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00df263560
Cadence QSPI IP has a adapted loop-back circuit which can be enabled by setting BYPASS field to 0 in READCAPTURE register. It enables use of QSPI return clock to latch the data rather than the internal QSPI reference clock. For high speed operations, adapted loop-back circuit using QSPI return clock helps to increase data valid window. Add DT parameter cdns,rclk-en to help enable adapted loop-back circuit for boards which do have QSPI return clock provided. Update binding documentation for the same. Signed-off-by: Vignesh R <vigneshr@ti.com> Acked-by: Rob Herring <robh@kernel.org> Acked-by: Marek Vasut <marek.vasut@gmail.com> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
62 lines
2.2 KiB
Plaintext
62 lines
2.2 KiB
Plaintext
* Cadence Quad SPI controller
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Required properties:
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- compatible : should be one of the following:
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Generic default - "cdns,qspi-nor".
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For TI 66AK2G SoC - "ti,k2g-qspi", "cdns,qspi-nor".
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- reg : Contains two entries, each of which is a tuple consisting of a
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physical address and length. The first entry is the address and
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length of the controller register set. The second entry is the
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address and length of the QSPI Controller data area.
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- interrupts : Unit interrupt specifier for the controller interrupt.
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- clocks : phandle to the Quad SPI clock.
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- cdns,fifo-depth : Size of the data FIFO in words.
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- cdns,fifo-width : Bus width of the data FIFO in bytes.
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- cdns,trigger-address : 32-bit indirect AHB trigger address.
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Optional properties:
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- cdns,is-decoded-cs : Flag to indicate whether decoder is used or not.
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- cdns,rclk-en : Flag to indicate that QSPI return clock is used to latch
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the read data rather than the QSPI clock. Make sure that QSPI return
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clock is populated on the board before using this property.
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Optional subnodes:
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Subnodes of the Cadence Quad SPI controller are spi slave nodes with additional
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custom properties:
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- cdns,read-delay : Delay for read capture logic, in clock cycles
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- cdns,tshsl-ns : Delay in nanoseconds for the length that the master
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mode chip select outputs are de-asserted between
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transactions.
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- cdns,tsd2d-ns : Delay in nanoseconds between one chip select being
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de-activated and the activation of another.
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- cdns,tchsh-ns : Delay in nanoseconds between last bit of current
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transaction and deasserting the device chip select
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(qspi_n_ss_out).
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- cdns,tslch-ns : Delay in nanoseconds between setting qspi_n_ss_out low
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and first bit transfer.
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Example:
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qspi: spi@ff705000 {
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compatible = "cdns,qspi-nor";
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#address-cells = <1>;
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#size-cells = <0>;
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reg = <0xff705000 0x1000>,
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<0xffa00000 0x1000>;
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interrupts = <0 151 4>;
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clocks = <&qspi_clk>;
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cdns,is-decoded-cs;
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cdns,fifo-depth = <128>;
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cdns,fifo-width = <4>;
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cdns,trigger-address = <0x00000000>;
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flash0: n25q00@0 {
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...
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cdns,read-delay = <4>;
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cdns,tshsl-ns = <50>;
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cdns,tsd2d-ns = <50>;
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cdns,tchsh-ns = <4>;
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cdns,tslch-ns = <4>;
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};
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};
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