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=-8.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 0A3C4C433DF for ; Mon, 25 May 2020 16:58:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAF6120870 for ; Mon, 25 May 2020 16:58:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="JNQq63iU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729554AbgEYQ6i (ORCPT ); Mon, 25 May 2020 12:58:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725834AbgEYQ6h (ORCPT ); Mon, 25 May 2020 12:58:37 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8EA25C061A0E; Mon, 25 May 2020 09:58:36 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id n18so9027003pfa.2; Mon, 25 May 2020 09:58:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=aPMULKZDeq0BX+s9zNJj5lw/mRPJ8V62Bi00UZ2hLPQ=; b=JNQq63iU315TudbF0LDZbx0/ESdXGRQ+JL6Q8ov8UoVeiVwyyIzm0oBHPCwmXZzuvs xnf7opyTEzKm/Ipk769HDtPHEhmuPMBMiFybuXo2NewIjgQbZ2tUv2JRc43WWqYc3yZ9 xJ3nkjKYoQFJgR7tVH4OJthhyecWG5WTE9Wkuf9TRujPbxby4YVsPnrYsnNVtlMyqeAM HEuiuXFX4Ezr6HR6tyzTDaNauY4TjnrvnoG/BEfOTgglxrJgVUDSP+Bc2+Xf9UcjgcAU vKZaPSahzBHFnvb/FO6EtDJHqAyKBvuTicmJl4bBYl1OxTuZtbXJVmPZNzBrLshZbfPN KopQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=aPMULKZDeq0BX+s9zNJj5lw/mRPJ8V62Bi00UZ2hLPQ=; b=Xvlc2EUH/caUJCsrjlKWXWNvCo5+z2u58lBfiIAXAQhmk8b67HBg2kUzxAVV/FpnFK 9GKjmwaAa+bwXDFlzsZ8CDyQx3ydT/Yb2BOJEeAGcsR+AcwNV+8qB44kSVpUCZAT9yqE gSHW0Q6s4QndT7SCtfbKFMZpIZuQKjvJJrq5JeOGThkPN8OsvQ979mLqQTmYp9zi6lTK CCailk6ysoyTfZDAP9l0WvhbIKbzY4MFkIUS/eP9S1BY6pRSkOpRmNzyG1qCqEGz2dSW PI3+LkgntyYf47HZjK5YVD6ZOSUCZmS5tx+wfT4ditrBWgg8qcb8DJpVaEFxBwGD+n/l xlQg== X-Gm-Message-State: AOAM5313AnsYyT5kQZ7cZWoEt7Sj7DY62n8hnW3F3teYsWQ6G5xNOp1K 6kdVBkAVEKhXudWRSbiMyG3+9yUg X-Google-Smtp-Source: ABdhPJyamdUHEpVQmhep6MniCPNxtcfAdKYfTqv1tOet1bkSJFZ/NVZIoCCC18ASwCtIF3W4ZjUrBg== X-Received: by 2002:a63:5116:: with SMTP id f22mr16311686pgb.100.1590425915574; Mon, 25 May 2020 09:58:35 -0700 (PDT) Received: from [10.230.188.43] ([192.19.223.252]) by smtp.gmail.com with ESMTPSA id e21sm11825840pga.71.2020.05.25.09.58.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 25 May 2020 09:58:34 -0700 (PDT) Subject: Re: [PATCH 07/15] PCI: brcmstb: Add control of rescal reset To: Jim Quinlan , Philipp Zabel Cc: Nicolas Saenz Julienne , Lorenzo Pieralisi , Rob Herring , Bjorn Helgaas , "maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "moderated list:BROADCOM BCM2711/BCM2835 ARM ARCHITECTURE" , "open list:PCI NATIVE HOST BRIDGE AND ENDPOINT DRIVERS" , open list References: <20200519203419.12369-1-james.quinlan@broadcom.com> <20200519203419.12369-8-james.quinlan@broadcom.com> <20200520072747.GB5213@pengutronix.de> From: Florian Fainelli Message-ID: Date: Mon, 25 May 2020 09:58:33 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Firefox/68.0 Thunderbird/68.8.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/21/2020 2:48 PM, Jim Quinlan wrote: > On Wed, May 20, 2020 at 3:27 AM Philipp Zabel wrote: >> >> Hi Jim, >> >> On Tue, May 19, 2020 at 04:34:05PM -0400, Jim Quinlan wrote: >>> From: Jim Quinlan >>> >>> Some STB chips have a special purpose reset controller named >>> RESCAL (reset calibration). This commit adds the control >>> of RESCAL as well as the ability to start and stop its >>> operation for PCIe HW. >>> >>> Signed-off-by: Jim Quinlan >>> --- >>> drivers/pci/controller/pcie-brcmstb.c | 81 ++++++++++++++++++++++++++- >>> 1 file changed, 80 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c >>> index 2c470104ba38..0787e8f6f7e5 100644 >>> --- a/drivers/pci/controller/pcie-brcmstb.c >>> +++ b/drivers/pci/controller/pcie-brcmstb.c >> [...] >>> @@ -1100,6 +1164,21 @@ static int brcm_pcie_probe(struct platform_device *pdev) >>> dev_err(&pdev->dev, "could not enable clock\n"); >>> return ret; >>> } >>> + pcie->rescal = devm_reset_control_get_shared(&pdev->dev, "rescal"); >>> + if (IS_ERR(pcie->rescal)) { >>> + if (PTR_ERR(pcie->rescal) == -EPROBE_DEFER) >>> + return -EPROBE_DEFER; >>> + pcie->rescal = NULL; >> >> This is effectively an optional reset control, so it is better to use: >> ↵ >> pcie->rescal = devm_reset_control_get_optional_shared(&pdev->dev, >> "rescal");↵ >> if (IS_ERR(pcie->rescal)) >> return PTR_ERR(pcie->rescal); >> >>> + } else { >>> + ret = reset_control_deassert(pcie->rescal); >>> + if (ret) >>> + dev_err(&pdev->dev, "failed to deassert 'rescal'\n"); >>> + } >> >> reset_control_* can handle rstc == NULL parameters for optional reset >> controls, so this can be done unconditionally: >> >> ret = reset_control_deassert(pcie->rescal);↵ >> if (ret)↵ >> dev_err(&pdev->dev, "failed to deassert 'rescal'\n");↵ >> >> Is rescal handled by the reset-brcmstb-rescal driver? Since that only >> implements the .reset op, I would expect reset_control_reset() here. > Where exactly? "reset.h" says that "Calling reset_control_rese()t is > not allowed on a shared reset control." so I'm not sure why you would > want me to invoke it. Yes this is handled by drivers/reset/reset-brcmstb-rescal.c which only implements a .reset() callback, what would be the appropriate API usage here given that this is a shared reset between AHCI and PCIe, should drivers/reset/reset-brcmstb-rescal.c not implement a .reset() callback and .assert() callback instead? >> Otherwise this looks like it'd be missing a reset_control_assert in >> remove. > I can add this. > Thanks, > Jim >> >> regards >> Philipp -- Florian