the hardware resource form TRM

DMA capabilities and channels

get the DAMC information Part 8. DMA Pasted image 20260920152131

DMA base address

regitser summary Part 8. DMA Pasted image 20260920152848 acces DMA registers

DMA MAX_OFFSET

get the offset register Pasted image 20260921102352

DMA clock

Enable the DMA clock before use Part2. CRU Pasted image 20260920153052

DMA reset

release reset at initialization;recover form error Part2. CRU Pasted image 20260920153616

Completion IRQ / Abort IRQ (request ID)

device-tree

Binding

/home/user/SDK/rk3xxx/kernel-6.1/Documentation/devicetree/bindings/dma/arm,pl330.yaml /home/user/SDK/rk3xxx/kernel-6.1/Documentation/devicetree/bindings/dma/dma-controller.yaml 查看DMA 设备树属性

        dmac0: dma-controller@2ab90000 {
                compatible = "arm,pl330", "arm,primecell";
                reg = <0x0 0x2ab90000 0x0 0x4000>;
                interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>,
                             <GIC_SPI 33 IRQ_TYPE_LEVEL_HIGH>;
                clocks = <&cru ACLK_DMAC0>;
                clock-names = "apb_pclk";
                #dma-cells = <1>;
                arm,pl330-periph-burst;
        };

        dmac1: dma-controller@2abb0000 {
                compatible = "arm,pl330", "arm,primecell";
                reg = <0x0 0x2abb0000 0x0 0x4000>;
                interrupts = <GIC_SPI 34 IRQ_TYPE_LEVEL_HIGH>,
                             <GIC_SPI 35 IRQ_TYPE_LEVEL_HIGH>;
                clocks = <&cru ACLK_DMAC1>;
                clock-names = "apb_pclk";
                #dma-cells = <1>;
                arm,pl330-periph-burst;
        };

        dmac2: dma-controller@2abd0000 {
                compatible = "arm,pl330", "arm,primecell";
                reg = <0x0 0x2abd0000 0x0 0x4000>;
                interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>,
                             <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
                clocks = <&cru ACLK_DMAC2>;
                clock-names = "apb_pclk";
                #dma-cells = <1>;
                arm,pl330-periph-burst;
        };

Change the target dts

在同目录下Makefile

+ dtb-$(CONFIG_ARCH_ROCKCHIP) += rk3576-test1-dma.dtb

把设备树加入编译

Add target config

Add SDK defconfig

新增板级配置碎片文件： /home/user/SDK/rk3xxx/kernel-6.1/arch/arm64/configs/rk3576-myboard.config

CONFIG_CAN=y
CONFIG_CAN_ROCKCHIP_CANFD=y

CONFIG_DMADEVICES=y
CONFIG_ARM_AMBA=y
CONFIG_DMA_ENGINE=y
CONFIG_PL330_DMA=y
CONFIG_DMATEST=y

在新板 SDK defconfig 中引用它：/home/user/SDK/rk3xxx/device/rockchip/.chips/rk3576/rockchip_rk3576_myboard_v10_defconfig 选择编译的dts和功能配置

  RK_UBOOT_SPL=y
  RK_KERNEL_DTS_NAME="rk3576-myboard-v10-linux"
  RK_KERNEL_CFG_FRAGMENTS="rk3576-myboard.config"

Change the SDK build target kernel

./build.sh lunch //切换配置

select target defconfig

DMATEST

测试命令

Parameter

Pasted image 20260929115033

调整测试参数

   echo 262208 > test_buf_size
   echo 262144 > transfer_size
   echo 1 > norandom
   echo 0 > noverify
   echo 100 > iterations
   echo 1 > threads_per_chan
   echo 5000 > timeout

指定dmac和channel

echo dma0chan0 > channel
echo 1 > run

MEM_TO_MEM DMATEST

Channel application and capability mask

Consumer在准备DMA之前，必须线取得支持当前操作的channel 当前模块要完成内存复制，因此申请channel时需要带上DMA_MEMCPY能力条件:

dma_cap_mask_t mask;

dma_cap_zero(mask);
dma_cap_set(DMA_MEMCPY, mask);

chan = dma_request_channel(mask, cc_dma, channel);

mask是capability mask，能力掩码，类型为dma_cap_mask_t。 Consumer用mask说明需要什么DMA能力，DMAEngine会把这些要求与各个Provider注册的dma_device.cap_mask进行比较

capabilities

dma_cap_zero()会清空mask,dma_cap_set()再降入当前需要的能力

module只设置了DMA_MEMCPY，因此DMAEngine只会继续检查声明支持内存复制的Provider 常用的capabilities如下： Pasted image 20260930113815

channel application and realse

Consumer通过下面的接口申请和释放channel

struct dma_chan *dma_request_channel(dma_cap_mask_t mask,
									dma_fliter_fn filter_fn,
									void *filter_param);
									
void dma_release_channel(struct dma_chan *chan);

dma_request_channel()的参数和返回结果如下： Pasted image 20260930152253 channel模块参数默认设置为dma0chan0。dma_request_channel()完成DMA_MEMCPY能力匹配后，还会通过cc_dma_filter()比较channel名称与这个参数，只有名称一致的channel才会返回。