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,URIBL_BLOCKED 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 3B1B2C433E1 for ; Thu, 2 Jul 2020 07:21:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 12CE92073E for ; Thu, 2 Jul 2020 07:21:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="QW+gWvDD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727948AbgGBHVt (ORCPT ); Thu, 2 Jul 2020 03:21:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726442AbgGBHVs (ORCPT ); Thu, 2 Jul 2020 03:21:48 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C6DAC08C5C1; Thu, 2 Jul 2020 00:21:48 -0700 (PDT) Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id DD6C522EEB; Thu, 2 Jul 2020 09:21:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1593674506; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=yYh2/aIFWhUNCc355H6HdrFH3gHWvQp1I0ovSaO/mqQ=; b=QW+gWvDDGXW32OkPetPXQmwmoBHdnbvoMHEmol7FzAO6BYr41/MKv+DCCo0zCbpwZoq+kg dOpbYm1g2XBrKRtuw2NpMfug4zS27QbuOjREIPQekpaGB+/wotQaQvuYSWiQaaBgC+2GnF 1hyTBcBy+7mkCs8Z4QWWpGE9TZPyK90= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Thu, 02 Jul 2020 09:21:45 +0200 From: Michael Walle To: Lee Jones 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 In-Reply-To: <20200702071402.GP1179328@dell> References: <20200622075145.1464020-1-lee.jones@linaro.org> <20200702071402.GP1179328@dell> User-Agent: Roundcube Webmail/1.4.6 Message-ID: X-Sender: michael@walle.cc Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 2020-07-02 09:14, schrieb Lee Jones: > 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? Still my sl28 mfd driver. There the sub devices just need a regmap. > This is set-up for based I2C drivers to call > into. 'client' is given to them as their .probe() arg. Ok, I see. Then this doesn't fit. -michael >> 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?