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Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-gate.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-gate.txt | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-gate.txt b/Documentation/devicetree/bindings/i2c/i2c-gate.txt new file mode 100644 index 000000000000..1846d236e656 --- /dev/null +++ b/Documentation/devicetree/bindings/i2c/i2c-gate.txt @@ -0,0 +1,41 @@ +An i2c gate is useful to e.g. reduce the digital noise for RF tuners connected +to the i2c bus. Gates are similar to arbitrators in that you need to perform +some kind of operation to access the i2c bus past the arbitrator/gate, but +there are no competing masters to consider for gates and therefore there is +no arbitration happening for gates. + +Common i2c gate properties. + +- i2c-gate child node + +Required properties for the i2c-gate child node: +- #address-cells = <1>; +- #size-cells = <0>; + +Optional properties for i2c-gate child node: +- Child nodes conforming to i2c bus binding + + +Example : + + /* + An Invensense mpu9150 at address 0x68 featuring an on-chip Asahi + Kasei ak8975 compass behind a gate. + */ + + mpu9150@68 { + compatible = "invensense,mpu9150"; + reg = <0x68>; + interrupt-parent = <&gpio1>; + interrupts = <18 1>; + + i2c-gate { + #address-cells = <1>; + #size-cells = <0>; + + ax8975@c { + compatible = "ak,ak8975"; + reg = <0x0c>; + }; + }; + }; |