// SPDX-License-Identifier: GPL-2.0-only
/*
* Driver for the Epson RTC module RX-8010 SJ
*
* Copyright(C) Timesys Corporation 2015
* Copyright(C) General Electric Company 2015
*/
#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#define RX8010_SEC 0x10
#define RX8010_MIN 0x11
#define RX8010_HOUR 0x12
#define RX8010_WDAY 0x13
#define RX8010_MDAY 0x14
#define RX8010_MONTH 0x15
#define RX8010_YEAR 0x16
#define RX8010_RESV17 0x17
#define RX8010_ALMIN 0x18
#define RX8010_ALHOUR 0x19
#define RX8010_ALWDAY 0x1A
#define RX8010_TCOUNT0 0x1B
#define RX8010_TCOUNT1 0x1C
#define RX8010_EXT 0x1D
#define RX8010_FLAG 0x1E
#define RX8010_CTRL 0x1F
/* 0x20 to 0x2F are user registers */
#define RX8010_RESV30 0x30
#define RX8010_RESV31 0x31
#define RX8010_IRQ 0x32
#define RX8010_EXT_WADA BIT(3)
#define RX8010_FLAG_VLF BIT(1)
#define RX8010_FLAG_AF BIT(3)
#define RX8010_FLAG_TF BIT(4)
#define RX8010_FLAG_UF BIT(5)
#define RX8010_CTRL_AIE BIT(3)
#define RX8010_CTRL_UIE BIT(5)
#define RX8010_CTRL_STOP BIT(6)
#define RX8010_CTRL_TEST BIT(7)
#define RX8010_ALARM_AE BIT(7)
static const struct i2c_device_id rx8010_id[] = {
{ "rx8010" },
{ }
};
MODULE_DEVICE_TABLE(i2c, rx8010_id);
static const __maybe_unused struct of_device_id rx8010_of_match[] = {
{ .compatible = "epson,rx8010" },
{ }
};
MODULE_DEVICE_TABLE(of, rx8010_of_match);
struct rx8010_data {
struct regmap *regs;
struct rtc_device *rtc;
u8 ctrlreg;
};
static irqreturn_t rx8010_irq_1_handler(int irq, void *dev_id)
{
struct i2c_client *client = dev_id;
struct rx8010_data *rx8010 = i2c_get_clientdata(client);
int flagreg, err;
rtc_lock(rx8010->rtc);
err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
if (err) {
rtc_unlock(rx8010->rtc);
return IRQ_NONE;
}
if (flagreg & RX8010_FLAG_VLF)
dev_warn(&client->dev, "Frequency stop detected\n");
if (flagreg & RX8010_FLAG_TF) {
flagreg &= ~RX8010_FLAG_TF;
rtc_update_irq(rx8010->rtc, 1, RTC_PF | RTC_IRQF);
}
if (flagreg & RX8010_FLAG_AF) {
flagreg &= ~RX8010_FLAG_AF;
rtc_update_irq(rx8010->rtc, 1, RTC_AF | RTC_IRQF);
}
if (flagreg & RX8010_FLAG_UF) {
flagreg &= ~RX8010_FLAG_UF;
rtc_update_irq(rx8010->rtc, 1, RTC_UF | RTC_IRQF);
}
err = regmap_write(rx8010->regs, RX8010_FLAG, flagreg);
rtc_unlock(rx8010->rtc);
return err ? IRQ_NONE : IRQ_HANDLED;
}
static int rx8010_get_time(struct device *dev, struct rtc_time *dt)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 date[RX8010_YEAR - RX8010_SEC + 1];
int flagreg, err;
err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
if (err)
return err;
if (flagreg & RX8010_FLAG_VLF) {
dev_warn(dev, "Frequency stop detected\n");
return -EINVAL;
}
err = regmap_bulk_read(rx8010->regs, RX8010_SEC, date, sizeof(date));
if (err)
return err;
dt->tm_sec = bcd2bin(date[RX8010_SEC - RX8010_SEC] & 0x7f);
dt->tm_min = bcd2bin(date[RX8010_MIN - RX8010_SEC] & 0x7f);
dt->tm_hour = bcd2bin(date[RX8010_HOUR - RX8010_SEC] & 0x3f);
dt->tm_mday = bcd2bin(date[RX8010_MDAY - RX8010_SEC] & 0x3f);
dt->tm_mon = bcd2bin(date[RX8010_MONTH - RX8010_SEC] & 0x1f) - 1;
dt->tm_year = bcd2bin(date[RX8010_YEAR - RX8010_SEC]) + 100;
dt->tm_wday = ffs(date[RX8010_WDAY - RX8010_SEC] & 0x7f);
return 0;
}
static int rx8010_set_time(struct device *dev, struct rtc_time *dt)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 date[RX8010_YEAR - RX8010_SEC + 1];
int err;
/* set STOP bit before changing clock/calendar */
err = regmap_set_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
if (err)
return err;
date[RX8010_SEC - RX8010_SEC] = bin2bcd(dt->tm_sec);
date[RX8010_MIN - RX8010_SEC] = bin2bcd(dt->tm_min);
date[RX8010_HOUR - RX8010_SEC] = bin2bcd(dt->tm_hour);
date[RX8010_MDAY - RX8010_SEC] = bin2bcd(dt->tm_mday);
date[RX8010_MONTH - RX8010_SEC] = bin2bcd(dt->tm_mon + 1);
date[RX8010_YEAR - RX8010_SEC] = bin2bcd(dt->tm_year - 100);
date[RX8010_WDAY - RX8010_SEC] = bin2bcd(1 << dt->tm_wday);
err = regmap_bulk_write(rx8010->regs, RX8010_SEC, date, sizeof(date));
if (err)
return err;
/* clear STOP bit after changing clock/calendar */
err = regmap_clear_bits(rx8010->regs, RX8010_CTRL, RX8010_CTRL_STOP);
if (err)
return err;
err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_VLF);
if (err)
return err;
return 0;
}
static int rx8010_init(struct device *dev)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 ctrl[2];
int need_clear = 0, err;
/* Initialize reserved registers as specified in datasheet */
err = regmap_write(rx8010->regs, RX8010_RESV17, 0xD8);
if (err)
return err;
err = regmap_write(rx8010->regs, RX8010_RESV30, 0x00);
if (err)
return err;
err = regmap_write(rx8010->regs, RX8010_RESV31, 0x08);
if (err)
return err;
err = regmap_write(rx8010->regs, RX8010_IRQ, 0x00);
if (err)
return err;
err = regmap_bulk_read(rx8010->regs, RX8010_FLAG, ctrl, 2);
if (err)
return err;
if (ctrl[0] & RX8010_FLAG_VLF)
dev_warn(dev, "Frequency stop was detected\n");
if (ctrl[0] & RX8010_FLAG_AF) {
dev_warn(dev, "Alarm was detected\n");
need_clear = 1;
}
if (ctrl[0] & RX8010_FLAG_TF)
need_clear = 1;
if (ctrl[0] & RX8010_FLAG_UF)
need_clear = 1;
if (need_clear) {
ctrl[0] &= ~(RX8010_FLAG_AF | RX8010_FLAG_TF | RX8010_FLAG_UF);
err = regmap_write(rx8010->regs, RX8010_FLAG, ctrl[0]);
if (err)
return err;
}
rx8010->ctrlreg = (ctrl[1] & ~RX8010_CTRL_TEST);
return 0;
}
static int rx8010_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 alarmvals[3];
int flagreg, err;
err = regmap_bulk_read(rx8010->regs, RX8010_ALMIN, alarmvals, 3);
if (err)
return err;
err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
if (err)
return err;
t->time.tm_sec = 0;
t->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
t->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
if (!(alarmvals[2] & RX8010_ALARM_AE))
t->time.tm_mday = bcd2bin(alarmvals[2] & 0x7f);
t->enabled = !!(rx8010->ctrlreg & RX8010_CTRL_AIE);
t->pending = (flagreg & RX8010_FLAG_AF) && t->enabled;
return 0;
}
static int rx8010_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
u8 alarmvals[3];
int err;
if (rx8010->ctrlreg & (RX8010_CTRL_AIE | RX8010_CTRL_UIE)) {
rx8010->ctrlreg &= ~(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
if (err)
return err;
}
err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
if (err)
return err;
alarmvals[0] = bin2bcd(t->time.tm_min);
alarmvals[1] = bin2bcd(t->time.tm_hour);
alarmvals[2] = bin2bcd(t->time.tm_mday);
err = regmap_bulk_write(rx8010->regs, RX8010_ALMIN, alarmvals, 2);
if (err)
return err;
err = regmap_clear_bits(rx8010->regs, RX8010_EXT, RX8010_EXT_WADA);
if (err)
return err;
if (alarmvals[2] == 0)
alarmvals[2] |= RX8010_ALARM_AE;
err = regmap_write(rx8010->regs, RX8010_ALWDAY, alarmvals[2]);
if (err)
return err;
if (t->enabled) {
if (rx8010->rtc->uie_rtctimer.enabled)
rx8010->ctrlreg |= RX8010_CTRL_UIE;
if (rx8010->rtc->aie_timer.enabled)
rx8010->ctrlreg |=
(RX8010_CTRL_AIE | RX8010_CTRL_UIE);
err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
if (err)
return err;
}
return 0;
}
static int rx8010_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
int err;
u8 ctrl;
ctrl = rx8010->ctrlreg;
if (enabled) {
if (rx8010->rtc->uie_rtctimer.enabled)
ctrl |= RX8010_CTRL_UIE;
if (rx8010->rtc->aie_timer.enabled)
ctrl |= (RX8010_CTRL_AIE | RX8010_CTRL_UIE);
} else {
if (!rx8010->rtc->uie_rtctimer.enabled)
ctrl &= ~RX8010_CTRL_UIE;
if (!rx8010->rtc->aie_timer.enabled)
ctrl &= ~RX8010_CTRL_AIE;
}
err = regmap_clear_bits(rx8010->regs, RX8010_FLAG, RX8010_FLAG_AF);
if (err)
return err;
if (ctrl != rx8010->ctrlreg) {
rx8010->ctrlreg = ctrl;
err = regmap_write(rx8010->regs, RX8010_CTRL, rx8010->ctrlreg);
if (err)
return err;
}
return 0;
}
static int rx8010_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
{
struct rx8010_data *rx8010 = dev_get_drvdata(dev);
int tmp, flagreg, err;
switch (cmd) {
case RTC_VL_READ:
err = regmap_read(rx8010->regs, RX8010_FLAG, &flagreg);
if (err)
return err;
tmp = flagreg & RX8010_FLAG_VLF ? RTC_VL_DATA_INVALID : 0;
return put_user(tmp, (unsigned int __user *)arg);
default:
return -ENOIOCTLCMD;
}
}
static const struct rtc_class_ops rx8010_rtc_ops = {
.read_time = rx8010_get_time,
.set_time = rx8010_set_time,
.ioctl = rx8010_ioctl,
.read_alarm = rx8010_read_alarm,
.set_alarm = rx8010_set_alarm,
.alarm_irq_enable = rx8010_alarm_irq_enable,
};
static const struct regmap_config rx8010_regmap_config = {
.name = "rx8010-rtc",
.reg_bits = 8,
.val_bits = 8,
};
static int rx8010_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct rx8010_data *rx8010;
int err = 0;
rx8010 = devm_kzalloc(dev, sizeof(*rx8010), GFP_KERNEL);
if (!rx8010)
return -ENOMEM;
i2c_set_clientdata(client, rx8010);
rx8010->regs = devm_regmap_init_i2c(client, &rx8010_regmap_config);
if (IS_ERR(rx8010->regs))
return PTR_ERR(rx8010->regs);
err = rx8010_init(dev);
if (err)
return err;
rx8010->rtc = devm_rtc_allocate_device(dev);
if (IS_ERR(rx8010->rtc))
return PTR_ERR(rx8010->rtc);
if (client->irq > 0) {
unsigned long irqflags = IRQF_TRIGGER_LOW;
if (dev_fwnode(&client->dev))
irqflags = 0;
err = devm_request_threaded_irq(dev, client->irq, NULL,
rx8010_irq_1_handler,
irqflags | IRQF_ONESHOT,
"rx8010", client);
if (err) {
dev_err(dev, "unable to request IRQ\n");
return err;
}
} else {
clear_bit(RTC_FEATURE_ALARM, rx8010->rtc->features);
}
rx8010->rtc->ops = &rx8010_rtc_ops;
rx8010->rtc->max_user_freq = 1;
rx8010->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
rx8010->rtc->range_max = RTC_TIMESTAMP_END_2099;
return devm_rtc_register_device(rx8010->rtc);
}
static struct i2c_driver rx8010_driver = {
.driver = {
.name = "rtc-rx8010",
.of_match_table = of_match_ptr(rx8010_of_match),
},
.probe = rx8010_probe,
.id_table = rx8010_id,
};
module_i2c_driver(rx8010_driver);
MODULE_AUTHOR("Akshay Bhat <[email protected]>");
MODULE_DESCRIPTION("Epson RX8010SJ RTC driver");
MODULE_LICENSE("GPL v2");
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