ata: sata_rcar: add gen[23] fallback compatibility strings
authorSimon Horman <horms+renesas@verge.net.au>
Tue, 11 Jul 2017 11:44:20 +0000 (13:44 +0200)
committerTejun Heo <tj@kernel.org>
Sat, 15 Jul 2017 11:07:28 +0000 (07:07 -0400)
commit6ac1d1532c888b030acb3b4ac82425448cb15198
tree0e64789cbff3a094d090bb8dcd226d73d36ef4af
parentae867937009397649db2284d32ff7c9a1a2c3665
ata: sata_rcar: add gen[23] fallback compatibility strings

Add fallback compatibility string for R-Car Gen 2 and 3.

In the case of Renesas R-Car hardware we know that there are generations of
SoCs, e.g. Gen 1 and 2. But beyond that its not clear what the relationship
between IP blocks might be. For example, I believe that r8a7790 is older
than r8a7791 but that doesn't imply that the latter is a descendant of the
former or vice versa.

We can, however, by examining the documentation and behaviour of the
hardware at run-time observe that the current driver implementation appears
to be compatible with the IP blocks on SoCs within a given generation.

For the above reasons and convenience when enabling new SoCs a
per-generation fallback compatibility string scheme being adopted for
drivers for Renesas SoCs.

Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Documentation/devicetree/bindings/ata/sata_rcar.txt
drivers/ata/sata_rcar.c