40 lines
1.4 KiB
Plaintext
40 lines
1.4 KiB
Plaintext
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NVIDIA Tegra124 SPI Slave controller.
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Required properties:
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- compatible : should be "nvidia,tegra124-spi-slave".
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- reg: Should contain SPI registers location and length.
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- interrupts: Should contain SPI interrupts.
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- nvidia,dma-request-selector : The Tegra DMA controller's phandle and
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request selector for this SPI controller.
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Recommended properties:
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- spi-max-frequency: Maximum SPI clocking speed of device in Hz. For slave,
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It must be at least 1.5 times bus rate.
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Optional properties:
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- nvidia,clock-always-on: Enable clock of spi always.
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- nvidia,maximum-dma-buffer-size: Maximum dma buffer size per transfer.
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If this is not available then 16K will be default. The value should
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be unit of byte.
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- nvidia,slave-ready-gpio: OUT GPIO from slave to report slave status. This
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GPIO, when asserted, implies slave controller is ready for transaction.
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When this GPIO is de-asserted, the master cannot initiate transaction
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with this slave.
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- nvidia,lsbyte-first: controls byte order; if enabled, least-significant-byte
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will be transmitted/received first.
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Example:
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spi@7000d600 {
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compatible = "nvidia,tegra124-spi-slave";
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reg = <0x7000d600 0x200>;
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interrupts = <0 82 0x04>;
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nvidia,dma-request-selector = <&apbdma 16>;
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spi-max-frequency = <25000000>;
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nvidia,clock-always-on;
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#address-cells = <1>;
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#size-cells = <0>;
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status = "disabled";
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nvidia,slave-ready-gpio = <&gpio TEGRA_GPIO(I, 3) GPIO_ACTIVE_LOW>; /*PI3*/
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nvidia,lsbyte-first;
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};
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