[RFC PATCH v3 3/8] rtc/ab3100: Update driver to address y2038/y2106 issues

[Xunlei Pang <pang.xunlei@linaro.org>]

This driver has a number of y2038/y2106 issues.

This patch resolves them by:
- Replace rtc_tm_to_time() with rtc_tm_to_time64()
- Replace rtc_time_to_tm() with rtc_time64_to_tm()
- Change ab3100_rtc_set_mmss() to use rtc_class_ops's set_mmss64()

After this patch, the driver should not have any remaining
y2038/y2106 issues.

Signed-off-by: Xunlei Pang <pang.xunlei@linaro.org>
---
 drivers/rtc/rtc-ab3100.c | 55 ++++++++++++++++++++++++------------------------
 1 file changed, 27 insertions(+), 28 deletions(-)

diff --git a/drivers/rtc/rtc-ab3100.c b/drivers/rtc/rtc-ab3100.c
index 1d0340f..9b725c5 100644
--- a/drivers/rtc/rtc-ab3100.c
+++ b/drivers/rtc/rtc-ab3100.c
@@ -43,21 +43,21 @@
 /*
  * RTC clock functions and device struct declaration
  */
-static int ab3100_rtc_set_mmss(struct device *dev, unsigned long secs)
+static int ab3100_rtc_set_mmss(struct device *dev, time64_t secs)
 {
 	u8 regs[] = {AB3100_TI0, AB3100_TI1, AB3100_TI2,
 		     AB3100_TI3, AB3100_TI4, AB3100_TI5};
 	unsigned char buf[6];
-	u64 fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
+	u64 hw_counter = secs * AB3100_RTC_CLOCK_RATE * 2;
 	int err = 0;
 	int i;
 
-	buf[0] = (fat_time) & 0xFF;
-	buf[1] = (fat_time >> 8) & 0xFF;
-	buf[2] = (fat_time >> 16) & 0xFF;
-	buf[3] = (fat_time >> 24) & 0xFF;
-	buf[4] = (fat_time >> 32) & 0xFF;
-	buf[5] = (fat_time >> 40) & 0xFF;
+	buf[0] = (hw_counter) & 0xFF;
+	buf[1] = (hw_counter >> 8) & 0xFF;
+	buf[2] = (hw_counter >> 16) & 0xFF;
+	buf[3] = (hw_counter >> 24) & 0xFF;
+	buf[4] = (hw_counter >> 32) & 0xFF;
+	buf[5] = (hw_counter >> 40) & 0xFF;
 
 	for (i = 0; i < 6; i++) {
 		err = abx500_set_register_interruptible(dev, 0,
@@ -75,7 +75,7 @@ static int ab3100_rtc_set_mmss(struct device *dev, unsigned long secs)
 
 static int ab3100_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
-	unsigned long time;
+	time64_t time;
 	u8 rtcval;
 	int err;
 
@@ -88,7 +88,7 @@ static int ab3100_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		dev_info(dev, "clock not set (lost power)");
 		return -EINVAL;
 	} else {
-		u64 fat_time;
+		u64 hw_counter;
 		u8 buf[6];
 
 		/* Read out time registers */
@@ -98,22 +98,21 @@ static int ab3100_rtc_read_time(struct device *dev, struct rtc_time *tm)
 		if (err != 0)
 			return err;
 
-		fat_time = ((u64) buf[5] << 40) | ((u64) buf[4] << 32) |
+		hw_counter = ((u64) buf[5] << 40) | ((u64) buf[4] << 32) |
 			((u64) buf[3] << 24) | ((u64) buf[2] << 16) |
 			((u64) buf[1] << 8) | (u64) buf[0];
-		time = (unsigned long) (fat_time /
-					(u64) (AB3100_RTC_CLOCK_RATE * 2));
+		time = hw_counter / (u64) (AB3100_RTC_CLOCK_RATE * 2);
 	}
 
-	rtc_time_to_tm(time, tm);
+	rtc_time64_to_tm(time, tm);
 
 	return rtc_valid_tm(tm);
 }
 
 static int ab3100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
-	unsigned long time;
-	u64 fat_time;
+	time64_t time;
+	u64 hw_counter;
 	u8 buf[6];
 	u8 rtcval;
 	int err;
@@ -134,11 +133,11 @@ static int ab3100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 						     AB3100_AL0, buf, 4);
 	if (err)
 		return err;
-	fat_time = ((u64) buf[3] << 40) | ((u64) buf[2] << 32) |
+	hw_counter = ((u64) buf[3] << 40) | ((u64) buf[2] << 32) |
 		((u64) buf[1] << 24) | ((u64) buf[0] << 16);
-	time = (unsigned long) (fat_time / (u64) (AB3100_RTC_CLOCK_RATE * 2));
+	time = hw_counter / (u64) (AB3100_RTC_CLOCK_RATE * 2);
 
-	rtc_time_to_tm(time, &alarm->time);
+	rtc_time64_to_tm(time, &alarm->time);
 
 	return rtc_valid_tm(&alarm->time);
 }
@@ -147,17 +146,17 @@ static int ab3100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
 {
 	u8 regs[] = {AB3100_AL0, AB3100_AL1, AB3100_AL2, AB3100_AL3};
 	unsigned char buf[4];
-	unsigned long secs;
-	u64 fat_time;
+	time64_t secs;
+	u64 hw_counter;
 	int err;
 	int i;
 
-	rtc_tm_to_time(&alarm->time, &secs);
-	fat_time = (u64) secs * AB3100_RTC_CLOCK_RATE * 2;
-	buf[0] = (fat_time >> 16) & 0xFF;
-	buf[1] = (fat_time >> 24) & 0xFF;
-	buf[2] = (fat_time >> 32) & 0xFF;
-	buf[3] = (fat_time >> 40) & 0xFF;
+	secs = rtc_tm_to_time64(&alarm->time);
+	hw_counter = secs * AB3100_RTC_CLOCK_RATE * 2;
+	buf[0] = (hw_counter >> 16) & 0xFF;
+	buf[1] = (hw_counter >> 24) & 0xFF;
+	buf[2] = (hw_counter >> 32) & 0xFF;
+	buf[3] = (hw_counter >> 40) & 0xFF;
 
 	/* Set the alarm */
 	for (i = 0; i < 4; i++) {
@@ -193,7 +192,7 @@ static int ab3100_rtc_irq_enable(struct device *dev, unsigned int enabled)
 
 static const struct rtc_class_ops ab3100_rtc_ops = {
 	.read_time	= ab3100_rtc_read_time,
-	.set_mmss	= ab3100_rtc_set_mmss,
+	.set_mmss64	= ab3100_rtc_set_mmss,
 	.read_alarm	= ab3100_rtc_read_alarm,
 	.set_alarm	= ab3100_rtc_set_alarm,
 	.alarm_irq_enable = ab3100_rtc_irq_enable,
-- 
1.9.1