drivers: spi: Add support for half-duplex (3-wire) SPI

Add support for half-duplex (3-wire) SPI operation using the Raspberry Pi Pico PIO. To allow control of the size of the driver, including half-duplex support is optional, under the control of Kconfig options. The original PIO source code is also included as a reference. Signed-off-by: Steve Boylan <[email protected]>
zephyrproject-rtos · Feb 29, 2024 · d842eb4 · d842eb4
1 parent a48c958
commit d842eb4
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diff --git a/drivers/spi/Kconfig.rpi_pico b/drivers/spi/Kconfig.rpi_pico
@@ -9,3 +9,31 @@ config SPI_RPI_PICO_PIO
 	select PICOSDK_USE_CLAIM
 	help
 	  Enable driving SPI via PIO on the PICO
+
+if SPI_RPI_PICO_PIO
+
+config SPI_RPI_PICO_PIO_HALF_DUPLEX
+	bool "PIO half-duplex support"
+	help
+	  Enable half-duplex (3-wire) operation.
+
+config SPI_RPI_PICO_PIO_8_BIT
+	bool "PIO 8-bit support"
+	default y
+	help
+	  Enable any addtional code needed to
+	  support 8-bit transfers.
+
+config SPI_RPI_PICO_PIO_16_BIT
+	bool "PIO 16-bit support"
+	help
+	  Enable any addtional code needed to
+	  support 16-bit transfers.
+
+config SPI_RPI_PICO_PIO_32_BIT
+	bool "PIO 32-bit support"
+	help
+	  Enable any addtional code needed to
+	  support 32-bit transfers.
+
+endif