From patchwork Thu Aug 29 10:53:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Siddharth Vadapalli X-Patchwork-Id: 13783016 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 E2008C83038 for ; Thu, 29 Aug 2024 10:57:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:CC:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8hOk9PuXGBpXAe2XkNZFCwoENS4wBkLV7iENTvnk1I4=; b=2CzP6dalLan7OgAMEea9oKo+U7 ODxKZ8iDIkKKjQZ/MADKyNl1mjM1GDXGwDDjkruqO0smZds7tAmdZkTFirw6tz8A9M7D7B5OGd1Af WL5yTbcvivnDdohMBxXBiPaYvfahs+g4WJEU0t0t76nRwK9BkEhfwtz0OGZYrpfEA7+SYIa7Pr+Is 19qlEUlD04lSwKjFDDFhTOyukWCehk3907lo8vpFZMy1wNJr26RnTn2NIwdV3qV7P6JaZpK+ayXL9 NR02L2tT2uHr4kTQPYQnY51lqi729mOdjjSDsZZIJLqrcMArQtkBmU/f8GrnyB8Gotwh0pwJcRv7q Sa1DkrEw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sjcpj-00000001fCu-0Ptn; Thu, 29 Aug 2024 10:56:55 +0000 Received: from fllv0015.ext.ti.com ([198.47.19.141]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sjcmd-00000001ePA-0j2J for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2024 10:53:44 +0000 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 47TArVR3026554; Thu, 29 Aug 2024 05:53:31 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1724928811; bh=8hOk9PuXGBpXAe2XkNZFCwoENS4wBkLV7iENTvnk1I4=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=EDlQzT32Mz6oq9+jtgsZgmL9v+wcg96oHj9WDJ8XE6URUq1dMZpG39PGrHVx49EaK Wmdam/9N2SMNL9iYcE7WZfqARpPZO95UZI+RUsno2P48IbMd9W6fEzV9ieYyKd1575 7LE2O15zToL+A7z4jU6eAFBdONh8H6bAWkd1bV8Q= Received: from DFLE109.ent.ti.com (dfle109.ent.ti.com [10.64.6.30]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 47TArUEs081129 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 29 Aug 2024 05:53:31 -0500 Received: from DFLE112.ent.ti.com (10.64.6.33) by DFLE109.ent.ti.com (10.64.6.30) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Thu, 29 Aug 2024 05:53:30 -0500 Received: from lelvsmtp5.itg.ti.com (10.180.75.250) by DFLE112.ent.ti.com (10.64.6.33) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Thu, 29 Aug 2024 05:53:30 -0500 Received: from uda0492258.dhcp.ti.com (uda0492258.dhcp.ti.com [10.24.72.81]) by lelvsmtp5.itg.ti.com (8.15.2/8.15.2) with ESMTP id 47TArHpT070385; Thu, 29 Aug 2024 05:53:26 -0500 From: Siddharth Vadapalli To: , , , , , , , , CC: , , , , , Subject: [PATCH v4 2/2] PCI: j721e: Enable ACSPCIE Refclk if "ti,syscon-acspcie-proxy-ctrl" exists Date: Thu, 29 Aug 2024 16:23:16 +0530 Message-ID: <20240829105316.1483684-3-s-vadapalli@ti.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240829105316.1483684-1-s-vadapalli@ti.com> References: <20240829105316.1483684-1-s-vadapalli@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240829_035343_350737_4DDE1CEE X-CRM114-Status: GOOD ( 18.55 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The ACSPCIE module is capable of driving the reference clock required by the PCIe Endpoint device. It is an alternative to on-board and external reference clock generators. Enabling the output from the ACSPCIE module's PAD IO Buffers requires clearing the "PAD IO disable" bits of the ACSPCIE_PROXY_CTRL register in the CTRL_MMR register space. Add support to enable the ACSPCIE reference clock output using the optional device-tree property "ti,syscon-acspcie-proxy-ctrl". Signed-off-by: Siddharth Vadapalli --- v3: https://lore.kernel.org/r/20240827055548.901285-3-s-vadapalli@ti.com/ Changes since v3: - Rebased patch on next-20240829. - Addressed Bjorn's feedback at: https://lore.kernel.org/r/20240828211906.GA38267@bhelgaas/ with the following changes: 1) Updated the implementation of j721e_enable_acspcie_refclk() by reducing the nested IF conditions to make it easier to read. 2) Updated the section invoking j721e_enable_acspcie_refclk() within j721e_pcie_ctrl_init() by returning 0 if "ti,syscon-acspcie-proxy-ctrl" isn't present and returning j721e_enable_acspcie_refclk() otherwise. v2: https://lore.kernel.org/r/20240729092855.1945700-3-s-vadapalli@ti.com/ Changes since v2: - Rebased patch on next-20240826. v1: https://lore.kernel.org/r/20240715120936.1150314-4-s-vadapalli@ti.com/ Changes since v1: - Addressed Bjorn's feedback at: https://lore.kernel.org/r/20240725211841.GA859405@bhelgaas/ with the following changes: 1) Updated $subject and commit message to indicate that this patch enables ACSPCIE reference clock output if the DT property is present. 2) Updated macro and comments to indicate that the BITS correspond to disabling ACSPCIE output, due to which clearing them enables the reference clock output. 3) Replaced "PAD" with "refclk" both in the function name and in the error prints. 4) Wrapped lines to be within the 80 character limit to match the rest of the driver. drivers/pci/controller/cadence/pci-j721e.c | 39 +++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c index 85718246016b..7f7732e2dcaa 100644 --- a/drivers/pci/controller/cadence/pci-j721e.c +++ b/drivers/pci/controller/cadence/pci-j721e.c @@ -44,6 +44,7 @@ enum link_status { #define J721E_MODE_RC BIT(7) #define LANE_COUNT(n) ((n) << 8) +#define ACSPCIE_PAD_DISABLE_MASK GENMASK(1, 0) #define GENERATION_SEL_MASK GENMASK(1, 0) struct j721e_pcie { @@ -220,6 +221,36 @@ static int j721e_pcie_set_lane_count(struct j721e_pcie *pcie, return ret; } +static int j721e_enable_acspcie_refclk(struct j721e_pcie *pcie, + struct regmap *syscon) +{ + struct device *dev = pcie->cdns_pcie->dev; + struct device_node *node = dev->of_node; + u32 mask = ACSPCIE_PAD_DISABLE_MASK; + struct of_phandle_args args; + u32 val; + int ret; + + ret = of_parse_phandle_with_fixed_args(node, + "ti,syscon-acspcie-proxy-ctrl", + 1, 0, &args); + if (ret) { + dev_err(dev, + "ti,syscon-acspcie-proxy-ctrl has invalid arguments\n"); + return ret; + } + + /* Clear PAD IO disable bits to enable refclk output */ + val = ~(args.args[0]); + ret = regmap_update_bits(syscon, 0, mask, val); + if (ret) { + dev_err(dev, "failed to enable ACSPCIE refclk: %d\n", ret); + return ret; + } + + return 0; +} + static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie) { struct device *dev = pcie->cdns_pcie->dev; @@ -259,7 +290,13 @@ static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie) return ret; } - return 0; + /* Enable ACSPCIE refclk output if the optional property exists */ + syscon = syscon_regmap_lookup_by_phandle_optional(node, + "ti,syscon-acspcie-proxy-ctrl"); + if (!syscon) + return 0; + + return j721e_enable_acspcie_refclk(pcie, syscon); } static int cdns_ti_pcie_config_read(struct pci_bus *bus, unsigned int devfn,