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=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 93B65C433B4 for ; Tue, 4 May 2021 13:46:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6947361175 for ; Tue, 4 May 2021 13:46:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231300AbhEDNra (ORCPT ); Tue, 4 May 2021 09:47:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:34866 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231216AbhEDNr3 (ORCPT ); Tue, 4 May 2021 09:47:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 3AC76610A0; Tue, 4 May 2021 13:46:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620135994; bh=GL0ZRSpX/6zSygCXqAdPcV7RkScUHDJZXypjcdpud44=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=fEGMIv0oM+g1r6aVpduh6RFeUVkttvBmB7GiMNAn/QyaGioxZfgKJ3EMMYO5VOvCQ GkiuPZ1MT9OwwV33LtSQxM3DwzPdnIZRmcFdMPTU0ylKxNxjp8FNx28xjTOW1z3Ua9 1Mx6NPHF6jlPiXfOyrJ54ZWDwj4XRDR2aOpJXiNrA7EQx+QMdxTfOW/nJ2WUvWzJjI eErgfHuxKaSJbNYxRMnum3MXeHPo4met0f3g/Hun6bNelKccAZpe8cQcFxmTBd9rDQ TO6LcN6S3DAIotWHnqcQ3MYJZ4Oe0P8uySJyGdHajR5uKCIJmqsTX3TJgmS3pw/AgR JmdG0nLamyLDQ== Date: Tue, 4 May 2021 08:46:32 -0500 From: Bjorn Helgaas To: Greentime Hu Cc: paul.walmsley@sifive.com, hes@sifive.com, erik.danie@sifive.com, zong.li@sifive.com, bhelgaas@google.com, robh+dt@kernel.org, aou@eecs.berkeley.edu, mturquette@baylibre.com, sboyd@kernel.org, lorenzo.pieralisi@arm.com, p.zabel@pengutronix.de, alex.dewar90@gmail.com, khilman@baylibre.com, hayashi.kunihiko@socionext.com, vidyas@nvidia.com, jh80.chung@samsung.com, linux-pci@vger.kernel.org, devicetree@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org Subject: Re: [PATCH v6 5/6] PCI: fu740: Add SiFive FU740 PCIe host controller driver Message-ID: <20210504134632.GA1088165@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210504105940.100004-6-greentime.hu@sifive.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, May 04, 2021 at 06:59:39PM +0800, Greentime Hu wrote: > From: Paul Walmsley > > Add driver for the SiFive FU740 PCIe host controller. > This controller is based on the DesignWare PCIe core. > > Signed-off-by: Paul Walmsley > Co-developed-by: Henry Styles > Signed-off-by: Henry Styles > Co-developed-by: Erik Danie > Signed-off-by: Erik Danie > Co-developed-by: Greentime Hu > Signed-off-by: Greentime Hu > --- > drivers/pci/controller/dwc/Kconfig | 10 + > drivers/pci/controller/dwc/Makefile | 1 + > drivers/pci/controller/dwc/pcie-fu740.c | 309 ++++++++++++++++++++++++ > 3 files changed, 320 insertions(+) > create mode 100644 drivers/pci/controller/dwc/pcie-fu740.c > > diff --git a/drivers/pci/controller/dwc/Kconfig b/drivers/pci/controller/dwc/Kconfig > index 22c5529e9a65..255d43b1661b 100644 > --- a/drivers/pci/controller/dwc/Kconfig > +++ b/drivers/pci/controller/dwc/Kconfig > @@ -318,4 +318,14 @@ config PCIE_AL > required only for DT-based platforms. ACPI platforms with the > Annapurna Labs PCIe controller don't need to enable this. > > +config PCIE_FU740 > + bool "SiFive FU740 PCIe host controller" > + depends on PCI_MSI_IRQ_DOMAIN > + depends on SOC_SIFIVE || COMPILE_TEST > + depends on GPIOLIB 1) I'm a little disappointed that I reported the build issue 6 days ago when we were already in the merge window, and it's taken until now to make some progress. 2) I would prefer not to depend on GPIOLIB because it reduces compile-test coverage. For example, the x86_64 defconfig does not enable GPIOLIB, so one must manually enable it to even be able to enable PCIE_FU740. Many other PCI controller drivers use GPIO, but no others depend on GPIOLIB, so I infer that in the !GPIOLIB case, gpio/consumer.h provides the stubs required for compile testing. We could have a conversation about whether it's better to explicitly depend on GPIOLIB here, or whether building a working FU740 driver implicitly depends on GPIOLIB being selected elsewhere. That implicit dependency *is* a little obscure, but I think that's what other drivers currently do, and I'd like to do this consistently unless there's a good reason otherwise. Here are some examples of other drivers: dwc/pci-dra7xx.c: config PCI_DRA7XX_HOST depends on SOC_DRA7XX || COMPILE_TEST config SOC_DRA7XX select ARCH_OMAP2PLUS config ARCH_OMAP2PLUS select GPIOLIB dwc/pci-meson.c: config PCI_MESON # doesn't, but probably *should* depend on "ARCH_MESON || COMPILE_TEST" menuconfig ARCH_MESON select GPIOLIB dwc/pcie-qcom.c: config PCIE_QCOM depends on OF && (ARCH_QCOM || COMPILE_TEST) config ARCH_QCOM select GPIOLIB pcie-rockchip.c: config PCIE_ROCKCHIP_HOST depends on ARCH_ROCKCHIP || COMPILE_TEST config ARCH_ROCKCHIP select GPIOLIB > + select PCIE_DW_HOST > + help > + Say Y here if you want PCIe controller support for the SiFive > + FU740. > + > endmenu