Baikal-T1 SPI driver for DW SPI core

modulename: spi-dw-bt1.ko

configname: CONFIG_SPI_DW_BT1

Linux Kernel Configuration
└─>Device Drivers
└─>SPI support
└─>Baikal-T1 SPI driver for DW SPI core
In linux kernel since version 5.1 (release Date: 2019-05-05)  
Baikal-T1 SoC is equipped with three DW APB SSI-based MMIO SPI
controllers. Two of them are pretty much normal: with IRQ, DMA,
FIFOs of 64 words depth, 4x CSs, but the third one as being a
part of the Baikal-T1 System Boot Controller has got a very
limited resources: no IRQ, no DMA, only a single native
chip-select and Tx/Rx FIFO with just 8 words depth available.
The later one is normally connected to an external SPI-nor flash
of 128Mb (in general can be of bigger size).

source code:
depends
CONFIG_SPI
CONFIG_SPI_DESIGNWARE
CONFIG_SPI_MASTER
CONFIG_COMPILE_TEST or CONFIG_MIPS_BAIKAL_T1

is selected by
CONFIG_SPI_DW_BT1_DIRMAP