M7350/kernel/drivers/rtc/rtc-mc13xxx.c

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/*
* Real Time Clock driver for Freescale MC13XXX PMIC
*
* (C) 2009 Sascha Hauer, Pengutronix
* (C) 2009 Uwe Kleine-Koenig, Pengutronix
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/mfd/mc13xxx.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#define DRIVER_NAME "mc13xxx-rtc"
#define MC13XXX_RTCTOD 20
#define MC13XXX_RTCTODA 21
#define MC13XXX_RTCDAY 22
#define MC13XXX_RTCDAYA 23
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#define SEC_PER_DAY (24 * 60 * 60)
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struct mc13xxx_rtc {
struct rtc_device *rtc;
struct mc13xxx *mc13xxx;
int valid;
};
static int mc13xxx_rtc_irq_enable_unlocked(struct device *dev,
unsigned int enabled, int irq)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
int (*func)(struct mc13xxx *mc13xxx, int irq);
if (!priv->valid)
return -ENODATA;
func = enabled ? mc13xxx_irq_unmask : mc13xxx_irq_mask;
return func(priv->mc13xxx, irq);
}
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static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
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{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
int ret;
mc13xxx_lock(priv->mc13xxx);
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ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, MC13XXX_IRQ_TODA);
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mc13xxx_unlock(priv->mc13xxx);
return ret;
}
static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned int seconds, days1, days2;
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if (!priv->valid)
return -ENODATA;
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do {
int ret;
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
if (ret)
return ret;
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
if (ret)
return ret;
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ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
if (ret)
return ret;
} while (days1 != days2);
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rtc_time_to_tm(days1 * SEC_PER_DAY + seconds, tm);
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return rtc_valid_tm(tm);
}
static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned int seconds, days;
unsigned int alarmseconds;
int ret;
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seconds = secs % SEC_PER_DAY;
days = secs / SEC_PER_DAY;
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mc13xxx_lock(priv->mc13xxx);
/*
* temporarily invalidate alarm to prevent triggering it when the day is
* already updated while the time isn't yet.
*/
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds);
if (unlikely(ret))
goto out;
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if (alarmseconds < SEC_PER_DAY) {
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ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, 0x1ffff);
if (unlikely(ret))
goto out;
}
/*
* write seconds=0 to prevent a day switch between writing days
* and seconds below
*/
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0);
if (unlikely(ret))
goto out;
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
if (unlikely(ret))
goto out;
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds);
if (unlikely(ret))
goto out;
/* restore alarm */
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if (alarmseconds < SEC_PER_DAY) {
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ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, alarmseconds);
if (unlikely(ret))
goto out;
}
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if (!priv->valid) {
ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
if (unlikely(ret))
goto out;
ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
}
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out:
priv->valid = !ret;
mc13xxx_unlock(priv->mc13xxx);
return ret;
}
static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned seconds, days;
unsigned long s1970;
int enabled, pending;
int ret;
mc13xxx_lock(priv->mc13xxx);
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
if (unlikely(ret))
goto out;
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if (seconds >= SEC_PER_DAY) {
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ret = -ENODATA;
goto out;
}
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
if (unlikely(ret))
goto out;
ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA,
&enabled, &pending);
out:
mc13xxx_unlock(priv->mc13xxx);
if (ret)
return ret;
alarm->enabled = enabled;
alarm->pending = pending;
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s1970 = days * SEC_PER_DAY + seconds;
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rtc_time_to_tm(s1970, &alarm->time);
dev_dbg(dev, "%s: %lu\n", __func__, s1970);
return 0;
}
static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned long s1970;
unsigned seconds, days;
int ret;
mc13xxx_lock(priv->mc13xxx);
/* disable alarm to prevent false triggering */
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff);
if (unlikely(ret))
goto out;
ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA);
if (unlikely(ret))
goto out;
ret = rtc_tm_to_time(&alarm->time, &s1970);
if (unlikely(ret))
goto out;
dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
s1970);
ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
MC13XXX_IRQ_TODA);
if (unlikely(ret))
goto out;
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seconds = s1970 % SEC_PER_DAY;
days = s1970 / SEC_PER_DAY;
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ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
if (unlikely(ret))
goto out;
ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds);
out:
mc13xxx_unlock(priv->mc13xxx);
return ret;
}
static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev)
{
struct mc13xxx_rtc *priv = dev;
struct mc13xxx *mc13xxx = priv->mc13xxx;
rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
mc13xxx_irq_ack(mc13xxx, irq);
return IRQ_HANDLED;
}
static irqreturn_t mc13xxx_rtc_update_handler(int irq, void *dev)
{
struct mc13xxx_rtc *priv = dev;
struct mc13xxx *mc13xxx = priv->mc13xxx;
rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);
mc13xxx_irq_ack(mc13xxx, irq);
return IRQ_HANDLED;
}
static const struct rtc_class_ops mc13xxx_rtc_ops = {
.read_time = mc13xxx_rtc_read_time,
.set_mmss = mc13xxx_rtc_set_mmss,
.read_alarm = mc13xxx_rtc_read_alarm,
.set_alarm = mc13xxx_rtc_set_alarm,
.alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
};
static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
{
struct mc13xxx_rtc *priv = dev;
struct mc13xxx *mc13xxx = priv->mc13xxx;
priv->valid = 0;
mc13xxx_irq_mask(mc13xxx, irq);
return IRQ_HANDLED;
}
static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
{
int ret;
struct mc13xxx_rtc *priv;
struct mc13xxx *mc13xxx;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
return -ENOMEM;
mc13xxx = dev_get_drvdata(pdev->dev.parent);
priv->mc13xxx = mc13xxx;
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priv->valid = 1;
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platform_set_drvdata(pdev, priv);
mc13xxx_lock(mc13xxx);
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mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST);
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ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
if (ret)
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goto err_irq_request;
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ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_1HZ,
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mc13xxx_rtc_update_handler, DRIVER_NAME, priv);
if (ret)
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goto err_irq_request;
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ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
if (ret)
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goto err_irq_request;
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mc13xxx_unlock(mc13xxx);
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priv->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
&mc13xxx_rtc_ops, THIS_MODULE);
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return 0;
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err_irq_request:
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_1HZ, priv);
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
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mc13xxx_unlock(mc13xxx);
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return ret;
}
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static int mc13xxx_rtc_remove(struct platform_device *pdev)
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{
struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
mc13xxx_lock(priv->mc13xxx);
mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv);
mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_1HZ, priv);
mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv);
mc13xxx_unlock(priv->mc13xxx);
return 0;
}
static const struct platform_device_id mc13xxx_rtc_idtable[] = {
{
.name = "mc13783-rtc",
}, {
.name = "mc13892-rtc",
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}, {
.name = "mc34708-rtc",
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},
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(platform, mc13xxx_rtc_idtable);
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static struct platform_driver mc13xxx_rtc_driver = {
.id_table = mc13xxx_rtc_idtable,
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.remove = mc13xxx_rtc_remove,
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.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
};
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module_platform_driver_probe(mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
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MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
MODULE_LICENSE("GPL v2");