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=-1.0 required=3.0 tests=FROM_EXCESS_BASE64, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 5F1B8C49ED6 for ; Sat, 14 Sep 2019 06:42:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3722C20692 for ; Sat, 14 Sep 2019 06:42:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726677AbfINGm3 convert rfc822-to-8bit (ORCPT ); Sat, 14 Sep 2019 02:42:29 -0400 Received: from mailoutvs41.siol.net ([185.57.226.232]:44870 "EHLO mail.siol.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726462AbfINGm2 (ORCPT ); Sat, 14 Sep 2019 02:42:28 -0400 Received: from localhost (localhost [127.0.0.1]) by mail.siol.net (Zimbra) with ESMTP id 2B7D6520C71; Sat, 14 Sep 2019 08:42:24 +0200 (CEST) X-Virus-Scanned: amavisd-new at psrvmta12.zcs-production.pri Received: from mail.siol.net ([127.0.0.1]) by localhost (psrvmta12.zcs-production.pri [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 0F_nRnEQ3SM1; Sat, 14 Sep 2019 08:42:23 +0200 (CEST) Received: from mail.siol.net (localhost [127.0.0.1]) by mail.siol.net (Zimbra) with ESMTPS id AF25E52132C; Sat, 14 Sep 2019 08:42:23 +0200 (CEST) Received: from jernej-laptop.localnet (cpe-86-58-59-25.static.triera.net [86.58.59.25]) (Authenticated sender: jernej.skrabec@siol.net) by mail.siol.net (Zimbra) with ESMTPA id 2E97D520C71; Sat, 14 Sep 2019 08:42:23 +0200 (CEST) From: Jernej =?utf-8?B?xaBrcmFiZWM=?= To: Maxime Ripard Cc: wens@csie.org, robh+dt@kernel.org, mark.rutland@arm.com, mchehab@kernel.org, hverkuil@xs4all.nl, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH 5/6] media: sun4i: Add H3 deinterlace driver Date: Sat, 14 Sep 2019 08:42:22 +0200 Message-ID: <3227980.eWD6USAIP4@jernej-laptop> In-Reply-To: <20190912202647.wfcjur7yxhlelvd6@localhost.localdomain> References: <20190912175132.411-1-jernej.skrabec@siol.net> <20190912175132.411-6-jernej.skrabec@siol.net> <20190912202647.wfcjur7yxhlelvd6@localhost.localdomain> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! Dne četrtek, 12. september 2019 ob 22:26:47 CEST je Maxime Ripard napisal(a): > Hi, > > On Thu, Sep 12, 2019 at 07:51:31PM +0200, Jernej Skrabec wrote: > > + dev->regmap = devm_regmap_init_mmio(dev->dev, dev->base, > > + &deinterlace_regmap_config); > > + if (IS_ERR(dev->regmap)) { > > + dev_err(dev->dev, "Couldn't create deinterlace regmap\n"); > > + > > + return PTR_ERR(dev->regmap); > > + } > > + > > + ret = clk_prepare_enable(dev->bus_clk); > > + if (ret) { > > + dev_err(dev->dev, "Failed to enable bus clock\n"); > > + > > + return ret; > > + } > > Do you need to keep the bus clock enabled all the time? Usually, for > the SoCs that have a reset line, you only need it to read / write to > the registers, not to have the controller actually running. > > If you don't, then regmap_init_mmio_clk will take care of that for > you. > > > + clk_set_rate(dev->mod_clk, 300000000); > > + > > + ret = clk_prepare_enable(dev->mod_clk); > > + if (ret) { > > + dev_err(dev->dev, "Failed to enable mod clock\n"); > > + > > + goto err_bus_clk; > > + } > > + > > + ret = clk_prepare_enable(dev->ram_clk); > > + if (ret) { > > + dev_err(dev->dev, "Failed to enable ram clock\n"); > > + > > + goto err_mod_clk; > > + } > > + > > + ret = reset_control_reset(dev->rstc); > > + if (ret) { > > + dev_err(dev->dev, "Failed to apply reset\n"); > > + > > + goto err_ram_clk; > > + } > > This could be moved to a runtime_pm hook, with get_sync called in the > open. That way you won't leave the device powered on if it's unused. Currently I'm looking at sun4i_csi.c as an example of runtime ops, but it seems a bit wrong to have suspend and resume function marked with __maybe_unused because they are the only functions which enable needed clocks. If CONFIG_PM is not enabled, then this driver simply won't work, because clocks will never get enabled. I guess I can implement runtime pm ops in the same way and add additional handling when CONFIG_PM is not enabled, right? BTW, which callback is get_sync? I don't see it in dev_pm_ops. I suppose I need only runtime_suspend and runtime_resume. Off topic: sun6i_csi.c includes linux/pm_runtime.h but it doesn't have any kind of power management as far as I can see. Best regards, Jernej > > > +struct deinterlace_dev { > > + struct v4l2_device v4l2_dev; > > + struct video_device vfd; > > + struct device *dev; > > + struct v4l2_m2m_dev *m2m_dev; > > + > > + /* Device file mutex */ > > + struct mutex dev_mutex; > > + > > + void __iomem *base; > > + struct regmap *regmap; > > Do you need to store the base address in that structure if you're > using the regmap? > > Maxime