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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=unavailable 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 4CDEAC04AA5 for ; Mon, 15 Oct 2018 10:49:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2464A2083C for ; Mon, 15 Oct 2018 10:49:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2464A2083C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=opensource.cirrus.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-clk-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726477AbeJOSd4 (ORCPT ); Mon, 15 Oct 2018 14:33:56 -0400 Received: from mx0b-001ae601.pphosted.com ([67.231.152.168]:44912 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726273AbeJOSd4 (ORCPT ); Mon, 15 Oct 2018 14:33:56 -0400 Received: from pps.filterd (m0077474.ppops.net [127.0.0.1]) by mx0b-001ae601.pphosted.com (8.16.0.23/8.16.0.23) with SMTP id w9FAn7Hn028178; Mon, 15 Oct 2018 05:49:07 -0500 Authentication-Results: ppops.net; spf=none smtp.mailfrom=ckeepax@opensource.cirrus.com Received: from mail3.cirrus.com ([87.246.76.56]) by mx0b-001ae601.pphosted.com with ESMTP id 2n3es3t35e-1; Mon, 15 Oct 2018 05:49:07 -0500 Received: from EX17.ad.cirrus.com (ex17.ad.cirrus.com [172.20.9.81]) by mail3.cirrus.com (Postfix) with ESMTP id A8096611C8B0; Mon, 15 Oct 2018 05:51:22 -0500 (CDT) Received: from imbe.wolfsonmicro.main (198.61.95.81) by EX17.ad.cirrus.com (172.20.9.81) with Microsoft SMTP Server id 14.3.408.0; Mon, 15 Oct 2018 11:49:06 +0100 Received: from imbe.wolfsonmicro.main (imbe.wolfsonmicro.main [198.61.95.81]) by imbe.wolfsonmicro.main (8.14.4/8.14.4) with ESMTP id w9FAn5qk011136; Mon, 15 Oct 2018 11:49:05 +0100 Date: Mon, 15 Oct 2018 11:49:05 +0100 From: Charles Keepax To: Stephen Boyd CC: , , , , , , , , , , , Subject: Re: [PATCH v2 3/5] clk: lochnagar: Add support for the Cirrus Logic Lochnagar Message-ID: <20181015104905.GF1653@imbe.wolfsonmicro.main> References: <20181008132542.19775-1-ckeepax@opensource.cirrus.com> <20181008132542.19775-3-ckeepax@opensource.cirrus.com> <153924124658.207691.10370075148426001371@swboyd.mtv.corp.google.com> <20181011132602.GD1653@imbe.wolfsonmicro.main> <153935999691.5275.1587207165396958375@swboyd.mtv.corp.google.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <153935999691.5275.1587207165396958375@swboyd.mtv.corp.google.com> User-Agent: Mutt/1.5.20 (2009-12-10) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1807170000 definitions=main-1810150100 Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Fri, Oct 12, 2018 at 08:59:56AM -0700, Stephen Boyd wrote: > Quoting Charles Keepax (2018-10-11 06:26:02) > > On Thu, Oct 11, 2018 at 12:00:46AM -0700, Stephen Boyd wrote: > > > Quoting Charles Keepax (2018-10-08 06:25:40) > > > > +struct lochnagar_clk_priv { > > > > + struct device *dev; > > > > + struct lochnagar *lochnagar; > > > > > > Is this used for anything besides getting the regmap? Can you get the > > > pointer to the parent in probe and use that to get the regmap pointer > > > from dev_get_remap() and also use the of_node of the parent to register > > > a clk provider? It would be nice to avoid including the mfd header file > > > unless it's providing something useful. > > > > > > > It is also used to find out which type of Lochnagar we have > > connected, which determines which clocks we should register. I > > Can that be done through some device ID? So the driver can be untangled > from the MFD part. > > > could perhaps pass that using another mechanism but we would > > still want to include the MFD stuff to get the register > > definitions. So this approach seems simplest. > > Can the register definitions be moved to this clk driver? > > Maybe you now get the hint, but I'd really like to be able to merge and > compile the clk driver all by itself without relying on the parent MFD > device to provide anything at compile time. > If you feel strongly but since the MFD needs to hold the regmap (which needs to define the read/volatile regs and defaults) these will need to be duplicate defines and personally i would rather only have one copy as it makes updating things much less error prone. > > > > + if (lclk->regmap.dir_mask) { > > > > + ret = regmap_update_bits(regmap, lclk->regmap.cfg_reg, > > > > + lclk->regmap.dir_mask, > > > > + lclk->regmap.dir_mask); > > > > + if (ret < 0) { > > > > + dev_err(priv->dev, "Failed to set %s direction: %d\n", > > > > > > What does direction mean? > > > > > > > Some of the clocks can both generate and receive a clock. For > > example the PSIA (external audio interface) MCLKs, the attached > > device could be expecting or providing a master audio clock. If > > the user assigns a parent to the clock we assume the attached > > device is providing a clock to us, otherwise we assume we are > > providing the clock. > > And this directionality is determined by dir_mask? It would be great if > this sort of information was in the commit text or in a comment in the > driver so we know what's going on here. > No problem will make this more clear. Thanks, Charles