drivers: counter: stm32_rtc: manage EXTI line in a proper manner

Instead of hardcoded EXTI line numbers and raw LL API calls, align the
STM32 RTC Counter driver with its Real-Time Clock counterpart:
- obtain EXTI line number from Devicetree
- use the EXTI INTC API instead of raw LL API calls

Fixes the build issue observed on STM32N6.

Signed-off-by: Mathieu Choplain <mathieu.choplain-ext@st.com>

Author: mathieuchopstm

drivers/counter/counter_stm32_rtc.c

@@ -85,28 +85,9 @@ LOG_MODULE_REGISTER(counter_rtc_stm32, CONFIG_COUNTER_LOG_LEVEL);
 /* Seconds from 1970-01-01T00:00:00 to 2000-01-01T00:00:00 */
 #define T_TIME_OFFSET 946684800
 
-#if defined(CONFIG_SOC_SERIES_STM32L4X)
-#define RTC_EXTI_LINE	LL_EXTI_LINE_18
-#elif defined(CONFIG_SOC_SERIES_STM32C0X) \
-	|| defined(CONFIG_SOC_SERIES_STM32G0X)
-#define RTC_EXTI_LINE	LL_EXTI_LINE_19
-#elif defined(CONFIG_SOC_SERIES_STM32F4X) \
-	|| defined(CONFIG_SOC_SERIES_STM32C5X) \
-	|| defined(CONFIG_SOC_SERIES_STM32F0X) \
-	|| defined(CONFIG_SOC_SERIES_STM32F1X) \
-	|| defined(CONFIG_SOC_SERIES_STM32F2X) \
-	|| defined(CONFIG_SOC_SERIES_STM32F3X) \
-	|| defined(CONFIG_SOC_SERIES_STM32F7X) \
-	|| defined(CONFIG_SOC_SERIES_STM32WBX) \
-	|| defined(CONFIG_SOC_SERIES_STM32G4X) \
-	|| defined(CONFIG_SOC_SERIES_STM32L0X) \
-	|| defined(CONFIG_SOC_SERIES_STM32L1X) \
-	|| defined(CONFIG_SOC_SERIES_STM32L5X) \
-	|| defined(CONFIG_SOC_SERIES_STM32H7X) \
-	|| defined(CONFIG_SOC_SERIES_STM32H5X) \
-	|| defined(CONFIG_SOC_SERIES_STM32WLX)
-#define RTC_EXTI_LINE	LL_EXTI_LINE_17
-#endif
+#if DT_INST_NODE_HAS_PROP(0, alrm_exti_line)
+#define RTC_EXTI_LINE_NUM DT_INST_PROP(0, alrm_exti_line)
+#endif /* DT_INST_NODE_HAS_PROP(0, alrm_exti_line) */
 
 #if defined(CONFIG_SOC_SERIES_STM32F1X)
 #define COUNTER_NO_DATE
@@ -761,21 +742,9 @@ void rtc_stm32_isr(const struct device *dev)
 		}
 	}
 
-#if defined(CONFIG_SOC_SERIES_STM32H7X) && defined(CONFIG_CPU_CORTEX_M4)
-	LL_C2_EXTI_ClearFlag_0_31(RTC_EXTI_LINE);
-#elif defined(CONFIG_SOC_SERIES_STM32C0X) \
-	|| defined(CONFIG_SOC_SERIES_STM32C5X) \
-	|| defined(CONFIG_SOC_SERIES_STM32G0X) \
-	|| defined(CONFIG_SOC_SERIES_STM32L5X) \
-	|| defined(CONFIG_SOC_SERIES_STM32H5X)
-	LL_EXTI_ClearRisingFlag_0_31(RTC_EXTI_LINE);
-#elif defined(CONFIG_SOC_SERIES_STM32U3X) \
-	|| defined(CONFIG_SOC_SERIES_STM32U5X) \
-	|| defined(CONFIG_SOC_SERIES_STM32WBAX)
-	/* RTC is not connected to EXTI for these SoC series */
-#else
-	LL_EXTI_ClearFlag_0_31(RTC_EXTI_LINE);
-#endif
+#if defined(RTC_EXTI_LINE_NUM)
+	stm32_exti_clear_pending(RTC_EXTI_LINE_NUM);
+#endif /* defined(RTC_EXTI_LINE_NUM) */
 }
 
 
@@ -843,16 +812,16 @@ static int rtc_stm32_init(const struct device *dev)
 	LL_RTC_EnableWriteProtection(STM32_ARG(RTC));
 #endif /* RTC_CR_BYPSHAD */
 
-#if defined(CONFIG_SOC_SERIES_STM32H7X) && defined(CONFIG_CPU_CORTEX_M4)
-	LL_C2_EXTI_EnableIT_0_31(RTC_EXTI_LINE);
-	LL_EXTI_EnableRisingTrig_0_31(RTC_EXTI_LINE);
-#elif defined(CONFIG_SOC_SERIES_STM32U3X) || defined(CONFIG_SOC_SERIES_STM32U5X) || \
-	  defined(CONFIG_SOC_SERIES_STM32WBAX)
-	/* RTC is not connected to EXTI for these SoC series */
-#else
-	LL_EXTI_EnableIT_0_31(RTC_EXTI_LINE);
-	LL_EXTI_EnableRisingTrig_0_31(RTC_EXTI_LINE);
-#endif
+#if defined(RTC_EXTI_LINE_NUM)
+	/* Trigger NVIC IRQ on RTC EXTI line rising edge */
+	ret = stm32_exti_enable(RTC_EXTI_LINE_NUM,
+				STM32_EXTI_TRIG_RISING,
+				STM32_EXTI_MODE_IT);
+	if (ret < 0) {
+		LOG_ERR("Failed to enable RTC EXTI line");
+		goto out_disable_bkup_access;
+	}
+#endif /* defined(RTC_EXTI_LINE_NUM) */
 
 out_disable_bkup_access:
 	stm32_backup_domain_disable_access();