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DS1302 is an half-duplex SPI device. The driver respects this fact now. Pin configurations should be implemented using SPI subsystem. Signed-off-by: Sergei Ianovich <ynvich@gmail.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
47 lines
1.1 KiB
Plaintext
47 lines
1.1 KiB
Plaintext
* Maxim/Dallas Semiconductor DS-1302 RTC
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Simple device which could be used to store date/time between reboots.
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The device uses the standard MicroWire half-duplex transfer timing.
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Master output is set on low clock and sensed by the RTC on the rising
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edge. Master input is set by the RTC on the trailing edge and is sensed
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by the master on low clock.
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Required properties:
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- compatible : Should be "maxim,ds1302"
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Required SPI properties:
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- reg : Should be address of the device chip select within
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the controller.
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- spi-max-frequency : DS-1302 has 500 kHz if powered at 2.2V,
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and 2MHz if powered at 5V.
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- spi-3wire : The device has a shared signal IN/OUT line.
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- spi-lsb-first : DS-1302 requires least significant bit first
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transfers.
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- spi-cs-high: DS-1302 has active high chip select line. This is
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required unless inverted in hardware.
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Example:
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spi@901c {
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#address-cells = <1>;
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#size-cells = <0>;
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compatible = "icpdas,lp8841-spi-rtc";
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reg = <0x901c 0x1>;
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rtc@0 {
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compatible = "maxim,ds1302";
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reg = <0>;
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spi-max-frequency = <500000>;
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spi-3wire;
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spi-lsb-first;
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spi-cs-high;
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};
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};
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