[PATCH 2/8] ARM: MCS814x: add Device Tree based MCS8140 board support
Florian Fainelli
florian at openwrt.org
Tue Jul 17 09:57:55 EDT 2012
On Tuesday 17 July 2012 13:53:13 Arnd Bergmann wrote:
> On Tuesday 17 July 2012, Florian Fainelli wrote:
> > On Tuesday 17 July 2012 13:19:43 Arnd Bergmann wrote:
> > > On Sunday 15 July 2012, Florian Fainelli wrote:
>
> > > > + adc {
> > > > + compatible = "simple-bus";
> > > > + #address-cells = <2>;
> > > > + #size-cells = <1>;
> > > > + // 8 64MB chip-selects
> > > > + ranges = <0 0 0x00000000 0x4000000 // sdram
> > > > + 1 0 0x04000000 0x4000000 // sdram
> > > > + 2 0 0x08000000 0x4000000 // reserved
> > > > + 3 0 0x0c000000 0x4000000 //
> > flash/localbus
> > > > + 4 0 0x10000000 0x4000000 //
> > flash/localbus
> > > > + 5 0 0x14000000 0x4000000 //
> > flash/localbus
> > > > + 6 0 0x18000000 0x4000000 //
> > flash/localbus
> > > > + 7 0 0x1c000000 0x4000000>; //
> > flash/localbus
> > > > +
> > > > + sdram: memory at 0,0 {
> > > > + reg = <0 0 0>;
> > > > + };
> > > > +
> > > > + nor: flash at 7,0 {
> > > > + reg = <7 0 0x4000000>;
> > > > + compatible = "cfi-flash";
> > > > + bank-width = <1>; // 8-bit external
> > flash
> > > > + #address-cells = <1>;
> > > > + #size-cells = <1>;
> > > > + };
> > > > + };
> > >
> > > Nice representation of the external buses. It does seem however that at
> > > least the nor flash entry is board specific and should be moved into the
> > > board .dts file.
> >
> > In fact, MCS8140 only supports 8-bit CFI Flash chips, so this really is
the
> > common point of all MCS8140-based boards. As you can see in the following
> > board-specific DTS patches, only the partition layout is different.
>
> But is the flash always connected to bank 7? It looks like you could easily
have
> a NIC on that one and the flash on a different bank.
In fact, the only constraint is that bank7 is the only one which can be used
for an external boot flash. I do not have any problem moving this to the per-
board DTS file.
--
Florian
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