include: zephyr: drivers: dma: add support for circular DMA

This macro will help us to enable the 5th bit CIRC on the DMA_CCRx
register for all stm32 series having this configuration.
Thus the DMA will be able to handle the circular buffers.

Signed-off-by: Fabrice DJIATSA <[email protected]>
co-authored-by: Cyril Fougeray <[email protected]>

Author: djiatsaf-st

include/zephyr/drivers/dma/dma_stm32.h

@@ -56,6 +56,8 @@
 		DT_INST_DMAS_CELL_BY_IDX(id, idx, channel_config)
 
 /* macros for channel-config */
+/* enable circular buffer */
+#define STM32_DMA_CONFIG_CYCLIC(config)                 ((config >> 5) & 0x1)
 /* direction defined on bits 6-7 */
 /* 0 -> MEM_TO_MEM, 1 -> MEM_TO_PERIPH, 2 -> PERIPH_TO_MEM */
 #define STM32_DMA_CONFIG_DIRECTION(config)		((config >> 6) & 0x3)