| Tom Rini | 53633a8 | 2024-02-29 12:33:36 -0500 | [diff] [blame] | 1 | Texas Instruments DMA Crossbar (DMA request router) |
| 2 | |
| 3 | Required properties: |
| 4 | - compatible: "ti,dra7-dma-crossbar" for DRA7xx DMA crossbar |
| 5 | "ti,am335x-edma-crossbar" for AM335x and AM437x |
| 6 | - reg: Memory map for accessing module |
| 7 | - #dma-cells: Should be set to match with the DMA controller's dma-cells |
| 8 | for ti,dra7-dma-crossbar and <3> for ti,am335x-edma-crossbar. |
| 9 | - dma-requests: Number of DMA requests the crossbar can receive |
| 10 | - dma-masters: phandle pointing to the DMA controller |
| 11 | |
| 12 | The DMA controller node need to have the following poroperties: |
| 13 | - dma-requests: Number of DMA requests the controller can handle |
| 14 | |
| 15 | Optional properties: |
| 16 | - ti,dma-safe-map: Safe routing value for unused request lines |
| 17 | - ti,reserved-dma-request-ranges: DMA request ranges which should not be used |
| 18 | when mapping xbar input to DMA request, they are either |
| 19 | allocated to be used by for example the DSP or they are used as |
| 20 | memcpy channels in eDMA. |
| 21 | |
| 22 | Notes: |
| 23 | When requesting channel via ti,dra7-dma-crossbar, the DMA clinet must request |
| 24 | the DMA event number as crossbar ID (input to the DMA crossbar). |
| 25 | |
| 26 | For ti,am335x-edma-crossbar: the meaning of parameters of dmas for clients: |
| 27 | dmas = <&edma_xbar 12 0 1>; where <12> is the DMA request number, <0> is the TC |
| 28 | the event should be assigned and <1> is the mux selection for in the crossbar. |
| 29 | When mux 0 is used the DMA channel can be requested directly from edma node. |
| 30 | |
| 31 | Example: |
| 32 | |
| 33 | /* DMA controller */ |
| 34 | sdma: dma-controller@4a056000 { |
| 35 | compatible = "ti,omap4430-sdma"; |
| 36 | reg = <0x4a056000 0x1000>; |
| 37 | interrupts = <GIC_SPI 7 IRQ_TYPE_LEVEL_HIGH>, |
| 38 | <GIC_SPI 8 IRQ_TYPE_LEVEL_HIGH>, |
| 39 | <GIC_SPI 9 IRQ_TYPE_LEVEL_HIGH>, |
| 40 | <GIC_SPI 10 IRQ_TYPE_LEVEL_HIGH>; |
| 41 | #dma-cells = <1>; |
| 42 | dma-channels = <32>; |
| 43 | dma-requests = <127>; |
| 44 | }; |
| 45 | |
| 46 | /* DMA crossbar */ |
| 47 | sdma_xbar: dma-router@4a002b78 { |
| 48 | compatible = "ti,dra7-dma-crossbar"; |
| 49 | reg = <0x4a002b78 0xfc>; |
| 50 | #dma-cells = <1>; |
| 51 | dma-requests = <205>; |
| 52 | ti,dma-safe-map = <0>; |
| 53 | /* Protect the sDMA request ranges: 10-14 and 100-126 */ |
| 54 | ti,reserved-dma-request-ranges = <10 5>, <100 27>; |
| 55 | dma-masters = <&sdma>; |
| 56 | }; |
| 57 | |
| 58 | /* DMA client */ |
| 59 | uart1: serial@4806a000 { |
| 60 | compatible = "ti,omap4-uart"; |
| 61 | reg = <0x4806a000 0x100>; |
| 62 | interrupts-extended = <&gic GIC_SPI 67 IRQ_TYPE_LEVEL_HIGH>; |
| 63 | ti,hwmods = "uart1"; |
| 64 | clock-frequency = <48000000>; |
| 65 | /* Requesting crossbar input 49 and 50 */ |
| 66 | dmas = <&sdma_xbar 49>, <&sdma_xbar 50>; |
| 67 | dma-names = "tx", "rx"; |
| 68 | }; |