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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.yaml
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
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Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/mmc/mmc-pwrseq-emmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Simple eMMC hardware reset provider binding
+
+maintainers:
+ - Ulf Hansson <ulf.hansson@linaro.org>
+
+description:
+ The purpose of this driver is to perform standard eMMC hw reset
+ procedure, as described 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.
+
+properties:
+ compatible:
+ const: mmc-pwrseq-emmc
+
+ reset-gpios:
+ minItems: 1
+ description:
+ 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.
+
+required:
+ - compatible
+ - reset-gpios
+
+additionalProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/gpio/gpio.h>
+ sdhci0_pwrseq {
+ compatible = "mmc-pwrseq-emmc";
+ reset-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+ };
+...