drivers/rtc/rtc-max8998.c - kernel/common - Git at Google

 /*
  * RTC driver for Maxim MAX8998
  *
  * Copyright (C) 2010 Samsung Electronics Co.Ltd
  * Author: Minkyu Kang <[email protected]>
  * Author: Joonyoung Shim <[email protected]>
  *
  *  This program is free software; you can redistribute  it and/or modify it
  *  under  the terms of  the GNU General  Public License as published by the
  *  Free Software Foundation;  either version 2 of the  License, or (at your
  *  option) any later version.
  *
  */

 #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 rtc_valid_tm(tm);
 }

 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[] = {
 	{ "max8998-rtc", TYPE_MAX8998 },
 	{ "lp3974-rtc", TYPE_LP3974 },
 	{ }
 };

 static struct platform_driver max8998_rtc_driver = {
 	.driver		= {
 		.name	= "max8998-rtc",
 		.owner	= THIS_MODULE,
 	},
 	.probe		= max8998_rtc_probe,
 	.id_table	= max8998_rtc_id,
 };

 module_platform_driver(max8998_rtc_driver);

 MODULE_AUTHOR("Minkyu Kang <[email protected]>");
 MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
 MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
 MODULE_LICENSE("GPL");
	/*
	* RTC driver for Maxim MAX8998
	*
	* Copyright (C) 2010 Samsung Electronics Co.Ltd
	* Author: Minkyu Kang <[email protected]>
	* Author: Joonyoung Shim <[email protected]>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*
	*/

	#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 rtc_valid_tm(tm);
	}

	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[] = {
	{ "max8998-rtc", TYPE_MAX8998 },
	{ "lp3974-rtc", TYPE_LP3974 },
	{ }
	};

	static struct platform_driver max8998_rtc_driver = {
	.driver = {
	.name = "max8998-rtc",
	.owner = THIS_MODULE,
	},
	.probe = max8998_rtc_probe,
	.id_table = max8998_rtc_id,
	};

	module_platform_driver(max8998_rtc_driver);

	MODULE_AUTHOR("Minkyu Kang <[email protected]>");
	MODULE_AUTHOR("Joonyoung Shim <[email protected]>");
	MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
	MODULE_LICENSE("GPL");