Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751631AbcLCWI6 (ORCPT ); Sat, 3 Dec 2016 17:08:58 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:33797 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751154AbcLCWIz (ORCPT ); Sat, 3 Dec 2016 17:08:55 -0500 MIME-Version: 1.0 In-Reply-To: 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> From: Dinh Nguyen Date: Sat, 3 Dec 2016 16:08:53 -0600 Message-ID: Subject: Re: [PATCH 39/39] mtd: nand: denali_dt: add compatible strings for UniPhier SoC variants To: Marek Vasut Cc: Masahiro Yamada , 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 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3466 Lines: 92 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. Dinh