From patchwork Sat Nov 16 01:37:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krishna chaitanya chundru X-Patchwork-Id: 13877428 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D44E194096; Sat, 16 Nov 2024 01:38:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.180.131 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731721096; cv=none; b=ET6FgXnwwxZ6oRAOcNJ7xpu7rZqrRwBtc6J5bUNyTjoSEFJmbpEAvj7bh9q06Ru5JvD5CGhKJ8ySh0K5DQrBsbKt3eTzeAsqzOAtakXB8i07PmRIX4kXDLfEfsS8x8teDsnS02xzkRc/niuudCgwKp9MUDPle+caKrfvGi8V6eU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731721096; c=relaxed/simple; bh=8z3ERRkzjY1Ds+rRxELQ1hmtyibkEmRtY8UUbg0rG50=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=JXNOalF5wtlSychubv9HqvhFg4ZVaLqqfpDctWxgaoce/4HJbNa3uG6iEA21YXArTpPOyvNbEkJZlLisdURokRhQvMcBkW1SH/ArOODhxEKWClEFjYCA/8bEwjrQSHuT41BepsCpdzx0r1gV/fM2q/vrcflEOnxsFNgVq7TI/Wc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com; spf=pass smtp.mailfrom=quicinc.com; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b=YsiIcmyu; arc=none smtp.client-ip=205.220.180.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="YsiIcmyu" Received: from pps.filterd (m0279872.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 4AFBsrd5002407; Sat, 16 Nov 2024 01:38:07 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= IIC8Klt4v5fdxPicO9OA39Kj1uKHyXLclhhigzYL8Os=; b=YsiIcmyuIxmP+W2n B1mdfeJdpxxqqoW+UF7vq5d+6pySYsHJOdTWU+5dyanYfiUkZ7HNaayCbECWgNCd XeK4LGq3MKXih01VuvoQvxQPs+pFKomkDqeOaxOrX344keBWddaRl4w1kbLMWR+m cFvlV6fPdint0t2o0+5O6oV7mc4mX0xX0usE9ufFRSUsRgEyfHnU8mdTgUqwz4gc qIVMNeteEcV/Ym8lQXzEtAVwIDd1WQnKAXvOrdl07ZN3g/pJ9n4vvivHLT0CvD5w MYYyrmTLOzxypKs+iDaVCZRBuWLrOkw6C/NrpL2Gv2yrQ/T3kDAM+0W6SWbagNqr 2ipdvA== Received: from nalasppmta03.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 42ww6duan2-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 16 Nov 2024 01:38:06 +0000 (GMT) Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA03.qualcomm.com (8.18.1.2/8.18.1.2) with ESMTPS id 4AG1c5nq010577 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Sat, 16 Nov 2024 01:38:05 GMT Received: from hu-krichai-hyd.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.9; Fri, 15 Nov 2024 17:37:58 -0800 From: Krishna chaitanya chundru Date: Sat, 16 Nov 2024 07:07:33 +0530 Subject: [PATCH 4/4] PCI: dwc: Add support for configuring lane equalization presets Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <20241116-presets-v1-4-878a837a4fee@quicinc.com> References: <20241116-presets-v1-0-878a837a4fee@quicinc.com> In-Reply-To: <20241116-presets-v1-0-878a837a4fee@quicinc.com> To: , , , Bjorn Andersson , Konrad Dybcio , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Bjorn Helgaas , Jingoo Han , "Manivannan Sadhasivam" , Lorenzo Pieralisi , =?utf-8?q?Krzysztof_Wilczy=C5=84?= =?utf-8?q?ski?= CC: , , , , "Krishna chaitanya chundru" X-Mailer: b4 0.14.1 X-Developer-Signature: v=1; a=ed25519-sha256; t=1731721058; l=4479; i=quic_krichai@quicinc.com; s=20230907; h=from:subject:message-id; bh=8z3ERRkzjY1Ds+rRxELQ1hmtyibkEmRtY8UUbg0rG50=; b=4YaiMjYOXtW8LVMtjeU+YEUrg4BJC/xt/iE9onhzvsPUYX/SDYQ7bfUUNGRrr2AClqAcTpY3k DStROwP+KAWBK87JEaz3k8VEa8RKTUlaB9KLmTtul9RPnrEmx2r8W27 X-Developer-Key: i=quic_krichai@quicinc.com; a=ed25519; pk=10CL2pdAKFyzyOHbfSWHCD0X0my7CXxj8gJScmn1FAg= X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: u1qz4OJ27PdUeMnkydVv8R8rlc6LIFvs X-Proofpoint-GUID: u1qz4OJ27PdUeMnkydVv8R8rlc6LIFvs X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1039,Hydra:6.0.680,FMLib:17.12.60.29 definitions=2024-09-06_09,2024-09-06_01,2024-09-02_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 mlxscore=0 phishscore=0 malwarescore=0 lowpriorityscore=0 impostorscore=0 suspectscore=0 clxscore=1015 adultscore=0 mlxlogscore=999 spamscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2411160011 PCIe equalization presets are predefined settings used to optimize signal integrity by compensating for signal loss and distortion in high-speed data transmission. Based upon the number of lanes and the data rate supported, read the devicetree property and write it in to the lane equalization control registers. Signed-off-by: Krishna chaitanya chundru --- drivers/pci/controller/dwc/pcie-designware-host.c | 39 +++++++++++++++++++++++ drivers/pci/controller/dwc/pcie-designware.h | 3 ++ include/uapi/linux/pci_regs.h | 3 ++ 3 files changed, 45 insertions(+) diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c index 2cd0acbf9e18..2e6abcafbd79 100644 --- a/drivers/pci/controller/dwc/pcie-designware-host.c +++ b/drivers/pci/controller/dwc/pcie-designware-host.c @@ -507,6 +507,10 @@ int dw_pcie_host_init(struct dw_pcie_rp *pp) if (pci->num_lanes < 1) pci->num_lanes = dw_pcie_link_get_max_link_width(pci); + ret = of_pci_get_equalization_presets(dev, &pp->presets, pci->num_lanes); + if (ret) + goto err_free_msi; + /* * Allocate the resource for MSG TLP before programming the iATU * outbound window in dw_pcie_setup_rc(). Since the allocation depends @@ -802,6 +806,40 @@ static int dw_pcie_iatu_setup(struct dw_pcie_rp *pp) return 0; } +static void dw_pcie_program_presets(struct dw_pcie *pci, u8 cap_id, u8 lane_eq_offset, + u8 lane_reg_size, u8 *presets, u8 num_lanes) +{ + u32 cap; + int i; + + cap = dw_pcie_find_ext_capability(pci, cap_id); + if (!cap) + return; + + /* + * Write preset values to the registers byte-by-byte for the given + * number of lanes and register size. + */ + for (i = 0; i < num_lanes * lane_reg_size; i++) + dw_pcie_writeb_dbi(pci, cap + lane_eq_offset + i, presets[i]); +} + +static void dw_pcie_config_presets(struct dw_pcie_rp *pp) +{ + struct dw_pcie *pci = to_dw_pcie_from_pp(pp); + enum pci_bus_speed speed = pcie_link_speed[pci->max_link_speed]; + + /* For data rate of 8 GT/S each lane equalization control is 16bits wide */ + if (speed >= PCIE_SPEED_8_0GT && pp->presets.eq_presets_8gts) + dw_pcie_program_presets(pci, PCI_EXT_CAP_ID_SECPCI, PCI_SECPCI_LE_CTRL, + 0x2, (u8 *)pp->presets.eq_presets_8gts, pci->num_lanes); + + /* For data rate of 16 GT/S each lane equalization control is 8bits wide */ + if (speed >= PCIE_SPEED_16_0GT && pp->presets.eq_presets_16gts) + dw_pcie_program_presets(pci, PCI_EXT_CAP_ID_PL_16GT, PCI_PL_16GT_LE_CTRL, + 0x1, pp->presets.eq_presets_16gts, pci->num_lanes); +} + int dw_pcie_setup_rc(struct dw_pcie_rp *pp) { struct dw_pcie *pci = to_dw_pcie_from_pp(pp); @@ -855,6 +893,7 @@ int dw_pcie_setup_rc(struct dw_pcie_rp *pp) PCI_COMMAND_MASTER | PCI_COMMAND_SERR; dw_pcie_writel_dbi(pci, PCI_COMMAND, val); + dw_pcie_config_presets(pp); /* * If the platform provides its own child bus config accesses, it means * the platform uses its own address translation component rather than diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h index 500e793c9361..b12b33944df4 100644 --- a/drivers/pci/controller/dwc/pcie-designware.h +++ b/drivers/pci/controller/dwc/pcie-designware.h @@ -25,6 +25,8 @@ #include #include +#include "../../pci.h" + /* DWC PCIe IP-core versions (native support since v4.70a) */ #define DW_PCIE_VER_365A 0x3336352a #define DW_PCIE_VER_460A 0x3436302a @@ -379,6 +381,7 @@ struct dw_pcie_rp { bool use_atu_msg; int msg_atu_index; struct resource *msg_res; + struct pci_eq_presets presets; }; struct dw_pcie_ep_ops { diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h index 12323b3334a9..68fc8873bc60 100644 --- a/include/uapi/linux/pci_regs.h +++ b/include/uapi/linux/pci_regs.h @@ -1118,6 +1118,9 @@ #define PCI_DLF_CAP 0x04 /* Capabilities Register */ #define PCI_DLF_EXCHANGE_ENABLE 0x80000000 /* Data Link Feature Exchange Enable */ +/* Secondary PCIe Capability 8.0 GT/s */ +#define PCI_SECPCI_LE_CTRL 0x0c /* Lane Equalization Control Register */ + /* Physical Layer 16.0 GT/s */ #define PCI_PL_16GT_LE_CTRL 0x20 /* Lane Equalization Control Register */ #define PCI_PL_16GT_LE_CTRL_DSP_TX_PRESET_MASK 0x0000000F