| Texas Instruments DMA Crossbar (DMA request router) |
| |
| Required properties: |
| - compatible: "ti,dra7-dma-crossbar" for DRA7xx DMA crossbar |
| "ti,am335x-edma-crossbar" for AM335x and AM437x |
| - reg: Memory map for accessing module |
| - #dma-cells: Should be set to match with the DMA controller's dma-cells |
| for ti,dra7-dma-crossbar and <3> for ti,am335x-edma-crossbar. |
| - dma-requests: Number of DMA requests the crossbar can receive |
| - dma-masters: phandle pointing to the DMA controller |
| |
| The DMA controller node need to have the following poroperties: |
| - dma-requests: Number of DMA requests the controller can handle |
| |
| Optional properties: |
| - ti,dma-safe-map: Safe routing value for unused request lines |
| - ti,reserved-dma-request-ranges: DMA request ranges which should not be used |
| when mapping xbar input to DMA request, they are either |
| allocated to be used by for example the DSP or they are used as |
| memcpy channels in eDMA. |
| |
| Notes: |
| When requesting channel via ti,dra7-dma-crossbar, the DMA client must request |
| the DMA event number as crossbar ID (input to the DMA crossbar). |
| |
| For ti,am335x-edma-crossbar: the meaning of parameters of dmas for clients: |
| dmas = <&edma_xbar 12 0 1>; where <12> is the DMA request number, <0> is the TC |
| the event should be assigned and <1> is the mux selection for in the crossbar. |
| When mux 0 is used the DMA channel can be requested directly from edma node. |
| |
| Example: |
| |
| /* DMA controller */ |
| sdma: dma-controller@4a056000 { |
| compatible = "ti,omap4430-sdma"; |
| reg = <0x4a056000 0x1000>; |
| interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>, |
| <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>, |
| <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>, |
| <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>; |
| #dma-cells = <1>; |
| dma-channels = <32>; |
| dma-requests = <127>; |
| }; |
| |
| /* DMA crossbar */ |
| sdma_xbar: dma-router@4a002b78 { |
| compatible = "ti,dra7-dma-crossbar"; |
| reg = <0x4a002b78 0xfc>; |
| #dma-cells = <1>; |
| dma-requests = <205>; |
| ti,dma-safe-map = <0>; |
| /* Protect the sDMA request ranges: 10-14 and 100-126 */ |
| ti,reserved-dma-request-ranges = <10 5>, <100 27>; |
| dma-masters = <&sdma>; |
| }; |
| |
| /* DMA client */ |
| uart1: serial@4806a000 { |
| compatible = "ti,omap4-uart"; |
| reg = <0x4806a000 0x100>; |
| interrupts-extended = <&gic GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>; |
| ti,hwmods = "uart1"; |
| clock-frequency = <48000000>; |
| /* Requesting crossbar input 49 and 50 */ |
| dmas = <&sdma_xbar 49>, <&sdma_xbar 50>; |
| dma-names = "tx", "rx"; |
| }; |
