support for amlogic the new SPI IP

Merge series from Xianwei Zhao <xianwei.zhao@amlogic.com>:

Introduced support for the new SPI IP (SPISG). The SPISG is
a communication-oriented SPI controller from Amlogic,supporting
three operation modes: PIO, block DMA, and scatter-gather DMA.

Add the drivers and device tree bindings corresponding to the SPISG.

Author: broonie

Documentation/devicetree/bindings/spi/amlogic,a4-spisg.yaml

@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright (C) 2025 Amlogic, Inc. All rights reserved
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/spi/amlogic,a4-spisg.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Amlogic SPI Scatter-Gather Controller
+
+maintainers:
+  - Xianwei Zhao <xianwei.zhao@amlogic.com>
+  - Sunny Luo <sunny.luo@amlogic.com>
+
+allOf:
+  - $ref: spi-controller.yaml#
+
+properties:
+  compatible:
+    const: amlogic,a4-spisg
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: core
+      - const: pclk
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - clock-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    spi@50000 {
+        compatible = "amlogic,a4-spisg";
+        reg = <0x50000 0x38>;
+        interrupts = <GIC_SPI 183 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clkc 37>,
+                 <&clkc 93>;
+        clock-names = "core", "pclk";
+        #address-cells = <1>;
+        #size-cells = <0>;
+    };

MAINTAINERS

@@ -1306,6 +1306,15 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/rtc/amlogic,a4-rtc.yaml
 F:	drivers/rtc/rtc-amlogic-a4.c
 
+AMLOGIC SPISG DRIVER
+M:	Sunny Luo <sunny.luo@amlogic.com>
+M:	Xianwei Zhao <xianwei.zhao@amlogic.com>
+L:	linux-amlogic@lists.infradead.org
+L:	linux-spi@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/spi/amlogic,a4-spisg.yaml
+F:	drivers/spi/spi-amlogic-spisg.c
+
 AMPHENOL CHIPCAP 2 DRIVER
 M:	Javier Carrasco <javier.carrasco.cruz@gmail.com>
 L:	linux-hwmon@vger.kernel.org

drivers/spi/Kconfig

@@ -99,6 +99,15 @@ 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_SPISG
+	tristate "Amlogic SPISG controller"
+	depends on COMMON_CLK
+	depends on ARCH_MESON || COMPILE_TEST
+	help
+	  This enables master mode support for the SPISG (SPI scatter-gather
+	  communication controller), which is available on platforms such as
+	  Amlogic A4 SoCs.
+
 config SPI_APPLE
 	tristate "Apple SoC SPI Controller platform driver"
 	depends on ARCH_APPLE || COMPILE_TEST

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-$(CONFIG_SPI_AMLOGIC_SPISG)		+= spi-amlogic-spisg.o
 obj-$(CONFIG_SPI_APPLE)			+= spi-apple.o
 obj-$(CONFIG_SPI_AR934X)		+= spi-ar934x.o
 obj-$(CONFIG_SPI_ARMADA_3700)		+= spi-armada-3700.o