zephyr/drivers/rtc/rtc_pcf8563.c

479 lines
13 KiB
C

/*
* Copyright (c) 2023 Alvaro Garcia Gomez <maxpowel@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/init.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/sys/util.h>
#include <stdint.h>
#include <string.h>
#include <zephyr/device.h>
#include <zephyr/drivers/gpio.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/rtc.h>
#include <zephyr/sys/timeutil.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(pcf8563);
#define DT_DRV_COMPAT nxp_pcf8563
#if DT_ANY_INST_HAS_PROP_STATUS_OKAY(int1_gpios) && \
(defined(CONFIG_RTC_ALARM) || defined(CONFIG_RTC_UPDATE))
/* The user may need only alarms but not interrupts so we will only
* include all the interrupt code if the user configured it in the dts
*/
#define PCF8563_INT1_GPIOS_IN_USE 1
#endif
/* The device registers */
#define PCF8563_TIME_DATE_REGISTER 0x02
#define PCF8563_ALARM_REGISTER 0x09
#define PCF8563_CONTROL1_REGISTER 0x00
#define PCF8563_CONTROL2_REGISTER 0x01
#define PCF8563_CONTROL2_REGISTER_TIE_EN (1 << 0)
#define PCF8563_CONTROL2_REGISTER_AIE_EN (1 << 1)
/* These masks were retrieved from the datasheet
* https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf
* page 6, section 8.2 Register organization.
* Basically, I clean the unused bits and the bits used
* for other stuff
*/
#define PCF8563_SECONDS_MASK GENMASK(6, 0)
#define PCF8563_MINUTES_MASK GENMASK(6, 0)
#define PCF8563_HOURS_MASK GENMASK(5, 0)
#define PCF8563_DAYS_MASK GENMASK(5, 0)
#define PCF8563_WEEKDAYS_MASK GENMASK(2, 0)
#define PCF8563_MONTHS_MASK GENMASK(4, 0)
/* RTC alarm time fields supported by the PCF8563, page 7 of the datasheet */
#define PCF8563_RTC_ALARM_TIME_MASK \
(RTC_ALARM_TIME_MASK_MINUTE | RTC_ALARM_TIME_MASK_HOUR | RTC_ALARM_TIME_MASK_MONTHDAY | \
RTC_ALARM_TIME_MASK_WEEKDAY)
struct pcf8563_config {
const struct i2c_dt_spec i2c;
#ifdef PCF8563_INT1_GPIOS_IN_USE
const struct gpio_dt_spec int1;
#endif
};
#ifdef PCF8563_INT1_GPIOS_IN_USE
/* This work will run the user callback function */
void callback_work_handler(struct k_work *work);
K_WORK_DEFINE(callback_work, callback_work_handler);
#endif
struct pcf8563_data {
#ifdef PCF8563_INT1_GPIOS_IN_USE
rtc_alarm_callback alarm_callback;
void *alarm_user_data;
const struct device *dev;
struct gpio_callback int1_callback;
struct k_work callback_work;
#endif
};
/**
* The format described below is described in the datasheet
* https://www.nxp.com/docs/en/data-sheet/PCF8563.pdf page 10 starting
* with 8.4.2 Register Minutes.
*
* For seconds, first bit is ignored (it is used to check the clock integrity).
* The the upper digit takes the next 3 bits for the tens place and then the rest
* bits for the unit
* So for example, value 43 is 40 * 10 + 3, so the tens digit is 4 and unit digit is 3.
* Then we put the number 3 in the last 4 bits and the number 4 in next 3 bits
* It uses BCD notation so the number 3 is 0011 and the number for is 100 so the final
* byte is 0 (ignored bit) 100 (the 4) 0011 (the 3) -> 0100001
* Luckily, zephyr provides a couple of functions to do exactlly this: bin2bcd and bcd2bin,
* but we will take care about the bits marked as non used in
* the datasheet because they may contain unexpected values. Applying a mask will help us
* to sanitize the read values
*/
int pcf8563_set_time(const struct device *dev, const struct rtc_time *new_time)
{
const struct pcf8563_config *config = dev->config;
int ret = 0;
uint8_t raw_time[7] = {0};
/* Set seconds */
raw_time[0] = bin2bcd(new_time->tm_sec);
/* Set minutes */
raw_time[1] = bin2bcd(new_time->tm_min);
/* Set hours */
raw_time[2] = bin2bcd(new_time->tm_hour);
/* Set days */
raw_time[3] = bin2bcd(new_time->tm_mday);
/* Set weekdays */
raw_time[4] = new_time->tm_wday;
/*Set month */
raw_time[5] = bin2bcd(new_time->tm_mon);
/* Set year */
raw_time[6] = bin2bcd(new_time->tm_year);
/* Write to device */
ret = i2c_burst_write_dt(&config->i2c, PCF8563_TIME_DATE_REGISTER,
raw_time, sizeof(raw_time));
if (ret) {
LOG_ERR("Error when setting time: %i", ret);
return ret;
}
return 0;
}
int pcf8563_get_time(const struct device *dev, struct rtc_time *dest_time)
{
const struct pcf8563_config *config = dev->config;
int ret = 0;
uint8_t raw_time[7] = {0};
ret = i2c_burst_read_dt(&config->i2c, PCF8563_TIME_DATE_REGISTER,
raw_time, sizeof(raw_time));
if (ret) {
LOG_ERR("Unable to get time. Err: %i", ret);
return ret;
}
/* Check integrity, if the first bit is 1 it is ok */
if (raw_time[0] & BIT(7)) {
LOG_WRN("Clock integrity failed");
return -ENODATA;
}
/* Nanoseconds */
dest_time->tm_nsec = 0;
/* Get seconds */
dest_time->tm_sec = bcd2bin(raw_time[0] & PCF8563_SECONDS_MASK);
/* Get minutes */
dest_time->tm_min = bcd2bin(raw_time[1] & PCF8563_MINUTES_MASK);
/* Get hours */
dest_time->tm_hour = bcd2bin(raw_time[2] & PCF8563_HOURS_MASK);
/* Get days */
dest_time->tm_mday = bcd2bin(raw_time[3] & PCF8563_DAYS_MASK);
/* Get weekdays */
dest_time->tm_wday = raw_time[4] & PCF8563_WEEKDAYS_MASK;
/* Get month */
dest_time->tm_mon = bcd2bin(raw_time[5] & PCF8563_MONTHS_MASK);
/* Get year */
dest_time->tm_year = bcd2bin(raw_time[6]);
/* Day number not used */
dest_time->tm_yday = -1;
/* DST not used */
dest_time->tm_isdst = -1;
return 0;
}
#ifdef CONFIG_RTC_ALARM
static int pcf8563_alarm_get_supported_fields(const struct device *dev, uint16_t id,
uint16_t *mask)
{
ARG_UNUSED(dev);
/* This device only has one channel*/
if (id != 0) {
LOG_ERR("invalid ID %d", id);
return -EINVAL;
}
*mask = PCF8563_RTC_ALARM_TIME_MASK;
return 0;
}
static int pcf8563_alarm_set_time(const struct device *dev, uint16_t id, uint16_t mask,
const struct rtc_time *timeptr)
{
const struct pcf8563_config *config = dev->config;
uint8_t regs[4];
int ret;
if (id != 0) {
LOG_ERR("invalid ID %d", id);
return -EINVAL;
}
if ((mask & ~(PCF8563_RTC_ALARM_TIME_MASK)) != 0) {
LOG_ERR("invalid alarm field mask 0x%04x", mask);
return -EINVAL;
}
/*
* The first bit is used as enabled/disabled flag.
* The mask will clean it and also the unused bits
*/
if ((mask & RTC_ALARM_TIME_MASK_MINUTE) != 0) {
regs[0] = bin2bcd(timeptr->tm_min) & PCF8563_MINUTES_MASK;
} else {
/* First bit to 1 is alarm disabled */
regs[0] = BIT(7);
}
if ((mask & RTC_ALARM_TIME_MASK_HOUR) != 0) {
regs[1] = bin2bcd(timeptr->tm_hour) & PCF8563_HOURS_MASK;
} else {
regs[1] = BIT(7);
}
if ((mask & RTC_ALARM_TIME_MASK_MONTHDAY) != 0) {
regs[2] = bin2bcd(timeptr->tm_mday) & PCF8563_DAYS_MASK;
} else {
regs[2] = BIT(7);
}
if ((mask & RTC_ALARM_TIME_MASK_WEEKDAY) != 0) {
regs[3] = bin2bcd(timeptr->tm_wday) & PCF8563_WEEKDAYS_MASK;
} else {
regs[3] = BIT(7);
}
ret = i2c_burst_write_dt(&config->i2c, PCF8563_ALARM_REGISTER, regs, sizeof(regs));
if (ret) {
LOG_ERR("Error when setting alarm: %i", ret);
return ret;
}
/* Dont forget to enable interrupts */
i2c_reg_write_byte_dt(
&config->i2c,
PCF8563_CONTROL2_REGISTER,
PCF8563_CONTROL2_REGISTER_TIE_EN | PCF8563_CONTROL2_REGISTER_AIE_EN
);
return 0;
}
static int pcf8563_alarm_get_time(const struct device *dev, uint16_t id, uint16_t *mask,
struct rtc_time *timeptr)
{
const struct pcf8563_config *config = dev->config;
uint8_t regs[4];
int err;
if (id != 0) {
LOG_ERR("invalid ID %d", id);
return -EINVAL;
}
err = i2c_burst_read_dt(&config->i2c, PCF8563_ALARM_REGISTER, regs, sizeof(regs));
if (err) {
LOG_ERR("Error when getting alarm time: %i", err);
return err;
}
/* Initialize data structure and mask */
memset(timeptr, 0U, sizeof(*timeptr));
*mask = 0U;
/* The first bit is the enabled flag */
if (regs[0] & BIT(7)) {
timeptr->tm_min = bcd2bin(regs[0] & GENMASK(6, 0));
*mask |= RTC_ALARM_TIME_MASK_MINUTE;
}
if (regs[1] & BIT(7)) {
timeptr->tm_hour = bcd2bin(regs[1] & GENMASK(5, 0));
*mask |= RTC_ALARM_TIME_MASK_HOUR;
}
if (regs[2] & BIT(7)) {
timeptr->tm_mday = bcd2bin(regs[2] & GENMASK(5, 0));
*mask |= RTC_ALARM_TIME_MASK_MONTHDAY;
}
if (regs[3] & BIT(7)) {
timeptr->tm_wday = bcd2bin(regs[3] & GENMASK(2, 0));
*mask |= RTC_ALARM_TIME_MASK_WEEKDAY;
}
return 0;
}
static int pcf8563_alarm_is_pending(const struct device *dev, uint16_t id)
{
/* The description of this register is at page 7, section 8.3.2 Register Control_status_2
* There are several kinds of alarms, but here we only need to know that anything but 0
* means that there was some kind of alarm active
*/
const struct pcf8563_config *config = dev->config;
uint8_t reg;
int err;
if (id != 0) {
LOG_ERR("invalid ID %d", id);
return -EINVAL;
}
err = i2c_reg_read_byte_dt(&config->i2c, PCF8563_CONTROL2_REGISTER, &reg);
if (err) {
LOG_ERR("Error when getting the control register 2: %i", err);
return err;
}
/* Only the last bits use useful here */
if (reg & GENMASK(3, 2)) {
/* Clean the alarm */
err = i2c_reg_write_byte_dt(&config->i2c, PCF8563_CONTROL2_REGISTER, GENMASK(1, 0));
if (err) {
LOG_ERR("Error when clearing alarms: %d", err);
return err;
}
/* There was an alarm */
return 1;
}
/* No alarms */
return 0;
}
#endif
#ifdef PCF8563_INT1_GPIOS_IN_USE
/* The logic related to the pin interrupt logic */
void callback_work_handler(struct k_work *work)
{
/* This function is run as a work so the user can spend here all the necessary time */
struct pcf8563_data *data = CONTAINER_OF(work, struct pcf8563_data, callback_work);
if (data->alarm_callback == NULL) {
LOG_WRN("No PCF8563 alarm callback function provided");
} else {
data->alarm_callback(data->dev, 0, data->alarm_user_data);
}
}
/* The function called when the clock alarm activates the interrupt*/
void gpio_callback_function(const struct device *dev, struct gpio_callback *cb,
uint32_t pins)
{
struct pcf8563_data *data = CONTAINER_OF(cb, struct pcf8563_data, int1_callback);
LOG_DBG("PCF8563 interrupt detected");
/* By using a work we are able to to run "heavier" code */
k_work_submit(&(data->callback_work));
}
static int pcf8563_alarm_set_callback(const struct device *dev, uint16_t id,
rtc_alarm_callback callback, void *user_data)
{
const struct pcf8563_config *config = dev->config;
struct pcf8563_data *data = dev->data;
int ret;
if (id != 0) {
LOG_ERR("invalid ID %d", id);
return -EINVAL;
}
data->alarm_callback = callback;
data->alarm_user_data = user_data;
data->dev = dev;
/* The PCF8563 int pin requires a pull up to work */
ret = gpio_pin_configure_dt(&config->int1, GPIO_INPUT | GPIO_PULL_UP);
if (ret < 0) {
LOG_ERR("Error %d: failed to configure %s pin %d",
ret, config->int1.port->name, config->int1.pin);
return ret;
}
ret = gpio_pin_interrupt_configure_dt(&config->int1, GPIO_INT_EDGE_FALLING);
if (ret < 0) {
LOG_ERR("Error %d: failed to configure interrupt on %s pin %d",
ret, config->int1.port->name, config->int1.pin);
return ret;
}
gpio_init_callback(&data->int1_callback, gpio_callback_function, BIT(config->int1.pin));
gpio_add_callback(config->int1.port, &data->int1_callback);
LOG_DBG("Alarm set");
return 0;
}
#endif
static const struct rtc_driver_api pcf8563_driver_api = {
.set_time = pcf8563_set_time,
.get_time = pcf8563_get_time,
#ifdef CONFIG_RTC_ALARM
.alarm_get_supported_fields = pcf8563_alarm_get_supported_fields,
.alarm_set_time = pcf8563_alarm_set_time,
.alarm_get_time = pcf8563_alarm_get_time,
.alarm_is_pending = pcf8563_alarm_is_pending,
#endif
#ifdef PCF8563_INT1_GPIOS_IN_USE
.alarm_set_callback = pcf8563_alarm_set_callback,
#endif
};
int pcf8563_init(const struct device *dev)
{
const struct pcf8563_config *config = dev->config;
int ret;
uint8_t reg;
#ifdef PCF8563_INT1_GPIOS_IN_USE
struct pcf8563_data *data = dev->data;
data->callback_work = callback_work;
#endif
if (!device_is_ready(config->i2c.bus)) {
LOG_ERR("Failed to get pointer to %s device!", config->i2c.bus->name);
return -EINVAL;
}
/* Check if it's alive. */
ret = i2c_reg_read_byte_dt(&config->i2c, PCF8563_CONTROL1_REGISTER, &reg);
if (ret) {
LOG_ERR("Failed to read from PCF85063! (err %i)", ret);
return -EIO;
}
LOG_INF("%s is initialized!", dev->name);
return 0;
}
#define PCF8563_INIT(inst) \
static const struct pcf8563_config pcf8563_config_##inst = { \
.i2c = I2C_DT_SPEC_INST_GET(inst), \
IF_ENABLED(PCF8563_INT1_GPIOS_IN_USE, \
(.int1 = GPIO_DT_SPEC_INST_GET_OR(inst, int1_gpios, {0}))) \
}; \
\
static struct pcf8563_data pcf8563_data_##inst; \
\
DEVICE_DT_INST_DEFINE(inst, &pcf8563_init, NULL, \
&pcf8563_data_##inst, &pcf8563_config_##inst, POST_KERNEL, \
CONFIG_RTC_INIT_PRIORITY, &pcf8563_driver_api);
DT_INST_FOREACH_STATUS_OKAY(PCF8563_INIT)