From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id ACE92C433E1 for ; Thu, 2 Jul 2020 07:14:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BCFA212CC for ; Thu, 2 Jul 2020 07:14:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Bh3F4Uz6" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726919AbgGBHOH (ORCPT ); Thu, 2 Jul 2020 03:14:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36344 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726717AbgGBHOG (ORCPT ); Thu, 2 Jul 2020 03:14:06 -0400 Received: from mail-wr1-x444.google.com (mail-wr1-x444.google.com [IPv6:2a00:1450:4864:20::444]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 05351C08C5DC for ; Thu, 2 Jul 2020 00:14:06 -0700 (PDT) Received: by mail-wr1-x444.google.com with SMTP id s10so26784203wrw.12 for ; Thu, 02 Jul 2020 00:14:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=o3u4LNhkJvyuHomAjDNCPqfO0iOI8WQ8Jc/N74gTZGE=; b=Bh3F4Uz6YB/0oYpUDIgJJC26ObFmRQmCjUjz6QKfjTaHwZDtwvglp+SC3/lQmchtyx Ugxzw+/Tu0aIpDjxxQGAFhIu2QXkvEgZo2eyES3kOcTdLjQ1iVg9a6ud9wONt2t+pEp6 UrP27DG1Wd/GaTShP0jJgUj0YKloJbkUGEO01JVOHfE6zZb4FT5uYBvek4DDbYMwXzOw EG9wp9faC33NPccfRsuRKZHs7PwnFbxTwbgIOSSe2RfaVkqwFMODRq/K+TrItjJLu5o4 YCfE53/YeCPZelKwxN3NlLfFEmRcA24sIlCQ+O0cauFOPcpzLq91xkUKjsNjsUCi/7ZF 71+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=o3u4LNhkJvyuHomAjDNCPqfO0iOI8WQ8Jc/N74gTZGE=; b=Tx75xnFh7EZqj4Zjv5syRG22kPtiuoM563Lx6kXnODXOGZfdwjzf0z4pMXYrV4BMcw ZivN92TfQeBg4L+6s37K/h3/ndEvFKWTreKd60IabNGqd8vjrwMMGciGeU9nlt7T103v 85Bc6F5QT/KE9VprkfkuXJYgzErpVQ9lt7ZPuIagoCj2h0xjbAig20Bc9mOePVKBBeQg DCIUxWjmhiJ4QewqXToYlq8FlC6lFiVI/PaMHq23IDRkI9pQtzVsJ84nMiB6hdLvFkC0 claNd02kQuUZQofgn91cx7fbT3fX8G5vOsmIIZkYY5XxKYS4G/6QI+xrpPd0bUyVFoVO psRA== X-Gm-Message-State: AOAM533DHWZD3Ih5QETzuRXWP5zOsAlWOOhv1FnwO8S6jw1/4zslKdlK zYeW5qiQtjslbTxSCL6WQFeDzg== X-Google-Smtp-Source: ABdhPJyhSbGW5S3al7dh0ndzsIo6zEVlOOXxDH0ER4Uy/aPfzgwtUwutAHOtsWcSaMkhJYjFmfBFqQ== X-Received: by 2002:adf:c3c7:: with SMTP id d7mr29132402wrg.51.1593674044679; Thu, 02 Jul 2020 00:14:04 -0700 (PDT) Received: from dell ([2.27.35.144]) by smtp.gmail.com with ESMTPSA id 104sm10289770wrl.25.2020.07.02.00.14.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Jul 2020 00:14:04 -0700 (PDT) Date: Thu, 2 Jul 2020 08:14:02 +0100 From: Lee Jones To: Michael Walle Cc: robh+dt@kernel.org, broonie@kernel.org, gregkh@linuxfoundation.org, andriy.shevchenko@linux.intel.com, devicetree@vger.kernel.org, linus.walleij@linaro.org, bgolaszewski@baylibre.com, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/1] mfd: Add I2C based System Configuaration (SYSCON) access Message-ID: <20200702071402.GP1179328@dell> References: <20200622075145.1464020-1-lee.jones@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 30 Jun 2020, Michael Walle wrote: > Hi Lee, > > I'm just trying to use this for my sl28 driver. Some remarks, see below. > > Am 2020-06-22 09:51, schrieb Lee Jones: > > The existing SYSCON implementation only supports MMIO (memory mapped) > > accesses, facilitated by Regmap. This extends support for registers > > held behind I2C busses. > > > > Signed-off-by: Lee Jones > > --- > > Changelog: > > > > v3 => v4 > > - Add ability to provide a non-default Regmap configuration > > > > v2 => v3 > > - Change 'is CONFIG' present check to include loadable modules > > - s/#ifdef CONFIG_MFD_SYSCON_I2C/#if > > IS_ENABLED(CONFIG_MFD_SYSCON_I2C)/ > > > > v1 => v2 > > - Remove legacy references to OF > > - Allow building as a module (fixes h8300 0-day issue) > > > > drivers/mfd/Kconfig | 7 +++ > > drivers/mfd/Makefile | 1 + > > drivers/mfd/syscon-i2c.c | 104 +++++++++++++++++++++++++++++++++ > > include/linux/mfd/syscon-i2c.h | 36 ++++++++++++ > > 4 files changed, 148 insertions(+) > > create mode 100644 drivers/mfd/syscon-i2c.c > > create mode 100644 include/linux/mfd/syscon-i2c.h > > > > [..] > > > +static struct regmap *syscon_i2c_get_regmap(struct i2c_client *client, > > + struct regmap_config *regmap_config) > > +{ > > + struct device *dev = &client->dev; > > + struct syscon *entry, *syscon = NULL; > > + > > + spin_lock(&syscon_i2c_list_slock); > > + > > + list_for_each_entry(entry, &syscon_i2c_list, list) > > + if (entry->dev == dev) { > > + syscon = entry; > > + break; > > + } > > + > > + spin_unlock(&syscon_i2c_list_slock); > > + > > + if (!syscon) > > + syscon = syscon_i2c_register(client, regmap_config); > > + > > + if (IS_ERR(syscon)) > > + return ERR_CAST(syscon); > > + > > + return syscon->regmap; > > +} > > + > > +struct regmap *syscon_i2c_to_regmap_config(struct i2c_client *client, > > + struct regmap_config *regmap_config) > > +{ > > + return syscon_i2c_get_regmap(client, regmap_config); > > +} > > +EXPORT_SYMBOL_GPL(syscon_i2c_to_regmap_config); > > + > > +struct regmap *syscon_i2c_to_regmap(struct i2c_client *client) > > +{ > > + return syscon_i2c_get_regmap(client, &syscon_i2c_regmap_config); > > +} > > +EXPORT_SYMBOL_GPL(syscon_i2c_to_regmap); > > What do you think about > > struct regmap *syscon_i2c_to_regmap(struct device *dev) > { > struct i2c_client *client = i2c_verify_client(dev); > > if (!client) > return ERR_PTR(-EINVAL); > > return syscon_i2c_get_regmap(client, &syscon_i2c_regmap_config); > } > > Or even move it to syscon_i2c_get_regmap(). > > This way, (a) a driver doesn't have to use "#include " just > to call to_i2c_client() (or i2c_verify_client()) and (b) you won't do it > all over again in all sub drivers. What is your use-case? This is set-up for based I2C drivers to call into. 'client' is given to them as their .probe() arg. > So you could just do a > regmap = syscon_i2c_to_regmap(pdev->dev.parent); > > I've also noticed that the mmio syscon uses device_node as parameter. What > was the reason to divert from that? Just curious. This is a helper for I2C clients. There aren't any OF helpers in here (yet). If you think they would be helpful we can add them. How do you see them being used? -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog