Re: [2/2] powerpc/fsl-booke: Add initial T1042RDB_PI board support

On Wed, 2014-07-30 at 23:37 -0500, Jain Priyanka-B32167 wrote:

-----Original Message-----
From: Wood Scott-B07421 
Sent: Thursday, July 31, 2014 1:43 AM
To: Jain Priyanka-B32167
Cc: devicetree@vger.kernel.org; linuxppc-dev@lists.ozlabs.org; Aggrwal Poonam-B10812; Kushwaha Prabhakar-B32579
Subject: Re: [2/2] powerpc/fsl-booke: Add initial T1042RDB_PI board support

On Wed, Jul 09, 2014 at 09:54:11AM +0530, Priyanka Jain wrote:

quoted

diff --git a/arch/powerpc/boot/dts/t104xrdb.dtsi 

b/arch/powerpc/boot/dts/t104xrdb.dtsi
index 9aaefa5..e7e765f 100644

--- a/arch/powerpc/boot/dts/t104xrdb.dtsi
+++ b/arch/powerpc/boot/dts/t104xrdb.dtsi

@@ -57,7 +57,8 @@
 		};
 
 		cpld@3,0 {
-			compatible = "fsl,t1040rdb-cpld","fsl,t1042rdb-cpld";
+			compatible = "fsl,t1040rdb-cpld","fsl,t1042rdb-cpld",
+					"fsl,t1042rdb_pi-cpld";
 			reg = <3 0 0x300>;
 		};
 	};

What's going on here?  This file is used by all three boards.  If you need to distinguish one board's CPLD from another's, you'll have to do it somewhere else.  If the CPLDs are exactly the same and no distinction needs to be made, then you don't need three compatible strings.  Even then, you may wish to specify the exact board as the first compatible string, but again you'll need to patch that in elsewhere so that it actually matches the board
.
As the register set of CPLD for all three boards is same, I am thinking of replacing this with t104srdb-cpld
compatible = "fsl,t104xrdb-cpld","
Is this OK?

No.  Wildcards aren't allowed in compatible strings, because you never
know what other devices might exist in the future that match the
wildcard.

If the CPLD logic is truly 100% identical, just pick one of the three to
be the canonical name.

-Scott