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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 2E879C433E6 for ; Sat, 2 Jan 2021 03:19:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 088BB2222F for ; Sat, 2 Jan 2021 03:19:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727403AbhABDS5 (ORCPT ); Fri, 1 Jan 2021 22:18:57 -0500 Received: from mga14.intel.com ([192.55.52.115]:61870 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727133AbhABDS5 (ORCPT ); Fri, 1 Jan 2021 22:18:57 -0500 IronPort-SDR: O2YgumPmjJ2Vb4qkXHiovgQTl9s3ftzjlnp5tfTWWaThdu4sD9TJENZdq8TEaQ7BDdT5T7LLeQ fqRKE7mqYMrA== X-IronPort-AV: E=McAfee;i="6000,8403,9851"; a="176026815" X-IronPort-AV: E=Sophos;i="5.78,469,1599548400"; d="scan'208";a="176026815" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Jan 2021 19:17:51 -0800 IronPort-SDR: +V6gPm97kcYBHH1v/MzMSPYsID6tQC3aB/LPUyJApk+nDsuRT6cHcHH/5/xatCVzklW1OeSMja gJScGCPb1H5Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.78,469,1599548400"; d="scan'208";a="349085244" Received: from yilunxu-optiplex-7050.sh.intel.com ([10.239.159.141]) by fmsmga008.fm.intel.com with ESMTP; 01 Jan 2021 19:17:50 -0800 From: Xu Yilun To: mdf@kernel.org, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org Cc: gregkh@linuxfoundation.org, trix@redhat.com, lgoncalv@redhat.com, yilun.xu@intel.com, hao.wu@intel.com Subject: [PATCH v5 2/2] Documentation: fpga: dfl: Add description for DFL UIO support Date: Sat, 2 Jan 2021 11:13:02 +0800 Message-Id: <1609557182-20787-3-git-send-email-yilun.xu@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1609557182-20787-1-git-send-email-yilun.xu@intel.com> References: <1609557182-20787-1-git-send-email-yilun.xu@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch adds description for UIO support for dfl devices on DFL bus. Signed-off-by: Xu Yilun --- v2: no doc in v1, add it for v2. v3: some documentation fixes. v4: documentation change since the driver matching is changed. v5: no change. --- Documentation/fpga/dfl.rst | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst index 0404fe6..b8497f3 100644 --- a/Documentation/fpga/dfl.rst +++ b/Documentation/fpga/dfl.rst @@ -7,6 +7,7 @@ Authors: - Enno Luebbers - Xiao Guangrong - Wu Hao +- Xu Yilun The Device Feature List (DFL) FPGA framework (and drivers according to this framework) hides the very details of low layer hardwares and provides @@ -502,6 +503,29 @@ FME Partial Reconfiguration Sub Feature driver (see drivers/fpga/dfl-fme-pr.c) could be a reference. +UIO support for DFL devices +=========================== +The purpose of an FPGA is to be reprogrammed with newly developed hardware +components. New hardware can instantiate a new private feature in the DFL, and +then get a DFL device in their system. In some cases users may need a userspace +driver for the DFL device: + +* Users may need to run some diagnostic test for their hardwares. +* Users may prototype the kernel driver in user space. +* Some hardware is designed for specific purposes and does not fit into one of + the standard kernel subsystems. + +This requires the direct access to the MMIO space and interrupt handling in +userspace. The dfl-uio-pdev module exposes the UIO device interfaces for this +purpose. It adds the uio_pdrv_genirq platform device with the resources of +the DFL feature, and lets the generic UIO platform device driver provide UIO +support to userspace. + +FPGA_DFL_UIO_PDEV should be selected to enable the dfl-uio-pdev module driver. +To support a new DFL feature been directly accessed via UIO, its feature id +should be added to the driver's id_table. + + Open discussion =============== FME driver exports one ioctl (DFL_FPGA_FME_PORT_PR) for partial reconfiguration -- 2.7.4