[PATCH 1/3] mtd: atmel_nand: move the hsmc_clk from nfc node to nand node

[Boris Brezillon]

Hi Jean-Christophe,

On Thu, 26 Feb 2015 19:49:09 +0800
Jean-Christophe PLAGNIOL-VILLARD <plagnioj at jcrosoft.com> wrote:

> 
> > On Feb 26, 2015, at 5:18 PM, Boris Brezillon <boris.brezillon at free-electrons.com> wrote:
> > 
> > Hi Josh,
> > 
> > On Tue, 10 Feb 2015 14:14:43 +0800
> > Josh Wu <josh.wu at atmel.com> wrote:
> > 
> >> Also add a new sama5d3_nand compatiable string for sama5d3 nand.
> >> 
> >> For sama5d3, sama5d4 chip, the pmecc became part of HSMC, they need the
> >> HSMC clock enabled to work.
> >> The NFC is a sub feature for current nand driver, it can be disabled.
> >> But if HSMC clock is controlled by NFC, so disable NFC will also disable
> >> the HSMC clock. then, it will make the PMECC fail to work.
> >> 
> >> So the solution is move the HSMC clock out of NFC to nand node. When
> >> nand driver probed, it will check whether the chip has HSMC, if yes then
> >> it will require a HSMC clock.
> > 
> > Do you plan to use the NAND chip without the NFC (I mean, is there a
> > reason for not using the NFC to access the NAND ?) ?
> > If you don't, why don't you just wait for the NFC before probing the
> > NAND chip it is attached to, so that the hmsc clk is properly claimed.
> you can as you can have 2 Nand on the d3 but only 1 NFC

I don't get your point ?
You can control several NAND chips with the same NFC.

-- 
Boris Brezillon, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com