// SPDX-License-Identifier: GPL-2.0-or-later
//
// Copyright (C) 2018 ROHM Semiconductors
//
// RTC driver for ROHM BD71828 and BD71815 PMIC
#include <linux/bcd.h>
#include <linux/mfd/rohm-bd71815.h>
#include <linux/mfd/rohm-bd71828.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
/*
* On BD71828 and BD71815 the ALM0 MASK is 14 bytes after the ALM0
* block start
*/
#define BD718XX_ALM_EN_OFFSET 14
/*
* We read regs RTC_SEC => RTC_YEAR
* this struct is ordered according to chip registers.
* Keep it u8 only (or packed) to avoid padding issues.
*/
struct bd70528_rtc_day {
u8 sec;
u8 min;
u8 hour;
} __packed;
struct bd70528_rtc_data {
struct bd70528_rtc_day time;
u8 week;
u8 day;
u8 month;
u8 year;
} __packed;
struct bd71828_rtc_alm {
struct bd70528_rtc_data alm0;
struct bd70528_rtc_data alm1;
u8 alm_mask;
u8 alm1_mask;
} __packed;
struct bd70528_rtc {
struct rohm_regmap_dev *parent;
struct regmap *regmap;
struct device *dev;
u8 reg_time_start;
u8 bd718xx_alm_block_start;
};
static inline void tmday2rtc(struct rtc_time *t, struct bd70528_rtc_day *d)
{
d->sec &= ~BD70528_MASK_RTC_SEC;
d->min &= ~BD70528_MASK_RTC_MINUTE;
d->hour &= ~BD70528_MASK_RTC_HOUR;
d->sec |= bin2bcd(t->tm_sec);
d->min |= bin2bcd(t->tm_min);
d->hour |= bin2bcd(t->tm_hour);
}
static inline void tm2rtc(struct rtc_time *t, struct bd70528_rtc_data *r)
{
r->day &= ~BD70528_MASK_RTC_DAY;
r->week &= ~BD70528_MASK_RTC_WEEK;
r->month &= ~BD70528_MASK_RTC_MONTH;
/*
* PM and 24H bits are not used by Wake - thus we clear them
* here and not in tmday2rtc() which is also used by wake.
*/
r->time.hour &= ~(BD70528_MASK_RTC_HOUR_PM | BD70528_MASK_RTC_HOUR_24H);
tmday2rtc(t, &r->time);
/*
* We do always set time in 24H mode.
*/
r->time.hour |= BD70528_MASK_RTC_HOUR_24H;
r->day |= bin2bcd(t->tm_mday);
r->week |= bin2bcd(t->tm_wday);
r->month |= bin2bcd(t->tm_mon + 1);
r->year = bin2bcd(t->tm_year - 100);
}
static inline void rtc2tm(struct bd70528_rtc_data *r, struct rtc_time *t)
{
t->tm_sec = bcd2bin(r->time.sec & BD70528_MASK_RTC_SEC);
t->tm_min = bcd2bin(r->time.min & BD70528_MASK_RTC_MINUTE);
t->tm_hour = bcd2bin(r->time.hour & BD70528_MASK_RTC_HOUR);
/*
* If RTC is in 12H mode, then bit BD70528_MASK_RTC_HOUR_PM
* is not BCD value but tells whether it is AM or PM
*/
if (!(r->time.hour & BD70528_MASK_RTC_HOUR_24H)) {
t->tm_hour %= 12;
if (r->time.hour & BD70528_MASK_RTC_HOUR_PM)
t->tm_hour += 12;
}
t->tm_mday = bcd2bin(r->day & BD70528_MASK_RTC_DAY);
t->tm_mon = bcd2bin(r->month & BD70528_MASK_RTC_MONTH) - 1;
t->tm_year = 100 + bcd2bin(r->year & BD70528_MASK_RTC_YEAR);
t->tm_wday = bcd2bin(r->week & BD70528_MASK_RTC_WEEK);
}
static int bd71828_set_alarm(struct device *dev, struct rtc_wkalrm *a)
{
int ret;
struct bd71828_rtc_alm alm;
struct bd70528_rtc *r = dev_get_drvdata(dev);
ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
sizeof(alm));
if (ret) {
dev_err(dev, "Failed to read alarm regs\n");
return ret;
}
tm2rtc(&a->time, &alm.alm0);
if (!a->enabled)
alm.alm_mask &= ~BD70528_MASK_ALM_EN;
else
alm.alm_mask |= BD70528_MASK_ALM_EN;
ret = regmap_bulk_write(r->regmap, r->bd718xx_alm_block_start, &alm,
sizeof(alm));
if (ret)
dev_err(dev, "Failed to set alarm time\n");
return ret;
}
static int bd71828_read_alarm(struct device *dev, struct rtc_wkalrm *a)
{
int ret;
struct bd71828_rtc_alm alm;
struct bd70528_rtc *r = dev_get_drvdata(dev);
ret = regmap_bulk_read(r->regmap, r->bd718xx_alm_block_start, &alm,
sizeof(alm));
if (ret) {
dev_err(dev, "Failed to read alarm regs\n");
return ret;
}
rtc2tm(&alm.alm0, &a->time);
a->time.tm_mday = -1;
a->time.tm_mon = -1;
a->time.tm_year = -1;
a->enabled = !!(alm.alm_mask & BD70528_MASK_ALM_EN);
a->pending = 0;
return 0;
}
static int bd71828_set_time(struct device *dev, struct rtc_time *t)
{
int ret;
struct bd70528_rtc_data rtc_data;
struct bd70528_rtc *r = dev_get_drvdata(dev);
ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
sizeof(rtc_data));
if (ret) {
dev_err(dev, "Failed to read RTC time registers\n");
return ret;
}
tm2rtc(t, &rtc_data);
ret = regmap_bulk_write(r->regmap, r->reg_time_start, &rtc_data,
sizeof(rtc_data));
if (ret)
dev_err(dev, "Failed to set RTC time\n");
return ret;
}
static int bd70528_get_time(struct device *dev, struct rtc_time *t)
{
struct bd70528_rtc *r = dev_get_drvdata(dev);
struct bd70528_rtc_data rtc_data;
int ret;
/* read the RTC date and time registers all at once */
ret = regmap_bulk_read(r->regmap, r->reg_time_start, &rtc_data,
sizeof(rtc_data));
if (ret) {
dev_err(dev, "Failed to read RTC time (err %d)\n", ret);
return ret;
}
rtc2tm(&rtc_data, t);
return 0;
}
static int bd71828_alm_enable(struct device *dev, unsigned int enabled)
{
int ret;
struct bd70528_rtc *r = dev_get_drvdata(dev);
unsigned int enableval = BD70528_MASK_ALM_EN;
if (!enabled)
enableval = 0;
ret = regmap_update_bits(r->regmap, r->bd718xx_alm_block_start +
BD718XX_ALM_EN_OFFSET, BD70528_MASK_ALM_EN,
enableval);
if (ret)
dev_err(dev, "Failed to change alarm state\n");
return ret;
}
static const struct rtc_class_ops bd71828_rtc_ops = {
.read_time = bd70528_get_time,
.set_time = bd71828_set_time,
.read_alarm = bd71828_read_alarm,
.set_alarm = bd71828_set_alarm,
.alarm_irq_enable = bd71828_alm_enable,
};
static irqreturn_t alm_hndlr(int irq, void *data)
{
struct rtc_device *rtc = data;
rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF | RTC_PF);
return IRQ_HANDLED;
}
static int bd70528_probe(struct platform_device *pdev)
{
struct bd70528_rtc *bd_rtc;
const struct rtc_class_ops *rtc_ops;
const char *irq_name;
int ret;
struct rtc_device *rtc;
int irq;
unsigned int hr;
u8 hour_reg;
enum rohm_chip_type chip = platform_get_device_id(pdev)->driver_data;
bd_rtc = devm_kzalloc(&pdev->dev, sizeof(*bd_rtc), GFP_KERNEL);
if (!bd_rtc)
return -ENOMEM;
bd_rtc->regmap = dev_get_regmap(pdev->dev.parent, NULL);
if (!bd_rtc->regmap) {
dev_err(&pdev->dev, "No regmap\n");
return -EINVAL;
}
bd_rtc->dev = &pdev->dev;
rtc_ops = &bd71828_rtc_ops;
switch (chip) {
case ROHM_CHIP_TYPE_BD71815:
irq_name = "bd71815-rtc-alm-0";
bd_rtc->reg_time_start = BD71815_REG_RTC_START;
/*
* See also BD718XX_ALM_EN_OFFSET:
* This works for BD71828 and BD71815 as they have same offset
* between ALM0 start and ALM0_MASK. If new ICs are to be
* added this requires proper check as ALM0_MASK is not located
* at the end of ALM0 block - but after all ALM blocks so if
* amount of ALMs differ the offset to enable/disable is likely
* to be incorrect and enable/disable must be given as own
* reg address here.
*/
bd_rtc->bd718xx_alm_block_start = BD71815_REG_RTC_ALM_START;
hour_reg = BD71815_REG_HOUR;
break;
case ROHM_CHIP_TYPE_BD71828:
irq_name = "bd71828-rtc-alm-0";
bd_rtc->reg_time_start = BD71828_REG_RTC_START;
bd_rtc->bd718xx_alm_block_start = BD71828_REG_RTC_ALM_START;
hour_reg = BD71828_REG_RTC_HOUR;
break;
default:
dev_err(&pdev->dev, "Unknown chip\n");
return -ENOENT;
}
irq = platform_get_irq_byname(pdev, irq_name);
if (irq < 0)
return irq;
platform_set_drvdata(pdev, bd_rtc);
ret = regmap_read(bd_rtc->regmap, hour_reg, &hr);
if (ret) {
dev_err(&pdev->dev, "Failed to reag RTC clock\n");
return ret;
}
if (!(hr & BD70528_MASK_RTC_HOUR_24H)) {
struct rtc_time t;
ret = rtc_ops->read_time(&pdev->dev, &t);
if (!ret)
ret = rtc_ops->set_time(&pdev->dev, &t);
if (ret) {
dev_err(&pdev->dev,
"Setting 24H clock for RTC failed\n");
return ret;
}
}
device_set_wakeup_capable(&pdev->dev, true);
device_wakeup_enable(&pdev->dev);
rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc)) {
dev_err(&pdev->dev, "RTC device creation failed\n");
return PTR_ERR(rtc);
}
rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
rtc->range_max = RTC_TIMESTAMP_END_2099;
rtc->ops = rtc_ops;
/* Request alarm IRQ prior to registerig the RTC */
ret = devm_request_threaded_irq(&pdev->dev, irq, NULL, &alm_hndlr,
IRQF_ONESHOT, "bd70528-rtc", rtc);
if (ret)
return ret;
return devm_rtc_register_device(rtc);
}
static const struct platform_device_id bd718x7_rtc_id[] = {
{ "bd71828-rtc", ROHM_CHIP_TYPE_BD71828 },
{ "bd71815-rtc", ROHM_CHIP_TYPE_BD71815 },
{ },
};
MODULE_DEVICE_TABLE(platform, bd718x7_rtc_id);
static struct platform_driver bd70528_rtc = {
.driver = {
.name = "bd70528-rtc"
},
.probe = bd70528_probe,
.id_table = bd718x7_rtc_id,
};
module_platform_driver(bd70528_rtc);
MODULE_AUTHOR("Matti Vaittinen <[email protected]>");
MODULE_DESCRIPTION("ROHM BD71828 and BD71815 PMIC RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:bd70528-rtc");
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