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=-8.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 30463C64EB4 for ; Fri, 30 Nov 2018 17:08:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE99D2145D for ; Fri, 30 Nov 2018 17:08:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Vy/evIQh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE99D2145D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727754AbeLAESC (ORCPT ); Fri, 30 Nov 2018 23:18:02 -0500 Received: from mail-it1-f195.google.com ([209.85.166.195]:33728 "EHLO mail-it1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727669AbeLAESA (ORCPT ); Fri, 30 Nov 2018 23:18:00 -0500 Received: by mail-it1-f195.google.com with SMTP id m8so2438398itk.0 for ; Fri, 30 Nov 2018 09:08:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Pkkhki6gOw8na4aLzcjKwCRPB4mHo2I09YZSWHEShAA=; b=Vy/evIQhFHTxXtmT1GrpIk+f15L2ffu7raGxmXLyznJ97xd7OTwSGnJAFFX+uRkwA4 uwN1XdUCR2VZQXBNz8QRNsbml8zb/rDSo534jymsRbkgVE+FU4wwDS629OP3j8GuF8K3 2Cklkw7iarnakGVEMiuZ4d0k8+FmT8mrbfNisiTsDezXx3F2IWi/SgoQZpB7exdlLlsD 6BLrRp3kcwRV1eB5Fjp73Iz9GvB0om+aoVYRI44rHJp83603OPgidFms0SXbmmXIzAvm IiwM8udIKza60NT80MMyJU69X056tIIxVlSjk8hxI7lcFp0YcgFeFPLJIrGt6p4dM1Gy /lHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Pkkhki6gOw8na4aLzcjKwCRPB4mHo2I09YZSWHEShAA=; b=LAgmHqlFtDw7PvvdiKGVPKNAD+Bvf0s2LUSaBgVeh9OwpN1wTotfujgNUJKxCAjYAt nKmUll2SHlPEfx7yaP+XS7BkWTUjpePP5iqtW3c3wwHzJVfYqP+pBOhfcJhjJckenrmd dp1gdBW07QO3864lCEJMH2lkA2/d6yZEMddFL5kY27wTM5lbBLPdpYZvZh9pN+dJywi+ /NGdAH7x3SN+VnKOh5p0+aPGC0gmSAJhyT3reA3ESTdUIQAl6vwM6tkipuCSqFKDzAYy hrFmi5BHqDp+F4ao0nflqLITmmnhElRooQW/DU7nZVPYlZkEkADiwQ5gk6kbEkdr+/he lYFg== X-Gm-Message-State: AA+aEWaTArGeLy+xS03LYWmZ+V3RxFqLiKoHN4SC+9f1AvaWBiO+3/p0 osj1HenroHkce5UASUbEDeQ= X-Google-Smtp-Source: AFSGD/VQMggFAhEpwbZ93hE177TGK5/CrwBSEO/MK9tOg9CiQLKBP0JEdWSeEvtfc8dSY/v2yKxBlw== X-Received: by 2002:a02:8ca8:: with SMTP id f37mr6067381jak.80.1543597682784; Fri, 30 Nov 2018 09:08:02 -0800 (PST) Received: from localhost.localdomain ([198.52.185.227]) by smtp.gmail.com with ESMTPSA id u26sm2143387iob.31.2018.11.30.09.08.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 30 Nov 2018 09:08:02 -0800 (PST) From: thesven73@gmail.com X-Google-Original-From: TheSven73@googlemail.com To: TheSven73@googlemail.com, Shawn Guo , Kees Cook , Rob Herring , Arnd Bergmann Cc: linux-kernel@vger.kernel.org Subject: [PATCH 2/2] bus: imx-weim: guard against timing configuration conflicts Date: Fri, 30 Nov 2018 12:07:54 -0500 Message-Id: <20181130170754.346-3-TheSven73@googlemail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181130170754.346-1-TheSven73@googlemail.com> References: <20181130170754.346-1-TheSven73@googlemail.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sven Van Asbroeck When adding weim child devices, there is a risk that the developer will (by mistake) specify more than one timing setting for the same chip select. The driver cannot support such a configuration. In case of conflict, this patch will print a warning to the log, and will ignore the child node in question. In this example, node acme@1 will be ignored, as it tries to modify timing settings for CS0: &weim { acme@0 { compatible = "acme,whatever"; reg = <0 0 0x100>; fsl,weim-cs-timing = ; }; acme@1 { compatible = "acme,whatnot"; reg = <0 0x500 0x100>; fsl,weim-cs-timing = ; }; }; However in this example, the driver will be happy: &weim { acme@0 { compatible = "acme,whatever"; reg = <0 0 0x100>; fsl,weim-cs-timing = ; }; acme@1 { compatible = "acme,whatnot"; reg = <0 0x500 0x100>; fsl,weim-cs-timing = ; }; }; Signed-off-by: Sven Van Asbroeck --- drivers/bus/imx-weim.c | 33 ++++++++++++++++++++++++++++++--- 1 file changed, 30 insertions(+), 3 deletions(-) diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c index 24f22285395d..114e503ec785 100644 --- a/drivers/bus/imx-weim.c +++ b/drivers/bus/imx-weim.c @@ -46,8 +46,18 @@ static const struct imx_weim_devtype imx51_weim_devtype = { }; #define MAX_CS_REGS_COUNT 6 +#define MAX_CS_REGS 6 #define OF_REG_SIZE 3 +struct cs_timing { + bool is_applied; + u32 regs[MAX_CS_REGS_COUNT]; +}; + +struct cs_timing_state { + struct cs_timing cs[MAX_CS_REGS]; +}; + static const struct of_device_id weim_id_table[] = { /* i.MX1/21 */ { .compatible = "fsl,imx1-weim", .data = &imx1_weim_devtype, }, @@ -112,11 +122,14 @@ static int __init imx_weim_gpr_setup(struct platform_device *pdev) } /* Parse and set the timing for this device. */ -static int __init weim_timing_setup(struct device_node *np, void __iomem *base, - const struct imx_weim_devtype *devtype) +static int __init weim_timing_setup(struct device *dev, + struct device_node *np, void __iomem *base, + const struct imx_weim_devtype *devtype, + struct cs_timing_state *ts) { u32 cs_idx, value[MAX_CS_REGS_COUNT]; int i, ret, reg_idx, num_regs; + struct cs_timing *cst; if (WARN_ON(devtype->cs_regs_count > MAX_CS_REGS_COUNT)) return -EINVAL; @@ -145,10 +158,23 @@ static int __init weim_timing_setup(struct device_node *np, void __iomem *base, if (cs_idx >= devtype->cs_count) return -EINVAL; + /* prevent re-configuring a CS that's already been configured */ + cst = &ts->cs[cs_idx]; + if (cst->is_applied && memcmp(value, cst->regs, + devtype->cs_regs_count*sizeof(u32))) { + dev_err(dev, "fsl,weim-cs-timing conflict on %pOF", np); + return -EINVAL; + } + /* set the timing for WEIM */ for (i = 0; i < devtype->cs_regs_count; i++) writel(value[i], base + cs_idx * devtype->cs_stride + i * 4); + if (!cst->is_applied) { + cst->is_applied = true; + memcpy(cst->regs, value, + devtype->cs_regs_count*sizeof(u32)); + } } return 0; @@ -165,6 +191,7 @@ static int __init weim_parse_dt(struct platform_device *pdev, const struct imx_weim_devtype *devtype = of_id->data; struct device_node *child; int ret, have_child = 0; + struct cs_timing_state ts = {}; if (devtype == &imx50_weim_devtype) { ret = imx_weim_gpr_setup(pdev); @@ -179,7 +206,7 @@ static int __init weim_parse_dt(struct platform_device *pdev, } for_each_available_child_of_node(pdev->dev.of_node, child) { - ret = weim_timing_setup(child, base, devtype); + ret = weim_timing_setup(&pdev->dev, child, base, devtype, &ts); if (ret) dev_warn(&pdev->dev, "%pOF set timing failed.\n", child); -- 2.17.1