221 lines
5.5 KiB
C
221 lines
5.5 KiB
C
/*
|
|
* Gemini OnChip RTC
|
|
*
|
|
* Copyright (C) 2009 Janos Laube <janos.dev@gmail.com>
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*
|
|
* Original code for older kernel 2.6.15 are form Stormlinksemi
|
|
* first update from Janos Laube for > 2.6.29 kernels
|
|
*
|
|
* checkpatch fixes and usage off rtc-lib code
|
|
* Hans Ulli Kroll <ulli.kroll@googlemail.com>
|
|
*/
|
|
|
|
#include <linux/rtc.h>
|
|
#include <linux/io.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
|
|
#include <mach/hardware.h>
|
|
|
|
#define DRV_NAME "rtc-gemini"
|
|
|
|
MODULE_DESCRIPTION("RTC driver for Gemini SoC");
|
|
MODULE_ALIAS("platform:" DRV_NAME);
|
|
MODULE_AUTHOR("Hans Ulli Kroll <ulli.kroll@googlemail.com>");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
struct gemini_rtc {
|
|
struct rtc_device *dev;
|
|
void __iomem *base;
|
|
int irq;
|
|
};
|
|
|
|
enum gemini_rtc_offsets {
|
|
GEMINI_RTC_SECOND = 0x00,
|
|
GEMINI_RTC_MINUTE = 0x04,
|
|
GEMINI_RTC_HOUR = 0x08,
|
|
GEMINI_RTC_DAYS = 0x0C,
|
|
GEMINI_RTC_ALARM_SECOND = 0x10,
|
|
GEMINI_RTC_ALARM_MINUTE = 0x14,
|
|
GEMINI_RTC_ALARM_HOUR = 0x18,
|
|
GEMINI_RTC_RECORD = 0x1C,
|
|
GEMINI_RTC_CR = 0x20
|
|
};
|
|
|
|
static irqreturn_t gemini_rtc_interrupt(int irq, void *dev)
|
|
{
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
/*
|
|
* Looks like the RTC in the Gemini SoC is (totaly) broken
|
|
* We can't read/write directly the time from RTC registers.
|
|
* We must do some "offset" calculation to get the real time
|
|
*
|
|
* The register "day" seams to be fixed, and the register "hour"
|
|
* has his own mind.
|
|
*
|
|
* Maybe we can write directly the hour and days since EPOCH
|
|
* but in this case the RTC will recalucate to some (other) strange values.
|
|
* If you write time to the registers you will not read the same values.
|
|
*
|
|
* This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
|
|
* the same thing, without the rtc-lib.c calls.
|
|
*/
|
|
|
|
static int gemini_rtc_read_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct gemini_rtc *rtc = dev_get_drvdata(dev);
|
|
|
|
unsigned int days, hour, min, sec;
|
|
unsigned long offset, time;
|
|
|
|
sec = readl(rtc->base + GEMINI_RTC_SECOND);
|
|
min = readl(rtc->base + GEMINI_RTC_MINUTE);
|
|
hour = readl(rtc->base + GEMINI_RTC_HOUR);
|
|
days = readl(rtc->base + GEMINI_RTC_DAYS);
|
|
offset = readl(rtc->base + GEMINI_RTC_RECORD);
|
|
|
|
time = offset + days * 86400 + hour * 3600 + min * 60 + sec;
|
|
|
|
rtc_time_to_tm(time, tm);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Maybe there is some hidden register to care ?
|
|
* looks like register GEMINI_RTC_DAY can count
|
|
* 365 days * 179 years >= 65535 (uint16)
|
|
*/
|
|
|
|
static int gemini_rtc_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
struct gemini_rtc *rtc = dev_get_drvdata(dev);
|
|
unsigned int sec, min, hour, day;
|
|
unsigned long offset, time;
|
|
|
|
if (tm->tm_year >= 2148) /* EPOCH Year + 179 */
|
|
return -EINVAL;
|
|
|
|
rtc_tm_to_time(tm , &time);
|
|
|
|
sec = readl(rtc->base + GEMINI_RTC_SECOND);
|
|
min = readl(rtc->base + GEMINI_RTC_MINUTE);
|
|
hour = readl(rtc->base + GEMINI_RTC_HOUR);
|
|
day = readl(rtc->base + GEMINI_RTC_DAYS);
|
|
|
|
offset = time - (day*86400 + hour*3600 + min*60 + sec);
|
|
|
|
writel(offset, rtc->base + GEMINI_RTC_RECORD);
|
|
writel(0x01, rtc->base + GEMINI_RTC_CR);
|
|
return 0;
|
|
}
|
|
|
|
static struct rtc_class_ops gemini_rtc_ops = {
|
|
.read_time = gemini_rtc_read_time,
|
|
.set_time = gemini_rtc_set_time,
|
|
};
|
|
|
|
static int gemini_rtc_probe(struct platform_device *pdev)
|
|
{
|
|
struct gemini_rtc *rtc;
|
|
struct device *dev = &pdev->dev;
|
|
struct resource *res;
|
|
int ret;
|
|
|
|
rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
|
|
if (unlikely(!rtc))
|
|
return -ENOMEM;
|
|
platform_set_drvdata(pdev, rtc);
|
|
|
|
rtc->irq = platform_get_irq(pdev, 0);
|
|
if (rtc->irq < 0) {
|
|
ret = -rtc->irq;
|
|
goto err_mem;
|
|
}
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
if (!res) {
|
|
ret = -ENODEV;
|
|
goto err_mem;
|
|
}
|
|
rtc->base = devm_ioremap(&pdev->dev, res->start,
|
|
res->end - res->start + 1);
|
|
|
|
ret = request_irq(rtc->irq, gemini_rtc_interrupt,
|
|
IRQF_SHARED, pdev->name, dev);
|
|
if (unlikely(ret))
|
|
goto err_mem;
|
|
|
|
rtc->dev = rtc_device_register(pdev->name, dev,
|
|
&gemini_rtc_ops, THIS_MODULE);
|
|
if (unlikely(IS_ERR(rtc->dev))) {
|
|
ret = PTR_ERR(rtc->dev);
|
|
goto err_irq;
|
|
}
|
|
return 0;
|
|
|
|
err_irq:
|
|
free_irq(rtc->irq, dev);
|
|
|
|
err_mem:
|
|
kfree(rtc);
|
|
return ret;
|
|
}
|
|
|
|
static int gemini_rtc_remove(struct platform_device *pdev)
|
|
{
|
|
struct gemini_rtc *rtc = platform_get_drvdata(pdev);
|
|
struct device *dev = &pdev->dev;
|
|
|
|
free_irq(rtc->irq, dev);
|
|
rtc_device_unregister(rtc->dev);
|
|
platform_set_drvdata(pdev, NULL);
|
|
kfree(rtc);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver gemini_rtc_driver = {
|
|
.driver = {
|
|
.name = DRV_NAME,
|
|
.owner = THIS_MODULE,
|
|
},
|
|
.probe = gemini_rtc_probe,
|
|
.remove = gemini_rtc_remove,
|
|
};
|
|
|
|
static int __init gemini_rtc_init(void)
|
|
{
|
|
int retval;
|
|
|
|
retval = platform_driver_register(&gemini_rtc_driver);
|
|
if (retval == 0)
|
|
pr_info(DRV_NAME ": registered successfully");
|
|
return retval;
|
|
}
|
|
|
|
static void __exit gemini_rtc_exit(void)
|
|
{
|
|
platform_driver_unregister(&gemini_rtc_driver);
|
|
}
|
|
|
|
module_init(gemini_rtc_init);
|
|
module_exit(gemini_rtc_exit);
|