// SPDX-License-Identifier: GPL-2.0+//// RTC driver for Maxim MAX8998//// Copyright (C) 2010 Samsung Electronics Co.Ltd// Author: Minkyu Kang <mk7.kang@samsung.com>// Author: Joonyoung Shim <jy0922.shim@samsung.com> #include <linux/module.h>#include <linux/i2c.h>#include <linux/slab.h>#include <linux/bcd.h>#include <linux/irqdomain.h>#include <linux/rtc.h>#include <linux/platform_device.h>#include <linux/mfd/max8998.h>#include <linux/mfd/max8998-private.h>#include <linux/delay.h> #define MAX8998_RTC_SEC			0x00#define MAX8998_RTC_MIN			0x01#define MAX8998_RTC_HOUR		0x02#define MAX8998_RTC_WEEKDAY		0x03#define MAX8998_RTC_DATE		0x04#define MAX8998_RTC_MONTH		0x05#define MAX8998_RTC_YEAR1		0x06#define MAX8998_RTC_YEAR2		0x07#define MAX8998_ALARM0_SEC		0x08#define MAX8998_ALARM0_MIN		0x09#define MAX8998_ALARM0_HOUR		0x0a#define MAX8998_ALARM0_WEEKDAY		0x0b#define MAX8998_ALARM0_DATE		0x0c#define MAX8998_ALARM0_MONTH		0x0d#define MAX8998_ALARM0_YEAR1		0x0e#define MAX8998_ALARM0_YEAR2		0x0f#define MAX8998_ALARM1_SEC		0x10#define MAX8998_ALARM1_MIN		0x11#define MAX8998_ALARM1_HOUR		0x12#define MAX8998_ALARM1_WEEKDAY		0x13#define MAX8998_ALARM1_DATE		0x14#define MAX8998_ALARM1_MONTH		0x15#define MAX8998_ALARM1_YEAR1		0x16#define MAX8998_ALARM1_YEAR2		0x17#define MAX8998_ALARM0_CONF		0x18#define MAX8998_ALARM1_CONF		0x19#define MAX8998_RTC_STATUS		0x1a#define MAX8998_WTSR_SMPL_CNTL		0x1b#define MAX8998_TEST			0x1f #define HOUR_12				(1 << 7)#define HOUR_PM				(1 << 5)#define ALARM0_STATUS			(1 << 1)#define ALARM1_STATUS			(1 << 2) enum {	RTC_SEC = 0,	RTC_MIN,	RTC_HOUR,	RTC_WEEKDAY,	RTC_DATE,	RTC_MONTH,	RTC_YEAR1,	RTC_YEAR2,}; struct max8998_rtc_info {	struct device		*dev;	struct max8998_dev	*max8998;	struct i2c_client	*rtc;	struct rtc_device	*rtc_dev;	int irq;	bool lp3974_bug_workaround;}; static void max8998_data_to_tm(u8 *data, struct rtc_time *tm){	tm->tm_sec = bcd2bin(data[RTC_SEC]);	tm->tm_min = bcd2bin(data[RTC_MIN]);	if (data[RTC_HOUR] & HOUR_12) {		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);		if (data[RTC_HOUR] & HOUR_PM)			tm->tm_hour += 12;	} else		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f); 	tm->tm_wday = data[RTC_WEEKDAY] & 0x07;	tm->tm_mday = bcd2bin(data[RTC_DATE]);	tm->tm_mon = bcd2bin(data[RTC_MONTH]);	tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;	tm->tm_year -= 1900;} static void max8998_tm_to_data(struct rtc_time *tm, u8 *data){	data[RTC_SEC] = bin2bcd(tm->tm_sec);	data[RTC_MIN] = bin2bcd(tm->tm_min);	data[RTC_HOUR] = bin2bcd(tm->tm_hour);	data[RTC_WEEKDAY] = tm->tm_wday;	data[RTC_DATE] = bin2bcd(tm->tm_mday);	data[RTC_MONTH] = bin2bcd(tm->tm_mon);	data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);	data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);} static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm){	struct max8998_rtc_info *info = dev_get_drvdata(dev);	u8 data[8];	int ret; 	ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);	if (ret < 0)		return ret; 	max8998_data_to_tm(data, tm); 	return 0;} static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm){	struct max8998_rtc_info *info = dev_get_drvdata(dev);	u8 data[8];	int ret; 	max8998_tm_to_data(tm, data); 	ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data); 	if (info->lp3974_bug_workaround)		msleep(2000); 	return ret;} static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm){	struct max8998_rtc_info *info = dev_get_drvdata(dev);	u8 data[8];	u8 val;	int ret; 	ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);	if (ret < 0)		return ret; 	max8998_data_to_tm(data, &alrm->time); 	ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);	if (ret < 0)		return ret; 	alrm->enabled = !!val; 	ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);	if (ret < 0)		return ret; 	if (val & ALARM0_STATUS)		alrm->pending = 1;	else		alrm->pending = 0; 	return 0;} static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info){	int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0); 	if (info->lp3974_bug_workaround)		msleep(2000); 	return ret;} static int max8998_rtc_start_alarm(struct max8998_rtc_info *info){	int ret;	u8 alarm0_conf = 0x77; 	/* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */	if (info->lp3974_bug_workaround)		alarm0_conf = 0x57; 	ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf); 	if (info->lp3974_bug_workaround)		msleep(2000); 	return ret;} static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm){	struct max8998_rtc_info *info = dev_get_drvdata(dev);	u8 data[8];	int ret; 	max8998_tm_to_data(&alrm->time, data); 	ret = max8998_rtc_stop_alarm(info);	if (ret < 0)		return ret; 	ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);	if (ret < 0)		return ret; 	if (info->lp3974_bug_workaround)		msleep(2000); 	if (alrm->enabled)		ret = max8998_rtc_start_alarm(info); 	return ret;} static int max8998_rtc_alarm_irq_enable(struct device *dev,					unsigned int enabled){	struct max8998_rtc_info *info = dev_get_drvdata(dev); 	if (enabled)		return max8998_rtc_start_alarm(info);	else		return max8998_rtc_stop_alarm(info);} static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data){	struct max8998_rtc_info *info = data; 	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF); 	return IRQ_HANDLED;} static const struct rtc_class_ops max8998_rtc_ops = {	.read_time = max8998_rtc_read_time,	.set_time = max8998_rtc_set_time,	.read_alarm = max8998_rtc_read_alarm,	.set_alarm = max8998_rtc_set_alarm,	.alarm_irq_enable = max8998_rtc_alarm_irq_enable,}; static int max8998_rtc_probe(struct platform_device *pdev){	struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);	struct max8998_platform_data *pdata = max8998->pdata;	struct max8998_rtc_info *info;	int ret; 	info = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info),			GFP_KERNEL);	if (!info)		return -ENOMEM; 	info->dev = &pdev->dev;	info->max8998 = max8998;	info->rtc = max8998->rtc; 	platform_set_drvdata(pdev, info); 	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc",			&max8998_rtc_ops, THIS_MODULE); 	if (IS_ERR(info->rtc_dev)) {		ret = PTR_ERR(info->rtc_dev);		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);		return ret;	} 	if (!max8998->irq_domain)		goto no_irq; 	info->irq = irq_create_mapping(max8998->irq_domain, MAX8998_IRQ_ALARM0);	if (!info->irq) {		dev_warn(&pdev->dev, "Failed to map alarm IRQ\n");		goto no_irq;	} 	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,				max8998_rtc_alarm_irq, 0, "rtc-alarm0", info); 	if (ret < 0)		dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",			info->irq, ret); no_irq:	dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name);	if (pdata && pdata->rtc_delay) {		info->lp3974_bug_workaround = true;		dev_warn(&pdev->dev, "LP3974 with RTC REGERR option."				" RTC updates will be extremely slow.\n");	} 	return 0;} static const struct platform_device_id max8998_rtc_id[] = {	{ .name = "max8998-rtc", .driver_data = TYPE_MAX8998 },	{ .name = "lp3974-rtc", .driver_data = TYPE_LP3974 },	{ }};MODULE_DEVICE_TABLE(platform, max8998_rtc_id); static struct platform_driver max8998_rtc_driver = {	.driver		= {		.name	= "max8998-rtc",	},	.probe		= max8998_rtc_probe,	.id_table	= max8998_rtc_id,}; module_platform_driver(max8998_rtc_driver); MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");MODULE_LICENSE("GPL");