[PATCH 1/2] rtc: add stubs for when CONFIG_RTC_CLASS is disabled

[PATCH 1/2] rtc: add stubs for when CONFIG_RTC_CLASS is disabled

[Ahmad Fatoum]

To allow using the RTC API in files that may optionally be
compiled with RTC support disabled, add dummy stubs.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 include/linux/rtc.h | 13 +++++++++++++
 include/rtc.h       | 10 ++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 3c5bb8c8dfc1..4fa999723de1 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -19,6 +19,8 @@
 #include <linux/nvmem-provider.h>
 #include <rtc.h>
 
+struct rtc_time;
+
 extern int rtc_month_days(unsigned int month, unsigned int year);
 extern int rtc_valid_tm(struct rtc_time *tm);
 extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
@@ -40,8 +42,19 @@ struct rtc_class_ops {
 
 extern int rtc_register(struct rtc_device *rtcdev);
 
+#ifdef CONFIG_RTC_CLASS
 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
+#else
+static inline int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm)
+{
+	return -ENOSYS;
+}
+static inline int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
+{
+	return -ENOSYS;
+}
+#endif
 
 static inline bool is_leap_year(unsigned int year)
 {
diff --git a/include/rtc.h b/include/rtc.h
index d7e103d163bc..0766f0408216 100644
--- a/include/rtc.h
+++ b/include/rtc.h
@@ -10,6 +10,8 @@
 #ifndef _RTC_H_
 #define _RTC_H_
 
+#include <linux/err.h>
+
 /*
  * The struct used to pass data from the generic interface code to
  * the hardware dependend low-level code ande vice versa. Identical
@@ -40,7 +42,15 @@ void to_tm (int, struct rtc_time *);
 unsigned long mktime (unsigned int, unsigned int, unsigned int,
 		      unsigned int, unsigned int, unsigned int);
 
+struct rtc_device;
+#ifdef CONFIG_RTC_CLASS
 extern struct rtc_device *rtc_lookup(const char *name);
+#else
+static inline struct rtc_device *rtc_lookup(const char *name)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif
 
 const char *time_str(struct rtc_time *tm);
 
-- 
2.39.2

[PATCH 2/2] rtc: return first RTC when rtc_lookup(NULL) is called

[Ahmad Fatoum]

We assume e.g. in hwclock, that we will have a rtc0 if we have any RTCs
at all. Instead of hardcoding specific names, let's just have
rtc_lookup(NULL) return the first best RTC.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 drivers/rtc/class.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c
index 3d6cfd6197a7..c09ec3f61ea2 100644
--- a/drivers/rtc/class.c
+++ b/drivers/rtc/class.c
@@ -18,11 +18,8 @@ struct rtc_device *rtc_lookup(const char *name)
 {
 	struct rtc_device *r;
 
-	if (!name)
-		return ERR_PTR(-ENODEV);
-
 	for_each_rtc(r) {
-		if (!strcmp(dev_name(&r->class_dev), name))
+		if (!name || !strcmp(dev_name(&r->class_dev), name))
 			return r;
 	}
 
-- 
2.39.2

Re: [PATCH 1/2] rtc: add stubs for when CONFIG_RTC_CLASS is disabled

[Sascha Hauer]

On Tue, 16 Jul 2024 14:03:29 +0200, Ahmad Fatoum wrote:
> To allow using the RTC API in files that may optionally be
> compiled with RTC support disabled, add dummy stubs.
> 
> 

Applied, thanks!

[1/2] rtc: add stubs for when CONFIG_RTC_CLASS is disabled
      https://git.pengutronix.de/cgit/barebox/commit/?id=7355b2e392e3 (link may not be stable)
[2/2] rtc: return first RTC when rtc_lookup(NULL) is called
      https://git.pengutronix.de/cgit/barebox/commit/?id=5e1c582171c8 (link may not be stable)

Best regards,
-- 
Sascha Hauer <s.hauer@pengutronix.de>