92 lines
3.7 KiB
Plaintext
92 lines
3.7 KiB
Plaintext
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Qualcomm Serial Peripheral Interface (SPI)
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Required properties:
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- compatible : Should be "qcom,spi-qup-v2".
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- reg : Offset and length of the register regions for the device
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- reg-names : Register region names referenced in reg above.
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Required register resource entries are:
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"spi_physical" : Physical address of controller register blocks.
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- interrupts : Interrupt numbers used by this controller
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- interrupt-names : Interrupt resource names referenced in interrupts above.
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Required interrupt resource entries are:
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"spi_irq" : QUP-core interrupt.
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- spi-max-frequency : Specifies maximum SPI clock frequency, Units - Hz.
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Required alias:
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- The desired bus-number is specified via an alias with the following format
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'spi{n}' where n is the bus number.
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Optional properties:
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- gpios : Specifies the gpio pins to be used for SPI CLK, MISO, MOSI in
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that order.
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- cs-gpios : Specifies the gpio pins to be used for chipselects.
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- qcom,infinite-mode: When missing or set to zero, QUP uses infinite-mode. When
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value is non-zero, the value is the number of words in maximum transfer
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length.
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- qcom,active-only : Vote for core clock when the application processor goes
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to active state and remove that vote when it goes to idle state. This flag may
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improve service time of first spi request at the expense of power consumption.
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When this entry is not present, voting is done by the runtime-pm callbacks.
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- qcom,master-id : Master endpoint number used for voting on clocks using the
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bus-scaling driver.
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Optional properties which are required for support of BAM-mode:
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- qcom,ver-reg-exists : Boolean. When present, allows driver to verify if HW
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version support latest features (e.g. BAM) and then enable them. Should be
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removed for legacy HW.
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- qcom,use-bam : Boolean. When present, enables BAM-mode.
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- qcom,bam-consumer-pipe-index : BAM consumer-pipe index.
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- qcom,bam-producer-pipe-index : BAM producer-pipe index.
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- reg-names : register region names referenced in reg.
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Required register resource for BAM are:
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"spi_bam_physical" : Physical address of BAM for this controller.
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- interrupt-names : interrupt resource names referenced in interrupts.
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Required interrupt resource from BAM are:
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"spi_bam_irq" : BAM interrupt used by the controller.
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Optional SPI slave nodes must be children of the SPI master node and contain
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the following properties.
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- reg: (required) chip-select address of the device.
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- compatible : (required) Name of SPI device following generic names.
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- spi-max-frequency : (required) Maximum SPI clocking speed of device in Hz
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- interrupts : (recommended) Should contain the SPI slave interrupt number
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encoded depending on the type of the interrupt controller.
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- interrupt-parent : (recommended) The phandle for the interrupt controller
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that services interrupts for this device.
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- spi-cpol : (optional) Empty property indicating device requires inverse
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clock polarity (CPOL) mode
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- spi-cpha : (optional) Empty property indicating device requires shifted
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clock phase (CPHA) mode
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- spi-cs-high : (optional) Empty property indicating device requires
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chip select active high
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Example:
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aliases {
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spi0 = &spi_0;
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};
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spi_0: spi@f9923000 {
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compatible = "qcom,spi-qup-v2";
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reg-names = "spi_physical", "spi_bam_physical";
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reg = <0xf9923000 0x1000>,
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<0xf9904000 0x10000>;
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interrupt-names = "spi_irq", "spi_bam_irq";
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interrupts = <0 95 0>, <0 238 0>;
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spi-max-frequency = <19200000>;
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#address-cells = <1>;
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#size-cells = <0>;
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gpios = <&msmgpio 3 0>, /* CLK */
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<&msmgpio 1 0>, /* MISO */
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<&msmgpio 0 0>; /* MOSI */
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cs-gpios = <&msmgpio 9 0>;
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qcom,infinite-mode = <0>;
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qcom,use-bam;
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qcom,bam-consumer-pipe-index = <12>;
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qcom,bam-producer-pipe-index = <13>;
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qcom,ver-reg-exists;
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qcom,master-id = <86>;
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};
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