From patchwork Wed Sep 18 08:13:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AngeloGioacchino Del Regno X-Patchwork-Id: 13806677 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 3CE6ACCD18B for ; Wed, 18 Sep 2024 08:17:12 +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-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=WgHfo+w380xK2B2oIcEiNNA9yO0ZNStdVFXh2NZJ/jE=; b=YpvvrG+SUbvP+KjdZE7YB1/TLM Qf0VcczZMgyaiIVNU7xDs0009mXXdxpqJwZQ/D3BCv9TZ3bnC+JwOlwAZ0T1a4J3CuuSMgj2tpjJt kEUy6rsH7BC7bmI4LAFizjsXdSKrpjmhhHLko6EvDSOVgvfbanODw3LeQgnFiXcBQl0FJwQBweGJt Rh3OpLO+oeVdbDhdb7N757qi2T4cVcEizJljmPINTdlyzTBHPimD07CXYWwCTL+vtLecoBekvOCse dZacJrIjn1TjKXmBI0r0o+6PYZLsp5g1TtlDJSlxtFYpkp7Jv9d795/hpR4i0phPwHhEPid35piJs G/5+oZ5g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1sqprx-00000007lu0-33lc; Wed, 18 Sep 2024 08:17:01 +0000 Received: from bali.collaboradmins.com ([2a01:4f8:201:9162::2]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1sqpoI-00000007l2P-1GDW; Wed, 18 Sep 2024 08:13:15 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1726647192; bh=hanknEKqGzrT3mPnV0cueYnM3TV4BgNLJUCxOnB8qt8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HDeqSBgKvgwjgbPSwk9fOl4FbkkWUEQKBYYPy3EKoteJf/92e5z/PRt8oV25VnNd+ R+l5yNBXq26kQH4sISngW6642stjUfbny02YuX0Z09zESXkPAzeZ5oSYcV3A3JjTFa Awq5rPY/VVHxDNsCey6D9/6FpzKcd5mW72V+5V4ewDsYfP0ruL+PxoIWXx5jJ8DcFo vlAShk5Rqki8yjNcKt1WRjk1AOzv2Yi2EFiw4TGqvM3N/W6Xb351DoRwmo14lieHkk FYu2MWttb75O3de5d3R6nyLP65tRl50GaAaIQxi2NG/RpmeViedrLhhIv8qokBt1uA awKZ9SyQwT7CA== Received: from IcarusMOD.eternityproject.eu (2-237-20-237.ip236.fastwebnet.it [2.237.20.237]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: kholk11) by bali.collaboradmins.com (Postfix) with ESMTPSA id 0E3E717E1003; Wed, 18 Sep 2024 10:13:12 +0200 (CEST) From: AngeloGioacchino Del Regno To: linux-pci@vger.kernel.org Cc: ryder.lee@mediatek.com, jianjun.wang@mediatek.com, lpieralisi@kernel.org, kw@linux.com, robh@kernel.org, bhelgaas@google.com, matthias.bgg@gmail.com, angelogioacchino.delregno@collabora.com, linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel@collabora.com, fshao@chromium.org Subject: [PATCH v3 2/2] PCI: mediatek-gen3: Add support for restricting link width Date: Wed, 18 Sep 2024 10:13:07 +0200 Message-ID: <20240918081307.51264-3-angelogioacchino.delregno@collabora.com> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240918081307.51264-1-angelogioacchino.delregno@collabora.com> References: <20240918081307.51264-1-angelogioacchino.delregno@collabora.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240918_011314_545360_97AED261 X-CRM114-Status: GOOD ( 14.88 ) 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 Add support for restricting the port's link width by specifying the num-lanes devicetree property in the PCIe node. The setting is done in the GEN_SETTINGS register (in the driver named as PCIE_SETTING_REG), where each set bit in [11:8] activates a set of lanes (from bits 11 to 8 respectively, x16/x8/x4/x2). Signed-off-by: AngeloGioacchino Del Regno Reviewed-by: Fei Shao Reviewed-by: Manivannan Sadhasivam --- drivers/pci/controller/pcie-mediatek-gen3.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c index 8d4b045633da..8dd2e5135b01 100644 --- a/drivers/pci/controller/pcie-mediatek-gen3.c +++ b/drivers/pci/controller/pcie-mediatek-gen3.c @@ -32,6 +32,7 @@ #define PCIE_BASE_CFG_SPEED GENMASK(15, 8) #define PCIE_SETTING_REG 0x80 +#define PCIE_SETTING_LINK_WIDTH GENMASK(11, 8) #define PCIE_SETTING_GEN_SUPPORT GENMASK(14, 12) #define PCIE_PCI_IDS_1 0x9c #define PCI_CLASS(class) (class << 8) @@ -168,6 +169,7 @@ struct mtk_msi_set { * @clks: PCIe clocks * @num_clks: PCIe clocks count for this port * @max_link_speed: Maximum link speed (PCIe Gen) for this port + * @num_lanes: Number of PCIe lanes for this port * @irq: PCIe controller interrupt number * @saved_irq_state: IRQ enable state saved at suspend time * @irq_lock: lock protecting IRQ register access @@ -189,6 +191,7 @@ struct mtk_gen3_pcie { struct clk_bulk_data *clks; int num_clks; u8 max_link_speed; + u8 num_lanes; int irq; u32 saved_irq_state; @@ -401,6 +404,14 @@ static int mtk_pcie_startup_port(struct mtk_gen3_pcie *pcie) val |= FIELD_PREP(PCIE_SETTING_GEN_SUPPORT, GENMASK(pcie->max_link_speed - 2, 0)); } + if (pcie->num_lanes) { + val &= ~PCIE_SETTING_LINK_WIDTH; + + /* Zero means one lane, each bit activates x2/x4/x8/x16 */ + if (pcie->num_lanes > 1) + val |= FIELD_PREP(PCIE_SETTING_LINK_WIDTH, + GENMASK(pcie->num_lanes >> 1, 0)); + }; writel_relaxed(val, pcie->base + PCIE_SETTING_REG); /* Set Link Control 2 (LNKCTL2) speed restriction, if any */ @@ -838,6 +849,7 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie) struct device *dev = pcie->dev; struct platform_device *pdev = to_platform_device(dev); struct resource *regs; + u32 num_lanes; regs = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pcie-mac"); if (!regs) @@ -883,6 +895,14 @@ static int mtk_pcie_parse_port(struct mtk_gen3_pcie *pcie) return pcie->num_clks; } + ret = of_property_read_u32(dev->of_node, "num-lanes", &num_lanes); + if (ret == 0) { + if (num_lanes == 0 || num_lanes > 16 || (num_lanes != 1 && num_lanes % 2)) + dev_warn(dev, "Invalid num-lanes, using controller defaults\n"); + else + pcie->num_lanes = num_lanes; + } + return 0; }