spi: add support for microchip fpga spi controllers

Add a driver for Microchip FPGA SPI controllers, specifically
supporting the "hard" controllers on PolarFire SoC.

Co-developed-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Daire McNamara <daire.mcnamara@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20220607073833.2331539-2-conor.dooley@microchip.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/Kconfig

@@ -575,6 +575,15 @@ config SPI_MESON_SPIFC
 	  This enables master mode support for the SPIFC (SPI flash
 	  controller) available in Amlogic Meson SoCs.
 
+config SPI_MICROCHIP_CORE
+	tristate "Microchip FPGA SPI controllers"
+	depends on SPI_MASTER
+	help
+	  This enables the SPI driver for Microchip FPGA SPI controllers.
+	  Say Y or M here if you want to use the "hard" controllers on
+	  PolarFire SoC.
+	  If built as a module, it will be called spi-microchip-core.
+
 config SPI_MT65XX
 	tristate "MediaTek SPI controller"
 	depends on ARCH_MEDIATEK || COMPILE_TEST

drivers/spi/Makefile

@@ -71,6 +71,7 @@ obj-$(CONFIG_SPI_LM70_LLP)		+= spi-lm70llp.o
 obj-$(CONFIG_SPI_LP8841_RTC)		+= spi-lp8841-rtc.o
 obj-$(CONFIG_SPI_MESON_SPICC)		+= spi-meson-spicc.o
 obj-$(CONFIG_SPI_MESON_SPIFC)		+= spi-meson-spifc.o
+obj-$(CONFIG_SPI_MICROCHIP_CORE)	+= spi-microchip-core.o
 obj-$(CONFIG_SPI_MPC512x_PSC)		+= spi-mpc512x-psc.o
 obj-$(CONFIG_SPI_MPC52xx_PSC)		+= spi-mpc52xx-psc.o
 obj-$(CONFIG_SPI_MPC52xx)		+= spi-mpc52xx.o