Query on using nvmem consumer API

Query on using nvmem consumer API

[maitysanchayan at gmail.com]

Hello Srinivas,

I have a device tree node as follows

                        ocotp: ocotp at 400a5000 {
                                compatible = "fsl,vf610-ocotp";
                                #address-cells = <1>;
                                #size-cells = <1>;
                                reg = <0x400a5000 0xCF0>;
                                clocks = <&clks VF610_CLK_OCOTP>;

                                ocotp_cfg: cfg at 410 {
                                        reg = <0x410 0x20>;
                                };
                        };

and a nvmem data consumer node as follows

        soc-bus {
                compatible = "fsl,vf610-soc-bus";
                nvmem = <&ocotp>;
                nvmem-names = "ocotp";
                nvmem-cell = <&ocotp_cfg>;
                nvmem-cell-names = "soc_id";
                status = "okay";
        };

I believe my device tree node entries are incorrect. I did like to
use the devm_nvmem_device/cell_get functions and then read using
cell or device consumer API's. I am looking at the NVMEM bindings
but it is not clear to me as to what the correct DT entries and
the corresponding arguments to devm_nvmem_device/cell_get should
be?

Can you help me out with as to what the correct entries and calls
should be?

I currently have
devm_nvmem_device_get(dev, "ocotp");
devm_nvmem_cell_get(dev, "soc_id");

where dev would be the soc-bus device.

Thanks & Regards,
Sanchayan.

Query on using nvmem consumer API

[Srinivas Kandagatla]

On 18/02/16 12:01, maitysanchayan at gmail.com wrote:
> Hello Srinivas,
>
> I have a device tree node as follows
>
>                          ocotp: ocotp at 400a5000 {
>                                  compatible = "fsl,vf610-ocotp";
>                                  #address-cells = <1>;
>                                  #size-cells = <1>;
>                                  reg = <0x400a5000 0xCF0>;
>                                  clocks = <&clks VF610_CLK_OCOTP>;
>
>                                  ocotp_cfg: cfg at 410 {
>                                          reg = <0x410 0x20>;
>                                  };
>                          };
>
> and a nvmem data consumer node as follows
>
>          soc-bus {
>                  compatible = "fsl,vf610-soc-bus";
>                  nvmem = <&ocotp>;
>                  nvmem-names = "ocotp";
>                  nvmem-cell = <&ocotp_cfg>;
>                  nvmem-cell-names = "soc_id";
>                  status = "okay";
>          };
>
> I believe my device tree node entries are incorrect. I did like to
> use the devm_nvmem_device/cell_get functions and then read using
> cell or device consumer API's. I am looking at the NVMEM bindings
> but it is not clear to me as to what the correct DT entries and
> the corresponding arguments to devm_nvmem_device/cell_get should
> be?
>
> Can you help me out with as to what the correct entries and calls
> should be?

Sure,

Firstly you should grab a nvmem cell and then use it as part of 
nvmem_read/write.

In your case you would do this in soc-bus device.

struct nvmem_cell *soc_id = devm_nvmem_cell_get(dev, "soc_id");
data = nvmem_cell_read(soc_id, &len);

There is some documentation at Documentation/nvmem/nvmem.txt
Let me know if you find any issues with the doc.


thanks,
srini


>
> I currently have
> devm_nvmem_device_get(dev, "ocotp");
> devm_nvmem_cell_get(dev, "soc_id");
>
> where dev would be the soc-bus device.
>
> Thanks & Regards,
> Sanchayan.
>