[PATCH 1/6] rtc: 88pm860x: fix possible race condition

[PATCH 1/6] rtc: 88pm860x: fix possible race condition

[Alexandre Belloni]

The RTC IRQ is requested before the struct rtc_device is allocated,
this may lead to a NULL pointer dereference in the IRQ handler.

To fix this issue, allocating the rtc_device struct before requesting
the RTC IRQ using devm_rtc_allocate_device, and use rtc_register_device
to register the RTC device.

Also remove the unnecessary error message as the core already prints the
info.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-88pm860x.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c
index 4743b16a8d84..1526402e126b 100644
--- a/drivers/rtc/rtc-88pm860x.c
+++ b/drivers/rtc/rtc-88pm860x.c
@@ -336,6 +336,10 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
 	info->dev = &pdev->dev;
 	dev_set_drvdata(&pdev->dev, info);
 
+	info->rtc_dev = devm_rtc_allocate_device(&pdev->dev);
+	if (IS_ERR(info->rtc_dev))
+		return PTR_ERR(info->rtc_dev);
+
 	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
 					rtc_update_handler, IRQF_ONESHOT, "rtc",
 					info);
@@ -377,13 +381,11 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
 		}
 	}
 
-	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc",
-					    &pm860x_rtc_ops, THIS_MODULE);
-	ret = PTR_ERR(info->rtc_dev);
-	if (IS_ERR(info->rtc_dev)) {
-		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
+	info->rtc_dev->ops = &pm860x_rtc_ops;
+
+	ret = rtc_register_device(info->rtc_dev);
+	if (ret)
 		return ret;
-	}
 
 	/*
 	 * enable internal XO instead of internal 3.25MHz clock since it can
-- 
2.24.1

[PATCH 2/6] rtc: 88pm860x: stop setting a default time

[Alexandre Belloni]

It doesn't make sense to set the RTC to a default value at probe time. Let
the core handle invalid date and time.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-88pm860x.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c
index 1526402e126b..d6aca28905e3 100644
--- a/drivers/rtc/rtc-88pm860x.c
+++ b/drivers/rtc/rtc-88pm860x.c
@@ -360,19 +360,6 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
 		dev_err(&pdev->dev, "Failed to read initial time.\n");
 		return ret;
 	}
-	if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
-		tm.tm_year = 70;
-		tm.tm_mon = 0;
-		tm.tm_mday = 1;
-		tm.tm_hour = 0;
-		tm.tm_min = 0;
-		tm.tm_sec = 0;
-		ret = pm860x_rtc_set_time(&pdev->dev, &tm);
-		if (ret < 0) {
-			dev_err(&pdev->dev, "Failed to set initial time.\n");
-			return ret;
-		}
-	}
 	rtc_tm_to_time(&tm, &ticks);
 	if (pm860x_rtc_dt_init(pdev, info)) {
 		if (pdata && pdata->sync) {
-- 
2.24.1

[PATCH 3/6] rtc: 88pm860x: stop calling unused callback

[Alexandre Belloni]

pdata->sync is not defined by any platform, stop calling it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-88pm860x.c | 18 +-----------------
 1 file changed, 1 insertion(+), 17 deletions(-)

diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c
index d6aca28905e3..0abf2b194938 100644
--- a/drivers/rtc/rtc-88pm860x.c
+++ b/drivers/rtc/rtc-88pm860x.c
@@ -28,7 +28,6 @@ struct pm860x_rtc_info {
 
 	int			irq;
 	int			vrtc;
-	int			(*sync)(unsigned int ticks);
 };
 
 #define REG_VRTC_MEAS1		0x7D
@@ -155,8 +154,6 @@ static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 	pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
 	pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
 
-	if (info->sync)
-		info->sync(ticks);
 	return 0;
 }
 
@@ -317,8 +314,6 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
 	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
 	struct pm860x_rtc_pdata *pdata = NULL;
 	struct pm860x_rtc_info *info;
-	struct rtc_time tm;
-	unsigned long ticks = 0;
 	int ret;
 
 	pdata = dev_get_platdata(&pdev->dev);
@@ -355,18 +350,7 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
 	pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
 	pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
 
-	ret = pm860x_rtc_read_time(&pdev->dev, &tm);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "Failed to read initial time.\n");
-		return ret;
-	}
-	rtc_tm_to_time(&tm, &ticks);
-	if (pm860x_rtc_dt_init(pdev, info)) {
-		if (pdata && pdata->sync) {
-			pdata->sync(ticks);
-			info->sync = pdata->sync;
-		}
-	}
+	pm860x_rtc_dt_init(pdev, info);
 
 	info->rtc_dev->ops = &pm860x_rtc_ops;
 
-- 
2.24.1

[PATCH 4/6] rtc: 88pm860x: set range

[Alexandre Belloni]

The 88pm860x RTC is a 32bit read only seconds counter with a 32bit offset.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-88pm860x.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c
index 0abf2b194938..f5933a08454c 100644
--- a/drivers/rtc/rtc-88pm860x.c
+++ b/drivers/rtc/rtc-88pm860x.c
@@ -353,6 +353,7 @@ static int pm860x_rtc_probe(struct platform_device *pdev)
 	pm860x_rtc_dt_init(pdev, info);
 
 	info->rtc_dev->ops = &pm860x_rtc_ops;
+	info->rtc_dev->range_max = U32_MAX;
 
 	ret = rtc_register_device(info->rtc_dev);
 	if (ret)
-- 
2.24.1

[PATCH 5/6] rtc: 88pm860x: stop mangling alarm time

[Alexandre Belloni]

The RTC core always passes a valid alarm time there is no need to modify
it.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-88pm860x.c | 41 +-------------------------------------
 1 file changed, 1 insertion(+), 40 deletions(-)

diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c
index f5933a08454c..e0b18227514b 100644
--- a/drivers/rtc/rtc-88pm860x.c
+++ b/drivers/rtc/rtc-88pm860x.c
@@ -75,33 +75,6 @@ static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
 	return 0;
 }
 
-/*
- * Calculate the next alarm time given the requested alarm time mask
- * and the current time.
- */
-static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
-				struct rtc_time *alrm)
-{
-	unsigned long next_time;
-	unsigned long now_time;
-
-	next->tm_year = now->tm_year;
-	next->tm_mon = now->tm_mon;
-	next->tm_mday = now->tm_mday;
-	next->tm_hour = alrm->tm_hour;
-	next->tm_min = alrm->tm_min;
-	next->tm_sec = alrm->tm_sec;
-
-	rtc_tm_to_time(now, &now_time);
-	rtc_tm_to_time(next, &next_time);
-
-	if (next_time < now_time) {
-		/* Advance one day */
-		next_time += 60 * 60 * 24;
-		rtc_time_to_tm(next_time, next);
-	}
-}
-
 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
@@ -187,7 +160,6 @@ static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 {
 	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
-	struct rtc_time now_tm, alarm_tm;
 	unsigned long ticks, base, data;
 	unsigned char buf[8];
 	int mask;
@@ -200,18 +172,7 @@ static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 		(buf[5] << 8) | buf[7];
 
-	/* load 32-bit read-only counter */
-	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
-	data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
-		(buf[1] << 8) | buf[0];
-	ticks = base + data;
-	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
-		base, data, ticks);
-
-	rtc_time_to_tm(ticks, &now_tm);
-	rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
-	/* get new ticks for alarm in 24 hours */
-	rtc_tm_to_time(&alarm_tm, &ticks);
+	rtc_tm_to_time(&alrm->time, &ticks);
 	data = ticks - base;
 
 	buf[0] = data & 0xff;
-- 
2.24.1

[PATCH 6/6] rtc: 88pm860x: switch to rtc_time64_to_tm/rtc_tm_to_time64

[Alexandre Belloni]

Call the 64bit versions of rtc_tm time conversion.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
---
 drivers/rtc/rtc-88pm860x.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-88pm860x.c b/drivers/rtc/rtc-88pm860x.c
index e0b18227514b..88bda3e072d8 100644
--- a/drivers/rtc/rtc-88pm860x.c
+++ b/drivers/rtc/rtc-88pm860x.c
@@ -95,7 +95,7 @@ static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
 	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 		base, data, ticks);
 
-	rtc_time_to_tm(ticks, tm);
+	rtc_time64_to_tm(ticks, tm);
 
 	return 0;
 }
@@ -112,7 +112,7 @@ static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
 			1900 + tm->tm_year);
 		return -EINVAL;
 	}
-	rtc_tm_to_time(tm, &ticks);
+	ticks = rtc_tm_to_time64(tm);
 
 	/* load 32-bit read-only counter */
 	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
@@ -150,7 +150,7 @@ static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
 		base, data, ticks);
 
-	rtc_time_to_tm(ticks, &alrm->time);
+	rtc_time64_to_tm(ticks, &alrm->time);
 	ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
 	alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
 	alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
@@ -172,7 +172,7 @@ static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
 	base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
 		(buf[5] << 8) | buf[7];
 
-	rtc_tm_to_time(&alrm->time, &ticks);
+	ticks = rtc_tm_to_time64(&alrm->time);
 	data = ticks - base;
 
 	buf[0] = data & 0xff;
-- 
2.24.1