| * 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; |
| }; |
| }; |
