sunxi cedar kernel module

Targeting mainline kernel - linux-4.11.y and higher.

Changes

• reserved memory CMA below 256M is used for dma_alloc_coherent (see the device tree file) instead of ION allocator.
• mmap has been modified to support MACC and DMA memory.
• interrupt status code 0xB (AVC (h264 encoder)) has been added for Allwinner A20.
• video engine has been added to the device tree.
• MMAP cached area and cache cleaning support has been added (cache-v7.S). It increases the framerate twice the uncached one.

Building

The first method quickly produces .ko module without building anything else.

Copy your .config file to the root of this repository and then run:

On the target machine

make KERNEL_SOURCE=.../linux-source

On the host machine (cross-compilation)

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- KERNEL_SOURCE=.../linux-source

Or whatever your CROCC_COMPILE prefix is.

Other build option

Remove or rename Makefile:

mv Makefile Makefile.bak

And then execute:

make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- KDIR=.../linux-source -f Makefile.linux

UPD

For Linux kernel >= 5.x nodes syscon and ve must be chanded in .dts file:

syscon: system-control@1c00000 {
			compatible = "allwinner,sun8i-h3-system-control","syscon";
			reg = <0x01c00000 0x1000>;
			#address-cells = <1>;
			#size-cells = <1>;
			ranges;

			sram_c: sram@1d00000 {
				compatible = "mmio-sram";
				reg = <0x01d00000 0x80000>;
				#address-cells = <1>;
				#size-cells = <1>;
				ranges = <0 0x01d00000 0x80000>;

				ve_sram: sram-section@0 {
					compatible = "allwinner,sun8i-h3-sram-c1",
					 "allwinner,sun4i-a10-sram-c1";
					reg = <0x000000 0x80000>;
				};
			};
		};

ve: video-engine@01c0e000 {
			compatible = "allwinner,sunxi-cedar-ve";
			reg = <0x01c0e000 0x1000>,
			          <0x01c00000 0x10>,
			          <0x01c20000 0x800>;
			memory-region = <&cma_pool>;
			syscon = <&syscon>;
			clocks = <&ccu CLK_BUS_VE>, <&ccu CLK_VE>,
			         <&ccu CLK_DRAM_VE>;
			clock-names = "ahb", "mod", "ram";
			resets = <&ccu RST_BUS_VE>;
			interrupts = <GIC_SPI 58 IRQ_TYPE_LEVEL_HIGH>;
			allwinner,sram = <&ve_sram 1>;
		};