rtc: max31335: add driver support

RTC driver for MAX31335 ±2ppm Automotive Real-Time Clock with
Integrated MEMS Resonator.

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Link: https://lore.kernel.org/r/20231120120114.48657-2-antoniu.miclaus@analog.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

Author: amiclaus

MAINTAINERS

@@ -12986,6 +12986,14 @@ F:	Documentation/devicetree/bindings/hwmon/adi,max31827.yaml
 F:	Documentation/hwmon/max31827.rst
 F:	drivers/hwmon/max31827.c
 
+MAX31335 RTC DRIVER
+M:	Antoniu Miclaus <antoniu.miclaus@analog.com>
+L:	linux-rtc@vger.kernel.org
+S:	Supported
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/rtc/adi,max31335.yaml
+F:	drivers/rtc/rtc-max31335.c
+
 MAX6650 HARDWARE MONITOR AND FAN CONTROLLER DRIVER
 L:	linux-hwmon@vger.kernel.org
 S:	Orphan

drivers/rtc/Kconfig

@@ -373,6 +373,19 @@ config RTC_DRV_MAX8997
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-max8997.
 
+config RTC_DRV_MAX31335
+	tristate "Analog Devices MAX31335"
+	depends on I2C
+	depends on COMMON_CLK
+	depends on HWMON || HWMON=n
+	select REGMAP_I2C
+	help
+	  If you say yes here you get support for the Analog Devices
+	  MAX31335.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called rtc-max31335.
+
 config RTC_DRV_MAX77686
 	tristate "Maxim MAX77686"
 	depends on MFD_MAX77686 || MFD_MAX77620 || MFD_MAX77714 || COMPILE_TEST

drivers/rtc/Makefile

@@ -89,6 +89,7 @@ obj-$(CONFIG_RTC_DRV_M48T35)	+= rtc-m48t35.o
 obj-$(CONFIG_RTC_DRV_M48T59)	+= rtc-m48t59.o
 obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o
 obj-$(CONFIG_RTC_DRV_MA35D1)	+= rtc-ma35d1.o
+obj-$(CONFIG_RTC_DRV_MAX31335)	+= rtc-max31335.o
 obj-$(CONFIG_RTC_DRV_MAX6900)	+= rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)	+= rtc-max6902.o
 obj-$(CONFIG_RTC_DRV_MAX6916)	+= rtc-max6916.o