/*
* Freescale STMP37XX/STMP378X Real Time Clock driver
*
* Copyright (c) 2007 Sigmatel, Inc.
* Peter Hartley, <peter.hartley@sigmatel.com>
*
* Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
*/
/*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <mach/common.h>
#define STMP3XXX_RTC_CTRL 0x0
#define STMP3XXX_RTC_CTRL_SET 0x4
#define STMP3XXX_RTC_CTRL_CLR 0x8
#define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001
#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002
#define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004
#define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ 0x00000008
#define STMP3XXX_RTC_STAT 0x10
#define STMP3XXX_RTC_STAT_STALE_SHIFT 16
#define STMP3XXX_RTC_STAT_RTC_PRESENT 0x80000000
#define STMP3XXX_RTC_SECONDS 0x30
#define STMP3XXX_RTC_ALARM 0x40
#define STMP3XXX_RTC_PERSISTENT0 0x60
#define STMP3XXX_RTC_PERSISTENT0_SET 0x64
#define STMP3XXX_RTC_PERSISTENT0_CLR 0x68
#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN 0x00000002
#define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004
#define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080
struct stmp3xxx_rtc_data {
struct rtc_device *rtc;
unsigned irq_count;
void __iomem *io;
int irq_alarm, irq_1msec;
};
static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data)
{
/*
* The datasheet doesn't say which way round the
* NEW_REGS/STALE_REGS bitfields go. In fact it's 0x1=P0,
* 0x2=P1, .., 0x20=P5, 0x40=ALARM, 0x80=SECONDS
*/
while (readl(rtc_data->io + STMP3XXX_RTC_STAT) &
(0x80 << STMP3XXX_RTC_STAT_STALE_SHIFT))
cpu_relax();
}
/* Time read/write */
static int stmp3xxx_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
stmp3xxx_wait_time(rtc_data);
rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_SECONDS), rtc_tm);
return 0;
}
static int stmp3xxx_rtc_set_mmss(struct device *dev, unsigned long t)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
writel(t, rtc_data->io + STMP3XXX_RTC_SECONDS);
stmp3xxx_wait_time(rtc_data);
return 0;
}
/* interrupt(s) handler */
static irqreturn_t stmp3xxx_rtc_interrupt(int irq, void *dev_id)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev_id);
u32 status;
u32 events = 0;
status = readl(rtc_data->io + STMP3XXX_RTC_CTRL) &
(STMP3XXX_RTC_CTRL_ALARM_IRQ |
STMP3XXX_RTC_CTRL_ONEMSEC_IRQ);
if (status & STMP3XXX_RTC_CTRL_ALARM_IRQ) {
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
events |= RTC_AF | RTC_IRQF;
}
if (status & STMP3XXX_RTC_CTRL_ONEMSEC_IRQ) {
writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
if (++rtc_data->irq_count % 1000 == 0) {
events |= RTC_UF | RTC_IRQF;
rtc_data->irq_count = 0;
}
}
if (events)
rtc_update_irq(rtc_data->rtc, 1, events);
return IRQ_HANDLED;
}
static int stmp3xxx_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
if (enabled) {
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_SET);
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_SET);
} else {
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
writel(STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
}
return 0;
}
static int stmp3xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
rtc_time_to_tm(readl(rtc_data->io + STMP3XXX_RTC_ALARM), &alm->time);
return 0;
}
static int stmp3xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
unsigned long t;
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);
rtc_tm_to_time(&alm->time, &t);
writel(t, rtc_data->io + STMP3XXX_RTC_ALARM);
return 0;
}
static struct rtc_class_ops stmp3xxx_rtc_ops = {
.alarm_irq_enable =
stmp3xxx_alarm_irq_enable,
.read_time = stmp3xxx_rtc_gettime,
.set_mmss = stmp3xxx_rtc_set_mmss,
.read_alarm = stmp3xxx_rtc_read_alarm,
.set_alarm = stmp3xxx_rtc_set_alarm,
};
static int stmp3xxx_rtc_remove(struct platform_device *pdev)
{
struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(pdev);
if (!rtc_data)
return 0;
writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
free_irq(rtc_data->irq_alarm, &pdev->dev);
free_irq(rtc_data->irq_1msec, &pdev->dev);
rtc_device_unregister(rtc_data->rtc);
platform_set_drvdata(pdev, NULL);
iounmap(rtc_data->io);
kfree(rtc_data);
return 0;
}
static int stmp3xxx_rtc_probe(struct platform_device *pdev)
{
struct stmp3xxx_rtc_data *rtc_data;
struct resource *r;
int err;
rtc_data = kzalloc(sizeof *rtc_data, GFP_KERNEL);
if (!rtc_data)
return -ENOMEM;
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
dev_err(&pdev->dev, "failed to get resource\n");
err = -ENXIO;
goto out_free;
}
rtc_data->io = ioremap(r->start, resource_size(r));
if (!rtc_data->io) {
dev_err(&pdev->dev, "ioremap failed\n");
err = -EIO;
goto out_free;
}
rtc_data->irq_alarm = platform_get_irq(pdev, 0);
rtc_data->irq_1msec = platform_get_irq(pdev, 1);
if (!(readl(STMP3XXX_RTC_STAT + rtc_data->io) &
STMP3XXX_RTC_STAT_RTC_PRESENT)) {
dev_err(&pdev->dev, "no device onboard\n");
err = -ENODEV;
goto out_remap;
}
platform_set_drvdata(pdev, rtc_data);
mxs_reset_block(rtc_data->io);
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
rtc_data->rtc = rtc_device_register(pdev->name, &pdev->dev,
&stmp3xxx_rtc_ops, THIS_MODULE);
if (IS_ERR(rtc_data->rtc)) {
err = PTR_ERR(rtc_data->rtc);
goto out_remap;
}
rtc_data->irq_count = 0;
err = request_irq(rtc_data->irq_alarm, stmp3xxx_rtc_interrupt,
IRQF_DISABLED, "RTC alarm", &pdev->dev);
if (err) {
dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
rtc_data->irq_alarm);
goto out_irq_alarm;
}
err = request_irq(rtc_data->irq_1msec, stmp3xxx_rtc_interrupt,
IRQF_DISABLED, "RTC tick", &pdev->dev);
if (err) {
dev_err(&pdev->dev, "Cannot claim IRQ%d\n",
rtc_data->irq_1msec);
goto out_irq1;
}
return 0;
out_irq1:
free_irq(rtc_data->irq_alarm, &pdev->dev);
out_irq_alarm:
writel(STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN |
STMP3XXX_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + STMP3XXX_RTC_CTRL_CLR);
rtc_device_unregister(rtc_data->rtc);
out_remap:
platform_set_drvdata(pdev, NULL);
iounmap(rtc_data->io);
out_free:
kfree(rtc_data);
return err;
}
#ifdef CONFIG_PM
static int stmp3xxx_rtc_suspend(struct platform_device *dev, pm_message_t state)
{
return 0;
}
static int stmp3xxx_rtc_resume(struct platform_device *dev)
{
struct stmp3xxx_rtc_data *rtc_data = platform_get_drvdata(dev);
mxs_reset_block(rtc_data->io);
writel(STMP3XXX_RTC_PERSISTENT0_ALARM_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE_EN |
STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + STMP3XXX_RTC_PERSISTENT0_CLR);
return 0;
}
#else
#define stmp3xxx_rtc_suspend NULL
#define stmp3xxx_rtc_resume NULL
#endif
static struct platform_driver stmp3xxx_rtcdrv = {
.probe = stmp3xxx_rtc_probe,
.remove = stmp3xxx_rtc_remove,
.suspend = stmp3xxx_rtc_suspend,
.resume = stmp3xxx_rtc_resume,
.driver = {
.name = "stmp3xxx-rtc",
.owner = THIS_MODULE,
},
};
static int __init stmp3xxx_rtc_init(void)
{
return platform_driver_register(&stmp3xxx_rtcdrv);
}
static void __exit stmp3xxx_rtc_exit(void)
{
platform_driver_unregister(&stmp3xxx_rtcdrv);
}
module_init(stmp3xxx_rtc_init);
module_exit(stmp3xxx_rtc_exit);
MODULE_DESCRIPTION("STMP3xxx RTC Driver");
MODULE_AUTHOR("dmitry pervushin <dpervushin@embeddedalley.com>");
MODULE_LICENSE("GPL");
