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// SPDX-License-Identifier: GPL-2.0-only
/*
* RTC driver for Maxim MAX8907
*
* Copyright (c) 2011-2012, NVIDIA Corporation.
*
* Based on drivers/rtc/rtc-max8925.c,
* Copyright (C) 2009-2010 Marvell International Ltd.
*/
#include <linux/bcd.h>
#include <linux/i2c.h>
#include <linux/mfd/max8907.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/slab.h>
enum {
RTC_SEC = 0,
RTC_MIN,
RTC_HOUR,
RTC_WEEKDAY,
RTC_DATE,
RTC_MONTH,
RTC_YEAR1,
RTC_YEAR2,
};
#define TIME_NUM 8
#define ALARM_1SEC (1 << 7)
#define HOUR_12 (1 << 7)
#define HOUR_AM_PM (1 << 5)
#define ALARM0_IRQ (1 << 3)
#define ALARM1_IRQ (1 << 2)
#define ALARM0_STATUS (1 << 2)
#define ALARM1_STATUS (1 << 1)
struct max8907_rtc {
struct max8907 *max8907;
struct regmap *regmap;
struct rtc_device *rtc_dev;
int irq;
};
static irqreturn_t max8907_irq_handler(int irq, void *data)
{
struct max8907_rtc *rtc = data;
regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static void regs_to_tm(u8 *regs, struct rtc_time *tm)
{
tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 +
bcd2bin(regs[RTC_YEAR1]) - 1900;
tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1;
tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f);
tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07);
if (regs[RTC_HOUR] & HOUR_12) {
tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f);
if (tm->tm_hour == 12)
tm->tm_hour = 0;
if (regs[RTC_HOUR] & HOUR_AM_PM)
tm->tm_hour += 12;
} else {
tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f);
}
tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f);
tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f);
}
static void tm_to_regs(struct rtc_time *tm, u8 *regs)
{
u8 high, low;
high = (tm->tm_year + 1900) / 100;
low = tm->tm_year % 100;
regs[RTC_YEAR2] = bin2bcd(high);
regs[RTC_YEAR1] = bin2bcd(low);
regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
regs[RTC_DATE] = bin2bcd(tm->tm_mday);
regs[RTC_WEEKDAY] = tm->tm_wday;
regs[RTC_HOUR] = bin2bcd(tm->tm_hour);
regs[RTC_MIN] = bin2bcd(tm->tm_min);
regs[RTC_SEC] = bin2bcd(tm->tm_sec);
}
static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct max8907_rtc *rtc = dev_get_drvdata(dev);
u8 regs[TIME_NUM];
int ret;
ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
TIME_NUM);
if (ret < 0)
return ret;
regs_to_tm(regs, tm);
return 0;
}
static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct max8907_rtc *rtc = dev_get_drvdata(dev);
u8 regs[TIME_NUM];
tm_to_regs(tm, regs);
return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
TIME_NUM);
}
static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8907_rtc *rtc = dev_get_drvdata(dev);
u8 regs[TIME_NUM];
unsigned int val;
int ret;
ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
TIME_NUM);
if (ret < 0)
return ret;
regs_to_tm(regs, &alrm->time);
ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val);
if (ret < 0)
return ret;
alrm->enabled = !!(val & 0x7f);
return 0;
}
static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8907_rtc *rtc = dev_get_drvdata(dev);
u8 regs[TIME_NUM];
int ret;
tm_to_regs(&alrm->time, regs);
/* Disable alarm while we update the target time */
ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0);
if (ret < 0)
return ret;
ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
TIME_NUM);
if (ret < 0)
return ret;
if (alrm->enabled)
ret = regmap_write(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x77);
return ret;
}
static const struct rtc_class_ops max8907_rtc_ops = {
.read_time = max8907_rtc_read_time,
.set_time = max8907_rtc_set_time,
.read_alarm = max8907_rtc_read_alarm,
.set_alarm = max8907_rtc_set_alarm,
};
static int max8907_rtc_probe(struct platform_device *pdev)
{
struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
struct max8907_rtc *rtc;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
platform_set_drvdata(pdev, rtc);
rtc->max8907 = max8907;
rtc->regmap = max8907->regmap_rtc;
rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc",
&max8907_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc->rtc_dev)) {
ret = PTR_ERR(rtc->rtc_dev);
dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
return ret;
}
rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc,
MAX8907_IRQ_RTC_ALARM0);
if (rtc->irq < 0)
return rtc->irq;
ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
max8907_irq_handler,
IRQF_ONESHOT, "max8907-alarm0", rtc);
if (ret < 0)
dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
rtc->irq, ret);
return ret;
}
static struct platform_driver max8907_rtc_driver = {
.driver = {
.name = "max8907-rtc",
},
.probe = max8907_rtc_probe,
};
module_platform_driver(max8907_rtc_driver);
MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");
MODULE_LICENSE("GPL v2");
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