1 files changed, 46 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.yaml b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.yaml
new file mode 100644
index 000000000000..77f746f57284
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-emmc.yaml
@@ -0,0 +1,46 @@
+# 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
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    sdhci0_pwrseq {
+      compatible = "mmc-pwrseq-emmc";
+      reset-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+    };
+...