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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-06-13 14:28:38 +0300 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-07-23 08:22:45 +0300 |
| commit | 2be5263c5df45bbd5ad49ea8c394aca6e709d204 (patch) | |
| tree | db7038184677d489f78cf4e3c3f66128200e8aec | |
| parent | d5e838275c80aeb96d4c0b81442a851dfef2e948 (diff) | |
| download | linux-2be5263c5df45bbd5ad49ea8c394aca6e709d204.tar.xz | |
dt-bindings: fsi: Document binding for the fsi-master-ast-cf "device"
This isn't per-se a real device, it's a pseudo-device that
represents the use of the Aspeed built-in ColdFire to
implement the FSI protocol by bitbanging the GPIOs instead
of doing it from the ARM core.
Thus it's a drop-in replacement for the existing
fsi-master-gpio pseudo-device for use on systems based
on the Aspeed chips. It has most of the same properties,
plus some more needed to operate the coprocessor.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Reviewed-by: Rob Herring <robh@kernel.org>
| -rw-r--r-- | Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt b/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt new file mode 100644 index 000000000000..3dc752db748b --- /dev/null +++ b/Documentation/devicetree/bindings/fsi/fsi-master-ast-cf.txt @@ -0,0 +1,36 @@ +Device-tree bindings for ColdFire offloaded gpio-based FSI master driver +------------------------------------------------------------------------ + +Required properties: + - compatible = + "aspeed,ast2400-cf-fsi-master" for an AST2400 based system + or + "aspeed,ast2500-cf-fsi-master" for an AST2500 based system + + - clock-gpios = <gpio-descriptor>; : GPIO for FSI clock + - data-gpios = <gpio-descriptor>; : GPIO for FSI data signal + - enable-gpios = <gpio-descriptor>; : GPIO for enable signal + - trans-gpios = <gpio-descriptor>; : GPIO for voltage translator enable + - mux-gpios = <gpio-descriptor>; : GPIO for pin multiplexing with other + functions (eg, external FSI masters) + - memory-region = <phandle>; : Reference to the reserved memory for + the ColdFire. Must be 2M aligned on + AST2400 and 1M aligned on AST2500 + - aspeed,sram = <phandle>; : Reference to the SRAM node. + - aspeed,cvic = <phandle>; : Reference to the CVIC node. + +Examples: + + fsi-master { + compatible = "aspeed,ast2500-cf-fsi-master", "fsi-master"; + + clock-gpios = <&gpio 0>; + data-gpios = <&gpio 1>; + enable-gpios = <&gpio 2>; + trans-gpios = <&gpio 3>; + mux-gpios = <&gpio 4>; + + memory-region = <&coldfire_memory>; + aspeed,sram = <&sram>; + aspeed,cvic = <&cvic>; + } |