linux/Documentation/devicetree/bindings/dma/renesas,usb-dmac.txt
Simon Horman 0b2eed4987 dmaengine: usb-dmac: Document SoC specific compatibility strings
In general Renesas hardware is not documented to the extent where the
relationship between IP blocks on different SoCs can be assumed although
they may appear to operate the same way. Furthermore the documentation
typically does not specify a version for individual IP blocks. For these
reasons a convention of using the SoC name in place of a version and
providing SoC-specific compatibility strings has been adopted.

Although not universally liked this convention is used in the bindings for
most drivers for Renesas hardware. The purpose of this patch is to
update the Renesas USB DMA Controller driver to follow this convention.

Cc: devicetree@vger.kernel.org
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
2015-12-10 09:43:11 +05:30

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* Renesas USB DMA Controller Device Tree bindings
Required Properties:
-compatible: "renesas,<soctype>-usb-dmac", "renesas,usb-dmac" as fallback.
Examples with soctypes are:
- "renesas,r8a7790-usb-dmac" (R-Car H2)
- "renesas,r8a7791-usb-dmac" (R-Car M2-W)
- "renesas,r8a7793-usb-dmac" (R-Car M2-N)
- "renesas,r8a7794-usb-dmac" (R-Car E2)
- "renesas,r8a7795-usb-dmac" (R-Car H3)
- reg: base address and length of the registers block for the DMAC
- interrupts: interrupt specifiers for the DMAC, one for each entry in
interrupt-names.
- interrupt-names: one entry per channel, named "ch%u", where %u is the
channel number ranging from zero to the number of channels minus one.
- clocks: a list of phandle + clock-specifier pairs.
- #dma-cells: must be <1>, the cell specifies the channel number of the DMAC
port connected to the DMA client.
- dma-channels: number of DMA channels
Example: R8A7790 (R-Car H2) USB-DMACs
usb_dmac0: dma-controller@e65a0000 {
compatible = "renesas,r8a7790-usb-dmac", "renesas,usb-dmac";
reg = <0 0xe65a0000 0 0x100>;
interrupts = <0 109 IRQ_TYPE_LEVEL_HIGH
0 109 IRQ_TYPE_LEVEL_HIGH>;
interrupt-names = "ch0", "ch1";
clocks = <&mstp3_clks R8A7790_CLK_USBDMAC0>;
#dma-cells = <1>;
dma-channels = <2>;
};
usb_dmac1: dma-controller@e65b0000 {
compatible = "renesas,usb-dmac";
reg = <0 0xe65b0000 0 0x100>;
interrupts = <0 110 IRQ_TYPE_LEVEL_HIGH
0 110 IRQ_TYPE_LEVEL_HIGH>;
interrupt-names = "ch0", "ch1";
clocks = <&mstp3_clks R8A7790_CLK_USBDMAC1>;
#dma-cells = <1>;
dma-channels = <2>;
};