Add documentation for gpio-addr-flash. This binding allow creating
flash devices that are paged using GPIOs.
Cc: devicetree@xxxxxxxxxxxxxxx
Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>
---
Changelog v3:
- Changes suggested by Rob Herring (Thanks!)
- Add gpio description
- Improve partition
.../bindings/mtd/gpio-addr-flash.txt | 54 +++++++++++++++++++
1 file changed, 54 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
new file mode 100644
index 000000000000..5006a26e1753
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt
@@ -0,0 +1,54 @@
+Memory Mapped flash with some address lines addressed using GPIOs
+
+Handle the case where a flash device is mostly addressed using physical
+line and supplemented by GPIOs. This way you can hook up say a 8MiB flash
+to a 2MiB memory range and use the GPIOs to select a particular range.
+
+ - compatible : "cfi-gpio-addr-flash"
+ - reg : Address range of the mtd chip that is memory mapped, this is,
+ on the previous example 2MiB.
+ - bank-width : Width (in bytes) of the bank. Equal to the
+ device width times the number of interleaved chips.
+ - gpios: List of GPIO specifiers that will be used to address the MSBs address
+ lines. The order goes from LSB to MSB.
+ - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip
+ is going to be probed. If omitted, assumed to be equal to "cfi_probe".
+ - #address-cells, #size-cells : Must be present if the device has
+ sub-nodes representing partitions (see below). In this case
+ both #address-cells and #size-cells must be equal to 1.
+
+The device tree may optionally contain sub-nodes describing partitions of the
+address space. Check partition.txt for more details.
+
+Example:
+
+ flash@300000 {
+ #address-cells = <1>;
+ #size-cells = <1>;
+ compatible = "cfi-gpio-addr-flash";
+ bank-width = <2>;
+ reg = < 0x00300000 0x00200000 >;
+ gpios = <&gpio_0 3 0>, <&gpio_0 4 0>;
+ partitions {
+ compatible = "fixed-partitions";
+ #address-cells = <1>;
+ #size-cells = <1>;
+
+ partition@0 {
+ reg = < 0x0 0x200000 >;
+ label = "Golden Bitstream";
+ };
+ partition@200000 {
+ reg = < 0x200000 0x200000 >;
+ label = "User Bitstream";
+ };
+ partition@400000 {
+ reg = < 0x400000 0x200000 >;
+ label = "V4L Controls";
+ };
+ partition@600000 {
+ reg = < 0x600000 0x200000 >;
+ label = "Production Data";
+ };
+ }
+ } ;
--
2.19.0
