[PATCH] mtd: mxc_nand: Set timing for v2 controllers

[boris.brezillon@free-electrons.com (Boris Brezillon)]

On Fri, 2 Sep 2016 14:43:53 +0200
Sascha Hauer <s.hauer@pengutronix.de> wrote:

> On Mon, Aug 29, 2016 at 10:50:50AM +0200, Boris Brezillon wrote:
> > Hi Sascha,
> > 
> > On Mon, 29 Aug 2016 10:35:58 +0200
> > Sascha Hauer <s.hauer@pengutronix.de> wrote:
> >   
> > > Hi Boris,
> > > 
> > > On Fri, Aug 26, 2016 at 09:46:53AM +0200, Boris Brezillon wrote:  
> > > > Hi Sascha,
> > > > 
> > > > On Tue, 23 Aug 2016 12:34:05 +0200
> > > > Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > > > 
> > > > AFAIR, you should apply the new mode on the NAND side
> > > > (ONFI_FEATURE_ADDR_TIMING_MODE) before applying the new config to the
> > > > controller.
> > > > 
> > > > See what's done here [1].
> > > > 
> > > > Note that on all the NANDs I tested, it seems to work even if you don't
> > > > set ONFI_FEATURE_ADDR_TIMING_MODE, but the ONFI Spec describes the
> > > > procedure as:    
> > > 
> > > Indeed, works here without notifying the NAND chip aswell. I wasn't even
> > > aware that there is a possibility to notify the NAND chip.
> > >   
> > > > 
> > > > 1/ detect supported modes
> > > > 2/ select one
> > > > 3/ apply it to the NAND using set(ONFI_FEATURE_ADDR_TIMING_MODE)
> > > > 4/ release the CS
> > > > 5/ adjust the controller setting to match the new config
> > > > 
> > > > On a side note, I really think we should handle this timing selection in
> > > > the core, and only ask the NAND controller drivers to adapt the
> > > > controller settings.    
> > > 
> > > I agree that the core should do this. Do you already have any thoughts
> > > how the API could could look like?  
> > 
> > I already provided a simple implementation a while ago [1]. Not sure it
> > handles all the corner cases though.  
> 
> I just picked up the patch and ported my mxc_nand patch over to it. See
> the result on the mailing list.

Thanks for doing that. I'll try to review the series soon.

Boris