From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, T_DKIMWL_WL_MED autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 888827D2EE for ; Sat, 1 Sep 2018 13:11:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727318AbeIARXJ (ORCPT ); Sat, 1 Sep 2018 13:23:09 -0400 Received: from mail-it0-f68.google.com ([209.85.214.68]:36429 "EHLO mail-it0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727378AbeIARXJ (ORCPT ); Sat, 1 Sep 2018 13:23:09 -0400 Received: by mail-it0-f68.google.com with SMTP id u13-v6so10530357iti.1 for ; Sat, 01 Sep 2018 06:11:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=6OBmkEzLXWZdBpezwe8RFhhwWFRCQX9SHKDEgZ+9NRI=; b=ulzWIWQuDhn/rtCywEf/jryrYuwjOnxXau5JUehFwvxSyihjLtSyM+U0WsoSnFfVrA 3uR4ia9l27WZeynbRQcGL5eXDMarDGJtGs2FJzESq5JLAu4lpfyDieQsVVad9HnKf+1R 3gezPG1t0Nzw6F8f3zQeL3jVWT31/875tRtu/GM/oBLmN+hrOs5OWlIT6i6gJgsjOlXF x5Gyujj9mMCMUPQsyT+jgwM+4oaluISyXaMdieO5kCFJ2ukClTRFsqffbKdux8Pv+8AN acJV0nplEIu/MMZDi3v3p+RPZ08nTylwAhqMGBkvDD3htg6byTUsXNXSKubE3qPTbCCq KL+g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=6OBmkEzLXWZdBpezwe8RFhhwWFRCQX9SHKDEgZ+9NRI=; b=dwikX1cRPgxlwzQ0XGYMTqV8JeItrNMaKNLTNl/csslOg440Zm1dgjQowyZtNI8lO8 B8YPG92tR9JzC5aHDMAuWnLPvfwLHsR2eAkmeXA5SX00KESxPcItn+SqHqUKD/UXF38H ypon4wSTrwZsbaJVKGgldftN3S76L3wioRkkoIz9rj3sD2G6S9qdBnIOhD23dxI0JWF+ sFa/UA9uncvHiaEvii6JJYDXhWuHsBaXTxjLwR0oH6RPWR9ZXoKvSXwmwrc2LbVeZ2Uz 5cliD31qqqSTgqoSdAxAwV/hAEq+wOgEVspaaGg32/xFbZ+347CQlWXzv+mwsPYp7n5/ jNEg== X-Gm-Message-State: APzg51CtNptLjo8/p+GEEEi9reX2fDjWrziEkleBYwtHm4k0e0xpQqFq vI3w2x1LB/Yvu0wi+SxIcInNteXuSQSDVjJibiZErA== X-Google-Smtp-Source: ANB0VdZDQt9gKLLdzNLoc42XLt1gzj0e8SKEt8vnTAxbNCggG5IFJHuhJzIFnnCWSSsQInKxxsdzgPGSgbuiWKQl2/g= X-Received: by 2002:a02:943:: with SMTP id f64-v6mr15187000jad.31.1535807466228; Sat, 01 Sep 2018 06:11:06 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a6b:a043:0:0:0:0:0 with HTTP; Sat, 1 Sep 2018 06:11:05 -0700 (PDT) In-Reply-To: <20180831203028.GC62862@ban.mtv.corp.google.com> References: <20180810080526.27207-1-brgl@bgdev.pl> <20180810080526.27207-3-brgl@bgdev.pl> <20180831203028.GC62862@ban.mtv.corp.google.com> From: Bartosz Golaszewski Date: Sat, 1 Sep 2018 15:11:05 +0200 Message-ID: Subject: Re: [PATCH v2 02/29] Documentation: nvmem: document lookup entries To: Brian Norris Cc: Jonathan Corbet , Sekhar Nori , Kevin Hilman , Russell King , Arnd Bergmann , Greg Kroah-Hartman , David Woodhouse , Boris Brezillon , Marek Vasut , Richard Weinberger , Grygorii Strashko , "David S . Miller" , Srinivas Kandagatla , Naren , Mauro Carvalho Chehab , Andrew Morton , Lukas Wunner , Dan Carpenter , Florian Fainelli , Ivan Khoronzhuk , Sven Van Asbroeck , Paolo Abeni , Alban Bedel , Rob Herring , David Lechner , Andrew Lunn , linux-doc , Linux Kernel Mailing List , Linux ARM , linux-i2c , "open list:MEMORY TECHNOLOGY..." , Linux-OMAP , netdev , Bartosz Golaszewski , briannorris@chromium.org Content-Type: text/plain; charset="UTF-8" Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org 2018-08-31 22:30 GMT+02:00 Brian Norris : > On Fri, Aug 10, 2018 at 10:04:59AM +0200, Bartosz Golaszewski wrote: >> From: Bartosz Golaszewski >> >> Describe the usage of nvmem cell lookup tables. >> >> Signed-off-by: Bartosz Golaszewski >> --- >> Documentation/nvmem/nvmem.txt | 28 ++++++++++++++++++++++++++++ >> 1 file changed, 28 insertions(+) >> >> diff --git a/Documentation/nvmem/nvmem.txt b/Documentation/nvmem/nvmem.txt >> index 8d8d8f58f96f..9d5e3ca2b4f3 100644 >> --- a/Documentation/nvmem/nvmem.txt >> +++ b/Documentation/nvmem/nvmem.txt >> @@ -58,6 +58,34 @@ static int qfprom_probe(struct platform_device *pdev) >> It is mandatory that the NVMEM provider has a regmap associated with its >> struct device. Failure to do would return error code from nvmem_register(). >> >> +Additionally it is possible to create nvmem cell lookup entries and register >> +them with the nvmem framework from machine code as shown in the example below: > > Maybe it's partially a lacking in the existing documentation, but what > does the "name" and the "nvmem_name" mean here? AFAICT, "nvmem_name" is > akin to a provider identifier; and "name" is a key to match with the > consumer. It feels like this should be in either the header / kerneldoc > or this file. Or maybe both. > > Does this mean there can only be a single "mac-address" cell in the > system? I have systems where there are multiple MACs provided in flash > storage, and we need to map them to ethernet0 and ethernet1. Is that > supported here? > This is a shortcoming of the nvmem subsystem we discussed under another patch in this series with Boris and Srinivas. I will try to post a series addressing this next week. Basically there's a global list of nvmem cells referenced only by name and unless you're using DT you can only have a single cell with given name. I will address it by introducing the standard dev_id/con_id resource association. Bart > Brian > >> +static struct nvmem_cell_lookup foobar_lookup = { >> + .info = { >> + .name = "mac-address", >> + .offset = 0xd000, >> + .bytes = ERH_ALEN, >> + }, >> + .nvmem_name = "foobar", >> +}; >> + >> +static void foobar_register(void) >> +{ >> + ... >> + nvmem_add_lookup_table(&foobar_lookup, 1); >> + ... >> +} >> + >> +A lookup entry table can be later removed if needed: >> + >> +static void foobar_fini(void) >> +{ >> + ... >> + nvmem_del_lookup_table(&foobar_lookup, 1); >> + ... >> +} >> + >> NVMEM Consumers >> +++++++++++++++ >> >> -- >> 2.18.0 >>