On Friday, July 1, 2016 11:17:25 AM CEST Jon Mason wrote:

On Fri, Jul 1, 2016 at 5:46 AM, Arnd Bergmann [off-list ref] wrote:

quoted

On Thursday, June 30, 2016 6:59:13 PM CEST Jon Mason wrote:

quoted

+
+Required properties:
+ - compatible: "brcm,bgmac-nsp"
+ - reg:                Address and length of the GMAC registers,
+               Address and length of the GMAC IDM registers
+ - reg-names:  Names of the registers.  Must have both "gmac_base" and
+               "idm_base"
+ - interrupts: Interrupt number
+

"brcm,bgmac-nsp" sounds a bit too general. As I understand, this is a family
of SoCs that might not all have the exact same implementation of this
ethernet device, as we can see from the long lookup table in bgmac_probe().

The Broadcom iProc family of SoCs contains:
Northstar
Northstar Plus
Cygnus
Northstar 2
a few SoCs that are under development
and a number of ethernet switches (which might never be officially supported)

Each one of these SoCs could have a different revision of the gmac IP
block, but they should be uniform within each SoC (though there might
be a A0/B0 change necessary).  The Northstar Plus product family has a
number of different implementations, but the SoC is unchanged.  So, I
think this might be too specific, when we really need a general compat
string.

Ok, thanks for the clarification, that sounds good enough.

Broadcom has a history of sharing IP blocks amongst the different
divisions.  So, this driver might be used on other SoC families (as it
apparently has been done in the past, based on the code you
reference).  I do not know of any way to know what legacy, non-iProc
chips have used this IP block.  I can make this "brcm,iproc-bgmac",
and add "brcm,iproc-nsp-bgmac" as an alternative compatible string in
this file (which I believe you are suggesting), but there might be
non-iProc SoCs that use this driver.  Is this acceptable?

If it is also used outside of iProc, then I see no need for the
extra compatible string, although it would not do any harm either.

Ideally we should name it whatever the name for this IP block is
inside of the company, with "nsp" as the designation for the variant
in Northstar Plus. A lot of Broadcom IP blocks themselves seem to have
some four-digit or five-digit number, maybe this one does too?

	Arnd