[PATCH v3 5/5] ARM: dts: imx28: changing usb compatible string as only "fsl,imx28-usb"

[Peter Chen]

On Fri, Oct 25, 2013 at 04:46:09PM +0800, Shawn Guo wrote:
> On Fri, Oct 25, 2013 at 04:14:30PM +0800, Peter Chen wrote:
> > > > @@ -1041,7 +1041,7 @@
> > > >  		ranges;
> > > >  
> > > >  		usb0: usb at 80080000 {
> > > > -			compatible = "fsl,imx28-usb", "fsl,imx27-usb";
> > > > +			compatible = "fsl,imx28-usb";
> > > 
> > > You shouldn't need the change as long as you put "fsl,imx28-usb" before
> > > "fsl,imx27-usb" in driver ci_hdrc_imx_dt_ids[] table.
> > > 
> > 
> > I know it can work without this dts change, but that driver change like
> > a workaround.
> 
> No, it's not a workaround.  Before of_match_device() gets improved to
> match the best one, it should just work that way.
> 

hmm, before of_match_device gets improved or it is well documented,
how user knows to organize device_id table.

> > Since the imx28-usb is not compatible with imx27-usb,
> > we'd better only keep "fsl, imx28-usb" compatible string at imx28 dtsi.
> 
> From hardware point of view, the USB block on imx28 *is* inherited from
> imx27, and compatible to imx27 USB block, even though we have a little
> difference to handle in software.  The compatible string is written in
> this way at the first place exactly for the reason we can save such
> DTS change when we have some little incompatibility to handle.
> 

OK, I agree, then the of_match_device really should be improved to get
above purpose. BTW, any reasons why esdhc has different compatible string
for every SoCs?

-- 

Best Regards,
Peter Chen