drivers: clock: stm32 common: update ahb prescaler

STM32C0 have a different prescaler for SYSCLK and for HCLK.
Updates the clock driver to use the appropriate prescaler for each series.

Signed-off-by: Guillaume Gautier <[email protected]>

Author: gautierg-st

drivers/clock_control/clock_stm32_ll_common.c

@@ -24,8 +24,13 @@
 #define z_hsi_divider(v) LL_RCC_HSI_DIV_ ## v
 #define hsi_divider(v) z_hsi_divider(v)
 
+#if defined(LL_RCC_HCLK_DIV_1)
+#define fn_ahb_prescaler(v) LL_RCC_HCLK_DIV_ ## v
+#define ahb_prescaler(v) fn_ahb_prescaler(v)
+#else
 #define fn_ahb_prescaler(v) LL_RCC_SYSCLK_DIV_ ## v
 #define ahb_prescaler(v) fn_ahb_prescaler(v)
+#endif
 
 #define fn_apb1_prescaler(v) LL_RCC_APB1_DIV_ ## v
 #define apb1_prescaler(v) fn_apb1_prescaler(v)
@@ -537,7 +542,7 @@ static void set_up_plls(void)
 	 */
 	if (LL_RCC_GetSysClkSource() == LL_RCC_SYS_CLKSOURCE_STATUS_PLL) {
 		stm32_clock_switch_to_hsi();
-		LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_1);
+		LL_RCC_SetAHBPrescaler(ahb_prescaler(1));
 	}
 	LL_RCC_PLL_Disable();
 
@@ -800,9 +805,9 @@ int stm32_clock_control_init(const struct device *dev)
 	set_up_plls();
 
 	if (DT_PROP(DT_NODELABEL(rcc), undershoot_prevention) &&
-		(STM32_CORE_PRESCALER == LL_RCC_SYSCLK_DIV_1) &&
+		(ahb_prescaler(STM32_CORE_PRESCALER) == ahb_prescaler(1)) &&
 		(MHZ(80) < CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC)) {
-		LL_RCC_SetAHBPrescaler(LL_RCC_SYSCLK_DIV_2);
+		LL_RCC_SetAHBPrescaler(ahb_prescaler(2));
 	} else {
 		LL_RCC_SetAHBPrescaler(ahb_prescaler(STM32_CORE_PRESCALER));
 	}
@@ -827,7 +832,7 @@ int stm32_clock_control_init(const struct device *dev)
 #endif /* STM32_SYSCLK_SRC_... */
 
 	if (DT_PROP(DT_NODELABEL(rcc), undershoot_prevention) &&
-		(STM32_CORE_PRESCALER == LL_RCC_SYSCLK_DIV_1) &&
+		(ahb_prescaler(STM32_CORE_PRESCALER) == ahb_prescaler(1)) &&
 		(MHZ(80) < CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC)) {
 		LL_RCC_SetAHBPrescaler(ahb_prescaler(STM32_CORE_PRESCALER));
 	}