spi: amlogic: add driver for Amlogic SPI Flash Controller

This driver provides support for the SPI mode of the Amlogic
Flash Controller. It supports both SPI NOR flash and SPI NAND
flash. For SPI NAND, the Host ECC hardware engine can be enabled.

The controller implements the SPI-MEM interface and does not
support generic SPI.

Signed-off-by: Feng Chen <feng.chen@amlogic.com>
Signed-off-by: Xianwei Zhao <xianwei.zhao@amlogic.com>
Link: https://patch.msgid.link/20250910-spifc-v6-2-1574aa9baebd@amlogic.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Feng Chen

drivers/spi/Kconfig

@@ -99,6 +99,16 @@ config SPI_AMLOGIC_SPIFC_A1
 	  This enables master mode support for the SPIFC (SPI flash
 	  controller) available in Amlogic A1 (A113L SoC).
 
+config SPI_AMLOGIC_SPIFC_A4
+	tristate "Amlogic A4 SPI Flash controller"
+	depends on ARCH_MESON || COMPILE_TEST
+	select REGMAP_MMIO
+	help
+	  This enables SPI mode on the NAND Flash Controller of Amlogic
+	  ARM SoCs. It supports SPI Nor Flash and SPI NAND Flash (Could
+	  enable Host ECC HW engine). The controller implements the
+	  SPI-MEM interface, it doesn't support generic SPI.
+
 config SPI_AMLOGIC_SPISG
 	tristate "Amlogic SPISG controller"
 	depends on COMMON_CLK

drivers/spi/Makefile

@@ -20,6 +20,7 @@ obj-$(CONFIG_SPI_ALTERA)		+= spi-altera-platform.o
 obj-$(CONFIG_SPI_ALTERA_CORE)		+= spi-altera-core.o
 obj-$(CONFIG_SPI_ALTERA_DFL)		+= spi-altera-dfl.o
 obj-$(CONFIG_SPI_AMLOGIC_SPIFC_A1)	+= spi-amlogic-spifc-a1.o
+obj-$(CONFIG_SPI_AMLOGIC_SPIFC_A4)	+= spi-amlogic-spifc-a4.o
 obj-$(CONFIG_SPI_AMLOGIC_SPISG)		+= spi-amlogic-spisg.o
 obj-$(CONFIG_SPI_APPLE)			+= spi-apple.o
 obj-$(CONFIG_SPI_AR934X)		+= spi-ar934x.o