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| -rw-r--r-- | Documentation/devicetree/bindings/soc/ti/keystone-navigator-dma.txt | 111 |
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diff --git a/Documentation/devicetree/bindings/soc/ti/keystone-navigator-dma.txt b/Documentation/devicetree/bindings/soc/ti/keystone-navigator-dma.txt new file mode 100644 index 000000000000..337c4ea5c57b --- /dev/null +++ b/Documentation/devicetree/bindings/soc/ti/keystone-navigator-dma.txt @@ -0,0 +1,111 @@ +Keystone Navigator DMA Controller + +This document explains the device tree bindings for the packet dma +on keystone devices. The Keystone Navigator DMA driver sets up the dma +channels and flows for the QMSS(Queue Manager SubSystem) who triggers +the actual data movements across clients using destination queues. Every +client modules like NETCP(Network Coprocessor), SRIO(Serial Rapid IO), +CRYPTO Engines etc has its own instance of dma hardware. QMSS has also +an internal packet DMA module which is used as an infrastructure DMA +with zero copy. + +Navigator DMA cloud layout: + ------------------ + | Navigator DMAs | + ------------------ + | + |-> DMA instance #0 + | + |-> DMA instance #1 + . + . + | + |-> DMA instance #n + +Navigator DMA properties: +Required properties: + - compatible: Should be "ti,keystone-navigator-dma" + - clocks: phandle to dma instances clocks. The clock handles can be as + many as the dma instances. The order should be maintained as per + the dma instances. + - ti,navigator-cloud-address: Should contain base address for the multi-core + navigator cloud and number of addresses depends on SOC integration + configuration.. Navigator cloud global address needs to be programmed + into DMA and the DMA uses it as the physical addresses to reach queue + managers. Note that these addresses though points to queue managers, + they are relevant only from DMA perspective. The QMSS may not choose to + use them since it has a different address space view to reach all + its components. + +DMA instance properties: +Required properties: + - reg: Should contain register location and length of the following dma + register regions. Register regions should be specified in the following + order. + - Global control register region (global). + - Tx DMA channel configuration register region (txchan). + - Rx DMA channel configuration register region (rxchan). + - Tx DMA channel Scheduler configuration register region (txsched). + - Rx DMA flow configuration register region (rxflow). + +Optional properties: + - reg-names: Names for the register regions. + - ti,enable-all: Enable all DMA channels vs clients opening specific channels + what they need. This property is useful for the userspace fast path + case where the linux drivers enables the channels used by userland + stack. + - ti,loop-back: To loopback Tx streaming I/F to Rx streaming I/F. Used for + infrastructure transfers. + - ti,rx-retry-timeout: Number of dma cycles to wait before retry on buffer + starvation. + +Example: + + knav_dmas: knav_dmas@0 { + compatible = "ti,keystone-navigator-dma"; + clocks = <&papllclk>, <&clkxge>; + #address-cells = <1>; + #size-cells = <1>; + ranges; + ti,navigator-cloud-address = <0x23a80000 0x23a90000 + 0x23aa0000 0x23ab0000>; + + dma_gbe: dma_gbe@0 { + reg = <0x2004000 0x100>, + <0x2004400 0x120>, + <0x2004800 0x300>, + <0x2004c00 0x120>, + <0x2005000 0x400>; + reg-names = "global", "txchan", "rxchan", + "txsched", "rxflow"; + }; + + dma_xgbe: dma_xgbe@0 { + reg = <0x2fa1000 0x100>, + <0x2fa1400 0x200>, + <0x2fa1800 0x200>, + <0x2fa1c00 0x200>, + <0x2fa2000 0x400>; + reg-names = "global", "txchan", "rxchan", + "txsched", "rxflow"; + }; + }; + +Navigator DMA client: +Required properties: + - ti,navigator-dmas: List of one or more DMA specifiers, each consisting of + - A phandle pointing to DMA instance node + - A DMA channel number as a phandle arg. + - ti,navigator-dma-names: Contains dma channel name for each DMA specifier in + the 'ti,navigator-dmas' property. + +Example: + + netcp: netcp@2090000 { + .. + ti,navigator-dmas = <&dma_gbe 22>, + <&dma_gbe 23>, + <&dma_gbe 8>; + ti,navigator-dma-names = "netrx0", "netrx1", "nettx"; + .. + }; |
