blob: fd06ee4ceddfc994b72fcee71505149d062c1a68 [file] [log] [blame] [edit]
/*
* Copyright (c) 2019-2020 Peter Bigot Consulting, LLC
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT maxim_ds3231
#include <zephyr/device.h>
#include <zephyr/drivers/rtc/maxim_ds3231.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/timeutil.h>
#include <zephyr/sys/util.h>
LOG_MODULE_REGISTER(DS3231, CONFIG_COUNTER_LOG_LEVEL);
#define REG_MONCEN_CENTURY 0x80
#define REG_HOURS_12H 0x40
#define REG_HOURS_PM 0x20
#define REG_HOURS_20 0x20
#define REG_HOURS_10 0x20
#define REG_DAYDATE_DOW 0x40
#define REG_ALARM_IGN 0x80
enum {
SYNCSM_IDLE,
SYNCSM_PREP_READ,
SYNCSM_FINISH_READ,
SYNCSM_PREP_WRITE,
SYNCSM_FINISH_WRITE,
};
struct register_map {
uint8_t sec;
uint8_t min;
uint8_t hour;
uint8_t dow;
uint8_t dom;
uint8_t moncen;
uint8_t year;
struct {
uint8_t sec;
uint8_t min;
uint8_t hour;
uint8_t date;
} __packed alarm1;
struct {
uint8_t min;
uint8_t hour;
uint8_t date;
} __packed alarm2;
uint8_t ctrl;
uint8_t ctrl_stat;
uint8_t aging;
int8_t temp_units;
uint8_t temp_frac256;
};
struct ds3231_config {
/* Common structure first because generic API expects this here. */
struct counter_config_info generic;
struct i2c_dt_spec bus;
struct gpio_dt_spec isw_gpios;
};
struct ds3231_data {
const struct device *ds3231;
struct register_map registers;
struct k_sem lock;
/* Timer structure used for synchronization */
struct k_timer sync_timer;
/* Work structures for the various cases of ISW interrupt. */
struct k_work alarm_work;
struct k_work sqw_work;
struct k_work sync_work;
/* Forward ISW interrupt to proper worker. */
struct gpio_callback isw_callback;
/* syncclock captured in the last ISW interrupt handler */
uint32_t isw_syncclock;
struct maxim_ds3231_syncpoint syncpoint;
struct maxim_ds3231_syncpoint new_sp;
time_t rtc_registers;
time_t rtc_base;
uint32_t syncclock_base;
/* Pointer to the structure used to notify when a synchronize
* or set operation completes. Null when nobody's waiting for
* such an operation, or when doing a no-notify synchronize
* through the signal API.
*/
union {
void *ptr;
struct sys_notify *notify;
struct k_poll_signal *signal;
} sync;
/* Handlers and state when using the counter alarm API. */
counter_alarm_callback_t counter_handler[2];
uint32_t counter_ticks[2];
/* Handlers and state for DS3231 alarm API. */
maxim_ds3231_alarm_callback_handler_t alarm_handler[2];
void *alarm_user_data[2];
uint8_t alarm_flags[2];
/* Flags recording requests for ISW monitoring. */
uint8_t isw_mon_req;
#define ISW_MON_REQ_Alarm 0x01
#define ISW_MON_REQ_Sync 0x02
/* Status of synchronization operations. */
uint8_t sync_state;
bool sync_signal;
};
/*
* Set and clear specific bits in the control register.
*
* This function assumes the device register cache is valid and will
* update the device only if the value changes as a result of applying
* the set and clear changes.
*
* Caches and returns the value with the changes applied.
*/
static int sc_ctrl(const struct device *dev,
uint8_t set,
uint8_t clear)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
struct register_map *rp = &data->registers;
uint8_t ctrl = (rp->ctrl & ~clear) | set;
int rc = ctrl;
if (rp->ctrl != ctrl) {
uint8_t buf[2] = {
offsetof(struct register_map, ctrl),
ctrl,
};
rc = i2c_write_dt(&cfg->bus, buf, sizeof(buf));
if (rc >= 0) {
rp->ctrl = ctrl;
rc = ctrl;
}
}
return rc;
}
int maxim_ds3231_ctrl_update(const struct device *dev,
uint8_t set_bits,
uint8_t clear_bits)
{
struct ds3231_data *data = dev->data;
k_sem_take(&data->lock, K_FOREVER);
int rc = sc_ctrl(dev, set_bits, clear_bits);
k_sem_give(&data->lock);
return rc;
}
/*
* Read the ctrl_stat register then set and clear bits in it.
*
* OSF, A1F, and A2F will be written with 1s if the corresponding bits
* do not appear in either set or clear. This ensures that if any
* flag becomes set between the read and the write that indicator will
* not be cleared.
*
* Returns the value as originally read (disregarding the effect of
* clears and sets).
*/
static inline int rsc_stat(const struct device *dev,
uint8_t set,
uint8_t clear)
{
uint8_t const ign = MAXIM_DS3231_REG_STAT_OSF | MAXIM_DS3231_ALARM1
| MAXIM_DS3231_ALARM2;
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
struct register_map *rp = &data->registers;
uint8_t addr = offsetof(struct register_map, ctrl_stat);
int rc;
rc = i2c_write_read_dt(&cfg->bus, &addr, sizeof(addr), &rp->ctrl_stat,
sizeof(rp->ctrl_stat));
if (rc >= 0) {
uint8_t stat = rp->ctrl_stat & ~clear;
if (rp->ctrl_stat != stat) {
uint8_t buf[2] = {
addr,
stat | (ign & ~(set | clear)),
};
rc = i2c_write_dt(&cfg->bus, buf, sizeof(buf));
}
if (rc >= 0) {
rc = rp->ctrl_stat;
}
}
return rc;
}
int maxim_ds3231_stat_update(const struct device *dev,
uint8_t set_bits,
uint8_t clear_bits)
{
struct ds3231_data *data = dev->data;
k_sem_take(&data->lock, K_FOREVER);
int rv = rsc_stat(dev, set_bits, clear_bits);
k_sem_give(&data->lock);
return rv;
}
/*
* Look for current users of the interrupt/square-wave signal and
* enable monitoring iff at least one consumer is active.
*/
static void validate_isw_monitoring(const struct device *dev)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
const struct register_map *rp = &data->registers;
uint8_t isw_mon_req = 0;
if (rp->ctrl & (MAXIM_DS3231_ALARM1 | MAXIM_DS3231_ALARM2)) {
isw_mon_req |= ISW_MON_REQ_Alarm;
}
if (data->sync_state != SYNCSM_IDLE) {
isw_mon_req |= ISW_MON_REQ_Sync;
}
LOG_DBG("ISW %p : %d ?= %d", cfg->isw_gpios.port, isw_mon_req,
data->isw_mon_req);
if ((cfg->isw_gpios.port != NULL)
&& (isw_mon_req != data->isw_mon_req)) {
int rc = 0;
/* Disable before reconfigure */
rc = gpio_pin_interrupt_configure_dt(&cfg->isw_gpios,
GPIO_INT_DISABLE);
if ((rc >= 0)
&& ((isw_mon_req & ISW_MON_REQ_Sync)
!= (data->isw_mon_req & ISW_MON_REQ_Sync))) {
if (isw_mon_req & ISW_MON_REQ_Sync) {
rc = sc_ctrl(dev, 0,
MAXIM_DS3231_REG_CTRL_INTCN
| MAXIM_DS3231_REG_CTRL_RS_Msk);
} else {
rc = sc_ctrl(dev, MAXIM_DS3231_REG_CTRL_INTCN, 0);
}
}
data->isw_mon_req = isw_mon_req;
/* Enable if any requests active */
if ((rc >= 0) && (isw_mon_req != 0)) {
rc = gpio_pin_interrupt_configure_dt(
&cfg->isw_gpios, GPIO_INT_EDGE_TO_ACTIVE);
}
LOG_INF("ISW reconfigure to %x: %d", isw_mon_req, rc);
}
}
static const uint8_t *decode_time(struct tm *tp,
const uint8_t *rp,
bool with_sec)
{
uint8_t reg;
if (with_sec) {
uint8_t reg = *rp++;
tp->tm_sec = bcd2bin(reg & 0x7F);
}
reg = *rp++;
tp->tm_min = bcd2bin(reg & 0x7F);
reg = *rp++;
tp->tm_hour = (reg & 0x0F);
if (REG_HOURS_12H & reg) {
/* 12-hour */
if (REG_HOURS_10 & reg) {
tp->tm_hour += 10;
}
if (REG_HOURS_PM & reg) {
tp->tm_hour += 12;
}
} else {
/* 24 hour */
tp->tm_hour += 10 * ((reg >> 4) & 0x03);
}
return rp;
}
static uint8_t decode_alarm(const uint8_t *ap,
bool with_sec,
time_t *tp)
{
struct tm tm = {
/* tm_year zero is 1900 with underflows a 32-bit counter
* representation. Use 1978-01, the first January after the
* POSIX epoch where the first day of the month is the first
* day of the week.
*/
.tm_year = 78,
};
const uint8_t *dp = decode_time(&tm, ap, with_sec);
uint8_t flags = 0;
uint8_t amf = MAXIM_DS3231_ALARM_FLAGS_IGNDA;
/* Done decoding time, now decode day/date. */
if (REG_DAYDATE_DOW & *dp) {
flags |= MAXIM_DS3231_ALARM_FLAGS_DOW;
/* Because tm.tm_wday does not contribute to the UNIX
* time that the civil time translates into, we need
* to also record the tm_mday for our selected base
* 1978-01 that will produce the correct tm_wday.
*/
tm.tm_mday = (*dp & 0x07);
tm.tm_wday = tm.tm_mday - 1;
} else {
tm.tm_mday = bcd2bin(*dp & 0x3F);
}
/* Walk backwards to extract the alarm mask flags. */
while (true) {
if (REG_ALARM_IGN & *dp) {
flags |= amf;
}
amf >>= 1;
if (dp-- == ap) {
break;
}
}
/* Convert to the reduced representation. */
*tp = timeutil_timegm(&tm);
return flags;
}
static int encode_alarm(uint8_t *ap,
bool with_sec,
time_t time,
uint8_t flags)
{
struct tm tm;
uint8_t val;
(void)gmtime_r(&time, &tm);
/* For predictable behavior the low 4 bits of flags
* (corresponding to AxMy) must be 0b1111, 0b1110, 0b1100,
* 0b1000, or 0b0000. This corresponds to the bitwise inverse
* being one less than a power of two.
*/
if (!is_power_of_two(1U + (0x0F & ~flags))) {
LOG_DBG("invalid alarm mask in flags: %02x", flags);
return -EINVAL;
}
if (with_sec) {
if (flags & MAXIM_DS3231_ALARM_FLAGS_IGNSE) {
val = REG_ALARM_IGN;
} else {
val = bin2bcd(tm.tm_sec);
}
*ap++ = val;
}
if (flags & MAXIM_DS3231_ALARM_FLAGS_IGNMN) {
val = REG_ALARM_IGN;
} else {
val = bin2bcd(tm.tm_min);
}
*ap++ = val;
if (flags & MAXIM_DS3231_ALARM_FLAGS_IGNHR) {
val = REG_ALARM_IGN;
} else {
val = bin2bcd(tm.tm_hour);
}
*ap++ = val;
if (flags & MAXIM_DS3231_ALARM_FLAGS_IGNDA) {
val = REG_ALARM_IGN;
} else if (flags & MAXIM_DS3231_ALARM_FLAGS_DOW) {
val = REG_DAYDATE_DOW | (tm.tm_wday + 1);
} else {
val = bin2bcd(tm.tm_mday);
}
*ap++ = val;
return 0;
}
static uint32_t decode_rtc(struct ds3231_data *data)
{
struct tm tm = { 0 };
const struct register_map *rp = &data->registers;
decode_time(&tm, &rp->sec, true);
tm.tm_wday = (rp->dow & 0x07) - 1;
tm.tm_mday = bcd2bin(rp->dom & 0x3F);
tm.tm_mon = 10 * (((0xF0 & ~REG_MONCEN_CENTURY) & rp->moncen) >> 4)
+ (rp->moncen & 0x0F) - 1;
tm.tm_year = bcd2bin(rp->year);
if (REG_MONCEN_CENTURY & rp->moncen) {
tm.tm_year += 100;
}
data->rtc_registers = timeutil_timegm(&tm);
return data->rtc_registers;
}
static int update_registers(const struct device *dev)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
uint32_t syncclock;
int rc;
uint8_t addr = 0;
data->syncclock_base = maxim_ds3231_read_syncclock(dev);
rc = i2c_write_read_dt(&cfg->bus, &addr, sizeof(addr), &data->registers,
sizeof(data->registers));
syncclock = maxim_ds3231_read_syncclock(dev);
if (rc < 0) {
return rc;
}
data->rtc_base = decode_rtc(data);
return 0;
}
int maxim_ds3231_get_alarm(const struct device *dev,
uint8_t id,
struct maxim_ds3231_alarm *cp)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
int rv = 0;
uint8_t addr;
uint8_t len;
if (id == 0) {
addr = offsetof(struct register_map, alarm1);
len = sizeof(data->registers.alarm1);
} else if (id < cfg->generic.channels) {
addr = offsetof(struct register_map, alarm2);
len = sizeof(data->registers.alarm2);
} else {
rv = -EINVAL;
goto out;
}
k_sem_take(&data->lock, K_FOREVER);
/* Update alarm structure */
uint8_t *rbp = &data->registers.sec + addr;
rv = i2c_write_read_dt(&cfg->bus, &addr, sizeof(addr), rbp, len);
if (rv < 0) {
LOG_DBG("get_config at %02x failed: %d\n", addr, rv);
goto out_locked;
}
*cp = (struct maxim_ds3231_alarm){ 0 };
cp->flags = decode_alarm(rbp, (id == 0), &cp->time);
cp->handler = data->alarm_handler[id];
cp->user_data = data->alarm_user_data[id];
out_locked:
k_sem_give(&data->lock);
out:
return rv;
}
static int cancel_alarm(const struct device *dev,
uint8_t id)
{
struct ds3231_data *data = dev->data;
data->alarm_handler[id] = NULL;
data->alarm_user_data[id] = NULL;
return sc_ctrl(dev, 0, MAXIM_DS3231_ALARM1 << id);
}
static int ds3231_counter_cancel_alarm(const struct device *dev,
uint8_t id)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
int rv = 0;
if (id >= cfg->generic.channels) {
rv = -EINVAL;
goto out;
}
k_sem_take(&data->lock, K_FOREVER);
rv = cancel_alarm(dev, id);
k_sem_give(&data->lock);
out:
/* Throw away information counter API disallows */
if (rv >= 0) {
rv = 0;
}
return rv;
}
static int set_alarm(const struct device *dev,
uint8_t id,
const struct maxim_ds3231_alarm *cp)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
uint8_t addr;
uint8_t len;
if (id == 0) {
addr = offsetof(struct register_map, alarm1);
len = sizeof(data->registers.alarm1);
} else if (id < cfg->generic.channels) {
addr = offsetof(struct register_map, alarm2);
len = sizeof(data->registers.alarm2);
} else {
return -EINVAL;
}
uint8_t buf[5] = { addr };
int rc = encode_alarm(buf + 1, (id == 0), cp->time, cp->flags);
if (rc < 0) {
return rc;
}
/* @todo resolve race condition: a previously stored alarm may
* trigger between clear of AxF and the write of the new alarm
* control.
*/
rc = rsc_stat(dev, 0U, (MAXIM_DS3231_ALARM1 << id));
if (rc >= 0) {
rc = i2c_write_dt(&cfg->bus, buf, len + 1);
}
if ((rc >= 0)
&& (cp->handler != NULL)) {
rc = sc_ctrl(dev, MAXIM_DS3231_ALARM1 << id, 0);
}
if (rc >= 0) {
memmove(&data->registers.sec + addr, buf + 1, len);
data->alarm_handler[id] = cp->handler;
data->alarm_user_data[id] = cp->user_data;
data->alarm_flags[id] = cp->flags;
validate_isw_monitoring(dev);
}
return rc;
}
int maxim_ds3231_set_alarm(const struct device *dev,
uint8_t id,
const struct maxim_ds3231_alarm *cp)
{
struct ds3231_data *data = dev->data;
k_sem_take(&data->lock, K_FOREVER);
int rc = set_alarm(dev, id, cp);
k_sem_give(&data->lock);
return rc;
}
int maxim_ds3231_check_alarms(const struct device *dev)
{
struct ds3231_data *data = dev->data;
const struct register_map *rp = &data->registers;
uint8_t mask = (MAXIM_DS3231_ALARM1 | MAXIM_DS3231_ALARM2);
k_sem_take(&data->lock, K_FOREVER);
/* Fetch and clear only the alarm flags that are not
* interrupt-enabled.
*/
int rv = rsc_stat(dev, 0U, (rp->ctrl & mask) ^ mask);
if (rv >= 0) {
rv &= mask;
}
k_sem_give(&data->lock);
return rv;
}
static int check_handled_alarms(const struct device *dev)
{
struct ds3231_data *data = dev->data;
const struct register_map *rp = &data->registers;
uint8_t mask = (MAXIM_DS3231_ALARM1 | MAXIM_DS3231_ALARM2);
/* Fetch and clear only the alarm flags that are
* interrupt-enabled. Leave any flags that are not enabled;
* it may be an alarm that triggered a wakeup.
*/
mask &= rp->ctrl;
int rv = rsc_stat(dev, 0U, mask);
if (rv > 0) {
rv &= mask;
}
return rv;
}
static void counter_alarm_forwarder(const struct device *dev,
uint8_t id,
uint32_t syncclock,
void *ud)
{
/* Dummy handler marking a counter callback. */
}
static void alarm_worker(struct k_work *work)
{
struct ds3231_data *data = CONTAINER_OF(work, struct ds3231_data,
alarm_work);
const struct device *ds3231 = data->ds3231;
const struct ds3231_config *cfg = ds3231->config;
k_sem_take(&data->lock, K_FOREVER);
int af = check_handled_alarms(ds3231);
while (af > 0) {
uint8_t id;
for (id = 0; id < cfg->generic.channels; ++id) {
if ((af & (MAXIM_DS3231_ALARM1 << id)) == 0) {
continue;
}
maxim_ds3231_alarm_callback_handler_t handler
= data->alarm_handler[id];
void *ud = data->alarm_user_data[id];
if (data->alarm_flags[id] & MAXIM_DS3231_ALARM_FLAGS_AUTODISABLE) {
int rc = cancel_alarm(ds3231, id);
LOG_DBG("autodisable %d: %d", id, rc);
validate_isw_monitoring(ds3231);
}
if (handler == counter_alarm_forwarder) {
counter_alarm_callback_t cb = data->counter_handler[id];
uint32_t ticks = data->counter_ticks[id];
data->counter_handler[id] = NULL;
data->counter_ticks[id] = 0;
if (cb) {
k_sem_give(&data->lock);
cb(ds3231, id, ticks, ud);
k_sem_take(&data->lock, K_FOREVER);
}
} else if (handler != NULL) {
k_sem_give(&data->lock);
handler(ds3231, id, data->isw_syncclock, ud);
k_sem_take(&data->lock, K_FOREVER);
}
}
af = check_handled_alarms(ds3231);
}
k_sem_give(&data->lock);
if (af < 0) {
LOG_ERR("failed to read alarm flags");
return;
}
LOG_DBG("ALARM %02x at %u latency %u", af, data->isw_syncclock,
maxim_ds3231_read_syncclock(ds3231) - data->isw_syncclock);
}
static void sqw_worker(struct k_work *work)
{
struct ds3231_data *data = CONTAINER_OF(work, struct ds3231_data, sqw_work);
uint32_t syncclock = maxim_ds3231_read_syncclock(data->ds3231);
/* This is a placeholder for potential application-controlled
* use of the square wave functionality.
*/
LOG_DBG("SQW %u latency %u", data->isw_syncclock,
syncclock - data->isw_syncclock);
}
static int read_time(const struct device *dev,
time_t *time)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
uint8_t addr = 0;
int rc = i2c_write_read_dt(&cfg->bus, &addr, sizeof(addr),
&data->registers, 7);
if (rc >= 0) {
*time = decode_rtc(data);
}
return rc;
}
static int ds3231_counter_get_value(const struct device *dev,
uint32_t *ticks)
{
struct ds3231_data *data = dev->data;
time_t time = 0;
k_sem_take(&data->lock, K_FOREVER);
int rc = read_time(dev, &time);
k_sem_give(&data->lock);
if (rc >= 0) {
*ticks = time;
}
return rc;
}
static void sync_finish(const struct device *dev,
int rc)
{
struct ds3231_data *data = dev->data;
struct sys_notify *notify = NULL;
struct k_poll_signal *signal = NULL;
if (data->sync_signal) {
signal = data->sync.signal;
} else {
notify = data->sync.notify;
}
data->sync.ptr = NULL;
data->sync_signal = false;
data->sync_state = SYNCSM_IDLE;
(void)validate_isw_monitoring(dev);
LOG_DBG("sync complete, notify %d to %p or %p\n", rc, notify, signal);
k_sem_give(&data->lock);
if (notify != NULL) {
maxim_ds3231_notify_callback cb =
(maxim_ds3231_notify_callback)sys_notify_finalize(notify, rc);
if (cb) {
cb(dev, notify, rc);
}
} else if (signal != NULL) {
k_poll_signal_raise(signal, rc);
}
}
static void sync_prep_read(const struct device *dev)
{
struct ds3231_data *data = dev->data;
int rc = sc_ctrl(dev, 0U, MAXIM_DS3231_REG_CTRL_INTCN
| MAXIM_DS3231_REG_CTRL_RS_Msk);
if (rc < 0) {
sync_finish(dev, rc);
return;
}
data->sync_state = SYNCSM_FINISH_READ;
validate_isw_monitoring(dev);
}
static void sync_finish_read(const struct device *dev)
{
struct ds3231_data *data = dev->data;
time_t time = 0;
(void)read_time(dev, &time);
data->syncpoint.rtc.tv_sec = time;
data->syncpoint.rtc.tv_nsec = 0;
data->syncpoint.syncclock = data->isw_syncclock;
sync_finish(dev, 0);
}
static void sync_timer_handler(struct k_timer *tmr)
{
struct ds3231_data *data = CONTAINER_OF(tmr, struct ds3231_data,
sync_timer);
LOG_INF("sync_timer fired");
k_work_submit(&data->sync_work);
}
static void sync_prep_write(const struct device *dev)
{
struct ds3231_data *data = dev->data;
uint32_t syncclock = maxim_ds3231_read_syncclock(dev);
uint32_t offset = syncclock - data->new_sp.syncclock;
uint32_t syncclock_Hz = maxim_ds3231_syncclock_frequency(dev);
uint32_t offset_s = offset / syncclock_Hz;
uint32_t offset_ms = (offset % syncclock_Hz) * 1000U / syncclock_Hz;
time_t when = data->new_sp.rtc.tv_sec;
when += offset_s;
offset_ms += data->new_sp.rtc.tv_nsec / NSEC_PER_USEC / USEC_PER_MSEC;
if (offset_ms >= MSEC_PER_SEC) {
offset_ms -= MSEC_PER_SEC;
} else {
when += 1;
}
uint32_t rem_ms = MSEC_PER_SEC - offset_ms;
if (rem_ms < 5) {
when += 1;
rem_ms += MSEC_PER_SEC;
}
data->new_sp.rtc.tv_sec = when;
data->new_sp.rtc.tv_nsec = 0;
data->sync_state = SYNCSM_FINISH_WRITE;
k_timer_start(&data->sync_timer, K_MSEC(rem_ms), K_NO_WAIT);
LOG_INF("sync %u in %u ms after %u", (uint32_t)when, rem_ms, syncclock);
}
static void sync_finish_write(const struct device *dev)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
time_t when = data->new_sp.rtc.tv_sec;
struct tm tm;
uint8_t buf[8];
uint8_t *bp = buf;
uint8_t val;
*bp++ = offsetof(struct register_map, sec);
(void)gmtime_r(&when, &tm);
val = bin2bcd(tm.tm_sec);
*bp++ = val;
val = bin2bcd(tm.tm_min);
*bp++ = val;
val = bin2bcd(tm.tm_hour);
*bp++ = val;
*bp++ = 1 + tm.tm_wday;
val = bin2bcd(tm.tm_mday);
*bp++ = val;
tm.tm_mon += 1;
val = bin2bcd(tm.tm_mon);
if (tm.tm_year >= 100) {
tm.tm_year -= 100;
val |= REG_MONCEN_CENTURY;
}
*bp++ = val;
val = bin2bcd(tm.tm_year);
*bp++ = val;
uint32_t syncclock = maxim_ds3231_read_syncclock(dev);
int rc = i2c_write_dt(&cfg->bus, buf, bp - buf);
if (rc >= 0) {
data->syncpoint.rtc.tv_sec = when;
data->syncpoint.rtc.tv_nsec = 0;
data->syncpoint.syncclock = syncclock;
LOG_INF("sync %u at %u", (uint32_t)when, syncclock);
}
sync_finish(dev, rc);
}
static void sync_worker(struct k_work *work)
{
struct ds3231_data *data = CONTAINER_OF(work, struct ds3231_data, sync_work);
uint32_t syncclock = maxim_ds3231_read_syncclock(data->ds3231);
bool unlock = true;
k_sem_take(&data->lock, K_FOREVER);
LOG_DBG("SYNC.%u %u latency %u", data->sync_state, data->isw_syncclock,
syncclock - data->isw_syncclock);
switch (data->sync_state) {
default:
case SYNCSM_IDLE:
break;
case SYNCSM_PREP_READ:
sync_prep_read(data->ds3231);
break;
case SYNCSM_FINISH_READ:
sync_finish_read(data->ds3231);
break;
case SYNCSM_PREP_WRITE:
sync_prep_write(data->ds3231);
break;
case SYNCSM_FINISH_WRITE:
sync_finish_write(data->ds3231);
unlock = false;
break;
}
if (unlock) {
k_sem_give(&data->lock);
}
}
static void isw_gpio_callback(const struct device *port,
struct gpio_callback *cb,
uint32_t pins)
{
struct ds3231_data *data = CONTAINER_OF(cb, struct ds3231_data,
isw_callback);
data->isw_syncclock = maxim_ds3231_read_syncclock(data->ds3231);
if (data->registers.ctrl & MAXIM_DS3231_REG_CTRL_INTCN) {
k_work_submit(&data->alarm_work);
} else if (data->sync_state != SYNCSM_IDLE) {
k_work_submit(&data->sync_work);
} else {
k_work_submit(&data->sqw_work);
}
}
int z_impl_maxim_ds3231_get_syncpoint(const struct device *dev,
struct maxim_ds3231_syncpoint *syncpoint)
{
struct ds3231_data *data = dev->data;
int rv = 0;
k_sem_take(&data->lock, K_FOREVER);
if (data->syncpoint.rtc.tv_sec == 0) {
rv = -ENOENT;
} else {
__ASSERT_NO_MSG(syncpoint != NULL);
*syncpoint = data->syncpoint;
}
k_sem_give(&data->lock);
return rv;
}
int maxim_ds3231_synchronize(const struct device *dev,
struct sys_notify *notify)
{
const struct ds3231_config *cfg = dev->config;
struct ds3231_data *data = dev->data;
int rv = 0;
if (notify == NULL) {
rv = -EINVAL;
goto out;
}
if (cfg->isw_gpios.port == NULL) {
rv = -ENOTSUP;
goto out;
}
k_sem_take(&data->lock, K_FOREVER);
if (data->sync_state != SYNCSM_IDLE) {
rv = -EBUSY;
goto out_locked;
}
data->sync_signal = false;
data->sync.notify = notify;
data->sync_state = SYNCSM_PREP_READ;
out_locked:
k_sem_give(&data->lock);
if (rv >= 0) {
k_work_submit(&data->sync_work);
}
out:
return rv;
}
int z_impl_maxim_ds3231_req_syncpoint(const struct device *dev,
struct k_poll_signal *sig)
{
const struct ds3231_config *cfg = dev->config;
struct ds3231_data *data = dev->data;
int rv = 0;
if (cfg->isw_gpios.port == NULL) {
rv = -ENOTSUP;
goto out;
}
k_sem_take(&data->lock, K_FOREVER);
if (data->sync_state != SYNCSM_IDLE) {
rv = -EBUSY;
goto out_locked;
}
data->sync_signal = true;
data->sync.signal = sig;
data->sync_state = SYNCSM_PREP_READ;
out_locked:
k_sem_give(&data->lock);
if (rv >= 0) {
k_work_submit(&data->sync_work);
}
out:
return rv;
}
int maxim_ds3231_set(const struct device *dev,
const struct maxim_ds3231_syncpoint *syncpoint,
struct sys_notify *notify)
{
const struct ds3231_config *cfg = dev->config;
struct ds3231_data *data = dev->data;
int rv = 0;
if ((syncpoint == NULL)
|| (notify == NULL)) {
rv = -EINVAL;
goto out;
}
if (cfg->isw_gpios.port == NULL) {
rv = -ENOTSUP;
goto out;
}
k_sem_take(&data->lock, K_FOREVER);
if (data->sync_state != SYNCSM_IDLE) {
rv = -EBUSY;
goto out_locked;
}
data->new_sp = *syncpoint;
data->sync_signal = false;
data->sync.notify = notify;
data->sync_state = SYNCSM_PREP_WRITE;
out_locked:
k_sem_give(&data->lock);
if (rv >= 0) {
k_work_submit(&data->sync_work);
}
out:
return rv;
}
static int ds3231_init(const struct device *dev)
{
struct ds3231_data *data = dev->data;
const struct ds3231_config *cfg = dev->config;
int rc;
/* Initialize and take the lock */
k_sem_init(&data->lock, 0, 1);
data->ds3231 = dev;
if (!device_is_ready(cfg->bus.bus)) {
LOG_ERR("I2C device not ready");
rc = -ENODEV;
goto out;
}
rc = update_registers(dev);
if (rc < 0) {
LOG_WRN("Failed to fetch registers: %d", rc);
goto out;
}
/* INTCN and AxIE to power-up default, RS to 1 Hz */
rc = sc_ctrl(dev,
MAXIM_DS3231_REG_CTRL_INTCN,
MAXIM_DS3231_REG_CTRL_RS_Msk
| MAXIM_DS3231_ALARM1 | MAXIM_DS3231_ALARM2);
if (rc < 0) {
LOG_WRN("Failed to reset config: %d", rc);
goto out;
}
/* Do not clear pending flags in the status register. This
* device may have been used for external wakeup, which can be
* detected using the extended API.
*/
if (cfg->isw_gpios.port != NULL) {
if (!device_is_ready(cfg->isw_gpios.port)) {
LOG_ERR("INTn/SQW GPIO device not ready");
rc = -ENODEV;
goto out;
}
k_timer_init(&data->sync_timer, sync_timer_handler, NULL);
k_work_init(&data->alarm_work, alarm_worker);
k_work_init(&data->sqw_work, sqw_worker);
k_work_init(&data->sync_work, sync_worker);
gpio_init_callback(&data->isw_callback,
isw_gpio_callback,
BIT(cfg->isw_gpios.pin));
rc = gpio_pin_configure_dt(&cfg->isw_gpios, GPIO_INPUT);
if (rc >= 0) {
rc = gpio_pin_interrupt_configure_dt(&cfg->isw_gpios,
GPIO_INT_DISABLE);
}
if (rc >= 0) {
rc = gpio_add_callback(cfg->isw_gpios.port,
&data->isw_callback);
if (rc < 0) {
LOG_ERR("Failed to configure ISW callback: %d",
rc);
}
}
}
out:
k_sem_give(&data->lock);
LOG_DBG("Initialized %d", rc);
if (rc > 0) {
rc = 0;
}
return rc;
}
static int ds3231_counter_start(const struct device *dev)
{
return -EALREADY;
}
static int ds3231_counter_stop(const struct device *dev)
{
return -ENOTSUP;
}
int ds3231_counter_set_alarm(const struct device *dev,
uint8_t id,
const struct counter_alarm_cfg *alarm_cfg)
{
struct ds3231_data *data = dev->data;
const struct register_map *rp = &data->registers;
const struct ds3231_config *cfg = dev->config;
time_t when;
int rc = 0;
if (id >= cfg->generic.channels) {
rc = -ENOTSUP;
goto out;
}
k_sem_take(&data->lock, K_FOREVER);
if (rp->ctrl & (MAXIM_DS3231_ALARM1 << id)) {
rc = -EBUSY;
goto out_locked;
}
if ((alarm_cfg->flags & COUNTER_ALARM_CFG_ABSOLUTE) == 0) {
rc = read_time(dev, &when);
if (rc >= 0) {
when += alarm_cfg->ticks;
}
} else {
when = alarm_cfg->ticks;
}
struct maxim_ds3231_alarm alarm = {
.time = (uint32_t)when,
.handler = counter_alarm_forwarder,
.user_data = alarm_cfg->user_data,
.flags = MAXIM_DS3231_ALARM_FLAGS_AUTODISABLE,
};
if (rc >= 0) {
data->counter_handler[id] = alarm_cfg->callback;
data->counter_ticks[id] = alarm.time;
rc = set_alarm(dev, id, &alarm);
}
out_locked:
k_sem_give(&data->lock);
out:
/* Throw away information counter API disallows */
if (rc >= 0) {
rc = 0;
}
return rc;
}
static uint32_t ds3231_counter_get_top_value(const struct device *dev)
{
return UINT32_MAX;
}
static uint32_t ds3231_counter_get_pending_int(const struct device *dev)
{
return 0;
}
static int ds3231_counter_set_top_value(const struct device *dev,
const struct counter_top_cfg *cfg)
{
return -ENOTSUP;
}
static const struct counter_driver_api ds3231_api = {
.start = ds3231_counter_start,
.stop = ds3231_counter_stop,
.get_value = ds3231_counter_get_value,
.set_alarm = ds3231_counter_set_alarm,
.cancel_alarm = ds3231_counter_cancel_alarm,
.set_top_value = ds3231_counter_set_top_value,
.get_pending_int = ds3231_counter_get_pending_int,
.get_top_value = ds3231_counter_get_top_value,
};
static const struct ds3231_config ds3231_0_config = {
.generic = {
.max_top_value = UINT32_MAX,
.freq = 1,
.flags = COUNTER_CONFIG_INFO_COUNT_UP,
.channels = 2,
},
.bus = I2C_DT_SPEC_INST_GET(0),
/* Driver does not currently use 32k GPIO. */
.isw_gpios = GPIO_DT_SPEC_INST_GET_OR(0, isw_gpios, {}),
};
static struct ds3231_data ds3231_0_data;
#if CONFIG_COUNTER_INIT_PRIORITY <= CONFIG_I2C_INIT_PRIORITY
#error CONFIG_COUNTER_INIT_PRIORITY must be greater than I2C_INIT_PRIORITY
#endif
DEVICE_DT_INST_DEFINE(0, ds3231_init, NULL, &ds3231_0_data,
&ds3231_0_config,
POST_KERNEL, CONFIG_COUNTER_INIT_PRIORITY,
&ds3231_api);
#ifdef CONFIG_USERSPACE
#include <zephyr/syscall_handler.h>
int z_vrfy_maxim_ds3231_get_syncpoint(const struct device *dev,
struct maxim_ds3231_syncpoint *syncpoint)
{
struct maxim_ds3231_syncpoint value;
int rv;
Z_OOPS(Z_SYSCALL_SPECIFIC_DRIVER(dev, K_OBJ_DRIVER_COUNTER, &ds3231_api));
Z_OOPS(Z_SYSCALL_MEMORY_WRITE(syncpoint, sizeof(*syncpoint)));
rv = z_impl_maxim_ds3231_get_syncpoint(dev, &value);
if (rv >= 0) {
Z_OOPS(z_user_to_copy(syncpoint, &value, sizeof(*syncpoint)));
}
return rv;
}
#include <syscalls/maxim_ds3231_get_syncpoint_mrsh.c>
int z_vrfy_maxim_ds3231_req_syncpoint(const struct device *dev,
struct k_poll_signal *sig)
{
Z_OOPS(Z_SYSCALL_SPECIFIC_DRIVER(dev, K_OBJ_DRIVER_COUNTER, &ds3231_api));
if (sig != NULL) {
Z_OOPS(Z_SYSCALL_OBJ(sig, K_OBJ_POLL_SIGNAL));
}
return z_impl_maxim_ds3231_req_syncpoint(dev, sig);
}
#include <syscalls/maxim_ds3231_req_syncpoint_mrsh.c>
#endif /* CONFIG_USERSPACE */