Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751612AbaDZAxn (ORCPT ); Fri, 25 Apr 2014 20:53:43 -0400 Received: from mail-pd0-f173.google.com ([209.85.192.173]:40921 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751139AbaDZAxl (ORCPT ); Fri, 25 Apr 2014 20:53:41 -0400 Message-ID: <535B0393.1080300@gmail.com> Date: Fri, 25 Apr 2014 17:53:39 -0700 From: Frank Rowand Reply-To: frowand.list@gmail.com User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/20130801 Thunderbird/17.0.8 MIME-Version: 1.0 To: Courtney Cavin CC: "Ivan T. Ivanov" , Samuel Ortiz , Lee Jones , Josh Cartwright , Grant Likely , Rob Herring , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" Subject: Re: [PATCH 1/2] mfd: pm8x41: add support for Qualcomm 8x41 PMICs References: <1398213110-28135-1-git-send-email-courtney.cavin@sonymobile.com> <1398259168.4724.217.camel@iivanov-dev> <535AFD96.90505@gmail.com> <20140426004048.GQ17066@sonymobile.com> In-Reply-To: <20140426004048.GQ17066@sonymobile.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/25/2014 5:40 PM, Courtney Cavin wrote: > On Sat, Apr 26, 2014 at 02:28:06AM +0200, Frank Rowand wrote: >> On 4/23/2014 6:19 AM, Ivan T. Ivanov wrote: > [...] >>>> +static int pm8x41_probe(struct spmi_device *sdev) >>>> +{ >>>> + struct regmap *regmap; >>>> + >>>> + regmap = devm_regmap_init_spmi_ext(sdev, &pm8x41_regmap_config); >>>> + if (IS_ERR(regmap)) { >>>> + dev_dbg(&sdev->dev, "regmap creation failed.\n"); >>>> + return PTR_ERR(regmap); >>>> + } >>>> + >>>> + return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev); >>> >>> I think that this will not going to work. For example in this particular >>> case, both controllers have "qcom,qpnp-revid" peripheral which is >>> located at offset 0x100. >>> >>> And the result is: >>> >>> [ 0.963944] sysfs: cannot create duplicate filename '/bus/platform/devices/100.revid' >> >> The duplicate filename error is because pm8x41_probe() is calling of_platform_populate() >> directly. >> >> If that call is removed then there is no attempt to create a revid file in >> /sys/bus/platform/devices. If I add your pm8841@4 node to my dts file, then >> the 100.revid file is properly created at >> >> /sys/firmware/devicetree/base/soc/qcom,spmi@fc4cf000/pm8841@4/qcom,revid@100 >> >> and no attempt is made to create /sys/bus/platform/devices/100.revid >> >> This appears to be correct to me, because I do not think revid should be created as >> a platform device. >> > > Wait, what? That's the entire point of this driver. > > [...] >>> Any suggestions? >> >> Remove of_platform_populate() from pm8x41_probe(). Do you know of any >> other reason it can not be removed? > > I do! If you remove it, the entire driver becomes a useless pile of > nothing! > > The PMICs targeted by this driver are mostly made up of independent > blocks which should be able to be written as standalone device drivers. > The design of this driver is to create a simple bus-like layer between > SPMI and these independent blocks. of_platform_populate() is what makes > it work. > > -Courtney > Hmmmm, yet another device tree conceptual thing for me to grok. I'll go off and see if a bus-like layer can exist without being a platform device. -Frank -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/