platform: cznic: turris-omnia-mcu: Make poweroff and wakeup code optional

Make the system poweroff and RTC wakeup part of the driver optional,
under a boolean config option. Move the dependency to RTC_CLASS to this
new option.

This makes the turris-omnia-mcu driver available for compilation even if
RTC_CLASS is disabled.

Fixes: ed46f1f ("platform: cznic: turris-omnia-mcu: fix Kconfig dependencies")
Signed-off-by: Marek Behún <kabel@kernel.org>
Link: https://lore.kernel.org/r/20240719085756.30598-4-kabel@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Author: elkablo

drivers/platform/cznic/Kconfig

@@ -18,15 +18,11 @@ config TURRIS_OMNIA_MCU
 	depends on I2C
 	depends on OF
 	depends on GPIOLIB
-	depends on RTC_CLASS
 	select GPIOLIB_IRQCHIP
 	help
 	  Say Y here to add support for the features implemented by the
 	  microcontroller on the CZ.NIC's Turris Omnia SOHO router.
 	  The features include:
-	  - board poweroff into true low power mode (with voltage regulators
-	    disabled) and the ability to configure wake up from this mode (via
-	    rtcwake)
 	  - GPIO pins
 	    - to get front button press events (the front button can be
 	      configured either to generate press events to the CPU or to change
@@ -45,6 +41,15 @@ config TURRIS_OMNIA_MCU
 
 if TURRIS_OMNIA_MCU
 
+config TURRIS_OMNIA_MCU_SYSOFF_WAKEUP
+	bool "Turris Omnia MCU system off and RTC wakeup"
+	default y
+	depends on RTC_CLASS
+	help
+	  Say Y here to add support for CZ.NIC's Turris Omnia board poweroff
+	  into true low power mode (with voltage regulators disabled) and the
+	  ability to configure wake up from this mode (via rtcwake).
+
 config TURRIS_OMNIA_MCU_WATCHDOG
 	bool "Turris Omnia MCU watchdog"
 	default y

drivers/platform/cznic/Makefile

@@ -3,6 +3,6 @@
 obj-$(CONFIG_TURRIS_OMNIA_MCU)	+= turris-omnia-mcu.o
 turris-omnia-mcu-y		:= turris-omnia-mcu-base.o
 turris-omnia-mcu-y		+= turris-omnia-mcu-gpio.o
-turris-omnia-mcu-y		+= turris-omnia-mcu-sys-off-wakeup.o
+turris-omnia-mcu-$(CONFIG_TURRIS_OMNIA_MCU_SYSOFF_WAKEUP)	+= turris-omnia-mcu-sys-off-wakeup.o
 turris-omnia-mcu-$(CONFIG_TURRIS_OMNIA_MCU_TRNG)		+= turris-omnia-mcu-trng.o
 turris-omnia-mcu-$(CONFIG_TURRIS_OMNIA_MCU_WATCHDOG)		+= turris-omnia-mcu-watchdog.o

drivers/platform/cznic/turris-omnia-mcu-base.c

@@ -198,7 +198,9 @@ static const struct attribute_group omnia_mcu_base_group = {
 static const struct attribute_group *omnia_mcu_groups[] = {
 	&omnia_mcu_base_group,
 	&omnia_mcu_gpio_group,
+#ifdef CONFIG_TURRIS_OMNIA_MCU_SYSOFF_WAKEUP
 	&omnia_mcu_poweroff_group,
+#endif
 	NULL
 };
 

drivers/platform/cznic/turris-omnia-mcu.h

@@ -42,10 +42,12 @@ struct omnia_mcu {
 	unsigned long last_status;
 	bool button_pressed_emul;
 
+#ifdef CONFIG_TURRIS_OMNIA_MCU_SYSOFF_WAKEUP
 	/* RTC device for configuring wake-up */
 	struct rtc_device *rtcdev;
 	u32 rtc_alarm;
 	bool front_button_poweron;
+#endif
 
 #ifdef CONFIG_TURRIS_OMNIA_MCU_WATCHDOG
 	/* MCU watchdog */
@@ -188,10 +190,17 @@ static inline int omnia_cmd_read_u8(const struct i2c_client *client, u8 cmd,
 
 extern const u8 omnia_int_to_gpio_idx[32];
 extern const struct attribute_group omnia_mcu_gpio_group;
-extern const struct attribute_group omnia_mcu_poweroff_group;
-
 int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu);
+
+#ifdef CONFIG_TURRIS_OMNIA_MCU_SYSOFF_WAKEUP
+extern const struct attribute_group omnia_mcu_poweroff_group;
 int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu);
+#else
+static inline int omnia_mcu_register_sys_off_and_wakeup(struct omnia_mcu *mcu)
+{
+	return 0;
+}
+#endif
 
 #ifdef CONFIG_TURRIS_OMNIA_MCU_TRNG
 int omnia_mcu_register_trng(struct omnia_mcu *mcu);