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rtc: add Freescale stmp37xx/378x driver
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Add support for RTC on the Freescale STMP37xx/378x platform.

Signed-off-by: dmitry pervushin <dpervushin@embeddedalley.com>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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dmitry pervushin authored and torvalds committed Sep 23, 2009
1 parent 6bff5fb commit df17f63
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10 changes: 10 additions & 0 deletions drivers/rtc/Kconfig
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Expand Up @@ -810,4 +810,14 @@ config RTC_DRV_COH901331
will be called "rtc-coh901331".


config RTC_DRV_STMP
tristate "Freescale STMP3xxx RTC"
depends on ARCH_STMP3XXX
help
If you say yes here you will get support for the onboard
STMP3xxx RTC.

This driver can also be built as a module. If so, the module
will be called rtc-stmp3xxx.

endif # RTC_CLASS
1 change: 1 addition & 0 deletions drivers/rtc/Makefile
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Expand Up @@ -83,3 +83,4 @@ obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
obj-$(CONFIG_RTC_DRV_PCF50633) += rtc-pcf50633.o
obj-$(CONFIG_RTC_DRV_PS3) += rtc-ps3.o
obj-$(CONFIG_RTC_DRV_COH901331) += rtc-coh901331.o
obj-$(CONFIG_RTC_DRV_STMP) += rtc-stmp3xxx.o
304 changes: 304 additions & 0 deletions drivers/rtc/rtc-stmp3xxx.c
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@@ -0,0 +1,304 @@
/*
* 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/init.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>

#include <mach/platform.h>
#include <mach/stmp3xxx.h>
#include <mach/regs-rtc.h>

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 (__raw_readl(rtc_data->io + HW_RTC_STAT) &
BF(0x80, RTC_STAT_STALE_REGS))
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(__raw_readl(rtc_data->io + HW_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);

__raw_writel(t, rtc_data->io + HW_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 = __raw_readl(rtc_data->io + HW_RTC_CTRL) &
(BM_RTC_CTRL_ALARM_IRQ | BM_RTC_CTRL_ONEMSEC_IRQ);

if (status & BM_RTC_CTRL_ALARM_IRQ) {
stmp3xxx_clearl(BM_RTC_CTRL_ALARM_IRQ,
rtc_data->io + HW_RTC_CTRL);
events |= RTC_AF | RTC_IRQF;
}

if (status & BM_RTC_CTRL_ONEMSEC_IRQ) {
stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ,
rtc_data->io + HW_RTC_CTRL);
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);
void __iomem *p = rtc_data->io + HW_RTC_PERSISTENT0,
*ctl = rtc_data->io + HW_RTC_CTRL;

if (enabled) {
stmp3xxx_setl(BM_RTC_PERSISTENT0_ALARM_EN |
BM_RTC_PERSISTENT0_ALARM_WAKE_EN, p);
stmp3xxx_setl(BM_RTC_CTRL_ALARM_IRQ_EN, ctl);
} else {
stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN |
BM_RTC_PERSISTENT0_ALARM_WAKE_EN, p);
stmp3xxx_clearl(BM_RTC_CTRL_ALARM_IRQ_EN, ctl);
}
return 0;
}

static int stmp3xxx_update_irq_enable(struct device *dev, unsigned int enabled)
{
struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev);

if (enabled)
stmp3xxx_setl(BM_RTC_CTRL_ONEMSEC_IRQ_EN,
rtc_data->io + HW_RTC_CTRL);
else
stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN,
rtc_data->io + HW_RTC_CTRL);
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(__raw_readl(rtc_data->io + HW_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);
__raw_writel(t, rtc_data->io + HW_RTC_ALARM);
return 0;
}

static struct rtc_class_ops stmp3xxx_rtc_ops = {
.alarm_irq_enable =
stmp3xxx_alarm_irq_enable,
.update_irq_enable =
stmp3xxx_update_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;

stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN | BM_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + HW_RTC_CTRL);
free_irq(rtc_data->irq_alarm, &pdev->dev);
free_irq(rtc_data->irq_1msec, &pdev->dev);
rtc_device_unregister(rtc_data->rtc);
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 (!(__raw_readl(HW_RTC_STAT + rtc_data->io) &
BM_RTC_STAT_RTC_PRESENT)) {
dev_err(&pdev->dev, "no device onboard\n");
err = -ENODEV;
goto out_remap;
}

stmp3xxx_reset_block(rtc_data->io, true);
stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN |
BM_RTC_PERSISTENT0_ALARM_WAKE_EN |
BM_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + HW_RTC_PERSISTENT0);
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;
}

platform_set_drvdata(pdev, rtc_data);

return 0;

out_irq1:
free_irq(rtc_data->irq_alarm, &pdev->dev);
out_irq_alarm:
stmp3xxx_clearl(BM_RTC_CTRL_ONEMSEC_IRQ_EN | BM_RTC_CTRL_ALARM_IRQ_EN,
rtc_data->io + HW_RTC_CTRL);
rtc_device_unregister(rtc_data->rtc);
out_remap:
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);

stmp3xxx_reset_block(rtc_data->io, true);
stmp3xxx_clearl(BM_RTC_PERSISTENT0_ALARM_EN |
BM_RTC_PERSISTENT0_ALARM_WAKE_EN |
BM_RTC_PERSISTENT0_ALARM_WAKE,
rtc_data->io + HW_RTC_PERSISTENT0);
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");

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