Re: [PATCH v2 12/25] dt-bindings: qcom_nandc: QPIC NAND documentation

[Abhishek Sahu]

On 2017-07-26 00:13, Abhishek Sahu wrote:
> On 2017-07-25 00:47, Rob Herring wrote:
> > On Wed, Jul 19, 2017 at 05:18:00PM +0530, Abhishek Sahu wrote:
> > > 1. QPIC NAND will use compatible string "qcom,qpic-nandc-v1.4.0"
> > > 2. QPIC NAND will 3 BAM channels: command, data tx and data rx
> > >    while EBI2 NAND uses only single ADM channel.
> > > 3. CRCI is only required for ADM DMA and its not required for
> > >    QPIC NAND.
> > >
> > > Signed-off-by: Abhishek Sahu <absahu@xxxxxxxxxxxxxx>
> > > ---
> > >  .../devicetree/bindings/mtd/qcom_nandc.txt         | 54 
> > > ++++++++++++++++++++--
> > >  1 file changed, 51 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/mtd/qcom_nandc.txt 
> > > b/Documentation/devicetree/bindings/mtd/qcom_nandc.txt
> > > index b24adfe..8efaeb0 100644
> > > --- a/Documentation/devicetree/bindings/mtd/qcom_nandc.txt
> > > +++ b/Documentation/devicetree/bindings/mtd/qcom_nandc.txt
> > > @@ -1,13 +1,15 @@
> > >  * Qualcomm NAND controller
> > >
> > >  Required properties:
> > > -- compatible:		should be "qcom,ebi2-nandc" - EBI2 NAND which uses 
> > > ADM
> > > -			DMA like IPQ8064.
> > > -
> > > +- compatible:		must be one of the following:
> > > +	* "qcom,ebi2-nandc" - EBI2 NAND which uses ADM DMA like IPQ8064.
> > > +	* "qcom,qpic-nandc-v1.4.0" - QPIC NAND v1.4.0 which uses BAM DMA 
> > > like IPQ4019.
> >
> > Looks like you have 2 SoCs and 2 versions of h/w. Use SoC specific
> > compatible strings.
>
>  We have 3 versions of NAND HW currently.
>  EBI2,
>  QPIC version 1.4.0
>  QPIC version 1.5.0
>
>  and multiple Qualcomm SoCs which use any one of these.
>
>  The original plan was to have compatible string for NAND version since
>  same NAND hardware is being in different SoC and SoC dtsi will simply
>  use its NAND version compatible string like other Qualcomm hardwares
>
>
> http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/dma/qcom_bam_dma.txt
>
> http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/spi/qcom,spi-qup.txt

 Following are the partial list for NAND controller and supported
 SoC

  EBI2:          IPQ8064, APQ8064, MSM7xx, MDM9x15
  QPIC v1.4.0    MDM9x25, MDM9x35, MDM9x45, IPQ4019
  QPIC v1.5.0    MDM9x55, IPQ8074

 so could we use NAND controller specific compatible strings instead of 
SoC
 since it will easy to maintain?

> > Rob