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linux/drivers/rtc/rtc-vt8500.c
Tony Prisk 2f90b68309 drivers/rtc/rtc-vt8500.c: fix handling of data passed in struct rtc_time 
tm_mon is 0..11, whereas vt8500 expects 1..12 for the month field,
causing invalid date errors for January, and causing the day field to
roll over incorrectly.

The century flag is only handled in vt8500_rtc_read_time, but not set in
vt8500_rtc_set_time.  This patch corrects the behaviour of the century
flag.

Signed-off-by: Edgar Toernig <froese@gmx.de>
Signed-off-by: Tony Prisk <linux@prisktech.co.nz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-01-04 16:11:48 -08:00

323 lines
8.9 KiB
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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>
#include <linux/of.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_12H (1 << 1) /* 12h 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) - 1;
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 + 1) << DATE_MONTH_S)
| (bin2bcd(tm->tm_mday))
| ((tm->tm_year >= 200) << DATE_CENTURY_S),
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 vt8500_rtc_probe(struct platform_device *pdev)
{
struct vt8500_rtc *vt8500_rtc;
int ret;
vt8500_rtc = devm_kzalloc(&pdev->dev,
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");
return -ENXIO;
}
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");
return -ENXIO;
}
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");
return -EBUSY;
}
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->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));
return ret;
}
static int 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));
platform_set_drvdata(pdev, NULL);
return 0;
}
static const struct of_device_id wmt_dt_ids[] = {
{ .compatible = "via,vt8500-rtc", },
{}
};
static struct platform_driver vt8500_rtc_driver = {
.probe = vt8500_rtc_probe,
.remove = vt8500_rtc_remove,
.driver = {
.name = "vt8500-rtc",
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(wmt_dt_ids),
},
};
module_platform_driver(vt8500_rtc_driver);
MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:vt8500-rtc");
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