drivers: spi: add et171 spi driver

The Egis ET171 SPI controller was based on Andes ATCSPI200,
but has since been modified. In particular, the WrTranCnt and RdTranCnt
fields from the SPI Transfer Control Register have been moved to dedicated
Wr_Tran_Cnt and Rd_Tran_Cnt registers.

Signed-off-by: jacob kung <jacob.kung@egistec.com>

Author: jacob730204

drivers/spi/CMakeLists.txt

@@ -23,6 +23,7 @@ zephyr_library_sources_ifdef(CONFIG_SPI_CC13XX_CC26XX spi_cc13xx_cc26xx.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_CC23X0 spi_cc23x0.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_CDNS spi_cdns.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_DW spi_dw.c)
+zephyr_library_sources_ifdef(CONFIG_SPI_EGIS_ET171 spi_egis_et171.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_EMUL spi_emul.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_GD32 spi_gd32.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_GRLIB_SPIMCTRL spi_grlib_spimctrl.c)

drivers/spi/Kconfig

@@ -103,6 +103,7 @@ source "drivers/spi/Kconfig.cc13xx_cc26xx"
 source "drivers/spi/Kconfig.cc23x0"
 source "drivers/spi/Kconfig.cdns"
 source "drivers/spi/Kconfig.dw"
+source "drivers/spi/Kconfig.egis_et171"
 source "drivers/spi/Kconfig.esp32"
 source "drivers/spi/Kconfig.gd32"
 source "drivers/spi/Kconfig.grlib_spimctrl"

drivers/spi/Kconfig.egis_et171

@@ -0,0 +1,23 @@
+# Kconfig Egis ET171 SPI configuration options
+#
+# Copyright (c) 2022 Andes Technology Corporation.
+# Copyright (c) 2025 Egis Technology Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+config SPI_EGIS_ET171
+	bool "Andes ATCSPI200-based Egis ET171 SPI driver"
+	default y
+	depends on DT_HAS_EGIS_ET171_SPI_ENABLED
+	help
+	  Enable driver for Andes ATCSPI200-based Egis ET171 SPI controller
+
+if SPI_EGIS_ET171
+
+config EGIS_SPI_DMA_MODE
+	bool "Using DMA mode for SPI driver"
+	default y
+	depends on DMA
+
+endif # SPI_EGIS_ET171