Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / Documentation / devicetree / bindings / mmc / mmc-pwrseq-emmc.txt

diff --git a/kernel/Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.txt b/kernel/Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.txt
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+* The simple eMMC hardware reset provider
+
+The purpose of this driver is to perform standard eMMC hw reset
+procedure, as descibed by Jedec 4.4 specification. This procedure is
+performed just after MMC core enabled power to the given mmc host (to
+fix possible issues if bootloader has left eMMC card in initialized or
+unknown state), and before performing complete system reboot (also in
+case of emergency reboot call). The latter is needed on boards, which
+doesn't have hardware reset logic connected to emmc card and (limited or
+broken) ROM bootloaders are unable to read second stage from the emmc
+card if the card is left in unknown or already initialized state.
+
+Required properties:
+- compatible : contains "mmc-pwrseq-emmc".
+- reset-gpios : contains a GPIO specifier. The reset GPIO is asserted
+       and then deasserted to perform eMMC card reset. To perform
+       reset procedure as described in Jedec 4.4 specification, the
+       gpio line should be defined as GPIO_ACTIVE_LOW.
+
+Example:
+
+       sdhci0_pwrseq {
+               compatible = "mmc-pwrseq-emmc";
+               reset-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+       }