[PATCH] rtc: bd70528: fix driver dependencies

From: Matti Vaittinen
Date: Mon Aug 12 2019 - 02:36:32 EST

With CONFIG_BD70528_WATCHDOG=m, a built-in rtc driver cannot call
into the low-level functions that are part of the watchdog module:

drivers/rtc/rtc-bd70528.o: In function `bd70528_set_time':
rtc-bd70528.c:(.text+0x22c): undefined reference to `bd70528_wdt_lock'
rtc-bd70528.c:(.text+0x2a8): undefined reference to `bd70528_wdt_unlock'
drivers/rtc/rtc-bd70528.o: In function `bd70528_set_rtc_based_timers':
rtc-bd70528.c:(.text+0x50c): undefined reference to `bd70528_wdt_set'

Add a Kconfig dependency which forces RTC to be a module if watchdog is a
module. If watchdog is not compiled at all the stub functions for watchdog
control are used. compiling the RTC without watchdog is fine.

Fixes: 32a4a4ebf768 ("rtc: bd70528: Initial support for ROHM bd70528 RTC")
Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Signed-off-by: Matti Vaittinen <matti.vaittinen@xxxxxxxxxxxxxxxxx>
Issue was found by kbuildbot from linux-next. Issue was addressed by
Arnd and Randy - but those solutions disallowed compiling the RTC
without watchdog. This patch is a result of discussion with Arnd and it
was created on top of Linus' tree (tag v5.3-rc4).
drivers/rtc/Kconfig | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index e72f65b61176..add43c337489 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -500,6 +500,7 @@ config RTC_DRV_M41T80_WDT
watchdog timer in the ST M41T60 and M41T80 RTC chips series.
config RTC_DRV_BD70528
tristate "ROHM BD70528 PMIC RTC"
+ depends on MFD_ROHM_BD70528 && (BD70528_WATCHDOG || !BD70528_WATCHDOG)
If you say Y here you will get support for the RTC
on ROHM BD70528 Power Management IC.

Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]