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Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/rtc/maxim-ds1302.txt | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt b/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt new file mode 100644 index 000000000000..ba470c56cdec --- /dev/null +++ b/Documentation/devicetree/bindings/rtc/maxim-ds1302.txt @@ -0,0 +1,46 @@ +* Maxim/Dallas Semiconductor DS-1302 RTC + +Simple device which could be used to store date/time between reboots. + +The device uses the standard MicroWire half-duplex transfer timing. +Master output is set on low clock and sensed by the RTC on the rising +edge. Master input is set by the RTC on the trailing edge and is sensed +by the master on low clock. + +Required properties: + +- compatible : Should be "maxim,ds1302" + +Required SPI properties: + +- reg : Should be address of the device chip select within + the controller. + +- spi-max-frequency : DS-1302 has 500 kHz if powered at 2.2V, + and 2MHz if powered at 5V. + +- spi-3wire : The device has a shared signal IN/OUT line. + +- spi-lsb-first : DS-1302 requires least significant bit first + transfers. + +- spi-cs-high: DS-1302 has active high chip select line. This is + required unless inverted in hardware. + +Example: + +spi@901c { + #address-cells = <1>; + #size-cells = <0>; + compatible = "icpdas,lp8841-spi-rtc"; + reg = <0x901c 0x1>; + + rtc@0 { + compatible = "maxim,ds1302"; + reg = <0>; + spi-max-frequency = <500000>; + spi-3wire; + spi-lsb-first; + spi-cs-high; + }; +}; |