[U-Boot] [PATCH] atmel nand patch CE don't care NAND

[Scott Wood]

On Tue, 8 Feb 2011 14:29:21 -0600
Scott Wood <scottwood at freescale.com> wrote:

> On Wed, Feb 02, 2011 at 04:11:29PM +0100, Michael Trimarchi wrote:
> > diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
> > index ab8bbb3..bda117a 100644
> > --- a/drivers/mtd/nand/atmel_nand.c
> > +++ b/drivers/mtd/nand/atmel_nand.c
> > @@ -249,8 +249,13 @@ static void at91_nand_hwcontrol(struct mtd_info *mtd,
> >  		if (ctrl & NAND_ALE)
> >  			IO_ADDR_W |= CONFIG_SYS_NAND_MASK_ALE;
> >  
> > +		/*
> > +		 * Nand CS don't care doesn't need the enable pin
> > +		 */
> > +#ifdef CONFIG_SYS_NAND_ENABLE_PIN
> >  		at91_set_gpio_value(CONFIG_SYS_NAND_ENABLE_PIN,
> >  				    !(ctrl & NAND_NCE));
> > +#endif
> 
> New CONFIG symbols need to be documented, and this particular one should
> probably be less generic.

Sorry, ignore that -- I see it's not new (it should still be documented,
but that's not this patch's problem).

The code change itself looks OK, just needs a better commit
message/comment. Some googling indicates that "CE don't care" refers to the
ability to deassert the chip enable line once an operation has been
initiated.  This seems to be different from not having control of CE at all
(is it just always asserted on these boards?).

-Scott