spi: bcmbca-hsspi: Add driver for newer HSSPI controller

The newer BCMBCA SoCs such as BCM6756, BCM4912 and BCM6855 include an
updated SPI controller that add the capability to allow the driver to
control chip select explicitly. Driver can control and keep cs low
between the transfers natively. Hence the dummy cs workaround or prepend
mode found in the bcm63xx-hsspi driver are no longer needed and this new
driver is much cleaner.
Signed-off-by: William Zhang <william.zhang@broadcom.com>
Link: https://lore.kernel.org/r/20230209200246.141520-15-william.zhang@broadcom.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/Kconfig

@@ -199,6 +199,15 @@ config SPI_BCM_QSPI
 	  based platforms. This driver works for both SPI master for SPI NOR
 	  flash device as well as MSPI device.
 
+config SPI_BCMBCA_HSSPI
+	tristate "Broadcom BCMBCA HS SPI controller driver"
+	depends on ARCH_BCMBCA || COMPILE_TEST
+	help
+	  This enables support for the High Speed SPI controller present on
+	  newer Broadcom BCMBCA SoCs. These SoCs include an updated SPI controller
+	  that adds the capability to allow the driver to control chip select
+	  explicitly.
+
 config SPI_BITBANG
 	tristate "Utilities for Bitbanging SPI masters"
 	help

drivers/spi/Makefile

@@ -30,6 +30,7 @@ obj-$(CONFIG_SPI_BCM2835)		+= spi-bcm2835.o
 obj-$(CONFIG_SPI_BCM2835AUX)		+= spi-bcm2835aux.o
 obj-$(CONFIG_SPI_BCM63XX)		+= spi-bcm63xx.o
 obj-$(CONFIG_SPI_BCM63XX_HSSPI)		+= spi-bcm63xx-hsspi.o
+obj-$(CONFIG_SPI_BCMBCA_HSSPI)		+= spi-bcmbca-hsspi.o
 obj-$(CONFIG_SPI_BCM_QSPI)		+= spi-iproc-qspi.o spi-brcmstb-qspi.o spi-bcm-qspi.o
 obj-$(CONFIG_SPI_BITBANG)		+= spi-bitbang.o
 obj-$(CONFIG_SPI_BUTTERFLY)		+= spi-butterfly.o