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 0013DC433E1 for ; Tue, 30 Jun 2020 22:32:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC8EF2074D for ; Tue, 30 Jun 2020 22:32:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="t6vc5s6u" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726151AbgF3WcS (ORCPT ); Tue, 30 Jun 2020 18:32:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726065AbgF3WcR (ORCPT ); Tue, 30 Jun 2020 18:32:17 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29F93C061755; Tue, 30 Jun 2020 15:32:17 -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 30B3822178; Wed, 1 Jul 2020 00:32:13 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1593556333; 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=kymP7n5gq8SfD4CIN2tLd7+wggUfKB3imhmzP7tcUP4=; b=t6vc5s6uEuxINBYJbZjC5EKWZj0j7BDMbUPAAE+h0DgatsM27trc+wUcj7wdnWLC35EYmP 34pq4kSPnlJiuY0M7USxm4VuTUMwtdsiDb+AzdTZRFjxG3juwnXf0DX+QtIgzOA+M4MTdh Po+IDZDz6Wh9JyjknKJ6mq65iXC+Ym0= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Wed, 01 Jul 2020 00:32:13 +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: References: <20200622075145.1464020-1-lee.jones@linaro.org> 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 Hi Lee, Am 2020-06-30 11:16, schrieb Michael Walle: > 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. > > 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. How is this supposed to be used? I had something like the following in mind: &i2c { cpld@4a { compatible = "simple-mfd"; reg = <0x4a>; gpio@4 { compatible = "vendor,gpio"; reg = <0x4>; }; }; }; But I think the childen are not enumerated if its an I2C device. And the actual i2c driver is also missing. -michael