/*
* RTC driver for Maxim MAX8925
*
* Copyright (C) 2009-2010 Marvell International Ltd.
* Haojian Zhuang <haojian.zhuang@marvell.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/mfd/max8925.h>
enum {
RTC_SEC = 0,
RTC_MIN,
RTC_HOUR,
RTC_WEEKDAY,
RTC_DATE,
RTC_MONTH,
RTC_YEAR1,
RTC_YEAR2,
};
#define MAX8925_RTC_SEC 0x00
#define MAX8925_RTC_MIN 0x01
#define MAX8925_RTC_HOUR 0x02
#define MAX8925_RTC_WEEKDAY 0x03
#define MAX8925_RTC_DATE 0x04
#define MAX8925_RTC_MONTH 0x05
#define MAX8925_RTC_YEAR1 0x06
#define MAX8925_RTC_YEAR2 0x07
#define MAX8925_ALARM0_SEC 0x08
#define MAX8925_ALARM0_MIN 0x09
#define MAX8925_ALARM0_HOUR 0x0a
#define MAX8925_ALARM0_WEEKDAY 0x0b
#define MAX8925_ALARM0_DATE 0x0c
#define MAX8925_ALARM0_MON 0x0d
#define MAX8925_ALARM0_YEAR1 0x0e
#define MAX8925_ALARM0_YEAR2 0x0f
#define MAX8925_ALARM1_SEC 0x10
#define MAX8925_ALARM1_MIN 0x11
#define MAX8925_ALARM1_HOUR 0x12
#define MAX8925_ALARM1_WEEKDAY 0x13
#define MAX8925_ALARM1_DATE 0x14
#define MAX8925_ALARM1_MON 0x15
#define MAX8925_ALARM1_YEAR1 0x16
#define MAX8925_ALARM1_YEAR2 0x17
#define MAX8925_RTC_CNTL 0x1b
#define MAX8925_RTC_STATUS 0x20
#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 max8925_rtc_info {
struct rtc_device *rtc_dev;
struct max8925_chip *chip;
struct i2c_client *rtc;
struct device *dev;
int irq;
};
static irqreturn_t rtc_update_handler(int irq, void *data)
{
struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
/* disable ALARM0 except for 1SEC alarm */
max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
return IRQ_HANDLED;
}
static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
{
if (len < TIME_NUM)
return -EINVAL;
tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
+ (buf[RTC_YEAR2] & 0xf) * 100
+ (buf[RTC_YEAR1] >> 4) * 10
+ (buf[RTC_YEAR1] & 0xf);
tm->tm_year -= 1900;
tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
+ (buf[RTC_MONTH] & 0x0f);
tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
+ (buf[RTC_DATE] & 0x0f);
tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
if (buf[RTC_HOUR] & HOUR_12) {
tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
+ (buf[RTC_HOUR] & 0x0f);
if (buf[RTC_HOUR] & HOUR_AM_PM)
tm->tm_hour += 12;
} else
tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
+ (buf[RTC_HOUR] & 0x0f);
tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
+ (buf[RTC_MIN] & 0x0f);
tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
+ (buf[RTC_SEC] & 0x0f);
return 0;
}
static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
{
unsigned char high, low;
if (len < TIME_NUM)
return -EINVAL;
high = (tm->tm_year + 1900) / 1000;
low = (tm->tm_year + 1900) / 100;
low = low - high * 10;
buf[RTC_YEAR2] = (high << 4) + low;
high = (tm->tm_year + 1900) / 10;
low = tm->tm_year + 1900;
low = low - high * 10;
high = high - (high / 10) * 10;
buf[RTC_YEAR1] = (high << 4) + low;
high = tm->tm_mon / 10;
low = tm->tm_mon;
low = low - high * 10;
buf[RTC_MONTH] = (high << 4) + low;
high = tm->tm_mday / 10;
low = tm->tm_mday;
low = low - high * 10;
buf[RTC_DATE] = (high << 4) + low;
buf[RTC_WEEKDAY] = tm->tm_wday;
high = tm->tm_hour / 10;
low = tm->tm_hour;
low = low - high * 10;
buf[RTC_HOUR] = (high << 4) + low;
high = tm->tm_min / 10;
low = tm->tm_min;
low = low - high * 10;
buf[RTC_MIN] = (high << 4) + low;
high = tm->tm_sec / 10;
low = tm->tm_sec;
low = low - high * 10;
buf[RTC_SEC] = (high << 4) + low;
return 0;
}
static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct max8925_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[TIME_NUM];
int ret;
ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
if (ret < 0)
goto out;
ret = tm_calc(tm, buf, TIME_NUM);
out:
return ret;
}
static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct max8925_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[TIME_NUM];
int ret;
ret = data_calc(buf, tm, TIME_NUM);
if (ret < 0)
goto out;
ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
out:
return ret;
}
static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8925_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[TIME_NUM];
int ret;
ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
if (ret < 0)
goto out;
ret = tm_calc(&alrm->time, buf, TIME_NUM);
if (ret < 0)
goto out;
ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
if (ret < 0)
goto out;
if (ret & ALARM0_IRQ) {
alrm->enabled = 0;
} else {
ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
if (ret < 0)
goto out;
if (!ret)
alrm->enabled = 0;
else
alrm->enabled = 1;
}
ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
if (ret < 0)
goto out;
if (ret & ALARM0_STATUS)
alrm->pending = 1;
else
alrm->pending = 0;
return 0;
out:
return ret;
}
static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct max8925_rtc_info *info = dev_get_drvdata(dev);
unsigned char buf[TIME_NUM];
int ret;
ret = data_calc(buf, &alrm->time, TIME_NUM);
if (ret < 0)
goto out;
ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
if (ret < 0)
goto out;
if (alrm->enabled)
/* only enable alarm on year/month/day/hour/min/sec */
ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
else
ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
if (ret < 0)
goto out;
out:
return ret;
}
static const struct rtc_class_ops max8925_rtc_ops = {
.read_time = max8925_rtc_read_time,
.set_time = max8925_rtc_set_time,
.read_alarm = max8925_rtc_read_alarm,
.set_alarm = max8925_rtc_set_alarm,
};
static int max8925_rtc_probe(struct platform_device *pdev)
{
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
struct max8925_rtc_info *info;
int ret;
info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
GFP_KERNEL);
if (!info)
return -ENOMEM;
info->chip = chip;
info->rtc = chip->rtc;
info->dev = &pdev->dev;
info->irq = platform_get_irq(pdev, 0);
ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
rtc_update_handler, IRQF_ONESHOT,
"rtc-alarm0", info);
if (ret < 0) {
dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
info->irq, ret);
return ret;
}
dev_set_drvdata(&pdev->dev, info);
/* XXX - isn't this redundant? */
platform_set_drvdata(pdev, info);
device_init_wakeup(&pdev->dev, 1);
info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
&max8925_rtc_ops, THIS_MODULE);
ret = PTR_ERR(info->rtc_dev);
if (IS_ERR(info->rtc_dev)) {
dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
return ret;
}
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int max8925_rtc_suspend(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
if (device_may_wakeup(dev))
chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
return 0;
}
static int max8925_rtc_resume(struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
if (device_may_wakeup(dev))
chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
static struct platform_driver max8925_rtc_driver = {
.driver = {
.name = "max8925-rtc",
.pm = &max8925_rtc_pm_ops,
},
.probe = max8925_rtc_probe,
};
module_platform_driver(max8925_rtc_driver);
MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");
