drivers: rtc: rtc_mc146818: Added RTC driver for Motorola MC146818B

Added RTC driver that supports Motorola MC146818B
Enabled RTC set/get time and alarm, alarm callback
and update callback.

Counter and RTC uses same hardware in case of
Motorola MC146818, so they can't be used at a time.

Updated stand-alone mc146818 counter dts instances
to support rtc and counter with same compatible
string of "motorola,mc146818" on ia32, atom,
apollo_lake, elhart_lake and raptor_lake platforms.

Signed-off-by: Anisetti Avinash Krishna <[email protected]>

Author: akanisetti

boards/x86/ehl_crb/ehl_crb.dts

@@ -21,4 +21,8 @@
 		zephyr,console = &uart2;
 		zephyr,shell-uart = &uart2;
 	};
+
+	aliases {
+		rtc = &rtc;
+	};
 };

boards/x86/ehl_crb/ehl_crb.yaml

@@ -9,6 +9,7 @@ ram: 2048
 supported:
   - gpio
   - smbus
+  - rtc
 testing:
   ignore_tags:
     - net

boards/x86/qemu_x86/qemu_x86.dts

@@ -29,6 +29,7 @@
 		uart-1 = &uart1;
 		eeprom-0 = &eeprom0;
 		eeprom-1 = &eeprom1;
+		rtc = &rtc;
 	};
 
 	chosen {

boards/x86/rpl_crb/rpl_crb.dts

@@ -23,5 +23,6 @@
 
 	aliases {
 		watchdog0 = &tco_wdt;
+		rtc = &rtc;
 	};
 };

boards/x86/rpl_crb/rpl_crb.yaml

@@ -8,6 +8,7 @@ ram: 2048
 supported:
   - smbus
   - watchdog
+  - rtc
 testing:
   ignore_tags:
     - net

drivers/counter/Kconfig.cmos

@@ -5,5 +5,5 @@
 
 config COUNTER_CMOS
 	bool "Counter driver for x86 CMOS/RTC clock"
-	default y
+	default y if !RTC
 	depends on DT_HAS_MOTOROLA_MC146818_ENABLED

drivers/rtc/CMakeLists.txt

@@ -6,3 +6,4 @@ zephyr_library()
 zephyr_library_sources_ifdef(CONFIG_USERSPACE rtc_handlers.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_EMUL rtc_emul.c)
 zephyr_library_sources_ifdef(CONFIG_RTC_PCF8523 rtc_pcf8523.c)
+zephyr_library_sources_ifdef(CONFIG_RTC_MOTOROLA_MC146818 rtc_mc146818.c)

drivers/rtc/Kconfig

@@ -37,5 +37,6 @@ config RTC_CALIBRATION
 
 source "drivers/rtc/Kconfig.emul"
 source "drivers/rtc/Kconfig.pcf8523"
+source "drivers/rtc/Kconfig.mc146818"
 
 endif # RTC

drivers/rtc/Kconfig.mc146818

@@ -0,0 +1,9 @@
+# Intel SoC RTC configuration options
+
+# Copyright (c) 2023 Intel Corporation
+# SPDX-License-Identifier: Apache-2.0
+
+config RTC_MOTOROLA_MC146818
+	bool "RTC driver for x86 CMOS/RTC clock"
+	default y if !COUNTER
+	depends on DT_HAS_MOTOROLA_MC146818_ENABLED