freebsd-skq/sys/dev/iicbus/ds1307.c
Luiz Otavio O Souza d7eb38c008 Add a driver for the Dallas/Maxim DS1307, another common i2c RTC.
Many thanks to ian who gently provided me the DS1307 breakout board.

Tested on:		Raspberry pi
Differential Revision:	https://reviews.freebsd.org/D2022
Reviewed by:		rpaulo
2015-03-20 19:51:24 +00:00

412 lines
10 KiB
C

/*-
* Copyright (c) 2015 Luiz Otavio O Souza <loos@FreeBSD.org>
* 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 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 AUTHOR 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 Maxim DS1307 I2C real-time clock/calendar.
*/
#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/module.h>
#include <sys/sysctl.h>
#include <dev/iicbus/iicbus.h>
#include <dev/iicbus/iiconf.h>
#ifdef FDT
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#endif
#include <dev/iicbus/ds1307reg.h>
#include "clock_if.h"
#include "iicbus_if.h"
struct ds1307_softc {
device_t sc_dev;
int sc_year0;
struct intr_config_hook enum_hook;
uint16_t sc_addr; /* DS1307 slave address. */
uint8_t sc_ctrl;
};
static void ds1307_start(void *);
static int
ds1307_read(device_t dev, uint16_t addr, uint8_t reg, uint8_t *data, size_t len)
{
struct iic_msg msg[2] = {
{ addr, IIC_M_WR | IIC_M_NOSTOP, 1, &reg },
{ addr, IIC_M_RD, len, data },
};
return (iicbus_transfer(dev, msg, nitems(msg)));
}
static int
ds1307_write(device_t dev, uint16_t addr, uint8_t *data, size_t len)
{
struct iic_msg msg[1] = {
{ addr, IIC_M_WR, len, data },
};
return (iicbus_transfer(dev, msg, nitems(msg)));
}
static int
ds1307_ctrl_read(struct ds1307_softc *sc)
{
int error;
sc->sc_ctrl = 0;
error = ds1307_read(sc->sc_dev, sc->sc_addr, DS1307_CONTROL,
&sc->sc_ctrl, sizeof(sc->sc_ctrl));
if (error) {
device_printf(sc->sc_dev, "cannot read from RTC.\n");
return (error);
}
return (0);
}
static int
ds1307_ctrl_write(struct ds1307_softc *sc)
{
int error;
uint8_t data[2];
data[0] = DS1307_CONTROL;
data[1] = sc->sc_ctrl & DS1307_CTRL_MASK;
error = ds1307_write(sc->sc_dev, sc->sc_addr, data, sizeof(data));
if (error != 0)
device_printf(sc->sc_dev, "cannot write to RTC.\n");
return (error);
}
static int
ds1307_osc_enable(struct ds1307_softc *sc)
{
int error;
uint8_t data[2], secs;
secs = 0;
error = ds1307_read(sc->sc_dev, sc->sc_addr, DS1307_SECS,
&secs, sizeof(secs));
if (error) {
device_printf(sc->sc_dev, "cannot read from RTC.\n");
return (error);
}
/* Check if the oscillator is disabled. */
if ((secs & DS1307_SECS_CH) == 0)
return (0);
device_printf(sc->sc_dev, "clock was halted, check the battery.\n");
data[0] = DS1307_SECS;
data[1] = secs & DS1307_SECS_MASK;
error = ds1307_write(sc->sc_dev, sc->sc_addr, data, sizeof(data));
if (error != 0)
device_printf(sc->sc_dev, "cannot write to RTC.\n");
return (error);
}
static int
ds1307_set_24hrs_mode(struct ds1307_softc *sc)
{
int error;
uint8_t data[2], hour;
hour = 0;
error = ds1307_read(sc->sc_dev, sc->sc_addr, DS1307_HOUR,
&hour, sizeof(hour));
if (error) {
device_printf(sc->sc_dev, "cannot read from RTC.\n");
return (error);
}
data[0] = DS1307_HOUR;
data[1] = hour & DS1307_HOUR_MASK;
error = ds1307_write(sc->sc_dev, sc->sc_addr, data, sizeof(data));
if (error != 0)
device_printf(sc->sc_dev, "cannot write to RTC.\n");
return (error);
}
static int
ds1307_sqwe_sysctl(SYSCTL_HANDLER_ARGS)
{
int sqwe, error, newv;
struct ds1307_softc *sc;
sc = (struct ds1307_softc *)arg1;
error = ds1307_ctrl_read(sc);
if (error != 0)
return (error);
sqwe = newv = (sc->sc_ctrl & DS1307_CTRL_SQWE) ? 1 : 0;
error = sysctl_handle_int(oidp, &newv, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (sqwe != newv) {
sc->sc_ctrl &= ~DS1307_CTRL_SQWE;
if (newv)
sc->sc_ctrl |= DS1307_CTRL_SQWE;
error = ds1307_ctrl_write(sc);
if (error != 0)
return (error);
}
return (error);
}
static int
ds1307_sqw_freq_sysctl(SYSCTL_HANDLER_ARGS)
{
int ds1307_sqw_freq[] = { 1, 4096, 8192, 32768 };
int error, freq, i, newf, tmp;
struct ds1307_softc *sc;
sc = (struct ds1307_softc *)arg1;
error = ds1307_ctrl_read(sc);
if (error != 0)
return (error);
tmp = (sc->sc_ctrl & DS1307_CTRL_RS_MASK);
if (tmp >= nitems(ds1307_sqw_freq))
tmp = nitems(ds1307_sqw_freq) - 1;
freq = ds1307_sqw_freq[tmp];
error = sysctl_handle_int(oidp, &freq, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (freq != ds1307_sqw_freq[tmp]) {
newf = 0;
for (i = 0; i < nitems(ds1307_sqw_freq); i++)
if (freq >= ds1307_sqw_freq[i])
newf = i;
sc->sc_ctrl &= ~DS1307_CTRL_RS_MASK;
sc->sc_ctrl |= newf;
error = ds1307_ctrl_write(sc);
if (error != 0)
return (error);
}
return (error);
}
static int
ds1307_sqw_out_sysctl(SYSCTL_HANDLER_ARGS)
{
int sqwe, error, newv;
struct ds1307_softc *sc;
sc = (struct ds1307_softc *)arg1;
error = ds1307_ctrl_read(sc);
if (error != 0)
return (error);
sqwe = newv = (sc->sc_ctrl & DS1307_CTRL_OUT) ? 1 : 0;
error = sysctl_handle_int(oidp, &newv, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (sqwe != newv) {
sc->sc_ctrl &= ~DS1307_CTRL_OUT;
if (newv)
sc->sc_ctrl |= DS1307_CTRL_OUT;
error = ds1307_ctrl_write(sc);
if (error != 0)
return (error);
}
return (error);
}
static int
ds1307_probe(device_t dev)
{
#ifdef FDT
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "dallas,ds1307") &&
!ofw_bus_is_compatible(dev, "maxim,ds1307"))
return (ENXIO);
#endif
device_set_desc(dev, "Maxim DS1307 RTC");
return (BUS_PROBE_DEFAULT);
}
static int
ds1307_attach(device_t dev)
{
struct ds1307_softc *sc;
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->sc_addr = iicbus_get_addr(dev);
sc->sc_year0 = 1900;
sc->enum_hook.ich_func = ds1307_start;
sc->enum_hook.ich_arg = dev;
/*
* We have to wait until interrupts are enabled. Usually I2C read
* and write only works when the interrupts are available.
*/
if (config_intrhook_establish(&sc->enum_hook) != 0)
return (ENOMEM);
return (0);
}
static void
ds1307_start(void *xdev)
{
device_t dev;
struct ds1307_softc *sc;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree_node;
struct sysctl_oid_list *tree;
dev = (device_t)xdev;
sc = device_get_softc(dev);
ctx = device_get_sysctl_ctx(dev);
tree_node = device_get_sysctl_tree(dev);
tree = SYSCTL_CHILDREN(tree_node);
config_intrhook_disestablish(&sc->enum_hook);
/* Set the 24 hours mode. */
if (ds1307_set_24hrs_mode(sc) != 0)
return;
/* Enable the oscillator if halted. */
if (ds1307_osc_enable(sc) != 0)
return;
/* Configuration parameters. */
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqwe",
CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0,
ds1307_sqwe_sysctl, "IU", "DS1307 square-wave enable");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqw_freq",
CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0,
ds1307_sqw_freq_sysctl, "IU",
"DS1307 square-wave output frequency");
SYSCTL_ADD_PROC(ctx, tree, OID_AUTO, "sqw_out",
CTLFLAG_RW | CTLTYPE_UINT | CTLFLAG_MPSAFE, sc, 0,
ds1307_sqw_out_sysctl, "IU", "DS1307 square-wave output state");
/* 1 second resolution. */
clock_register(dev, 1000000);
}
static int
ds1307_gettime(device_t dev, struct timespec *ts)
{
int error;
struct clocktime ct;
struct ds1307_softc *sc;
uint8_t data[7];
sc = device_get_softc(dev);
memset(data, 0, sizeof(data));
error = ds1307_read(sc->sc_dev, sc->sc_addr, DS1307_SECS,
data, sizeof(data));
if (error != 0) {
device_printf(dev, "cannot read from RTC.\n");
return (error);
}
ct.nsec = 0;
ct.sec = FROMBCD(data[DS1307_SECS] & DS1307_SECS_MASK);
ct.min = FROMBCD(data[DS1307_MINS] & DS1307_MINS_MASK);
ct.hour = FROMBCD(data[DS1307_HOUR] & DS1307_HOUR_MASK);
ct.day = FROMBCD(data[DS1307_DATE] & DS1307_DATE_MASK);
ct.dow = data[DS1307_WEEKDAY] & DS1307_WEEKDAY_MASK;
ct.mon = FROMBCD(data[DS1307_MONTH] & DS1307_MONTH_MASK);
ct.year = FROMBCD(data[DS1307_YEAR] & DS1307_YEAR_MASK);
ct.year += sc->sc_year0;
if (ct.year < POSIX_BASE_YEAR)
ct.year += 100; /* assume [1970, 2069] */
return (clock_ct_to_ts(&ct, ts));
}
static int
ds1307_settime(device_t dev, struct timespec *ts)
{
int error;
struct clocktime ct;
struct ds1307_softc *sc;
uint8_t data[8];
sc = device_get_softc(dev);
/* Accuracy is only one second. */
if (ts->tv_nsec >= 500000000)
ts->tv_sec++;
ts->tv_nsec = 0;
clock_ts_to_ct(ts, &ct);
memset(data, 0, sizeof(data));
data[0] = DS1307_SECS;
data[DS1307_SECS + 1] = TOBCD(ct.sec);
data[DS1307_MINS + 1] = TOBCD(ct.min);
data[DS1307_HOUR + 1] = TOBCD(ct.hour);
data[DS1307_DATE + 1] = TOBCD(ct.day);
data[DS1307_WEEKDAY + 1] = ct.dow;
data[DS1307_MONTH + 1] = TOBCD(ct.mon);
data[DS1307_YEAR + 1] = TOBCD(ct.year % 100);
/* Write the time back to RTC. */
error = ds1307_write(dev, sc->sc_addr, data, sizeof(data));
if (error != 0)
device_printf(dev, "cannot write to RTC.\n");
return (error);
}
static device_method_t ds1307_methods[] = {
DEVMETHOD(device_probe, ds1307_probe),
DEVMETHOD(device_attach, ds1307_attach),
DEVMETHOD(clock_gettime, ds1307_gettime),
DEVMETHOD(clock_settime, ds1307_settime),
DEVMETHOD_END
};
static driver_t ds1307_driver = {
"ds1307",
ds1307_methods,
sizeof(struct ds1307_softc),
};
static devclass_t ds1307_devclass;
DRIVER_MODULE(ds1307, iicbus, ds1307_driver, ds1307_devclass, NULL, NULL);
MODULE_VERSION(ds1307, 1);
MODULE_DEPEND(ds1307, iicbus, 1, 1, 1);