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 A3466C43381 for ; Wed, 13 Jan 2021 02:00:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 524BB23117 for ; Wed, 13 Jan 2021 02:00:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727556AbhAMB77 (ORCPT ); Tue, 12 Jan 2021 20:59:59 -0500 Received: from mga02.intel.com ([134.134.136.20]:20593 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725601AbhAMB76 (ORCPT ); Tue, 12 Jan 2021 20:59:58 -0500 IronPort-SDR: k+0wFNwN1Q90QwPFh9bSGl19Uxv8SoMgxx0YSUOH6PbDD6bRnIJMCP3h2olcMjHIUYSa+cIYO/ Ce+Ic7AGjqhg== X-IronPort-AV: E=McAfee;i="6000,8403,9862"; a="165222731" X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="165222731" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 17:59:17 -0800 IronPort-SDR: 8V9yMjTis3wyTh7a1t9oICRlztM8UZ2GrXUQvYCKkjUtOqSIO3+FURT8rWqOSDTuUYSuBe7W9l 96w7uxxZneVA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="363726063" Received: from yilunxu-optiplex-7050.sh.intel.com ([10.239.159.141]) by orsmga002.jf.intel.com with ESMTP; 12 Jan 2021 17:59:15 -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 v6 2/2] Documentation: fpga: dfl: Add description for DFL UIO support Date: Wed, 13 Jan 2021 09:54:08 +0800 Message-Id: <1610502848-30345-3-git-send-email-yilun.xu@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1610502848-30345-1-git-send-email-yilun.xu@intel.com> References: <1610502848-30345-1-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. v6: improve the title of the userspace driver support section. some word improvement. --- Documentation/fpga/dfl.rst | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/fpga/dfl.rst b/Documentation/fpga/dfl.rst index 0404fe6..c33b6d0 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. +Userspace driver 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 direct access to MMIO space and interrupt handling from +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