From patchwork Wed May 6 15:14:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kishon Vijay Abraham I X-Patchwork-Id: 11531361 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 53EBE15E6 for ; Wed, 6 May 2020 15:15:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3D23E214D8 for ; Wed, 6 May 2020 15:15:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="v/QD2fBb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729097AbgEFPPC (ORCPT ); Wed, 6 May 2020 11:15:02 -0400 Received: from fllv0016.ext.ti.com ([198.47.19.142]:37088 "EHLO fllv0016.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728972AbgEFPPC (ORCPT ); Wed, 6 May 2020 11:15:02 -0400 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by fllv0016.ext.ti.com (8.15.2/8.15.2) with ESMTP id 046FEoGT005154; Wed, 6 May 2020 10:14:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1588778090; bh=4Sxi02H9RpRJe5ickAsHEIaYUb+VzvWXaGZ7c+DHSbE=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=v/QD2fBbvN9qPGLPeGN9ZtpDMqy8BTB1x0smt0UJMj86b1cGVFbF45nvGyvXGis1P pu6yK8kJIfJE3T6+VPoYagGvSWDy3RKIMP6hjqrQYNtEilAPrhUtnyRG9KlNxpotxm 9OPjfLDw6D7CyHq8gseMNVA2QeBDXMPGKfxOGFuM= Received: from DFLE107.ent.ti.com (dfle107.ent.ti.com [10.64.6.28]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 046FEokX058758 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 6 May 2020 10:14:50 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE107.ent.ti.com (10.64.6.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Wed, 6 May 2020 10:14:49 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Wed, 6 May 2020 10:14:49 -0500 Received: from a0393678ub.india.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 046FEUgA119457; Wed, 6 May 2020 10:14:46 -0500 From: Kishon Vijay Abraham I To: Bjorn Helgaas , Rob Herring , Lorenzo Pieralisi , Arnd Bergmann , Tom Joseph CC: Greg Kroah-Hartman , , , , , , Subject: [PATCH v4 04/14] PCI: cadence: Add support to start link and verify link status Date: Wed, 6 May 2020 20:44:19 +0530 Message-ID: <20200506151429.12255-5-kishon@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200506151429.12255-1-kishon@ti.com> References: <20200506151429.12255-1-kishon@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org Add cdns_pcie_ops to start link and verify link status. The registers to start link and to check link status is in Platform specific PCIe wrapper. Add support for platform specific drivers to add callback functions for the PCIe Cadence core to start link and verify link status. Signed-off-by: Kishon Vijay Abraham I Reviewed-by: Rob Herring --- .../pci/controller/cadence/pcie-cadence-ep.c | 8 +++++ .../controller/cadence/pcie-cadence-host.c | 28 +++++++++++++++++ drivers/pci/controller/cadence/pcie-cadence.h | 30 +++++++++++++++++++ 3 files changed, 66 insertions(+) diff --git a/drivers/pci/controller/cadence/pcie-cadence-ep.c b/drivers/pci/controller/cadence/pcie-cadence-ep.c index 1fdae37843ef..14021d760482 100644 --- a/drivers/pci/controller/cadence/pcie-cadence-ep.c +++ b/drivers/pci/controller/cadence/pcie-cadence-ep.c @@ -354,8 +354,10 @@ static int cdns_pcie_ep_start(struct pci_epc *epc) { struct cdns_pcie_ep *ep = epc_get_drvdata(epc); struct cdns_pcie *pcie = &ep->pcie; + struct device *dev = pcie->dev; struct pci_epf *epf; u32 cfg; + int ret; /* * BIT(0) is hardwired to 1, hence function 0 is always enabled @@ -366,6 +368,12 @@ static int cdns_pcie_ep_start(struct pci_epc *epc) cfg |= BIT(epf->func_no); cdns_pcie_writel(pcie, CDNS_PCIE_LM_EP_FUNC_CFG, cfg); + ret = cdns_pcie_start_link(pcie); + if (ret) { + dev_err(dev, "Failed to start link\n"); + return ret; + } + return 0; } diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c index 465607202bb5..a60b9627cfbf 100644 --- a/drivers/pci/controller/cadence/pcie-cadence-host.c +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c @@ -3,6 +3,7 @@ // Cadence PCIe host controller driver. // Author: Cyrille Pitchen +#include #include #include #include @@ -197,6 +198,23 @@ static int cdns_pcie_host_init(struct device *dev, return err; } +static int cdns_pcie_host_wait_for_link(struct cdns_pcie *pcie) +{ + struct device *dev = pcie->dev; + int retries; + + /* Check if the link is up or not */ + for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) { + if (cdns_pcie_link_up(pcie)) { + dev_info(dev, "Link up\n"); + return 0; + } + usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX); + } + + return -ETIMEDOUT; +} + int cdns_pcie_host_setup(struct cdns_pcie_rc *rc) { struct device *dev = rc->pcie.dev; @@ -256,6 +274,16 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc) pcie->mem_res = res; + ret = cdns_pcie_start_link(pcie); + if (ret) { + dev_err(dev, "Failed to start link\n"); + return ret; + } + + ret = cdns_pcie_host_wait_for_link(pcie); + if (ret) + dev_dbg(dev, "PCIe link never came up\n"); + ret = cdns_pcie_host_init(dev, &resources, rc); if (ret) return ret; diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h index 70b6b25153e8..a6c4816b68c0 100644 --- a/drivers/pci/controller/cadence/pcie-cadence.h +++ b/drivers/pci/controller/cadence/pcie-cadence.h @@ -10,6 +10,11 @@ #include #include +/* Parameters for the waiting for link up routine */ +#define LINK_WAIT_MAX_RETRIES 10 +#define LINK_WAIT_USLEEP_MIN 90000 +#define LINK_WAIT_USLEEP_MAX 100000 + /* * Local Management Registers */ @@ -226,6 +231,9 @@ enum cdns_pcie_msg_routing { struct cdns_pcie_ops { u32 (*read)(void __iomem *addr, int size); void (*write)(void __iomem *addr, int size, u32 value); + int (*start_link)(struct cdns_pcie *pcie); + void (*stop_link)(struct cdns_pcie *pcie); + bool (*link_up)(struct cdns_pcie *pcie); }; /** @@ -445,6 +453,28 @@ static inline u32 cdns_pcie_ep_fn_readl(struct cdns_pcie *pcie, u8 fn, u32 reg) return readl(addr); } +static inline int cdns_pcie_start_link(struct cdns_pcie *pcie) +{ + if (pcie->ops->start_link) + return pcie->ops->start_link(pcie); + + return 0; +} + +static inline void cdns_pcie_stop_link(struct cdns_pcie *pcie) +{ + if (pcie->ops->stop_link) + pcie->ops->stop_link(pcie); +} + +static inline bool cdns_pcie_link_up(struct cdns_pcie *pcie) +{ + if (pcie->ops->link_up) + return pcie->ops->link_up(pcie); + + return true; +} + #ifdef CONFIG_PCIE_CADENCE_HOST int cdns_pcie_host_setup(struct cdns_pcie_rc *rc); #else