STM32: Add SPI RTIO support

drivers/spi/Kconfig.stm32

@@ -15,6 +15,7 @@ if SPI_STM32
 
 config SPI_STM32_INTERRUPT
 	bool "STM32 MCU SPI Interrupt Support"
+	default y if SPI_RTIO
 	help
 	  Enable Interrupt support for the SPI Driver of STM32 family.
 
@@ -49,4 +50,30 @@ config SPI_STM32_BUSY_FLAG_TIMEOUT
 
 endif # SPI_STM32_ERRATA_BUSY
 
+if SPI_RTIO
+
+config SPI_STM32_RTIO_SQ_SIZE
+	int "Number of available submission queue entries"
+	default 8 # Sensible default that covers most common SPI transactions
+	help
+	  When RTIO is used with SPI, each driver holds a context whose blocking API
+	  calls are used to perform SPI transactions. This queue needs to be as deep
+	  as the longest set of spi_buf_set used, where normal SPI operations are
+	  used (equal length buffers). It may need to be slightly deeper where the
+	  SPI buffers set for transmit/receive do not always matched equally in
+	  length as these are transformed into normal transceives.
+
+config SPI_STM32_RTIO_CQ_SIZE
+	int "Number of available completion queue entries"
+	default 8 # Sensible default that covers most common SPI transactions
+	help
+	  When RTIO is used with SPI, each driver holds a context whose blocking API
+	  calls are used to perform SPI transactions. This queue needs to be as deep
+	  as the longest set of spi_buf_set used, where normal SPI operations are
+	  used (equal length buffers). It may need to be slightly deeper where the
+	  SPI buffers set for transmit/receive do not always matched equally in
+	  length as these are transformed into normal transceives.
+
+endif # SPI_RTIO
+
 endif # SPI_STM32