* Copyright (c) 2003 Wasabi Systems, Inc.

/* $NetBSD: ds1307.c,v 1.40 2023/01/24 07:09:48 mlelstv Exp $ */

/*
* Copyright (c) 2003 Wasabi Systems, Inc.
* All rights reserved.
*
* Written by Steve C. Woodford and Jason R. Thorpe for Wasabi Systems, Inc.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the NetBSD Project by
* Wasabi Systems, Inc.
* 4. The name of Wasabi Systems, Inc. may not be used to endorse
* or promote products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``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 WASABI SYSTEMS, INC
* 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: ds1307.c,v 1.40 2023/01/24 07:09:48 mlelstv Exp $");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/uio.h>
#include <sys/conf.h>
#include <sys/event.h>

#include <dev/clock_subr.h>

#include <dev/i2c/i2cvar.h>
#include <dev/i2c/ds1307reg.h>
#include <dev/sysmon/sysmonvar.h>

#include "ioconf.h"
#include "opt_dsrtc.h"

struct dsrtc_model {
const i2c_addr_t *dm_valid_addrs;
uint16_t dm_model;
uint8_t dm_ch_reg;
uint8_t dm_ch_value;
uint8_t dm_vbaten_reg;
uint8_t dm_vbaten_value;
uint8_t dm_rtc_start;
uint8_t dm_rtc_size;
uint8_t dm_nvram_start;
uint8_t dm_nvram_size;
uint8_t dm_flags;
#define DSRTC_FLAG_CLOCK_HOLD 0x01
#define DSRTC_FLAG_BCD 0x02
#define DSRTC_FLAG_TEMP 0x04
#define DSRTC_FLAG_VBATEN 0x08
#define DSRTC_FLAG_YEAR_START_2K 0x10
#define DSRTC_FLAG_CLOCK_HOLD_REVERSED 0x20
};

static const i2c_addr_t ds1307_valid_addrs[] = { DS1307_ADDR, 0 };
static const struct dsrtc_model ds1307_model = {
.dm_valid_addrs = ds1307_valid_addrs,
.dm_model = 1307,
.dm_ch_reg = DSXXXX_SECONDS,
.dm_ch_value = DS1307_SECONDS_CH,
.dm_rtc_start = DS1307_RTC_START,
.dm_rtc_size = DS1307_RTC_SIZE,
.dm_nvram_start = DS1307_NVRAM_START,
.dm_nvram_size = DS1307_NVRAM_SIZE,
.dm_flags = DSRTC_FLAG_BCD | DSRTC_FLAG_CLOCK_HOLD,
};

static const struct dsrtc_model ds1339_model = {
.dm_valid_addrs = ds1307_valid_addrs,
.dm_model = 1339,
.dm_rtc_start = DS1339_RTC_START,
.dm_rtc_size = DS1339_RTC_SIZE,
.dm_flags = DSRTC_FLAG_BCD,
};

static const struct dsrtc_model ds1340_model = {
.dm_valid_addrs = ds1307_valid_addrs,
.dm_model = 1340,
.dm_ch_reg = DSXXXX_SECONDS,
.dm_ch_value = DS1340_SECONDS_EOSC,
.dm_rtc_start = DS1340_RTC_START,
.dm_rtc_size = DS1340_RTC_SIZE,
.dm_flags = DSRTC_FLAG_BCD,
};

static const struct dsrtc_model ds1672_model = {
.dm_valid_addrs = ds1307_valid_addrs,
.dm_model = 1672,
.dm_rtc_start = DS1672_RTC_START,
.dm_rtc_size = DS1672_RTC_SIZE,
.dm_ch_reg = DS1672_CONTROL,
.dm_ch_value = DS1672_CONTROL_CH,
.dm_flags = 0,
};

static const struct dsrtc_model ds3231_model = {
.dm_valid_addrs = ds1307_valid_addrs,
.dm_model = 3231,
.dm_rtc_start = DS3232_RTC_START,
.dm_rtc_size = DS3232_RTC_SIZE,
.dm_flags = DSRTC_FLAG_BCD | DSRTC_FLAG_TEMP,
};

static const struct dsrtc_model ds3232_model = {
.dm_valid_addrs = ds1307_valid_addrs,
.dm_model = 3232,
.dm_rtc_start = DS3232_RTC_START,
.dm_rtc_size = DS3232_RTC_SIZE,
.dm_nvram_start = DS3232_NVRAM_START,
.dm_nvram_size = DS3232_NVRAM_SIZE,
/*
* XXX
* the DS3232 likely has the temperature sensor too but I can't
* easily verify or test that right now
*/
.dm_flags = DSRTC_FLAG_BCD,
};

static const i2c_addr_t mcp7940_valid_addrs[] = { MCP7940_ADDR, 0 };
static const struct dsrtc_model mcp7940_model = {
.dm_valid_addrs = mcp7940_valid_addrs,
.dm_model = 7940,
.dm_rtc_start = DS1307_RTC_START,
.dm_rtc_size = DS1307_RTC_SIZE,
.dm_ch_reg = DSXXXX_SECONDS,
.dm_ch_value = DS1307_SECONDS_CH,
.dm_vbaten_reg = DSXXXX_DAY,
.dm_vbaten_value = MCP7940_TOD_DAY_VBATEN,
.dm_nvram_start = MCP7940_NVRAM_START,
.dm_nvram_size = MCP7940_NVRAM_SIZE,
.dm_flags = DSRTC_FLAG_BCD | DSRTC_FLAG_CLOCK_HOLD |
DSRTC_FLAG_VBATEN | DSRTC_FLAG_CLOCK_HOLD_REVERSED,
};

static const struct device_compatible_entry compat_data[] = {
{ .compat = "dallas,ds1307", .data = &ds1307_model },
{ .compat = "maxim,ds1307", .data = &ds1307_model },
{ .compat = "i2c-ds1307", .data = &ds1307_model },

{ .compat = "dallas,ds1339", .data = &ds1339_model },
{ .compat = "maxim,ds1339", .data = &ds1339_model },

{ .compat = "dallas,ds1340", .data = &ds1340_model },
{ .compat = "maxim,ds1340", .data = &ds1340_model },

{ .compat = "dallas,ds1672", .data = &ds1672_model },
{ .compat = "maxim,ds1672", .data = &ds1672_model },

{ .compat = "dallas,ds3231", .data = &ds3231_model },
{ .compat = "maxim,ds3231", .data = &ds3231_model },

{ .compat = "dallas,ds3232", .data = &ds3232_model },
{ .compat = "maxim,ds3232", .data = &ds3232_model },

{ .compat = "microchip,mcp7940", .data = &mcp7940_model },

DEVICE_COMPAT_EOL
};

struct dsrtc_softc {
device_t sc_dev;
i2c_tag_t sc_tag;
uint8_t sc_address;
bool sc_open;
struct dsrtc_model sc_model;
struct todr_chip_handle sc_todr;
struct sysmon_envsys *sc_sme;
envsys_data_t sc_sensor;
};

static void dsrtc_attach(device_t, device_t, void *);
static int dsrtc_match(device_t, cfdata_t, void *);

CFATTACH_DECL_NEW(dsrtc, sizeof(struct dsrtc_softc),
dsrtc_match, dsrtc_attach, NULL, NULL);

dev_type_open(dsrtc_open);
dev_type_close(dsrtc_close);
dev_type_read(dsrtc_read);
dev_type_write(dsrtc_write);

const struct cdevsw dsrtc_cdevsw = {
.d_open = dsrtc_open,
.d_close = dsrtc_close,
.d_read = dsrtc_read,
.d_write = dsrtc_write,
.d_ioctl = noioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER
};

static int dsrtc_gettime_ymdhms(struct todr_chip_handle *, struct clock_ymdhms *);
static int dsrtc_settime_ymdhms(struct todr_chip_handle *, struct clock_ymdhms *);
static int dsrtc_clock_read_ymdhms(struct dsrtc_softc *, struct clock_ymdhms *);
static int dsrtc_clock_write_ymdhms(struct dsrtc_softc *, struct clock_ymdhms *);

static int dsrtc_gettime_timeval(struct todr_chip_handle *, struct timeval *);
static int dsrtc_settime_timeval(struct todr_chip_handle *, struct timeval *);
static int dsrtc_clock_read_timeval(struct dsrtc_softc *, time_t *);
static int dsrtc_clock_write_timeval(struct dsrtc_softc *, time_t);

static int dsrtc_read_temp(struct dsrtc_softc *, uint32_t *);
static void dsrtc_refresh(struct sysmon_envsys *, envsys_data_t *);

static const struct dsrtc_model *
dsrtc_model_by_number(u_int model)
{
const struct device_compatible_entry *dce;
const struct dsrtc_model *dm;

/* no model given, assume it's a DS1307 */
if (model == 0)
return &ds1307_model;

for (dce = compat_data; dce->compat != NULL; dce++) {
dm = dce->data;
if (dm->dm_model == model)
return dm;
}
return NULL;
}

static const struct dsrtc_model *
dsrtc_model_by_compat(const struct i2c_attach_args *ia)
{
const struct dsrtc_model *dm = NULL;
const struct device_compatible_entry *dce;

if ((dce = iic_compatible_lookup(ia, compat_data)) != NULL)
dm = dce->data;

return dm;
}

static bool
dsrtc_is_valid_addr_for_model(const struct dsrtc_model *dm, i2c_addr_t addr)
{

for (int i = 0; dm->dm_valid_addrs[i] != 0; i++) {
if (addr == dm->dm_valid_addrs[i])
return true;
}
return false;
}

static int
dsrtc_match(device_t parent, cfdata_t cf, void *arg)
{
struct i2c_attach_args *ia = arg;
const struct dsrtc_model *dm;
int match_result;

if (iic_use_direct_match(ia, cf, compat_data, &match_result))
return match_result;

dm = dsrtc_model_by_number(cf->cf_flags & 0xffff);
if (dm == NULL)
return 0;

if (dsrtc_is_valid_addr_for_model(dm, ia->ia_addr))
return I2C_MATCH_ADDRESS_ONLY;

return 0;
}

static void
dsrtc_attach(device_t parent, device_t self, void *arg)
{
struct dsrtc_softc *sc = device_private(self);
struct i2c_attach_args *ia = arg;
const struct dsrtc_model *dm;
prop_dictionary_t dict = device_properties(self);
bool base_2k = FALSE;

if ((dm = dsrtc_model_by_compat(ia)) == NULL)
dm = dsrtc_model_by_number(device_cfdata(self)->cf_flags);

if (dm == NULL) {
aprint_error(": unable to determine model!\n");
return;
}

aprint_naive(": Real-time Clock%s\n",
dm->dm_nvram_size > 0 ? "/NVRAM" : "");
aprint_normal(": DS%u Real-time Clock%s\n", dm->dm_model,
dm->dm_nvram_size > 0 ? "/NVRAM" : "");

sc->sc_tag = ia->ia_tag;
sc->sc_address = ia->ia_addr;
sc->sc_model = *dm;
sc->sc_dev = self;
sc->sc_open = 0;
sc->sc_todr.cookie = sc;

if (dm->dm_flags & DSRTC_FLAG_BCD) {
sc->sc_todr.todr_gettime_ymdhms = dsrtc_gettime_ymdhms;
sc->sc_todr.todr_settime_ymdhms = dsrtc_settime_ymdhms;
} else {
sc->sc_todr.todr_gettime = dsrtc_gettime_timeval;
sc->sc_todr.todr_settime = dsrtc_settime_timeval;
}
sc->sc_todr.todr_setwen = NULL;

#ifdef DSRTC_YEAR_START_2K
sc->sc_model.dm_flags |= DSRTC_FLAG_YEAR_START_2K;
#endif

prop_dictionary_get_bool(dict, "base_year_is_2000", &base_2k);
if (base_2k) sc->sc_model.dm_flags |= DSRTC_FLAG_YEAR_START_2K;

todr_attach(&sc->sc_todr);
if ((sc->sc_model.dm_flags & DSRTC_FLAG_TEMP) != 0) {
int error;

sc->sc_sme = sysmon_envsys_create();
sc->sc_sme->sme_name = device_xname(self);
sc->sc_sme->sme_cookie = sc;
sc->sc_sme->sme_refresh = dsrtc_refresh;

sc->sc_sensor.units = ENVSYS_STEMP;
sc->sc_sensor.state = ENVSYS_SINVALID;
sc->sc_sensor.flags = 0;
(void)strlcpy(sc->sc_sensor.desc, "temperature",
sizeof(sc->sc_sensor.desc));

if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
aprint_error_dev(self, "unable to attach sensor\n");
goto bad;
}

error = sysmon_envsys_register(sc->sc_sme);
if (error) {
aprint_error_dev(self,
"error %d registering with sysmon\n", error);
goto bad;
}
}
return;
bad:
sysmon_envsys_destroy(sc->sc_sme);
}

/*ARGSUSED*/
int
dsrtc_open(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct dsrtc_softc *sc;

if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return ENXIO;

/* XXX: Locking */
if (sc->sc_open)
return EBUSY;

sc->sc_open = true;
return 0;
}

/*ARGSUSED*/
int
dsrtc_close(dev_t dev, int flag, int fmt, struct lwp *l)
{
struct dsrtc_softc *sc;

if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return ENXIO;

sc->sc_open = false;
return 0;
}

/*ARGSUSED*/
int
dsrtc_read(dev_t dev, struct uio *uio, int flags)
{
struct dsrtc_softc *sc;
int error;

if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return ENXIO;

const struct dsrtc_model * const dm = &sc->sc_model;
if (uio->uio_offset < 0 || uio->uio_offset >= dm->dm_nvram_size)
return EINVAL;

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return error;

while (uio->uio_resid && uio->uio_offset < dm->dm_nvram_size) {
uint8_t ch, cmd;
const u_int a = uio->uio_offset;
cmd = a + dm->dm_nvram_start;
if ((error = iic_exec(sc->sc_tag,
uio->uio_resid > 1 ? I2C_OP_READ : I2C_OP_READ_WITH_STOP,
sc->sc_address, &cmd, 1, &ch, 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"%s: read failed at 0x%x: %d\n",
__func__, a, error);
return error;
}
if ((error = uiomove(&ch, 1, uio)) != 0) {
iic_release_bus(sc->sc_tag, 0);
return error;
}
}

iic_release_bus(sc->sc_tag, 0);

return 0;
}

/*ARGSUSED*/
int
dsrtc_write(dev_t dev, struct uio *uio, int flags)
{
struct dsrtc_softc *sc;
int error;

if ((sc = device_lookup_private(&dsrtc_cd, minor(dev))) == NULL)
return ENXIO;

const struct dsrtc_model * const dm = &sc->sc_model;
if (uio->uio_offset >= dm->dm_nvram_size)
return EINVAL;

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0)
return error;

while (uio->uio_resid && uio->uio_offset < dm->dm_nvram_size) {
uint8_t cmdbuf[2];
const u_int a = (int)uio->uio_offset;
cmdbuf[0] = a + dm->dm_nvram_start;
if ((error = uiomove(&cmdbuf[1], 1, uio)) != 0)
break;

if ((error = iic_exec(sc->sc_tag,
uio->uio_resid ? I2C_OP_WRITE : I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"%s: write failed at 0x%x: %d\n",
__func__, a, error);
break;
}
}

iic_release_bus(sc->sc_tag, 0);

return error;
}

static int
dsrtc_gettime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
{
struct dsrtc_softc *sc = ch->cookie;
struct clock_ymdhms check;
int retries;

memset(dt, 0, sizeof(*dt));
memset(&check, 0, sizeof(check));

/*
* Since we don't support Burst Read, we have to read the clock twice
* until we get two consecutive identical results.
*/
retries = 5;
do {
dsrtc_clock_read_ymdhms(sc, dt);
dsrtc_clock_read_ymdhms(sc, &check);
} while (memcmp(dt, &check, sizeof(check)) != 0 && --retries);

return 0;
}

static int
dsrtc_settime_ymdhms(struct todr_chip_handle *ch, struct clock_ymdhms *dt)
{
struct dsrtc_softc *sc = ch->cookie;

if (dsrtc_clock_write_ymdhms(sc, dt) == 0)
return -1;

return 0;
}

static int
dsrtc_clock_read_ymdhms(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
{
struct dsrtc_model * const dm = &sc->sc_model;
uint8_t bcd[DSXXXX_RTC_SIZE], cmdbuf[1];
int error;

KASSERT(DSXXXX_RTC_SIZE >= dm->dm_rtc_size);

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus: %d\n",
__func__, error);
return 0;
}

/* Read each RTC register in order. */
for (u_int i = 0; !error && i < dm->dm_rtc_size; i++) {
cmdbuf[0] = dm->dm_rtc_start + i;

error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP,
sc->sc_address, cmdbuf, 1, &bcd[i], 1, 0);
}

/* Done with I2C */
iic_release_bus(sc->sc_tag, 0);

if (error != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to read rtc at 0x%x: %d\n",
__func__, cmdbuf[0], error);
return 0;
}

/*
* Convert the RTC's register values into something useable
*/
dt->dt_sec = bcdtobin(bcd[DSXXXX_SECONDS] & DSXXXX_SECONDS_MASK);
dt->dt_min = bcdtobin(bcd[DSXXXX_MINUTES] & DSXXXX_MINUTES_MASK);

if ((bcd[DSXXXX_HOURS] & DSXXXX_HOURS_12HRS_MODE) != 0) {
dt->dt_hour = bcdtobin(bcd[DSXXXX_HOURS] &
DSXXXX_HOURS_12MASK) % 12; /* 12AM -> 0, 12PM -> 12 */
if (bcd[DSXXXX_HOURS] & DSXXXX_HOURS_12HRS_PM)
dt->dt_hour += 12;
} else
dt->dt_hour = bcdtobin(bcd[DSXXXX_HOURS] &
DSXXXX_HOURS_24MASK);

dt->dt_day = bcdtobin(bcd[DSXXXX_DATE] & DSXXXX_DATE_MASK);
dt->dt_mon = bcdtobin(bcd[DSXXXX_MONTH] & DSXXXX_MONTH_MASK);

/* XXX: Should be an MD way to specify EPOCH used by BIOS/Firmware */
if (sc->sc_model.dm_flags & DSRTC_FLAG_YEAR_START_2K)
dt->dt_year = bcdtobin(bcd[DSXXXX_YEAR]) + 2000;
else {
dt->dt_year = bcdtobin(bcd[DSXXXX_YEAR]) + POSIX_BASE_YEAR;
if (bcd[DSXXXX_MONTH] & DSXXXX_MONTH_CENTURY)
dt->dt_year += 100;
}

return 1;
}

static int
dsrtc_clock_write_ymdhms(struct dsrtc_softc *sc, struct clock_ymdhms *dt)
{
struct dsrtc_model * const dm = &sc->sc_model;
uint8_t bcd[DSXXXX_RTC_SIZE], cmdbuf[2];
int error, offset;

KASSERT(DSXXXX_RTC_SIZE >= dm->dm_rtc_size);

/*
* Convert our time representation into something the DSXXXX
* can understand.
*/
bcd[DSXXXX_SECONDS] = bintobcd(dt->dt_sec);
bcd[DSXXXX_MINUTES] = bintobcd(dt->dt_min);
bcd[DSXXXX_HOURS] = bintobcd(dt->dt_hour); /* DSXXXX_HOURS_12HRS_MODE=0 */
bcd[DSXXXX_DATE] = bintobcd(dt->dt_day);
bcd[DSXXXX_DAY] = bintobcd(dt->dt_wday);
bcd[DSXXXX_MONTH] = bintobcd(dt->dt_mon);

if (sc->sc_model.dm_flags & DSRTC_FLAG_YEAR_START_2K) {
offset = 2000;
} else {
offset = POSIX_BASE_YEAR;
}

bcd[DSXXXX_YEAR] = bintobcd((dt->dt_year - offset) % 100);
if (dt->dt_year - offset >= 100)
bcd[DSXXXX_MONTH] |= DSXXXX_MONTH_CENTURY;

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus: %d\n",
__func__, error);
return 0;
}

/* Stop the clock */
cmdbuf[0] = dm->dm_ch_reg;

if ((error = iic_exec(sc->sc_tag, I2C_OP_READ, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"%s: failed to read Hold Clock: %d\n",
__func__, error);
return 0;
}

if (sc->sc_model.dm_flags & DSRTC_FLAG_CLOCK_HOLD_REVERSED)
cmdbuf[1] &= ~dm->dm_ch_value;
else
cmdbuf[1] |= dm->dm_ch_value;

if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE, sc->sc_address,
cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"%s: failed to write Hold Clock: %d\n",
__func__, error);
return 0;
}

/*
* Write registers in reverse order. The last write (to the Seconds
* register) will undo the Clock Hold, above.
*/
uint8_t op = I2C_OP_WRITE;
for (signed int i = dm->dm_rtc_size - 1; i >= 0; i--) {
cmdbuf[0] = dm->dm_rtc_start + i;
if ((dm->dm_flags & DSRTC_FLAG_VBATEN) &&
dm->dm_rtc_start + i == dm->dm_vbaten_reg)
bcd[i] |= dm->dm_vbaten_value;
if (dm->dm_rtc_start + i == dm->dm_ch_reg) {
op = I2C_OP_WRITE_WITH_STOP;
if (dm->dm_flags & DSRTC_FLAG_CLOCK_HOLD_REVERSED)
bcd[i] |= dm->dm_ch_value;
}
if ((error = iic_exec(sc->sc_tag, op, sc->sc_address,
cmdbuf, 1, &bcd[i], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"%s: failed to write rtc at 0x%x: %d\n",
__func__, i, error);
/* XXX: Clock Hold is likely still asserted! */
return 0;
}
}
/*
* If the clock hold register isn't the same register as seconds,
* we need to reenable the clock.
*/
if (op != I2C_OP_WRITE_WITH_STOP) {
cmdbuf[0] = dm->dm_ch_reg;
if (dm->dm_flags & DSRTC_FLAG_CLOCK_HOLD_REVERSED)
cmdbuf[1] |= dm->dm_ch_value;
else
cmdbuf[1] &= ~dm->dm_ch_value;

if ((error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP,
sc->sc_address, cmdbuf, 1, &cmdbuf[1], 1, 0)) != 0) {
iic_release_bus(sc->sc_tag, 0);
aprint_error_dev(sc->sc_dev,
"%s: failed to Hold Clock: %d\n",
__func__, error);
return 0;
}
}

iic_release_bus(sc->sc_tag, 0);

return 1;
}

static int
dsrtc_gettime_timeval(struct todr_chip_handle *ch, struct timeval *tv)
{
struct dsrtc_softc *sc = ch->cookie;
struct timeval check;
int retries;

memset(tv, 0, sizeof(*tv));
memset(&check, 0, sizeof(check));

/*
* Since we don't support Burst Read, we have to read the clock twice
* until we get two consecutive identical results.
*/
retries = 5;
do {
dsrtc_clock_read_timeval(sc, &tv->tv_sec);
dsrtc_clock_read_timeval(sc, &check.tv_sec);
} while (memcmp(tv, &check, sizeof(check)) != 0 && --retries);

return 0;
}

static int
dsrtc_settime_timeval(struct todr_chip_handle *ch, struct timeval *tv)
{
struct dsrtc_softc *sc = ch->cookie;

if (dsrtc_clock_write_timeval(sc, tv->tv_sec) == 0)
return -1;

return 0;
}

/*
* The RTC probably has a nice Clock Burst Read/Write command, but we can't use
* it, since some I2C controllers don't support anything other than single-byte
* transfers.
*/
static int
dsrtc_clock_read_timeval(struct dsrtc_softc *sc, time_t *tp)
{
const struct dsrtc_model * const dm = &sc->sc_model;
uint8_t buf[4];
int error;

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus: %d\n",
__func__, error);
return 0;
}

/* read all registers: */
uint8_t reg = dm->dm_rtc_start;
error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
&reg, 1, buf, 4, 0);

/* Done with I2C */
iic_release_bus(sc->sc_tag, 0);

if (error != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to read rtc at 0x%x: %d\n",
__func__, reg, error);
return 0;
}

uint32_t v = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
*tp = v;

aprint_debug_dev(sc->sc_dev, "%s: cntr=0x%08"PRIx32"\n",
__func__, v);

return 1;
}

static int
dsrtc_clock_write_timeval(struct dsrtc_softc *sc, time_t t)
{
const struct dsrtc_model * const dm = &sc->sc_model;
size_t buflen = dm->dm_rtc_size + 2;
/* XXX: the biggest dm_rtc_size we have now is 7, so we should be ok */
uint8_t buf[16];
int error;

KASSERT((dm->dm_flags & DSRTC_FLAG_CLOCK_HOLD) == 0);
KASSERT(dm->dm_ch_reg == dm->dm_rtc_start + 4);

buf[0] = dm->dm_rtc_start;
buf[1] = (t >> 0) & 0xff;
buf[2] = (t >> 8) & 0xff;
buf[3] = (t >> 16) & 0xff;
buf[4] = (t >> 24) & 0xff;
buf[5] = 0;

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus: %d\n",
__func__, error);
return 0;
}

error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_address,
&buf, buflen, NULL, 0, 0);

/* Done with I2C */
iic_release_bus(sc->sc_tag, 0);

/* send data */
if (error != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to set time: %d\n",
__func__, error);
return 0;
}

return 1;
}

static int
dsrtc_read_temp(struct dsrtc_softc *sc, uint32_t *temp)
{
int error, tc;
uint8_t reg = DS3232_TEMP_MSB;
uint8_t buf[2];

if ((sc->sc_model.dm_flags & DSRTC_FLAG_TEMP) == 0)
return ENOTSUP;

if ((error = iic_acquire_bus(sc->sc_tag, 0)) != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to acquire I2C bus: %d\n",
__func__, error);
return 0;
}

/* read temperature registers: */
error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_address,
&reg, 1, buf, 2, 0);

/* Done with I2C */
iic_release_bus(sc->sc_tag, 0);

if (error != 0) {
aprint_error_dev(sc->sc_dev,
"%s: failed to read temperature: %d\n",
__func__, error);
return 0;
}

/* convert to microkelvin */
tc = buf[0] * 1000000 + (buf[1] >> 6) * 250000;
*temp = tc + 273150000;
return 1;
}

static void
dsrtc_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
struct dsrtc_softc *sc = sme->sme_cookie;
uint32_t temp = 0; /* XXX gcc */

if (dsrtc_read_temp(sc, &temp) == 0) {
edata->state = ENVSYS_SINVALID;
return;
}

edata->value_cur = temp;

edata->state = ENVSYS_SVALID;
}