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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EB07CC9830E for ; Thu, 24 Sep 2026 14:15:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=as28B0UHPI0oMbfQz//tM+HqacwzrdnvzKyHANegbwc=; b=i+kBVjAhVUIt+W ukxGl0GaHaepTxxfTOUlmMZyC/Opxftks8wzQ8+CxDWpS8bFxKoZNAxV/LE0tHr1htVb/GOBnMoy8 9xb2cTb21drjFVo9QrmhyEuXokh051SJEnxNjaKlmkzBFQ87z07o+VZCjnwDXeMGzbE+69JCzmvJ+ H8jBz41dNAvfGLBQE7xWJkffjz+eOVUeAtmP3+oIWCnyB/AcuEFL1CUzo39BS8PIyXvKQfhsFZhvk f9wvSkgjsbblXZ9BOaFItOYl8qnY4N1aU8fj8Px8OY7SibW5BZonmGgllHMzD8CZhYvWvuk82ZJw9 V+4uZDRmNWNzUyLSJJqw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9kEE-0000000BE0y-0HYt; Thu, 24 Sep 2026 14:15:14 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x9kEC-0000000BE0T-31i4; Thu, 24 Sep 2026 14:15:12 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 2528540448; Thu, 24 Sep 2026 14:15:12 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63DEC1F000FF; Thu, 24 Sep 2026 14:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790259312; bh=qTdT0Pnje9Db4mI6g9mHhsv+qLxeAIpDfVpVO6cj1T4=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=JBKRD+OWoeubfRo5gPpJwJc3aBMFeibR3f8yEydfDyM/bk4aLgeJhsqPPKSne3YB7 D+PszabqrNryBW7EUSo1MmBTKDVi/qN+CYKGZ1oJ+viLpE/IEZqRy0/10rQ17k8vAy FhQ1OyGdoF50czcfuhC8SDUE127jKXnseOA9YJb7GqhAEWN++OY2k/sTUx3IxAaANL FLVDY6A1Uvtv45K1xBTseTEM/28NTBxZcU1dGulqv2zfZR7IGoWOmUEep3eWv4+8s0 BW4HCdA79Idm/IA/CMxP6yNFiNUzYtuAk2MHyi9ybiG1g3KFb9Nzey3h/oQUAUvinc 94UZc61v0Rpkg== Date: Thu, 24 Sep 2026 15:15:05 +0100 From: Lee Jones To: Stefan =?iso-8859-1?Q?D=F6singer?= Cc: Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Philipp Zabel , Brian Masney , Vinod Koul , Neil Armstrong , Russell King , Brian Masney , Jerome Brunet , Manivannan Sadhasivam , linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-phy@lists.infradead.org, mfd@lists.linux.dev Subject: Re: [PATCH v12 04/12] mfd: zx297520v3: Add a clock and reset MFD driver Message-ID: <20260924141505.GF453446@google.com> References: <20260923-zx29clk-v12-0-9c243796b6d2@gmail.com> <20260923-zx29clk-v12-4-9c243796b6d2@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20260923-zx29clk-v12-4-9c243796b6d2@gmail.com> X-BeenThere: linux-phy@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux Phy Mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "linux-phy" Errors-To: linux-phy-bounces+linux-phy=archiver.kernel.org@lists.infradead.org On Wed, 23 Sep 2026, Stefan D=F6singer wrote: > This driver registers child devices for the zx297520v3 clock and reset > controllers. The clk-zx297520v3 and reset-zte-zx297520v3 submitted in > the next patches will drive the respective functionalities. > = > Signed-off-by: Stefan D=F6singer > = > --- > = > Changes v12: > Added comments elaborating on the role of the driver and the hardware. > = > Regarding the names: zx297520v3 is the SoC's name (chip marking, boot > messages). TOPCRM, MATRIXCRM, LSPCRM are ZTE's names for the MMIO blocks > in their downstream sources. Sadly no datasheet is available. "clk", > "reset" names for the child nodes are mine. > = > Regarding personal copyright: I am not affiliated with ZTE nor paid by > them. This is my personal hobby project. I am using knowledge extracted > from ZTE's kernel dumps, but not code. > = > Changes v10 (All Lee Jones): > *) drop "select REGMAP_MMIO" > *) Drop comment about unimplemented hwlocks > *) Use MFD_CELL_[NAME|OF] > *) Renamed the device type enum and its values > *) Use device_get_match_data instead of the of_ variant > *) Improved debug messages > = > Changes v9: > Deassert the LSP reset and enable the LSP pclk here. In practice the > boot rom needs to do that because it prints to an LSP-connected UART and > reads the boot policy from the LSP connected flash chip. > = > In doing so, I migrated the match data to an enum as mfd.md suggests. > = > Changes v8: > *) Remove .of_compatible from PHY mfd child > = > *) Move to drivers/mfd (Sashiko) > = > For me either soc/zte or mfd/ is fine. Note though that this MFD parent > is very specific to the zx297520v3 SoC. I don't expect this to be reused > anywhere else. There are two more MFD-ish devices in there: soc_sys at > 0x140000, which I plan to handle in the same driver, and an i2c PMIC, > which would get its own host driver. > = > *) Use PLATFORM_DEVID_AUTO (Sashiko). NONE was intentional as I only > ever expect one instance, but I don't see any harm in doing the standard > thing and use AUTO > = > *) On the suggestion not to put the link to mfd_cells[] into match data: > I see that it is spelled out in Sashiko's mfd.md, written by Lee Jones, > the MFD maintainer. I would appreciate some education on the rationale > behind it: Putting a pointer into the void *data is a common pattern in > the kernel. I don't understand in which situation this can possibly > break? > = > Both structs are static const in the same compilation unit. data is a > const void *, not a uintptr_t or kernel_ulong_t, so it seems passing a > pointer is the intended use. What am I missing? > = > Changes v7: > Add phy MFD child > = > Changes v6: Make the ZTE SoC driver section depend on HAS_IOMEM > (Sashiko). The entire MFD section, which contains MFD_CORE, depends on > HAS_IOMEM even with COMPILE_TEST. > = > Add a NULL ptr check for of_device_get_match_data (Sashiko). While not > uniform, rave-sp, rohm-bd9576, atc260x, da9052-i2c protect against > incorrect manual attachment that way. > = > Add lspclk here as well in an attempt to satisfy both Conor Dooley, who > asks for MFD for top and matrix, and Philipp Zabel, who prefers aux but > at least wants the reset driver limited to one driver type. > = > Changes v5: Use MFD instead of Aux bus for top and matrix crm because of > extra functionality: Reboot in top, hwlock in Matrix. > = > LSP clocks stay with the aux bus and are thus not handled in this > driver. The clk driver will bind directly to the lspcrm node. > --- > MAINTAINERS | 1 + > drivers/mfd/Kconfig | 12 +++++ > drivers/mfd/Makefile | 2 + > drivers/mfd/zte-zx297520v3-crm.c | 111 +++++++++++++++++++++++++++++++++= ++++++ > 4 files changed, 126 insertions(+) Doesn't apply. Please bring the MAINTAINERS changes out into their own patch -- = Lee Jones -- = linux-phy mailing list linux-phy@lists.infradead.org https://lists.infradead.org/mailman/listinfo/linux-phy