drivers: clock: stm32: stm32c03 fail to build

[nandojve]

Describe the bug

The stm32c0 fail to build because of missing apb2_prescaler.

Expected behavior
All stm32 SoC should build with a default value for apb to avoid this issue.

Impact
Not possible to build when using timers3.

include/generated/zephyr/devicetree_generated.h:931:36: error: 'DT_N_S_soc_S_rcc_40021000_P_apb2_prescaler' undeclared (first use in this function); did you mean 'DT_N_S_soc_S_rcc_40021000_P_apb1_prescaler'?
  931 | #define DT_N_NODELABEL_rcc         DT_N_S_soc_S_rcc_40021000
      |                                    ^~~~~~~~~~~~~~~~~~~~~~~~~
include/zephyr/devicetree.h:5231:29: note: in definition of macro 'DT_CAT3'
 5231 | #define DT_CAT3(a1, a2, a3) a1 ## a2 ## a3
      |                             ^~
include/zephyr/drivers/clock_control/stm32_clock_control.h:73:33: note: in expansion of macro 'DT_PROP'
   73 | #define STM32_APB2_PRESCALER    DT_PROP(DT_NODELABEL(rcc), apb2_prescaler)
      |                                 ^~~~~~~

Environment (please complete the following information):

• OS: Linux
• Toolchain Zephyr SDK 0.17
• Commit mainline

[mathieuchopstm]

I have not been able to reproduce this error by building both samples/drivers/counter/alarm/ and tests/drivers/pwm/pwm_api/ for board nucleo_c031c6, and the error message you provided does not indicate in which place the macro is being expanded.

As far as I can tell, there are only three places where STM32_APB2_PRESCALER is used, all of which make sure the property exists before using the macro, so I'm a bit confused as to where it comes from.

Can you please give instructions on how to reproduce the issue?

---

1. Should not cause the error: gated behind property existance check
   

   zephyr/drivers/clock_control/clock_stm32_ll_common.c

   Lines 342 to 344 in 72694a9

   	#if DT_NODE_HAS_PROP(DT_NODELABEL(rcc), apb2_prescaler)
   	uint32_t apb2_clock = get_bus_clock(ahb_clock, STM32_APB2_PRESCALER);
   	#elif defined(STM32_CLOCK_BUS_APB2)

2. Should not cause the error: gated behind !CONFIG_SOC_SERIES_STM32C0X
   

   zephyr/drivers/pwm/pwm_stm32.c

   Lines 248 to 257 in 72694a9

   	#if !defined(CONFIG_SOC_SERIES_STM32C0X) && !defined(CONFIG_SOC_SERIES_STM32F0X) && \
   	!defined(CONFIG_SOC_SERIES_STM32G0X) && !defined(CONFIG_SOC_SERIES_STM32U0X)
   	else {
   	#if defined(CONFIG_SOC_SERIES_STM32MP1X)
   	apb_psc = (uint32_t)(READ_BIT(RCC->APB2DIVR, RCC_APB2DIVR_APB2DIV));
   	#else
   	apb_psc = STM32_APB2_PRESCALER;
   	#endif
   	}
   	#endif

3. Should not cause the error: gated behind !HAS_COMPAT(st,stm32f0-rcc)
   

   zephyr/drivers/counter/counter_ll_stm32_timer.c

   Lines 400 to 408 in 72694a9

   	#if !DT_HAS_COMPAT_STATUS_OKAY(st_stm32f0_rcc)
   	else {
   	#if defined(CONFIG_SOC_SERIES_STM32MP1X)
   	apb_psc = (uint32_t)(READ_BIT(RCC->APB2DIVR, RCC_APB2DIVR_APB2DIV));
   	#else
   	apb_psc = STM32_APB2_PRESCALER;
   	#endif /* CONFIG_SOC_SERIES_STM32MP1X */
   	}
   	#endif /* ! st_stm32f0_rcc */

   
   which is the compatible used by STM32C0 RCC:
   

   zephyr/dts/arm/st/c0/stm32c0.dtsi

   Lines 103 to 104 in 72694a9

   	rcc: rcc@40021000 {
   	compatible = "st,stm32f0-rcc";

[nandojve]

Hi @mathieuchopstm ,

You are right! This was found initially when the #70951 was open. I was searching on mainline about STM32_APB2_PRESCALER, after your report, and found that current PWM driver have a different implementation we have on #70951.

zephyr/drivers/pwm/pwm_stm32.c

Lines 248 to 258 in 88b9cb6

	#if !defined(CONFIG_SOC_SERIES_STM32C0X) && !defined(CONFIG_SOC_SERIES_STM32F0X) && \
	!defined(CONFIG_SOC_SERIES_STM32G0X) && !defined(CONFIG_SOC_SERIES_STM32U0X)
	else {
	#if defined(CONFIG_SOC_SERIES_STM32MP1X)
	apb_psc = (uint32_t)(READ_BIT(RCC->APB2DIVR, RCC_APB2DIVR_APB2DIV));
	#else
	apb_psc = STM32_APB2_PRESCALER;
	#endif
	}
	#endif
	#endif

With this it is not necessary the #83544 patch since the problem was found inside the freq-meter.