock.
*/
clock_register_flags(sc->dev, 1000000, CLOCKF_SETTIME_NO_ADJ);
clock_schedule(sc->dev, 1);
return;
}
static int
rtc8583_probe(device_t dev)
{
#ifdef FDT
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (ofw_bus_search_compatible(dev, compat_data)->ocd_data != 0) {
device_set_desc(dev, "EPSON RTC-8583");
return (BUS_PROBE_DEFAULT);
}
#endif
return (ENXIO);
}
static int
rtc8583_attach(device_t dev)
{
struct rtc8583_softc *sc;
sc = device_get_softc(dev);
sc->dev = dev;
sc->busdev = device_get_parent(sc->dev);
/*
* Chip init must wait until interrupts are enabled. Often i2c access
* works only when the interrupts are available.
*/
sc->init_hook.ich_func = rtc8583_init;
sc->init_hook.ich_arg = sc;
if (config_intrhook_establish(&sc->init_hook) != 0)
return (ENOMEM);
return (0);
}
static int
rtc8583_detach(device_t dev)
{
clock_unregister(dev);
return (0);
}
static int
rtc8583_gettime(device_t dev, struct timespec *ts)
{
struct rtc8583_softc *sc;
struct bcd_clocktime bct;
struct time_regs tregs;
uint8_t y, ytmp, sreg;
int err;
sc = device_get_softc(dev);
/* Read the bcd time registers. */
if ((err = iicdev_readfrom(sc->dev, RTC8583_SC_REG, &tregs, sizeof(tregs),
IIC_WAIT)) != 0)
return (err);
y = tregs.day >> 6;
/* Get year from user SRAM */
rtc8583_read1(sc, RTC8583_USERSRAM_REG, &sreg);
/*
* Check if year adjustment is required.
* RTC has only 2 bits for year value (i.e. maximum is 4 years), so
* full year value is stored in user SRAM and updated manually or
* by this code.
*/
ytmp = sreg & 0x03;
if (ytmp != y) {
/* shift according to difference */
sreg += y - ytmp;
/* check if overflow happened */
if (ytmp > y)
sreg += 4;
if ((err = iicbus_request_bus(sc->busdev, sc->dev, IIC_WAIT)) != 0)
return (err);
rtc8583_write1(sc, RTC8583_USERSRAM_REG, sreg);
iicbus_release_bus(sc->busdev, sc->dev);
}
if (!validbcd(tregs.msec))
return (EINVAL);
/* The 'msec' reg is actually 1/100ths, in bcd. */
bct.nsec = bcd2bin(tregs.msec) * 10 * 1000 * 1000;
bct.sec = tregs.sec;
bct.min = tregs.min;
bct.hour = tregs.hour & 0x3f;
bct.day = tregs.day & 0x3f;
bct.mon = tregs.month & 0x1f;
bct.year = bin2bcd(sreg % 100);
clock_dbgprint_bcd(sc->dev, CLOCK_DBG_READ, &bct);
return (clock_bcd_to_ts(&bct, ts, false));
}
static int
rtc8583_settime(device_t dev, struct timespec *ts)
{
struct rtc8583_softc *sc;
struct bcd_clocktime bct;
struct time_regs tregs;
uint8_t sreg;
int err;
sc = device_get_softc(dev);
ts->tv_sec -= utc_offset();
clock_ts_to_bcd(ts, &bct, false);
clock_dbgprint_bcd(sc->dev, CLOCK_DBG_WRITE, &bct);
/* The 'msec' reg is actually 1/100ths, in bcd. */
tregs.msec = bin2bcd(ts->tv_nsec / (10 * 1000 * 1000));
tregs.sec = bct.sec;
tregs.min = bct.min;
tregs.hour = bct.hour;
tregs.day = bct.day | (bct.year & 0x03 << 6);
tregs.month = bct.mon;
if ((err = iicbus_request_bus(sc->busdev, sc->dev, IIC_WAIT)) != 0)
return (err);
err = rtc8583_writeto(sc->dev, RTC8583_SC_REG, &tregs,
sizeof(tregs), IIC_WAIT);
sreg = bcd2bin(bct.year & 0xff);
/* save to year to sram */
rtc8583_write1(sc, RTC8583_USERSRAM_REG, sreg);
iicbus_release_bus(sc->busdev, sc->dev);
return (err);
}
static device_method_t rtc8583_methods[] = {
/* device_if methods */
DEVMETHOD(device_probe, rtc8583_probe),
DEVMETHOD(device_attach, rtc8583_attach),
DEVMETHOD(device_detach, rtc8583_detach),
/* clock_if methods */
DEVMETHOD(clock_gettime, rtc8583_gettime),
DEVMETHOD(clock_settime, rtc8583_settime),
DEVMETHOD_END,
};
static driver_t rtc8583_driver = {
"rtc8583",
rtc8583_methods,
sizeof(struct rtc8583_softc),
};
static devclass_t rtc8583_devclass;
DRIVER_MODULE(rtc8583, iicbus, rtc8583_driver, rtc8583_devclass, NULL, NULL);
MODULE_VERSION(rtc8583, 1);
MODULE_DEPEND(rtc8583, iicbus, IICBUS_MINVER, IICBUS_PREFVER, IICBUS_MAXVER);