From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Mon, 23 Nov 2015 17:58:46 +0100 Subject: [PATCH 07/13] bus: mvebu-mbus: provide api for obtaining IO and DRAM window information In-Reply-To: References: <1448178839-3541-1-git-send-email-mw@semihalf.com> <5746764.cNlI6PeatM@wuerfel> Message-ID: <13065265.iV8IxW6ybQ@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Sunday 22 November 2015 22:24:01 Marcin Wojtas wrote: > > 2015-11-22 21:02 GMT+01:00 Arnd Bergmann : > > On Sunday 22 November 2015 08:53:53 Marcin Wojtas wrote: > >> This commit enables finding appropriate mbus window and obtaining its > >> target id and attribute for given physical address in two separate > >> routines, both for IO and DRAM windows. This functionality > >> is needed for Armada XP/38x Network Controller's Buffer Manager and > >> PnC configuration. > >> > >> Signed-off-by: Marcin Wojtas > >> > >> [DRAM window information reference in LKv3.10] > >> Signed-off-by: Evan Wang > >> > > > > It's too long ago to remember all the details, but I thought we > > had designed this so the configuration can just be done by > > describing it in DT. What am I missing? > > > > And those functions do not break this approach. They just enable > finding and reading the settings of MBUS windows done during initial > configuration. Please remember that mvebu-mbus driver fills the MBUS > windows registers basing on DT, however it just configures access CPU > - DRAM/perfipheral. > > In this particular case only physical adresses of buffers are known > and we have to 'open windows' between BM <-> DRAM and NETA <-> BM > internal memory. Hence instead of hardcoding size/target/attribute, we > can take information stored in CPU DRAM/IO windows registers. > > Ok, got it. Thanks for the explanation. Arnd