drivers/flash: stm32wb: Add HSEM

Add HSEM for Flash access since shared between 2 cores.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

drivers/flash/flash_stm32.c

@@ -34,19 +34,33 @@
 #define STM32_FLASH_TIMEOUT	(K_MSEC(25))
 #endif
 
+#define CFG_HW_FLASH_SEMID	2
+
 /*
  * This is named flash_stm32_sem_take instead of flash_stm32_lock (and
  * similarly for flash_stm32_sem_give) to avoid confusion with locking
  * actual flash pages.
  */
 static inline void flash_stm32_sem_take(struct device *dev)
 {
+
+#ifdef CONFIG_SOC_SERIES_STM32WBX
+	while (LL_HSEM_1StepLock(HSEM, CFG_HW_FLASH_SEMID))
+		;
+#endif /* CONFIG_SOC_SERIES_STM32WBX */
+
 	k_sem_take(&FLASH_STM32_PRIV(dev)->sem, K_FOREVER);
 }
 
 static inline void flash_stm32_sem_give(struct device *dev)
 {
+
 	k_sem_give(&FLASH_STM32_PRIV(dev)->sem);
+
+#ifdef CONFIG_SOC_SERIES_STM32WBX
+	LL_HSEM_ReleaseLock(HSEM, CFG_HW_FLASH_SEMID, 0);
+#endif /* CONFIG_SOC_SERIES_STM32WBX */
+
 }
 
 #if !defined(CONFIG_SOC_SERIES_STM32WBX)
@@ -279,6 +293,10 @@ static int stm32_flash_init(struct device *dev)
 	}
 #endif
 
+#ifdef CONFIG_SOC_SERIES_STM32WBX
+	LL_AHB3_GRP1_EnableClock(LL_AHB3_GRP1_PERIPH_HSEM);
+#endif /* CONFIG_SOC_SERIES_STM32WBX */
+
 	k_sem_init(&p->sem, 1, 1);
 
 	return flash_stm32_write_protection(dev, false);

soc/arm/st_stm32/stm32wb/soc.h

@@ -43,6 +43,10 @@
 #include <stm32wbxx_ll_system.h>
 #endif /* CONFIG_CLOCK_CONTROL_STM32_CUBE */
 
+#ifdef CONFIG_FLASH
+#include <stm32wbxx_ll_hsem.h>
+#endif /* CONFIG_FLASH */
+
 #endif /* !_ASMLANGUAGE */
 
 #endif /* _STM32WBX_SOC_H_ */