linux/drivers/rtc/rtc-mt6397.c
Yang Yingliang d3b43eb505 rtc: mt6397: check return value after calling platform_get_resource()
It will cause null-ptr-deref if platform_get_resource() returns NULL,
we need check the return value.

Fixes: fc2979118f ("rtc: mediatek: Add MT6397 RTC driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20220505125043.1594771-1-yangyingliang@huawei.com
2022-05-19 12:05:48 +02:00

364 lines
9.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014-2015 MediaTek Inc.
* Author: Tianping.Fang <tianping.fang@mediatek.com>
*/
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/mfd/mt6397/rtc.h>
#include <linux/mod_devicetable.h>
static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
{
int ret;
u32 data;
ret = regmap_write(rtc->regmap, rtc->addr_base + rtc->data->wrtgr, 1);
if (ret < 0)
return ret;
ret = regmap_read_poll_timeout(rtc->regmap,
rtc->addr_base + RTC_BBPU, data,
!(data & RTC_BBPU_CBUSY),
MTK_RTC_POLL_DELAY_US,
MTK_RTC_POLL_TIMEOUT);
if (ret < 0)
dev_err(rtc->rtc_dev->dev.parent,
"failed to write WRTGR: %d\n", ret);
return ret;
}
static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
{
struct mt6397_rtc *rtc = data;
u32 irqsta, irqen;
int ret;
ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta);
if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) {
rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
irqen = irqsta & ~RTC_IRQ_EN_AL;
mutex_lock(&rtc->lock);
if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
irqen) == 0)
mtk_rtc_write_trigger(rtc);
mutex_unlock(&rtc->lock);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
struct rtc_time *tm, int *sec)
{
int ret;
u16 data[RTC_OFFSET_COUNT];
mutex_lock(&rtc->lock);
ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
data, RTC_OFFSET_COUNT);
if (ret < 0)
goto exit;
tm->tm_sec = data[RTC_OFFSET_SEC];
tm->tm_min = data[RTC_OFFSET_MIN];
tm->tm_hour = data[RTC_OFFSET_HOUR];
tm->tm_mday = data[RTC_OFFSET_DOM];
tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_TC_MTH_MASK;
tm->tm_year = data[RTC_OFFSET_YEAR];
ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
exit:
mutex_unlock(&rtc->lock);
return ret;
}
static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
time64_t time;
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
int days, sec, ret;
do {
ret = __mtk_rtc_read_time(rtc, tm, &sec);
if (ret < 0)
goto exit;
} while (sec < tm->tm_sec);
/* HW register use 7 bits to store year data, minus
* RTC_MIN_YEAR_OFFSET before write year data to register, and plus
* RTC_MIN_YEAR_OFFSET back after read year from register
*/
tm->tm_year += RTC_MIN_YEAR_OFFSET;
/* HW register start mon from one, but tm_mon start from zero. */
tm->tm_mon--;
time = rtc_tm_to_time64(tm);
/* rtc_tm_to_time64 covert Gregorian date to seconds since
* 01-01-1970 00:00:00, and this date is Thursday.
*/
days = div_s64(time, 86400);
tm->tm_wday = (days + 4) % 7;
exit:
return ret;
}
static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
int ret;
u16 data[RTC_OFFSET_COUNT];
tm->tm_year -= RTC_MIN_YEAR_OFFSET;
tm->tm_mon++;
data[RTC_OFFSET_SEC] = tm->tm_sec;
data[RTC_OFFSET_MIN] = tm->tm_min;
data[RTC_OFFSET_HOUR] = tm->tm_hour;
data[RTC_OFFSET_DOM] = tm->tm_mday;
data[RTC_OFFSET_MTH] = tm->tm_mon;
data[RTC_OFFSET_YEAR] = tm->tm_year;
mutex_lock(&rtc->lock);
ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
data, RTC_OFFSET_COUNT);
if (ret < 0)
goto exit;
/* Time register write to hardware after call trigger function */
ret = mtk_rtc_write_trigger(rtc);
exit:
mutex_unlock(&rtc->lock);
return ret;
}
static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct rtc_time *tm = &alm->time;
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
u32 irqen, pdn2;
int ret;
u16 data[RTC_OFFSET_COUNT];
mutex_lock(&rtc->lock);
ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen);
if (ret < 0)
goto err_exit;
ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2);
if (ret < 0)
goto err_exit;
ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
data, RTC_OFFSET_COUNT);
if (ret < 0)
goto err_exit;
alm->enabled = !!(irqen & RTC_IRQ_EN_AL);
alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
mutex_unlock(&rtc->lock);
tm->tm_sec = data[RTC_OFFSET_SEC] & RTC_AL_SEC_MASK;
tm->tm_min = data[RTC_OFFSET_MIN] & RTC_AL_MIN_MASK;
tm->tm_hour = data[RTC_OFFSET_HOUR] & RTC_AL_HOU_MASK;
tm->tm_mday = data[RTC_OFFSET_DOM] & RTC_AL_DOM_MASK;
tm->tm_mon = data[RTC_OFFSET_MTH] & RTC_AL_MTH_MASK;
tm->tm_year = data[RTC_OFFSET_YEAR] & RTC_AL_YEA_MASK;
tm->tm_year += RTC_MIN_YEAR_OFFSET;
tm->tm_mon--;
return 0;
err_exit:
mutex_unlock(&rtc->lock);
return ret;
}
static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
struct rtc_time *tm = &alm->time;
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
int ret;
u16 data[RTC_OFFSET_COUNT];
tm->tm_year -= RTC_MIN_YEAR_OFFSET;
tm->tm_mon++;
mutex_lock(&rtc->lock);
ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
data, RTC_OFFSET_COUNT);
if (ret < 0)
goto exit;
data[RTC_OFFSET_SEC] = ((data[RTC_OFFSET_SEC] & ~(RTC_AL_SEC_MASK)) |
(tm->tm_sec & RTC_AL_SEC_MASK));
data[RTC_OFFSET_MIN] = ((data[RTC_OFFSET_MIN] & ~(RTC_AL_MIN_MASK)) |
(tm->tm_min & RTC_AL_MIN_MASK));
data[RTC_OFFSET_HOUR] = ((data[RTC_OFFSET_HOUR] & ~(RTC_AL_HOU_MASK)) |
(tm->tm_hour & RTC_AL_HOU_MASK));
data[RTC_OFFSET_DOM] = ((data[RTC_OFFSET_DOM] & ~(RTC_AL_DOM_MASK)) |
(tm->tm_mday & RTC_AL_DOM_MASK));
data[RTC_OFFSET_MTH] = ((data[RTC_OFFSET_MTH] & ~(RTC_AL_MTH_MASK)) |
(tm->tm_mon & RTC_AL_MTH_MASK));
data[RTC_OFFSET_YEAR] = ((data[RTC_OFFSET_YEAR] & ~(RTC_AL_YEA_MASK)) |
(tm->tm_year & RTC_AL_YEA_MASK));
if (alm->enabled) {
ret = regmap_bulk_write(rtc->regmap,
rtc->addr_base + RTC_AL_SEC,
data, RTC_OFFSET_COUNT);
if (ret < 0)
goto exit;
ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK,
RTC_AL_MASK_DOW);
if (ret < 0)
goto exit;
ret = regmap_update_bits(rtc->regmap,
rtc->addr_base + RTC_IRQ_EN,
RTC_IRQ_EN_ONESHOT_AL,
RTC_IRQ_EN_ONESHOT_AL);
if (ret < 0)
goto exit;
} else {
ret = regmap_update_bits(rtc->regmap,
rtc->addr_base + RTC_IRQ_EN,
RTC_IRQ_EN_ONESHOT_AL, 0);
if (ret < 0)
goto exit;
}
/* All alarm time register write to hardware after calling
* mtk_rtc_write_trigger. This can avoid race condition if alarm
* occur happen during writing alarm time register.
*/
ret = mtk_rtc_write_trigger(rtc);
exit:
mutex_unlock(&rtc->lock);
return ret;
}
static const struct rtc_class_ops mtk_rtc_ops = {
.read_time = mtk_rtc_read_time,
.set_time = mtk_rtc_set_time,
.read_alarm = mtk_rtc_read_alarm,
.set_alarm = mtk_rtc_set_alarm,
};
static int mtk_rtc_probe(struct platform_device *pdev)
{
struct resource *res;
struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
struct mt6397_rtc *rtc;
int ret;
rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL);
if (!rtc)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -EINVAL;
rtc->addr_base = res->start;
rtc->data = of_device_get_match_data(&pdev->dev);
rtc->irq = platform_get_irq(pdev, 0);
if (rtc->irq < 0)
return rtc->irq;
rtc->regmap = mt6397_chip->regmap;
mutex_init(&rtc->lock);
platform_set_drvdata(pdev, rtc);
rtc->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
if (IS_ERR(rtc->rtc_dev))
return PTR_ERR(rtc->rtc_dev);
ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
mtk_rtc_irq_handler_thread,
IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
"mt6397-rtc", rtc);
if (ret) {
dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
rtc->irq, ret);
return ret;
}
device_init_wakeup(&pdev->dev, 1);
rtc->rtc_dev->ops = &mtk_rtc_ops;
return devm_rtc_register_device(rtc->rtc_dev);
}
#ifdef CONFIG_PM_SLEEP
static int mt6397_rtc_suspend(struct device *dev)
{
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
enable_irq_wake(rtc->irq);
return 0;
}
static int mt6397_rtc_resume(struct device *dev)
{
struct mt6397_rtc *rtc = dev_get_drvdata(dev);
if (device_may_wakeup(dev))
disable_irq_wake(rtc->irq);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(mt6397_pm_ops, mt6397_rtc_suspend,
mt6397_rtc_resume);
static const struct mtk_rtc_data mt6358_rtc_data = {
.wrtgr = RTC_WRTGR_MT6358,
};
static const struct mtk_rtc_data mt6397_rtc_data = {
.wrtgr = RTC_WRTGR_MT6397,
};
static const struct of_device_id mt6397_rtc_of_match[] = {
{ .compatible = "mediatek,mt6323-rtc", .data = &mt6397_rtc_data },
{ .compatible = "mediatek,mt6358-rtc", .data = &mt6358_rtc_data },
{ .compatible = "mediatek,mt6397-rtc", .data = &mt6397_rtc_data },
{ }
};
MODULE_DEVICE_TABLE(of, mt6397_rtc_of_match);
static struct platform_driver mtk_rtc_driver = {
.driver = {
.name = "mt6397-rtc",
.of_match_table = mt6397_rtc_of_match,
.pm = &mt6397_pm_ops,
},
.probe = mtk_rtc_probe,
};
module_platform_driver(mtk_rtc_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Tianping Fang <tianping.fang@mediatek.com>");
MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");