spi_nxp_lpspi: Use default RTIO submit

For the CPU-based drivers, delete the old MCUX based RTIO driver and use
the default RTIO submit implementation instead.

Rationale:
- 300 LOC -> 1 LOC to maintain.
- MCUX SDK based driver cannot control the chip select for the transfer
  properly, but the new spi_nxp_lpspi.c driver can. So this fixes the
  bug with the PCS when using RTIO.

Also enable the default RTIO implementation for DMA based driver.
In the future a DMA based RTIO driver with custom implementation can be
designed, but for CPU based transfer, which is already not optimal
performance, code maintenance is more important. Only requirement is
asynchronous submit, which is accomplished by p4wq in rtio workq.

Signed-off-by: Declan Snyder <[email protected]>

Author: decsny

drivers/spi/spi_nxp_lpspi/CMakeLists.txt

@@ -3,4 +3,3 @@
 zephyr_library_sources_ifdef(CONFIG_SPI_MCUX_LPSPI spi_nxp_lpspi_common.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_MCUX_LPSPI_NORMAL spi_nxp_lpspi.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_MCUX_LPSPI_DMA spi_nxp_lpspi_dma.c)
-zephyr_library_sources_ifdef(CONFIG_SPI_MCUX_LPSPI_RTIO spi_mcux_lpspi_rtio.c)

drivers/spi/spi_nxp_lpspi/Kconfig

@@ -12,7 +12,6 @@ config SPI_MCUX_LPSPI
 
 if SPI_MCUX_LPSPI
 
-if !SPI_RTIO
 config SPI_MCUX_LPSPI_DMA
 	bool "MCUX LPSPI SPI DMA Support"
 	select DMA
@@ -27,25 +26,5 @@ config SPI_MCUX_LPSPI_NORMAL
 	depends on $(dt_compat_any_not_has_prop,$(DT_COMPAT_NXP_LPSPI),dmas) || !SPI_MCUX_LPSPI_DMA
 	help
 	  Use the traditional (non-RTIO) SPI driver for NXP LPSPI.
-endif # !SPI_RTIO
-
-if SPI_RTIO
-config SPI_MCUX_LPSPI_RTIO
-	bool "NXP MCUX LPSPI RTIO based driver"
-	default y
-	help
-	  Use the RTIO-based SPI driver for the NXP LPSPI.
-
-config SPI_MCUX_RTIO_SQ_SIZE
-	int "number of available submission queue entries"
-	default 8 # sensible default that covers most common spi transactions
-	help
-	  when rtio is use with spi each driver holds a context with which blocking
-	  api calls use to perform spi transactions. this queue needs to be as deep
-	  as the longest set of spi_buf_sets used, where normal spi operations are
-	  used (equal length buffers). it may need to be slightly deeper where the
-	  spi buffer sets for transmit/receive are not always matched equally in
-	  length as these are transformed into normal transceives.
-endif # SPI_RTIO
 
 endif # SPI_MCUX_LPSPI

drivers/spi/spi_nxp_lpspi/spi_mcux_lpspi_rtio.c

@@ -319,6 +319,9 @@ static DEVICE_API(spi, spi_mcux_driver_api) = {
 	.transceive = spi_mcux_transceive_sync,
 #ifdef CONFIG_SPI_ASYNC
 	.transceive_async = spi_mcux_transceive_async,
+#endif
+#ifdef CONFIG_SPI_RTIO
+	.iodev_submit = spi_rtio_iodev_default_submit,
 #endif
 	.release = spi_mcux_release,
 };

drivers/spi/spi_nxp_lpspi/spi_nxp_lpspi.c

@@ -388,6 +388,9 @@ static DEVICE_API(spi, spi_mcux_driver_api) = {
 	.transceive = spi_nxp_dma_transceive_sync,
 #ifdef CONFIG_SPI_ASYNC
 	.transceive_async = spi_nxp_dma_transceive_async,
+#endif
+#ifdef CONFIG_SPI_RTIO
+	.iodev_submit = spi_rtio_iodev_default_submit,
 #endif
 	.release = spi_mcux_release,
 };

drivers/spi/spi_nxp_lpspi/spi_nxp_lpspi_dma.c

@@ -5,6 +5,7 @@
  */
 
 #include <zephyr/drivers/spi.h>
+#include <zephyr/drivers/spi/rtio.h>
 #include <zephyr/drivers/pinctrl.h>
 #include <zephyr/drivers/clock_control.h>
 #include <zephyr/irq.h>