Re: [PATCH v4 1/2] mtd: mediatek: device tree docs for MTK Smart Device Gen1 NAND

Jorge Ramirez
2016-05-10T11:57:49Z

On 05/06/2016 09:38 AM, Boris Brezillon wrote:
> Hi Jorge,
>
> On Fri, 29 Apr 2016 12:17:21 -0400
> Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org> wrote:
>
>> This patch adds documentation support for Smart Device Gen1 type of
>> NAND controllers.
>>
>> Signed-off-by: Jorge Ramirez-Ortiz <jorge.ramirez-ortiz@linaro.org>
>> ---
>> Documentation/devicetree/bindings/mtd/mtk-nand.txt | 161 +++++++++++++++++++++
>> 1 file changed, 161 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/mtd/mtk-nand.txt
>>
>> diff --git a/Documentation/devicetree/bindings/mtd/mtk-nand.txt b/Documentation/devicetree/bindings/mtd/mtk-nand.txt
>> new file mode 100644
>> index 0000000..175767d
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/mtd/mtk-nand.txt
> [...]
>
>> +
>> +Children nodes properties:
>> +- reg: Chip Select Signal, default 0.
>> + Set as reg = <0>, <1> when need 2 CS.
>> +Optional:
>> +- nand-on-flash-bbt: Store BBT on NAND Flash.
>> +- nand-ecc-mode: the NAND ecc mode (check driver for supported modes)
>> +- nand-ecc-step-size: Number of data bytes covered by a single ECC step.
>> + The controller only supports 512 and 1024.
>> + For large page NANDs ther recommended value is 1024.
>> +- nand-ecc-strength: Number of bits to correct per ECC step.
>> + The valid values that the controller supports are: 4, 6,
>> + 8, 10, 12, 14, 16, 18, 20, 22, 24, 28, 32, 36, 40, 44,
>> + 48, 52, 56, 60.
>> + The strength should be calculated as follows:
>> + E = (S - F) * 8 / 14
>> + S = O / (P / Q)
>> + E :nand-ecc-strength;
>> + S :spare size per sector;
>> + F : FDM size, should be in the range [1,8].
>> + It is used to store free oob data.
>> + O : oob size;
>> + P : page size;
>> + Q :nand-ecc-step-size
>> + If the result does not match any one of the listed
>> + choices above, please select the smaller valid value from
>> + the list.
>> + (otherwise the driver will do the clamping at runtime).
>> +- vmch-supply: NAND power supply.
> Where is this supply name coming from? I most datasheets I see Vdd or
> Vcc, but nothing close to Vmch.
>
>
>

um yes we are removing this since we dont use it (it is the NAND vcc on
some other MTK platform to do power management via regulator).