spi: Add driver for the RZ/V2H(P) RSPI IP

The Renesas RZ/V2H(P) RSPI IP supports 4-wire and 3-wire
serial communications in both host role and target role.
It can use a DMA, but the I/O can also be driven by the
processor.

RX-only, TX-only, and RX-TX operations are available in
DMA mode, while in processor I/O mode it only RX-TX
operations are supported.

Add a driver to support 4-wire serial communications as
host role in processor I/O mode.

Signed-off-by: Fabrizio Castro <[email protected]>

Link: https://patch.msgid.link/[email protected]
Signed-off-by: Mark Brown <[email protected]>

Author: Fabrizio Castro

drivers/spi/Kconfig

@@ -923,6 +923,14 @@ config SPI_RSPI
 	help
 	  SPI driver for Renesas RSPI and QSPI blocks.
 
+config SPI_RZV2H_RSPI
+	tristate "Renesas RZ/V2H RSPI controller"
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  RSPI driver for the Renesas RZ/V2H Serial Peripheral Interface (RSPI).
+	  RSPI supports both SPI host and SPI target roles. This option only
+	  enables the SPI host role.
+
 config SPI_RZV2M_CSI
 	tristate "Renesas RZ/V2M CSI controller"
 	depends on ARCH_RENESAS || COMPILE_TEST

drivers/spi/Makefile

@@ -126,6 +126,7 @@ obj-$(CONFIG_MACH_REALTEK_RTL)		+= spi-realtek-rtl.o
 obj-$(CONFIG_SPI_REALTEK_SNAND)		+= spi-realtek-rtl-snand.o
 obj-$(CONFIG_SPI_RPCIF)			+= spi-rpc-if.o
 obj-$(CONFIG_SPI_RSPI)			+= spi-rspi.o
+obj-$(CONFIG_SPI_RZV2H_RSPI)		+= spi-rzv2h-rspi.o
 obj-$(CONFIG_SPI_RZV2M_CSI)		+= spi-rzv2m-csi.o
 obj-$(CONFIG_SPI_S3C64XX)		+= spi-s3c64xx.o
 obj-$(CONFIG_SPI_SC18IS602)		+= spi-sc18is602.o