freebsd-dev/sys/dev/iicbus/ds1307.c

438 lines
11 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;
struct intr_config_hook
enum_hook;
uint8_t sc_ctrl;
bool sc_mcp7941x;
bool sc_use_ampm;
};
static void ds1307_start(void *);
#ifdef FDT
static const struct ofw_compat_data ds1307_compat_data[] = {
{"dallas,ds1307", (uintptr_t)"Dallas DS1307 RTC"},
{"maxim,ds1307", (uintptr_t)"Maxim DS1307 RTC"},
{"microchip,mcp7941x", (uintptr_t)"Microchip MCP7941x RTC"},
{ NULL, 0 }
};
#endif
static int
ds1307_read1(device_t dev, uint8_t reg, uint8_t *data)
{
return (iicdev_readfrom(dev, reg, data, 1, IIC_INTRWAIT));
}
static int
ds1307_write1(device_t dev, uint8_t reg, uint8_t data)
{
return (iicdev_writeto(dev, reg, &data, 1, IIC_INTRWAIT));
}
static int
ds1307_ctrl_read(struct ds1307_softc *sc)
{
int error;
sc->sc_ctrl = 0;
error = ds1307_read1(sc->sc_dev, DS1307_CONTROL, &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 ctrl;
ctrl = sc->sc_ctrl & DS1307_CTRL_MASK;
error = ds1307_write1(sc->sc_dev, DS1307_CONTROL, ctrl);
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, sqwe_bit;
struct ds1307_softc *sc;
sc = (struct ds1307_softc *)arg1;
error = ds1307_ctrl_read(sc);
if (error != 0)
return (error);
if (sc->sc_mcp7941x)
sqwe_bit = MCP7941X_CTRL_SQWE;
else
sqwe_bit = DS1307_CTRL_SQWE;
sqwe = newv = (sc->sc_ctrl & sqwe_bit) ? 1 : 0;
error = sysctl_handle_int(oidp, &newv, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (sqwe != newv) {
sc->sc_ctrl &= ~sqwe_bit;
if (newv)
sc->sc_ctrl |= sqwe_bit;
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
const struct ofw_compat_data *compat;
if (!ofw_bus_status_okay(dev))
return (ENXIO);
compat = ofw_bus_search_compatible(dev, ds1307_compat_data);
if (compat->ocd_str == NULL)
return (ENXIO);
device_set_desc(dev, (const char *)compat->ocd_data);
return (BUS_PROBE_DEFAULT);
#else
device_set_desc(dev, "Maxim DS1307 RTC");
return (BUS_PROBE_NOWILDCARD);
#endif
}
static int
ds1307_attach(device_t dev)
{
struct ds1307_softc *sc;
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->enum_hook.ich_func = ds1307_start;
sc->enum_hook.ich_arg = dev;
#ifdef FDT
if (ofw_bus_is_compatible(dev, "microchip,mcp7941x"))
sc->sc_mcp7941x = 1;
#endif
/*
* 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 int
ds1307_detach(device_t dev)
{
clock_unregister(dev);
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;
uint8_t secs;
uint8_t osc_en;
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);
/* Check if the oscillator is disabled. */
if (ds1307_read1(sc->sc_dev, DS1307_SECS, &secs) != 0) {
device_printf(sc->sc_dev, "cannot read from RTC.\n");
return;
}
if (sc->sc_mcp7941x)
osc_en = 0x80;
else
osc_en = 0x00;
if (((secs & DS1307_SECS_CH) ^ osc_en) != 0) {
device_printf(sc->sc_dev,
"WARNING: RTC clock stopped, check the battery.\n");
}
/* 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");
/*
* Register as a clock with 1 second resolution. Schedule the
* clock_settime() method to be called just after top-of-second;
* resetting the time resets top-of-second in the hardware.
*/
clock_register_flags(dev, 1000000, CLOCKF_SETTIME_NO_ADJ);
clock_schedule(dev, 1);
}
static int
ds1307_gettime(device_t dev, struct timespec *ts)
{
int error;
struct bcd_clocktime bct;
struct ds1307_softc *sc;
uint8_t data[7], hourmask, st_mask;
sc = device_get_softc(dev);
error = iicdev_readfrom(sc->sc_dev, DS1307_SECS, data, sizeof(data),
IIC_INTRWAIT);
if (error != 0) {
device_printf(dev, "cannot read from RTC.\n");
return (error);
}
/* If the clock halted, we don't have good data. */
if (sc->sc_mcp7941x)
st_mask = 0x80;
else
st_mask = 0x00;
if (((data[DS1307_SECS] & DS1307_SECS_CH) ^ st_mask) != 0)
return (EINVAL);
/* If chip is in AM/PM mode remember that. */
if (data[DS1307_HOUR] & DS1307_HOUR_USE_AMPM) {
sc->sc_use_ampm = true;
hourmask = DS1307_HOUR_MASK_12HR;
} else
hourmask = DS1307_HOUR_MASK_24HR;
bct.nsec = 0;
bct.ispm = (data[DS1307_HOUR] & DS1307_HOUR_IS_PM) != 0;
bct.sec = data[DS1307_SECS] & DS1307_SECS_MASK;
bct.min = data[DS1307_MINS] & DS1307_MINS_MASK;
bct.hour = data[DS1307_HOUR] & hourmask;
bct.day = data[DS1307_DATE] & DS1307_DATE_MASK;
bct.mon = data[DS1307_MONTH] & DS1307_MONTH_MASK;
bct.year = data[DS1307_YEAR] & DS1307_YEAR_MASK;
clock_dbgprint_bcd(sc->sc_dev, CLOCK_DBG_READ, &bct);
return (clock_bcd_to_ts(&bct, ts, sc->sc_use_ampm));
}
static int
ds1307_settime(device_t dev, struct timespec *ts)
{
struct bcd_clocktime bct;
struct ds1307_softc *sc;
int error, year;
uint8_t data[7];
uint8_t pmflags;
sc = device_get_softc(dev);
/*
* We request a timespec with no resolution-adjustment. That also
* disables utc adjustment, so apply that ourselves.
*/
ts->tv_sec -= utc_offset();
clock_ts_to_bcd(ts, &bct, sc->sc_use_ampm);
clock_dbgprint_bcd(sc->sc_dev, CLOCK_DBG_WRITE, &bct);
/* If the chip is in AM/PM mode, adjust hour and set flags as needed. */
if (sc->sc_use_ampm) {
pmflags = DS1307_HOUR_USE_AMPM;
if (bct.ispm)
pmflags |= DS1307_HOUR_IS_PM;
} else
pmflags = 0;
data[DS1307_SECS] = bct.sec;
data[DS1307_MINS] = bct.min;
data[DS1307_HOUR] = bct.hour | pmflags;
data[DS1307_DATE] = bct.day;
data[DS1307_WEEKDAY] = bct.dow;
data[DS1307_MONTH] = bct.mon;
data[DS1307_YEAR] = bct.year & 0xff;
if (sc->sc_mcp7941x) {
data[DS1307_SECS] |= MCP7941X_SECS_ST;
data[DS1307_WEEKDAY] |= MCP7941X_WEEKDAY_VBATEN;
year = bcd2bin(bct.year >> 8) * 100 + bcd2bin(bct.year & 0xff);
if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
data[DS1307_MONTH] |= MCP7941X_MONTH_LPYR;
}
/* Write the time back to RTC. */
error = iicdev_writeto(sc->sc_dev, DS1307_SECS, data, sizeof(data),
IIC_INTRWAIT);
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(device_detach, ds1307_detach),
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);