forked from Minki/linux
721e049717
Some devices need a while to boot their firmware after providing clks / de-asserting resets before they are ready to receive sdio commands. This commits adds a post-power-on-delay-ms devicetree property to mmc-pwrseq-simple for use with such devices. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
30 lines
1.0 KiB
Plaintext
30 lines
1.0 KiB
Plaintext
* The simple MMC power sequence provider
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The purpose of the simple MMC power sequence provider is to supports a set of
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common properties between various SOC designs. It thus enables us to use the
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same provider for several SOC designs.
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Required properties:
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- compatible : contains "mmc-pwrseq-simple".
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Optional properties:
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- reset-gpios : contains a list of GPIO specifiers. The reset GPIOs are asserted
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at initialization and prior we start the power up procedure of the card.
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They will be de-asserted right after the power has been provided to the
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card.
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- clocks : Must contain an entry for the entry in clock-names.
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See ../clocks/clock-bindings.txt for details.
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- clock-names : Must include the following entry:
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"ext_clock" (External clock provided to the card).
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- post-power-on-delay-ms : Delay in ms after powering the card and
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de-asserting the reset-gpios (if any)
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Example:
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sdhci0_pwrseq {
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compatible = "mmc-pwrseq-simple";
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reset-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
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clocks = <&clk_32768_ck>;
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clock-names = "ext_clock";
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}
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