drivers: spi: siwx91x: Add siwx91x SPI primary driver

boards/silabs/radio_boards/siwx917_rb4338a/siwx917_rb4338a.yaml

@@ -16,5 +16,6 @@ supported:
   - i2c
   - pwm
   - watchdog
+  - spi
   - wifi
 vendor: silabs

drivers/clock_control/clock_control_silabs_siwx91x.c

@@ -13,6 +13,7 @@
 #include "rsi_rom_ulpss_clk.h"
 #include "rsi_rom_clks.h"
 #include "rsi_sysrtc.h"
+#include "rsi_pll.h"
 #include "clock_update.h"
 #include "sl_si91x_clock_manager.h"
 
@@ -77,6 +78,10 @@ static int siwx91x_clock_on(const struct device *dev, clock_control_subsys_t sys
 		 */
 		rsi_sysrtc_clk_set(RSI_SYSRTC_CLK_32kHz_Xtal, 0);
 		break;
+	case SIWX91X_CLK_GSPI:
+		RSI_PS_M4ssPeriPowerUp(M4SS_PWRGATE_ULP_EFUSE_PERI);
+		RSI_CLK_GspiClkConfig(M4CLK, GSPI_INTF_PLL_CLK);
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -141,6 +146,9 @@ static int siwx91x_clock_get_rate(const struct device *dev, clock_control_subsys
 	case SIWX91X_CLK_WATCHDOG:
 		*rate = LF_FSM_CLOCK_FREQUENCY;
 		return 0;
+	case SIWX91X_CLK_GSPI:
+		*rate = RSI_CLK_GetBaseClock(M4_GSPI);
+		return 0;
 	default:
 		/* For now, no other driver need clock rate */
 		return -EINVAL;

drivers/spi/CMakeLists.txt

@@ -56,6 +56,7 @@ zephyr_library_sources_ifdef(CONFIG_SPI_SAM0 spi_sam0.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_SEDI spi_sedi.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_SIFIVE spi_sifive.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_SILABS_EUSART spi_silabs_eusart.c)
+zephyr_library_sources_ifdef(CONFIG_SPI_SILABS_SIWX91X_GSPI spi_silabs_siwx91x_gspi.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_SILABS_USART spi_silabs_usart.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_SMARTBOND spi_smartbond.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_STM32 spi_ll_stm32.c)

drivers/spi/Kconfig

@@ -133,6 +133,7 @@ source "drivers/spi/Kconfig.sam0"
 source "drivers/spi/Kconfig.sedi"
 source "drivers/spi/Kconfig.sifive"
 source "drivers/spi/Kconfig.silabs_eusart"
+source "drivers/spi/Kconfig.silabs_siwx91x_gspi"
 source "drivers/spi/Kconfig.silabs_usart"
 source "drivers/spi/Kconfig.smartbond"
 source "drivers/spi/Kconfig.spi_emul"

drivers/spi/Kconfig.silabs_siwx91x_gspi

@@ -0,0 +1,28 @@
+# Copyright (c) 2025 Silicon Laboratories Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+config SPI_SILABS_SIWX91X_GSPI
+	bool "Silabs GSPI SPI Primary controller driver"
+	default y
+	depends on DT_HAS_SILABS_GSPI_ENABLED
+	select GPIO
+	select PINCTRL
+	help
+	  Enable the GSPI SPI primary driver for the Silabs SiWx91x SoC series.
+
+if SPI_SILABS_SIWX91X_GSPI
+
+config SPI_SILABS_SIWX91X_GSPI_DMA
+	bool "DMA Support"
+	select DMA
+	help
+	  Enable DMA support for SIWX91X MCU GSPI driver.
+
+config SPI_SILABS_SIWX91X_GSPI_DMA_MAX_BLOCKS
+	int "Maximum DMA transfer block per channel for a transaction."
+	depends on SPI_SILABS_SIWX91X_GSPI_DMA
+	default 16
+	help
+	  One block is needed for every chunk found in the SPI transaction and every 1024 bytes
+
+endif # SPI_SILABS_SIWX91X_GSPI