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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 7E8D5C48BD6 for ; Wed, 26 Jun 2019 11:10:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5523C2082F for ; Wed, 26 Jun 2019 11:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726628AbfFZLKp (ORCPT ); Wed, 26 Jun 2019 07:10:45 -0400 Received: from mga04.intel.com ([192.55.52.120]:54032 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725930AbfFZLKp (ORCPT ); Wed, 26 Jun 2019 07:10:45 -0400 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 26 Jun 2019 04:10:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.63,419,1557212400"; d="scan'208";a="184831100" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.145]) by fmsmga004.fm.intel.com with ESMTP; 26 Jun 2019 04:10:44 -0700 Received: from andy by smile with local (Exim 4.92) (envelope-from ) id 1hg5p5-0006Qp-Ec; Wed, 26 Jun 2019 14:10:43 +0300 Date: Wed, 26 Jun 2019 14:10:43 +0300 From: Andy Shevchenko To: Lee Jones Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mfd: Add support for Merrifield Basin Cove PMIC Message-ID: <20190626111043.GJ9224@smile.fi.intel.com> References: <20190612101945.55065-1-andriy.shevchenko@linux.intel.com> <20190624161348.GB21119@dell> <20190626092601.GH9224@smile.fi.intel.com> <20190626101727.GN21119@dell> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190626101727.GN21119@dell> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jun 26, 2019 at 11:17:27AM +0100, Lee Jones wrote: > On Wed, 26 Jun 2019, Andy Shevchenko wrote: > > On Mon, Jun 24, 2019 at 05:13:48PM +0100, Lee Jones wrote: > > > On Wed, 12 Jun 2019, Andy Shevchenko wrote: > > > > Add an MFD driver for Intel Merrifield Basin Cove PMIC. > > > > + for (i = 0; i < ARRAY_SIZE(irq_level2_resources); i++) { > > > > + ret = platform_get_irq(pdev, i); > > > > > > If you already know the order, define the children's device IDs in the > > > parent's shared header ('intel_soc_pmic_mrfld.h'?) and retreive them > > > like: > > > > > > platform_get_irq(pdev->parent, ); > > > > > > Then you can skip all of this platform device -> platform device hoop > > > jumping. > > > > The idea of MFD is to get children to be parent agnostic > > (at least to some extent). What you are proposing here > > seems like disadvantage from MFD philosophy. No? > > Not at all. The idea of MFD is to split up support for monolithic h/w > such that they can be handled properly by their appropriate > subsystems, and by extension, maintained by the associated subject > matter experts. > > Children are often aware of their parents (some siblings are even > aware of each other!), and many expect and depend on the data-sets > provided by their parents. Yes, that's true and that's why I put wording "to some extent" above. > For instance (this example may come to bite me in the behind, but), > taken from this very patch, where is this consumed? > > platform_set_drvdata(pdev, pmic); Yes. It's used in children. BUT. This structure covers several PMIC chips and the children driver doesn't know which generation / version of PMIC is serving. What you are proposing with the change is to strictly link the children driver to PMIC gen X ver Y, while above example doesn't do that. So, I'm not convinced it's a good change to have. -- With Best Regards, Andy Shevchenko