diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/devicetree/bindings/dma/snps-dma.txt | 70 |
1 files changed, 36 insertions, 34 deletions
diff --git a/Documentation/devicetree/bindings/dma/snps-dma.txt b/Documentation/devicetree/bindings/dma/snps-dma.txt index 5bb3dfb6f1d..d58675ea1ab 100644 --- a/Documentation/devicetree/bindings/dma/snps-dma.txt +++ b/Documentation/devicetree/bindings/dma/snps-dma.txt @@ -3,59 +3,61 @@ Required properties: - compatible: "snps,dma-spear1340" - reg: Address range of the DMAC registers -- interrupt-parent: Should be the phandle for the interrupt controller - that services interrupts for this device - interrupt: Should contain the DMAC interrupt number -- nr_channels: Number of channels supported by hardware -- is_private: The device channels should be marked as private and not for by the - general purpose DMA channel allocator. False if not passed. +- dma-channels: Number of channels supported by hardware +- dma-requests: Number of DMA request lines supported, up to 16 +- dma-masters: Number of AHB masters supported by the controller +- #dma-cells: must be <3> - chan_allocation_order: order of allocation of channel, 0 (default): ascending, 1: descending - chan_priority: priority of channels. 0 (default): increase from chan 0->n, 1: increase from chan n->0 - block_size: Maximum block size supported by the controller -- nr_masters: Number of AHB masters supported by the controller - data_width: Maximum data width supported by hardware per AHB master (0 - 8bits, 1 - 16bits, ..., 5 - 256bits) -- slave_info: - - bus_id: name of this device channel, not just a device name since - devices may have more than one channel e.g. "foo_tx". For using the - dw_generic_filter(), slave drivers must pass exactly this string as - param to filter function. - - cfg_hi: Platform-specific initializer for the CFG_HI register - - cfg_lo: Platform-specific initializer for the CFG_LO register - - src_master: src master for transfers on allocated channel. - - dst_master: dest master for transfers on allocated channel. + + +Optional properties: +- interrupt-parent: Should be the phandle for the interrupt controller + that services interrupts for this device +- is_private: The device channels should be marked as private and not for by the + general purpose DMA channel allocator. False if not passed. Example: - dma@fc000000 { + dmahost: dma@fc000000 { compatible = "snps,dma-spear1340"; reg = <0xfc000000 0x1000>; interrupt-parent = <&vic1>; interrupts = <12>; - nr_channels = <8>; + dma-channels = <8>; + dma-requests = <16>; + dma-masters = <2>; + #dma-cells = <3>; chan_allocation_order = <1>; chan_priority = <1>; block_size = <0xfff>; - nr_masters = <2>; data_width = <3 3 0 0>; + }; - slave_info { - uart0-tx { - bus_id = "uart0-tx"; - cfg_hi = <0x4000>; /* 0x8 << 11 */ - cfg_lo = <0>; - src_master = <0>; - dst_master = <1>; - }; - spi0-tx { - bus_id = "spi0-tx"; - cfg_hi = <0x2000>; /* 0x4 << 11 */ - cfg_lo = <0>; - src_master = <0>; - dst_master = <0>; - }; - }; +DMA clients connected to the Designware DMA controller must use the format +described in the dma.txt file, using a four-cell specifier for each channel. +The four cells in order are: + +1. A phandle pointing to the DMA controller +2. The DMA request line number +3. Source master for transfers on allocated channel +4. Destination master for transfers on allocated channel + +Example: + + serial@e0000000 { + compatible = "arm,pl011", "arm,primecell"; + reg = <0xe0000000 0x1000>; + interrupts = <0 35 0x4>; + status = "disabled"; + dmas = <&dmahost 12 0 1>, + <&dmahost 13 0 1 0>; + dma-names = "rx", "rx"; }; |