summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/nvmem/nvmem.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/nvmem/nvmem.txt')
-rw-r--r--Documentation/devicetree/bindings/nvmem/nvmem.txt80
1 files changed, 80 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/nvmem/nvmem.txt b/Documentation/devicetree/bindings/nvmem/nvmem.txt
new file mode 100644
index 000000000000..b52bc11e9597
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/nvmem.txt
@@ -0,0 +1,80 @@
+= NVMEM(Non Volatile Memory) Data Device Tree Bindings =
+
+This binding is intended to represent the location of hardware
+configuration data stored in NVMEMs like eeprom, efuses and so on.
+
+On a significant proportion of boards, the manufacturer has stored
+some data on NVMEM, for the OS to be able to retrieve these information
+and act upon it. Obviously, the OS has to know about where to retrieve
+these data from, and where they are stored on the storage device.
+
+This document is here to document this.
+
+= Data providers =
+Contains bindings specific to provider drivers and data cells as children
+of this node.
+
+Optional properties:
+ read-only: Mark the provider as read only.
+
+= Data cells =
+These are the child nodes of the provider which contain data cell
+information like offset and size in nvmem provider.
+
+Required properties:
+reg: specifies the offset in byte within the storage device.
+
+Optional properties:
+
+bits: Is pair of bit location and number of bits, which specifies offset
+ in bit and number of bits within the address range specified by reg property.
+ Offset takes values from 0-7.
+
+For example:
+
+ /* Provider */
+ qfprom: qfprom@00700000 {
+ ...
+
+ /* Data cells */
+ tsens_calibration: calib@404 {
+ reg = <0x404 0x10>;
+ };
+
+ tsens_calibration_bckp: calib_bckp@504 {
+ reg = <0x504 0x11>;
+ bits = <6 128>
+ };
+
+ pvs_version: pvs-version@6 {
+ reg = <0x6 0x2>
+ bits = <7 2>
+ };
+
+ speed_bin: speed-bin@c{
+ reg = <0xc 0x1>;
+ bits = <2 3>;
+
+ };
+ ...
+ };
+
+= Data consumers =
+Are device nodes which consume nvmem data cells/providers.
+
+Required-properties:
+nvmem-cells: list of phandle to the nvmem data cells.
+nvmem-cell-names: names for the each nvmem-cells specified. Required if
+ nvmem-cells is used.
+
+Optional-properties:
+nvmem : list of phandles to nvmem providers.
+nvmem-names: names for the each nvmem provider. required if nvmem is used.
+
+For example:
+
+ tsens {
+ ...
+ nvmem-cells = <&tsens_calibration>;
+ nvmem-cell-names = "calibration";
+ };