On Wed, Apr 15, 2009 at 10:44 AM, Stephen Neuendorffer <stephen.neuendorf...@xilinx.com> wrote: > > >> -----Original Message----- >> From: Grant Likely [mailto:grant.lik...@secretlab.ca] >> Sent: Wednesday, April 15, 2009 9:03 AM >> To: Stephen Neuendorffer >> Cc: John Linn; jwbo...@linux.vnet.ibm.com; >> linux-fbdev-de...@lists.sourceforge.net; linuxppc- >> d...@ozlabs.org; akonova...@ru.mvista.com; adap...@gmail.com; Suneel Garapati >> Subject: Re: [PATCH] [V3] Xilinx : Framebuffer Driver: Add PLB support and >> cleanup DCR >> >> On Wed, Apr 15, 2009 at 9:58 AM, Stephen Neuendorffer >> <stephen.neuendorf...@xilinx.com> wrote: >> >> > - rc = of_address_to_resource(op->node, 0, &res); >> >> > - if (rc) { >> >> > - dev_err(&op->dev, "invalid address\n"); >> >> > - return rc; >> >> > + /* >> >> > + * To check whether the core is connected directly to DCR or PLB >> >> > + * interface and initialize the tft_access accordingly. >> >> > + */ >> >> > + p = (u32 *)of_get_property(op->node, "xlnx,dcr-splb-slave-if", >> >> > NULL); >> >> >> >> Hmmm. This binding is undocumented. It would be better to make the >> >> decision on the presence/absence of the dcr-reg and/or reg properties. >> > >> > For backward compatibility with the 'old' way, the device tree generator >> > for this core has both >> dcr-reg and reg properties (where the reg has been translated back through >> the bridge). >> >> So, what is in the regs and dcr-regs properties when DCR is used? >> >> How about when MMIO is used? >> > > Currently: > Core has DCR access, connected DCR bus: > device tree contains dcr-reg property. > Core has DCR access, accessed through plb->dcr bridge: > device tree contains dcr-reg property, AND for backward compatibility > with the > old driver, a reg property which contains the apparent registers on > the bus. > Core has PLB access: > device tree contains reg property only. > > So, I guess it really doesn't matter... The only interesting case is the > second one where (because the way the reg property is published), either > method will work... So, nevermind, the device tree question is completely > independent and I agree with your comment that there's probably not a need > for a separate binding. > > What I do think would be nice (at some point in the future maybe) is perhaps > a bit of DCR_or_PLB abstraction for this core and the ll_temac driver to > share which would avoid duplicating the code in each driver as to whether it > uses DCR or PLB access...
Good idea. g. > > Steve > > > This email and any attachments are intended for the sole use of the named > recipient(s) and contain(s) confidential information that may be proprietary, > privileged or copyrighted under applicable law. If you are not the intended > recipient, do not read, copy, or forward this email message or any > attachments. Delete this email message and any attachments immediately. > > > -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
