linux/drivers/rtc/rtc-vt8500.c

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/*
* drivers/rtc/rtc-vt8500.c
*
* Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
*
* Based on rtc-pxa.c
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
/*
* Register definitions
*/
#define VT8500_RTC_TS 0x00 /* Time set */
#define VT8500_RTC_DS 0x04 /* Date set */
#define VT8500_RTC_AS 0x08 /* Alarm set */
#define VT8500_RTC_CR 0x0c /* Control */
#define VT8500_RTC_TR 0x10 /* Time read */
#define VT8500_RTC_DR 0x14 /* Date read */
#define VT8500_RTC_WS 0x18 /* Write status */
#define VT8500_RTC_CL 0x20 /* Calibration */
#define VT8500_RTC_IS 0x24 /* Interrupt status */
#define VT8500_RTC_ST 0x28 /* Status */
#define INVALID_TIME_BIT (1 << 31)
#define DATE_CENTURY_S 19
#define DATE_YEAR_S 11
#define DATE_YEAR_MASK (0xff << DATE_YEAR_S)
#define DATE_MONTH_S 6
#define DATE_MONTH_MASK (0x1f << DATE_MONTH_S)
#define DATE_DAY_MASK 0x3f
#define TIME_DOW_S 20
#define TIME_DOW_MASK (0x07 << TIME_DOW_S)
#define TIME_HOUR_S 14
#define TIME_HOUR_MASK (0x3f << TIME_HOUR_S)
#define TIME_MIN_S 7
#define TIME_MIN_MASK (0x7f << TIME_MIN_S)
#define TIME_SEC_MASK 0x7f
#define ALARM_DAY_S 20
#define ALARM_DAY_MASK (0x3f << ALARM_DAY_S)
#define ALARM_DAY_BIT (1 << 29)
#define ALARM_HOUR_BIT (1 << 28)
#define ALARM_MIN_BIT (1 << 27)
#define ALARM_SEC_BIT (1 << 26)
#define ALARM_ENABLE_MASK (ALARM_DAY_BIT \
| ALARM_HOUR_BIT \
| ALARM_MIN_BIT \
| ALARM_SEC_BIT)
#define VT8500_RTC_CR_ENABLE (1 << 0) /* Enable RTC */
#define VT8500_RTC_CR_24H (1 << 1) /* 24h time format */
#define VT8500_RTC_CR_SM_ENABLE (1 << 2) /* Enable periodic irqs */
#define VT8500_RTC_CR_SM_SEC (1 << 3) /* 0: 1Hz/60, 1: 1Hz */
#define VT8500_RTC_CR_CALIB (1 << 4) /* Enable calibration */
#define VT8500_RTC_IS_ALARM (1 << 0) /* Alarm interrupt status */
struct vt8500_rtc {
void __iomem *regbase;
struct resource *res;
int irq_alarm;
struct rtc_device *rtc;
spinlock_t lock; /* Protects this structure */
};
static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
{
struct vt8500_rtc *vt8500_rtc = dev_id;
u32 isr;
unsigned long events = 0;
spin_lock(&vt8500_rtc->lock);
/* clear interrupt sources */
isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
spin_unlock(&vt8500_rtc->lock);
if (isr & VT8500_RTC_IS_ALARM)
events |= RTC_AF | RTC_IRQF;
rtc_update_irq(vt8500_rtc->rtc, 1, events);
return IRQ_HANDLED;
}
static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
u32 date, time;
date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
+ ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
return 0;
}
static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
if (tm->tm_year < 100) {
dev_warn(dev, "Only years 2000-2199 are supported by the "
"hardware!\n");
return -EINVAL;
}
writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
| (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
| (bin2bcd(tm->tm_mday)),
vt8500_rtc->regbase + VT8500_RTC_DS);
writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
| (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
| (bin2bcd(tm->tm_min) << TIME_MIN_S)
| (bin2bcd(tm->tm_sec)),
vt8500_rtc->regbase + VT8500_RTC_TS);
return 0;
}
static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
u32 isr, alarm;
alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
return rtc_valid_tm(&alrm->time);
}
static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
| (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
| (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
| (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
| (bin2bcd(alrm->time.tm_sec)),
vt8500_rtc->regbase + VT8500_RTC_AS);
return 0;
}
static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
if (enabled)
tmp |= ALARM_ENABLE_MASK;
else
tmp &= ~ALARM_ENABLE_MASK;
writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
return 0;
}
static const struct rtc_class_ops vt8500_rtc_ops = {
.read_time = vt8500_rtc_read_time,
.set_time = vt8500_rtc_set_time,
.read_alarm = vt8500_rtc_read_alarm,
.set_alarm = vt8500_rtc_set_alarm,
.alarm_irq_enable = vt8500_alarm_irq_enable,
};
static int __devinit vt8500_rtc_probe(struct platform_device *pdev)
{
struct vt8500_rtc *vt8500_rtc;
int ret;
vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL);
if (!vt8500_rtc)
return -ENOMEM;
spin_lock_init(&vt8500_rtc->lock);
platform_set_drvdata(pdev, vt8500_rtc);
vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!vt8500_rtc->res) {
dev_err(&pdev->dev, "No I/O memory resource defined\n");
ret = -ENXIO;
goto err_free;
}
vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
if (vt8500_rtc->irq_alarm < 0) {
dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
ret = -ENXIO;
goto err_free;
}
vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start,
resource_size(vt8500_rtc->res),
"vt8500-rtc");
if (vt8500_rtc->res == NULL) {
dev_err(&pdev->dev, "failed to request I/O memory\n");
ret = -EBUSY;
goto err_free;
}
vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start,
resource_size(vt8500_rtc->res));
if (!vt8500_rtc->regbase) {
dev_err(&pdev->dev, "Unable to map RTC I/O memory\n");
ret = -EBUSY;
goto err_release;
}
/* Enable RTC and set it to 24-hour mode */
writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H,
vt8500_rtc->regbase + VT8500_RTC_CR);
vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev,
&vt8500_rtc_ops, THIS_MODULE);
if (IS_ERR(vt8500_rtc->rtc)) {
ret = PTR_ERR(vt8500_rtc->rtc);
dev_err(&pdev->dev,
"Failed to register RTC device -> %d\n", ret);
goto err_unmap;
}
ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0,
"rtc alarm", vt8500_rtc);
if (ret < 0) {
dev_err(&pdev->dev, "can't get irq %i, err %d\n",
vt8500_rtc->irq_alarm, ret);
goto err_unreg;
}
return 0;
err_unreg:
rtc_device_unregister(vt8500_rtc->rtc);
err_unmap:
iounmap(vt8500_rtc->regbase);
err_release:
release_mem_region(vt8500_rtc->res->start,
resource_size(vt8500_rtc->res));
err_free:
kfree(vt8500_rtc);
return ret;
}
static int __devexit vt8500_rtc_remove(struct platform_device *pdev)
{
struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
free_irq(vt8500_rtc->irq_alarm, vt8500_rtc);
rtc_device_unregister(vt8500_rtc->rtc);
/* Disable alarm matching */
writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
iounmap(vt8500_rtc->regbase);
release_mem_region(vt8500_rtc->res->start,
resource_size(vt8500_rtc->res));
kfree(vt8500_rtc);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver vt8500_rtc_driver = {
.probe = vt8500_rtc_probe,
.remove = __devexit_p(vt8500_rtc_remove),
.driver = {
.name = "vt8500-rtc",
.owner = THIS_MODULE,
},
};
static int __init vt8500_rtc_init(void)
{
return platform_driver_register(&vt8500_rtc_driver);
}
module_init(vt8500_rtc_init);
static void __exit vt8500_rtc_exit(void)
{
platform_driver_unregister(&vt8500_rtc_driver);
}
module_exit(vt8500_rtc_exit);
MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:vt8500-rtc");