Re: [PATCH v1 2/2] mtd: rawnand: Add NAND controller support on Intel LGM SoC

[Ramuthevar, Vadivel MuruganX]

Hi Martin,

ÂÂÂ Thank you so much for review comments and your time...

On 16/4/2020 6:05 am, Martin Blumenstingl wrote:
> Hi,
>
> first of all: thank you for working on upstreaming this.
> Especially since you are going to use the new exec_op style in v2 as
> Boris suggested.
>
> > From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
> >
> > This patch adds the new IP of Nand Flash Controller(NFC) support
> > on Intel's Lightning Mountain(LGM) SoC.
> >
> > DMA is used for burst data transfer operation, also DMA HW supports
> > aligned 32bit memory address and aligned data access by default.
> > DMA burst of 8 supported. Data register used to support the read/write
> > operation from/to device.
> I am wondering how this new hardware is different from the Lantiq NAND
> controller IP - for which there is already a driver in mainline (it's
> in drivers/mtd/nand/raw/xway_nand.c).
> The CON and WAIT registers look suspiciously similar.
>
> As far as I understand the "old" SoCs (VRX200 and earlier) don't have
> a built-in ECC engine. This seems to have changed with ARX300 though
> (again, AFAIK).
>
> A bit of lineage on these SoCs (initially these were developed by
> Infineon. Lantiq then started as an Infineon spin-off in 2009 and
> was then acquired by Intel in 2015):
> - Danube
> - ARX100 from 2008/2009
> - VRX200 from 2009/2010
> - ARX300 from 2014
> - GRX350 from 2015/2016
> - GRX550 from 2017
> - and now finally: LGM from 2020 (est.)
>
> The existing xway_nand driver supports the Danube, ARX100 and VRX200
> SoCs.
Lantiq upstreamed a driver for an older version of this IP core 8 years 
ago, see here:
https://elixir.bootlin.com/linux/v5.5.6/source/drivers/mtd/nand/raw/xway_nand.c 
It does not support DMA and ECC.
This upstream driver works with the xrx200, I do not know how well it 
works with other SoCs.

Regards
Vadivel
> Best regards,
> Martin