On 16/06/15 23:53, Stephen Boyd wrote:
On 05/21/2015 09:44 AM, Srinivas Kandagatla wrote:
diff --git a/Documentation/devicetree/bindings/nvmem/nvmem.txt b/Documentation/devicetree/bindings/nvmem/nvmem.txt
new file mode 100644
index 0000000..ecea654
--- /dev/null
+++ b/Documentation/devicetree/bindings/nvmem/nvmem.txt
@@ -0,0 +1,84 @@
+= NVMEM Data Device Tree Bindings =
+
+This binding is intended to represent the location of hardware
+configuration data stored in NVMEMs.
It would be worthwhile spelling out what NVMEM stands for.
+
+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
+to this node.
children of this node?
Yep, will fix the text
+
+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 that storage device, start bit
+ in the byte and the length in bits of the data we care about.
+ There could be more then one offset-length pairs in this property.
s/then/than/
Yep.
+
+Optional properties:
+
+bit-offset: specifies the offset in bit within the address range specified
+ by reg property. Can take values from 0-7.
+nbits: specifies number of bits this cell occupies starting from bit-offset.
+
Hopefully the consumer knows the endianness of the data stored.
As we read byte-byte, does it matter, as long as consumer gets them in
the same order as its stored.
+For example:
+
+ /* Provider */
+ qfprom: qfprom@00700000 {
+ ...
+
+ /* Data cells */
+ tsens_calibration: calib@404 {
+ reg = <0x404 0x10>;
+ };
+
+ tsens_calibration_bckp: calib_bckp@504 {
+ reg = <0x504 0x11>;
+ bit-offset = 6;
+ nbits = 128;
+ };
+
+ pvs_version: pvs-version@6 {
+ reg = <0x6 0x2>
+ bit-offset = 7;
+ nbits = 2;
+ };
+
+ speed_bin: speed-bin@c{
+ reg = <0xc 0x1>;
+ bit-offset = 2;
+ nbits = 3;
+
+ };
+ ...
+ };
+
+= Data consumers =
+Are device nodes which consume nvmem data cells/providers.
+
+Required-properties:
+nvmem-cell: list of phandle to the nvmem data cells.
+nvmem-cell-names: names for the each nvmem-cell specified
+
+Optional-properties:
+nvmem : list of phandles to nvmem providers.
+nvmem-names: names for the each nvmem provider.
Is nvmem-names required if nvmem is used?
Yes, will fix it.
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