[PATCH] ARM: RTC: allow driver methods to return error

Allow RTC drivers to return error codes from their read_time
or read_alarm methods.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>

arch/arm/common/rtctime.c

@@ -141,10 +141,10 @@ void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now, struct rtc
 	next->tm_sec = alrm->tm_sec;
 }
 
-static inline void rtc_read_time(struct rtc_ops *ops, struct rtc_time *tm)
+static inline int rtc_read_time(struct rtc_ops *ops, struct rtc_time *tm)
 {
 	memset(tm, 0, sizeof(struct rtc_time));
-	ops->read_time(tm);
+	return ops->read_time(tm);
 }
 
 static inline int rtc_set_time(struct rtc_ops *ops, struct rtc_time *tm)
@@ -163,8 +163,7 @@ static inline int rtc_read_alarm(struct rtc_ops *ops, struct rtc_wkalrm *alrm)
 	int ret = -EINVAL;
 	if (ops->read_alarm) {
 		memset(alrm, 0, sizeof(struct rtc_wkalrm));
-		ops->read_alarm(alrm);
-		ret = 0;
+		ret = ops->read_alarm(alrm);
 	}
 	return ret;
 }
@@ -283,7 +282,9 @@ static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 		break;
 
 	case RTC_RD_TIME:
-		rtc_read_time(ops, &tm);
+		ret = rtc_read_time(ops, &tm);
+		if (ret)
+			break;
 		ret = copy_to_user(uarg, &tm, sizeof(tm));
 		if (ret)
 			ret = -EFAULT;
@@ -424,8 +425,7 @@ static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eo
 	struct rtc_time tm;
 	char *p = page;
 
-	rtc_read_time(ops, &tm);
-
+	if (rtc_read_time(ops, &tm) == 0) {
 		p += sprintf(p,
 			"rtc_time\t: %02d:%02d:%02d\n"
 			"rtc_date\t: %04d-%02d-%02d\n"
@@ -433,6 +433,7 @@ static int rtc_read_proc(char *page, char **start, off_t off, int count, int *eo
 			tm.tm_hour, tm.tm_min, tm.tm_sec,
 			tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 			rtc_epoch);
+	}
 
 	if (rtc_read_alarm(ops, &alrm) == 0) {
 		p += sprintf(p, "alrm_time\t: ");

arch/arm/mach-integrator/time.c

@@ -40,25 +40,32 @@ static int integrator_set_rtc(void)
 	return 1;
 }
 
-static void rtc_read_alarm(struct rtc_wkalrm *alrm)
+static int rtc_read_alarm(struct rtc_wkalrm *alrm)
 {
 	rtc_time_to_tm(readl(rtc_base + RTC_MR), &alrm->time);
+	return 0;
 }
 
-static int rtc_set_alarm(struct rtc_wkalrm *alrm)
+static inline int rtc_set_alarm(struct rtc_wkalrm *alrm)
 {
 	unsigned long time;
 	int ret;
 
+	/*
+	 * At the moment, we can only deal with non-wildcarded alarm times.
+	 */
+	ret = rtc_valid_tm(&alrm->time);
+	if (ret == 0)
 		ret = rtc_tm_to_time(&alrm->time, &time);
 	if (ret == 0)
 		writel(time, rtc_base + RTC_MR);
 	return ret;
 }
 
-static void rtc_read_time(struct rtc_time *tm)
+static int rtc_read_time(struct rtc_time *tm)
 {
 	rtc_time_to_tm(readl(rtc_base + RTC_DR), tm);
+	return 0;
 }
 
 /*
@@ -69,7 +76,7 @@ static void rtc_read_time(struct rtc_time *tm)
  * edge of the 1Hz clock, we must write the time one second
  * in advance.
  */
-static int rtc_set_time(struct rtc_time *tm)
+static inline int rtc_set_time(struct rtc_time *tm)
 {
 	unsigned long time;
 	int ret;

drivers/char/s3c2410-rtc.c

@@ -116,7 +116,7 @@ static void s3c2410_rtc_setfreq(int freq)
 
 /* Time read/write */
 
-static void s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
+static int s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
 {
 	unsigned int have_retried = 0;
 
@@ -151,6 +151,8 @@ static void s3c2410_rtc_gettime(struct rtc_time *rtc_tm)
 
 	rtc_tm->tm_year += 100;
 	rtc_tm->tm_mon -= 1;
+
+	return 0;
 }
 
 
@@ -171,7 +173,7 @@ static int s3c2410_rtc_settime(struct rtc_time *tm)
 	return 0;
 }
 
-static void s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
+static int s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
 {
 	struct rtc_time *alm_tm = &alrm->time;
 	unsigned int alm_en;
@@ -231,6 +233,8 @@ static void s3c2410_rtc_getalarm(struct rtc_wkalrm *alrm)
 	}
 
 	/* todo - set alrm->enabled ? */
+
+	return 0;
 }
 
 static int s3c2410_rtc_setalarm(struct rtc_wkalrm *alrm)

include/asm-arm/rtc.h

@@ -18,9 +18,9 @@ struct rtc_ops {
 	void		(*release)(void);
 	int		(*ioctl)(unsigned int, unsigned long);
 
-	void		(*read_time)(struct rtc_time *);
+	int		(*read_time)(struct rtc_time *);
 	int		(*set_time)(struct rtc_time *);
-	void		(*read_alarm)(struct rtc_wkalrm *);
+	int		(*read_alarm)(struct rtc_wkalrm *);
 	int		(*set_alarm)(struct rtc_wkalrm *);
 	int		(*proc)(char *buf);
 };