Merge branch 'topic-arcpgu-updates' of https://github.com/foss-for-synopsys-dwc-arc-processors/linux into drm-next

Please pull this mini-series that allows ARC PGU to use
dedicated memory location as framebuffer backing storage.

* 'topic-arcpgu-updates' of https://github.com/foss-for-synopsys-dwc-arc-processors/linux:
ARC: [axs10x] Specify reserved memory for frame buffer
drm/arcpgu: use dedicated memory area for frame buffer

arch/arc/boot/dts/axc001.dtsi

···
 	memory {
 		#address-cells = <1>;
 		#size-cells = <1>;
-		ranges = <0x00000000 0x80000000 0x40000000>;
+		ranges = <0x00000000 0x80000000 0x20000000>;
 		device_type = "memory";
-		reg = <0x80000000 0x20000000>;	/* 512MiB */
+		reg = <0x80000000 0x1b000000>;	/* (512 - 32) MiB */
+	};
+
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+		/*
+		 * We just move frame buffer area to the very end of
+		 * available DDR. And even though in case of ARC770 there's
+		 * no strict requirement for a frame-buffer to be in any
+		 * particular location it allows us to use the same
+		 * base board's DT node for ARC PGU as for ARc HS38.
+		 */
+		frame_buffer: frame_buffer@9e000000 {
+			compatible = "shared-dma-pool";
+			reg = <0x9e000000 0x2000000>;
+			no-map;
+		};
 	};
 };

arch/arc/boot/dts/axc003.dtsi

···
 		device_type = "memory";
 		reg = <0x80000000 0x20000000>;	/* 512MiB */
 	};
+
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+		/*
+		 * Move frame buffer out of IOC aperture (0x8z-0xAz).
+		 */
+		frame_buffer: frame_buffer@be000000 {
+			compatible = "shared-dma-pool";
+			reg = <0xbe000000 0x2000000>;
+			no-map;
+		};
+	};
 };

arch/arc/boot/dts/axc003_idu.dtsi

···
 		device_type = "memory";
 		reg = <0x80000000 0x20000000>;	/* 512MiB */
 	};
+
+	reserved-memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		ranges;
+		/*
+		 * Move frame buffer out of IOC aperture (0x8z-0xAz).
+		 */
+		frame_buffer: frame_buffer@be000000 {
+			compatible = "shared-dma-pool";
+			reg = <0xbe000000 0x2000000>;
+			no-map;
+		};
+	};
 };

arch/arc/boot/dts/axs10x_mb.dtsi

···
 			encoder-slave = <&adv7511>;
 			clocks = <&pguclk>;
 			clock-names = "pxlclk";
-
+			memory-region = <&frame_buffer>;
 			port {
 				pgu_output: endpoint {
 					remote-endpoint = <&adv7511_input>;

drivers/gpu/drm/arc/arcpgu_drv.c

···
 #include <drm/drm_fb_cma_helper.h>
 #include <drm/drm_gem_cma_helper.h>
 #include <drm/drm_atomic_helper.h>
+#include <linux/of_reserved_mem.h>
 
 #include "arcpgu.h"
 #include "arcpgu_regs.h"
···
 
 	dev_info(drm->dev, "arc_pgu ID: 0x%x\n",
 		 arc_pgu_read(arcpgu, ARCPGU_REG_ID));
+
+	/* Get the optional framebuffer memory resource */
+	ret = of_reserved_mem_device_init(drm->dev);
+	if (ret && ret != -ENODEV)
+		return ret;
 
 	if (dma_set_mask_and_coherent(drm->dev, DMA_BIT_MASK(32)))
 		return -ENODEV;