Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 47 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
new file mode 100644
index 000000000..486a17d53
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/gpio-control-nand.txt
@@ -0,0 +1,47 @@
+GPIO assisted NAND flash
+
+The GPIO assisted NAND flash uses a memory mapped interface to
+read/write the NAND commands and data and GPIO pins for the control
+signals.
+
+Required properties:
+- compatible : "gpio-control-nand"
+- reg : should specify localbus chip select and size used for the chip.  The
+  resource describes the data bus connected to the NAND flash and all accesses
+  are made in native endianness.
+- #address-cells, #size-cells : Must be present if the device has sub-nodes
+  representing partitions.
+- gpios : Specifies the GPIO pins to control the NAND device.  The order of
+  GPIO references is:  RDY, nCE, ALE, CLE, and nWP. nCE and nWP are optional.
+
+Optional properties:
+- bank-width : Width (in bytes) of the device.  If not present, the width
+  defaults to 1 byte.
+- chip-delay : chip dependent delay for transferring data from array to
+  read registers (tR).  If not present then a default of 20us is used.
+- gpio-control-nand,io-sync-reg : A 64-bit physical address for a read
+  location used to guard against bus reordering with regards to accesses to
+  the GPIO's and the NAND flash data bus.  If present, then after changing
+  GPIO state and before and after command byte writes, this register will be
+  read to ensure that the GPIO accesses have completed.
+
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. See partition.txt for more detail.
+
+Examples:
+
+gpio-nand@1,0 {
+	compatible = "gpio-control-nand";
+	reg = <1 0x0000 0x2>;
+	#address-cells = <1>;
+	#size-cells = <1>;
+	gpios = <&banka 1 0>,	/* RDY */
+		<0>, 		/* nCE */
+		<&banka 3 0>, 	/* ALE */
+		<&banka 4 0>, 	/* CLE */
+		<0>;		/* nWP */
+
+	partition@0 {
+	...
+	};
+};