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linux/drivers/rtc/rtc-mc13xxx.c
Uwe Kleine-König 99c3a1367d rtc: mc13xxx: Convert to platform remove callback returning void 
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230304133028.2135435-17-u.kleine-koenig@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2023-03-17 23:03:17 +01:00

364 lines
7.9 KiB
C
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// SPDX-License-Identifier: GPL-2.0
/*
* Real Time Clock driver for Freescale MC13XXX PMIC
*
* (C) 2009 Sascha Hauer, Pengutronix
* (C) 2009 Uwe Kleine-Koenig, Pengutronix
*/
#include <linux/mfd/mc13xxx.h>
#include <linux/platform_device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.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
#define SEC_PER_DAY (24 * 60 * 60)
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);
}
static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
unsigned int enabled)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
int ret;
mc13xxx_lock(priv->mc13xxx);
ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, MC13XXX_IRQ_TODA);
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;
if (!priv->valid)
return -ENODATA;
do {
int ret;
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
if (ret)
return ret;
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
if (ret)
return ret;
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
if (ret)
return ret;
} while (days1 != days2);
rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm);
return 0;
}
static int mc13xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
unsigned int seconds, days;
unsigned int alarmseconds;
int ret;
days = div_s64_rem(rtc_tm_to_time64(tm), SEC_PER_DAY, &seconds);
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;
if (alarmseconds < SEC_PER_DAY) {
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 */
if (alarmseconds < SEC_PER_DAY) {
ret = mc13xxx_reg_write(priv->mc13xxx,
MC13XXX_RTCTODA, alarmseconds);
if (unlikely(ret))
goto out;
}
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);
}
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 int seconds, days;
time64_t s1970;
int enabled, pending;
int ret;
mc13xxx_lock(priv->mc13xxx);
ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
if (unlikely(ret))
goto out;
if (seconds >= SEC_PER_DAY) {
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;
s1970 = (time64_t)days * SEC_PER_DAY + seconds;
rtc_time64_to_tm(s1970, &alarm->time);
dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970);
return 0;
}
static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
time64_t s1970;
u32 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;
s1970 = rtc_tm_to_time64(&alarm->time);
dev_dbg(dev, "%s: %s %lld\n", __func__, alarm->enabled ? "on" : "off",
(long long)s1970);
ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
MC13XXX_IRQ_TODA);
if (unlikely(ret))
goto out;
days = div_s64_rem(s1970, SEC_PER_DAY, &seconds);
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 const struct rtc_class_ops mc13xxx_rtc_ops = {
.read_time = mc13xxx_rtc_read_time,
.set_time = mc13xxx_rtc_set_time,
.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;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
mc13xxx = dev_get_drvdata(pdev->dev.parent);
priv->mc13xxx = mc13xxx;
priv->valid = 1;
priv->rtc = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(priv->rtc))
return PTR_ERR(priv->rtc);
platform_set_drvdata(pdev, priv);
priv->rtc->ops = &mc13xxx_rtc_ops;
/* 15bit days + hours, minutes, seconds */
priv->rtc->range_max = (timeu64_t)(1 << 15) * SEC_PER_DAY - 1;
mc13xxx_lock(mc13xxx);
mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST);
ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
if (ret)
goto err_irq_request;
ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
if (ret)
goto err_irq_request;
mc13xxx_unlock(mc13xxx);
ret = devm_rtc_register_device(priv->rtc);
if (ret) {
mc13xxx_lock(mc13xxx);
goto err_irq_request;
}
return 0;
err_irq_request:
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
mc13xxx_unlock(mc13xxx);
return ret;
}
static void mc13xxx_rtc_remove(struct platform_device *pdev)
{
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_RTCRST, priv);
mc13xxx_unlock(priv->mc13xxx);
}
static const struct platform_device_id mc13xxx_rtc_idtable[] = {
{
.name = "mc13783-rtc",
}, {
.name = "mc13892-rtc",
}, {
.name = "mc34708-rtc",
},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, mc13xxx_rtc_idtable);
static struct platform_driver mc13xxx_rtc_driver = {
.id_table = mc13xxx_rtc_idtable,
.remove_new = mc13xxx_rtc_remove,
.driver = {
.name = DRIVER_NAME,
},
};
module_platform_driver_probe(mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
MODULE_LICENSE("GPL v2");
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