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=-4.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 6D6EBC433DF for ; Wed, 1 Jul 2020 21:03:16 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3D61F2082F for ; Wed, 1 Jul 2020 21:03:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="FtCAkzKQ"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="UktANATK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3D61F2082F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=walle.cc Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=bwc+ZjeeTOKuQWxzwqP/YKgTQoRIIrBGijfo3YWZBDM=; b=FtCAkzKQv6DCupStlAptS/ISj /qaSBGFZ4ENkQ/M1AM6o//ImE5zyHB2Yg5JIt0AFB/FO2m3iWbEYj2/P+w9526vSF63fbLIXuHzfq ij6soph7s+uCX1vRpYvstJHnR45VaxUwGnmIx2+Q456nXPK/vMXyCFYUydNrotnDFZJdMIa67qul1 lmt5ytUiobRnX668mSce3j5ZPBH67t2VXFDGVhSXlesOlZnPgCI8A380rJE5CtlXVOVbb17aMsGDM 7/8SLhyVuLmpr+rjcnz1YlN81T3h5SbiEoddj7SleNs4zke7hU5Q3G0C3Mnmztpn5YGgaJLCtCrZ4 2MFN/Sk+A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jqjrT-0000Dd-A6; Wed, 01 Jul 2020 21:01:43 +0000 Received: from ssl.serverraum.org ([176.9.125.105]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jqjrQ-0000Cs-FN for linux-arm-kernel@lists.infradead.org; Wed, 01 Jul 2020 21:01:41 +0000 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 AB42D22EDB; Wed, 1 Jul 2020 23:01:26 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1593637288; 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=IOFU47nrxw5qL2tii3DxgI2RI1/Kw9UJjEA3s1N5uyw=; b=UktANATK3hu7R5H0TAb511eCIMHUzX7B7NDgraKITRbmC33hu+6q7nU35GEwkXwZPBPV6x VPGJ+Y/ayr6EKBeOh+Fpgct2vWQynbbH6vaxclqITGwEMRd5BEUD8V/QSHt+eIZjfszMdk KRSOgapM91rvmdmT573cLxiXVd2kba8= MIME-Version: 1.0 Date: Wed, 01 Jul 2020 23:01:26 +0200 From: Michael Walle To: Lee Jones Subject: Re: [PATCH v4 1/1] mfd: Add I2C based System Configuaration (SYSCON) access In-Reply-To: <20200701070434.GP1179328@dell> References: <20200622075145.1464020-1-lee.jones@linaro.org> <20200701070434.GP1179328@dell> User-Agent: Roundcube Webmail/1.4.6 Message-ID: <5d1d41504172d86d395b0135923f6f02@walle.cc> X-Sender: michael@walle.cc X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200701_170140_750809_D203209F X-CRM114-Status: GOOD ( 27.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: devicetree@vger.kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, bgolaszewski@baylibre.com, broonie@kernel.org, andriy.shevchenko@linux.intel.com, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Am 2020-07-01 09:04, schrieb Lee Jones: > On Wed, 01 Jul 2020, Michael Walle wrote: > >> 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>; >> }; >> }; >> }; > > Yes, that was the idea. > >> But I think the childen are not enumerated if its an I2C device. And >> the actual i2c driver is also missing. > > What do you mean? Can you elaborate? There is no i2c_driver instance who would create the regmap. If I'm reading the I2C code correctly, it won't probe any i2c device of a bus if there is no i2c_driver with an associated .probe() or .probe_new(). And even if it is probed, its subnodes won't be enumerated; the "simple-mfd" code only works for MMIO busses, right? Or I'm getting something really wrong here.. -michael _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel