spi: sifive: Add driver for the SiFive SPI controller

Add driver for the SiFive SPI controller
on the HiFive Unleashed board.
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Emil Renner Berthing <kernel@esmil.dk>
Signed-off-by: Yash Shah <yash.shah@sifive.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/Kconfig

@@ -651,6 +651,12 @@ config SPI_SH_HSPI
 	help
 	  SPI driver for SuperH HSPI blocks.
 
+config SPI_SIFIVE
+	tristate "SiFive SPI controller"
+	depends on HAS_IOMEM
+	help
+	  This exposes the SPI controller IP from SiFive.
+
 config SPI_SIRF
 	tristate "CSR SiRFprimaII SPI controller"
 	depends on SIRF_DMA

drivers/spi/Makefile

@@ -95,6 +95,7 @@ obj-$(CONFIG_SPI_SH)			+= spi-sh.o
 obj-$(CONFIG_SPI_SH_HSPI)		+= spi-sh-hspi.o
 obj-$(CONFIG_SPI_SH_MSIOF)		+= spi-sh-msiof.o
 obj-$(CONFIG_SPI_SH_SCI)		+= spi-sh-sci.o
+obj-$(CONFIG_SPI_SIFIVE)		+= spi-sifive.o
 obj-$(CONFIG_SPI_SIRF)		+= spi-sirf.o
 obj-$(CONFIG_SPI_SLAVE_MT27XX)          += spi-slave-mt27xx.o
 obj-$(CONFIG_SPI_SPRD)			+= spi-sprd.o