Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751433AbcLEDo4 (ORCPT ); Sun, 4 Dec 2016 22:44:56 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:36351 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751223AbcLEDox (ORCPT ); Sun, 4 Dec 2016 22:44:53 -0500 Subject: Re: [PATCH 39/39] mtd: nand: denali_dt: add compatible strings for UniPhier SoC variants To: Masahiro Yamada , Dinh Nguyen References: <1480183585-592-1-git-send-email-yamada.masahiro@socionext.com> <1480183585-592-40-git-send-email-yamada.masahiro@socionext.com> <20161201160511.ahlibszokg547wxk@rob-hp-laptop> Cc: Rob Herring , "linux-mtd@lists.infradead.org" , "devicetree@vger.kernel.org" , Linux Kernel Mailing List , Boris Brezillon , Brian Norris , Richard Weinberger , David Woodhouse , Cyrille Pitchen , Mark Rutland , Dinh Nguyen , Alan Tull , Chin Liang See , Dinh Nguyen From: Marek Vasut Message-ID: <563ec35c-0964-b696-0f5b-79ec38d4620b@gmail.com> Date: Mon, 5 Dec 2016 04:44:37 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4117 Lines: 108 On 12/05/2016 04:30 AM, Masahiro Yamada wrote: > Hi Dinh, > > > 2016-12-04 7:08 GMT+09:00 Dinh Nguyen : >> Hi, >> >> On Fri, Dec 2, 2016 at 8:49 PM, Marek Vasut wrote: >>> On 12/03/2016 03:41 AM, Masahiro Yamada wrote: >>>> Hi Rob, >>> >>> Hi! >>> >>>> 2016-12-03 1:26 GMT+09:00 Rob Herring : >>>> >>>>>> >>>>>> >>>>>> (Plan A) >>>>>> "denali,socfpga-nand" (for Altera SOCFPGA variant) >>>>>> "denali,uniphier-nand-v1" (for old Socionext UniPhier family variant) >>>>>> "denali,uniphier-nand-v2" (for new Socionext UniPhier family variant) >>>>>> >>>>>> (Plan B) >>>>>> "altera,denali-nand" (for Altera SOCFPGA variant) >>>>>> "socionext,denali-nand-v5a" (for old Socionext UniPhier family variant) >>>>>> "socionext,denali-nand-v5b" (for new Socionext UniPhier family variant) >>>> >>>>> Let the Altera folks worry about their stuff. At least for soft IP in >>>>> FPGA, it's a bit of a special case. The old string can remain as bad >>>>> as it is. >>>> >>>> >>>> Hmm, I am not sure if this IP would fit in FPGA >>>> (to use it along with NIOS-II?) >>>> >>>> (even if it happened, nothing of this IP would be customizable on users' side. >>>> When buying the IP, SoC vendors submit a list of desired features. >>>> Denali (now Cadence) generates the RTL according to the configuration sheet. >>>> The function is fixed at this point. So, generic compatible would be >>>> useless anyway.) >>>> >>>> >>>> If we are talking about SOCFPGA, >>>> SOCFPGA is not only FPGA. Rather "SOC" + "FPGA". >>>> It consists of two parts: >>>> [1] SOC part (Cortex-A9 + various hard-wired peripherals such UART, >>>> USB, SD, NAND, ...) >>>> [2] FPGA part (User design logic) >>>> >>>> The Denali NAND controller is included in [1]. >>>> So, as far as we talk about the Denali on SOCFPGA, >>>> it is as hard-wired as Intel, Socionext's ones. >>> >>> That's correct, the Denali NAND IP in altera socfpga is a hardware >>> block. You can make it available to the fabric too, but by default >>> it's used by the ARM part of the chip, so for this discussion, you >>> can forget that the FPGA part exists altogether. >>> >>> I would be in favor of plan B, since it seems to be the more often >>> taken approach. A nice example is ci-hdrc: >>> >>> $ git grep compatible drivers/usb/chipidea/ >>> >>>>> I simply would do "socionext,uniphier-v5b-nand" (and v5a). >>>>> The fact that it is denali is part of the documentation. >>>>> >>>> >>>> Let me think about this. >>>> >>>> Socionext bought two version of Denali IP, >>>> and we are now re-using the newer one (v5b) for several SoCs. >>>> Socionext has some more product lines other than Uniphier SoC family, >>>> perhaps wider re-use might happen in the future. >>>> >>>> At first, I included "uniphier" in compatible, but I am still wondering >>>> if such a specific string is good or not. >>>> >>>> Also, comments from Altera engineers are appreciated. >> >> Sorry, it's taken me a while to add comments. My altera email is very spotty now >> that the Intel merge is completed. Please use dinguyen@kernel.org for any future >> communications. >> >> Yes, everything that is said so far for the NAND controller on the >> SoCFPGA is correct. I added the binding for the controller a while >> back, but unfortunately, we never added the NAND interface to the >> devkit, so we did not do much in terms of enabling it. >> >> I think the only SoCFPGA board I know that has the NAND interface active is >> the TRCom board, but I have never seen that board. >> >> I don't have any strong opinions on this matter, just as long as the >> original binding >> "denali,denali-nand-dt" is kept, and I think Rob was ok with keeping >> that binding. >> > > I am proposing to add "altera,denali-nand" for Altera. > For what, do you need the generic compatible? > This IP has no default for it to fallback to. IMO just for compatibility reasons with old DTs . I'm also for "altera,denali-nand" or maybe "altera,socfpga-denali-nand" to be more precise ? -- Best regards, Marek Vasut