linux/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.txt
Gareth Williams 2f324ac7cf
dt-bindings: snps,dw-apb-ssi: Add optional clock bindings documentation
Add documentation to the Synopsys SPI dt-bindings to support an
optional interface clock that may be used for register access.

Signed-off-by: Phil Edworthy <phil.edworthy@renesas.com>
Signed-off-by: Gareth Williams <gareth.williams.jx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-03-20 17:20:52 +00:00

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Synopsys DesignWare AMBA 2.0 Synchronous Serial Interface.
Required properties:
- compatible : "snps,dw-apb-ssi" or "mscc,<soc>-spi", where soc is "ocelot" or
"jaguar2", or "amazon,alpine-dw-apb-ssi"
- reg : The register base for the controller. For "mscc,<soc>-spi", a second
register set is required (named ICPU_CFG:SPI_MST)
- interrupts : One interrupt, used by the controller.
- #address-cells : <1>, as required by generic SPI binding.
- #size-cells : <0>, also as required by generic SPI binding.
- clocks : phandles for the clocks, see the description of clock-names below.
The phandle for the "ssi_clk" is required. The phandle for the "pclk" clock
is optional. If a single clock is specified but no clock-name, it is the
"ssi_clk" clock. If both clocks are listed, the "ssi_clk" must be first.
Optional properties:
- clock-names : Contains the names of the clocks:
"ssi_clk", for the core clock used to generate the external SPI clock.
"pclk", the interface clock, required for register access.
- cs-gpios : Specifies the gpio pins to be used for chipselects.
- num-cs : The number of chipselects. If omitted, this will default to 4.
- reg-io-width : The I/O register width (in bytes) implemented by this
device. Supported values are 2 or 4 (the default).
Child nodes as per the generic SPI binding.
Example:
spi@fff00000 {
compatible = "snps,dw-apb-ssi";
reg = <0xfff00000 0x1000>;
interrupts = <0 154 4>;
#address-cells = <1>;
#size-cells = <0>;
clocks = <&spi_m_clk>;
num-cs = <2>;
cs-gpios = <&gpio0 13 0>,
<&gpio0 14 0>;
};