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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 188E4C433E6 for ; Tue, 19 Jan 2021 06:38:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E16B1230FA for ; Tue, 19 Jan 2021 06:38:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727646AbhASGia (ORCPT ); Tue, 19 Jan 2021 01:38:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60870 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726354AbhASGWY (ORCPT ); Tue, 19 Jan 2021 01:22:24 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68CCAC0613C1; Mon, 18 Jan 2021 22:21:43 -0800 (PST) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 891F74FB; Tue, 19 Jan 2021 07:21:39 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1611037299; bh=oycY286DBGm4St4onQa1c4S5+VXtXeEA4g/WsCAkTEA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KyKTq0F10qKo6fweXrR1GW+OuWxqk8Sk9CM7gySc/0/ditqB/bQSDemuttmg9d8Pg H9N0VvOjym4NyA68xBgPZ+LEkrKuZj5VO7QgfT0xnGD4KQq3RytMxpK9C8o4JBlgQR 6/teXyPqNlCiE152MSPR8cgKBHqNuu6zoA3heuS4= Date: Tue, 19 Jan 2021 08:21:23 +0200 From: Laurent Pinchart To: Daniel Scally Cc: Andy Shevchenko , linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-gpio@vger.kernel.org, linux-i2c@vger.kernel.org, platform-driver-x86@vger.kernel.org, devel@acpica.org, rjw@rjwysocki.net, lenb@kernel.org, andy@kernel.org, mika.westerberg@linux.intel.com, linus.walleij@linaro.org, bgolaszewski@baylibre.com, wsa@kernel.org, lee.jones@linaro.org, hdegoede@redhat.com, mgross@linux.intel.com, robert.moore@intel.com, erik.kaneda@intel.com, sakari.ailus@linux.intel.com, kieran.bingham@ideasonboard.com Subject: Re: [PATCH v2 6/7] platform: x86: Add intel_skl_int3472 driver Message-ID: References: <20210118003428.568892-1-djrscally@gmail.com> <20210118003428.568892-7-djrscally@gmail.com> <20210118144606.GO4077@smile.fi.intel.com> <75e99a06-4579-44ee-5f20-8f2ee3309a68@gmail.com> <1053125f-7cb2-8aa0-3204-24df62986184@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1053125f-7cb2-8aa0-3204-24df62986184@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hi Daniel, On Tue, Jan 19, 2021 at 12:11:40AM +0000, Daniel Scally wrote: > On 18/01/2021 21:19, Daniel Scally wrote: > >>>> +static const struct clk_ops skl_int3472_clock_ops = { > >>>> + .prepare = skl_int3472_clk_prepare, > >>>> + .unprepare = skl_int3472_clk_unprepare, > >>>> + .enable = skl_int3472_clk_enable, > >>>> + .disable = skl_int3472_clk_disable, > >>>> +}; > >> > >> Yeah, sounds like reinventing clk-gpio.c. > >> > >> static const struct clk_ops clk_gpio_gate_ops = { > >> .enable = clk_gpio_gate_enable, > >> .disable = clk_gpio_gate_disable, > >> .is_enabled = clk_gpio_gate_is_enabled, > >> }; > >> > >> (Or is it mux? It has support there as well. > >> > > Hmm, yeah, this looks like it would work actually. So I think I'd need to: > > > > 1. Make enabling INTEL_SKL_INT3472 also enable the clk-gpio driver > > > > 2. Register a platform device to bind to the clk-gpio driver > > > > 3. Register a gpio lookup table so that the clk-gpio driver can find the > > gpio in question using gpiod_get() > > > > And that looks like it will work; I'll try it. > > I'm more and more confident that this will work, but it has some > knock-on effects: > > The both clk and regulator gpio driver expects to be able to fetch the > GPIO using devm_gpiod_get(&pdev->dev, "enable", ...). That won't work of > course, so we need to add another GPIO lookup table so those drivers can > see the GPIOs. For that, we need to know what dev_name(&pdev->dev) will > be so we can set the .dev_id member of a gpiod_lookup_table to that > value, but that isn't set until _after_ the pdev is registered (because > it has to figure out the id, we can't manually set the IDs because there > could be more than one instance of int3472-discrete bound to multiple > PMIC devices, and we don't know which id the current one should have). > Finally, we can't wait until the device is registered because it > immediately probes, can't find the GPIO and then fails probe. > > It's similar problem that causes us to need the i2c-acpi name format > macros, but complicated by the dynamic ID part of dev_name(&pdev->dev) > > Solving it is a bit of a sticky one; perhaps something like moving the > dev_set_name() part of platform_device_add() [1] to its own function, > that's called in both platform_device_alloc() and > platform_device_register(). That way it would be available before the > device itself was registered, meaning we could create the lookup table > before it probes the driver. > > (also, Laurent, if we did it this way we wouldn't be able to also handle > the led-indicator GPIO here without some fairly major rework) Given the additional complexity I don't think it's worth it, your implementation is fine and code duplication with clk-gpio is minimal. > [1] > https://elixir.bootlin.com/linux/latest/source/drivers/base/platform.c#L563 -- Regards, Laurent Pinchart