From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f173.google.com (mail-pf1-f173.google.com [209.85.210.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8B52827E06C for ; Thu, 27 Nov 2025 19:19:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764271177; cv=none; b=BBqPOC9mJa3oILymuo8GP2g5Bsp1nm+HoiCmI3ZTnJNsXSmo5y85ATmkAjMM9KzohmAF31adFwxWZozUVAc6mjUo40YCqMlyGDNzjGFA3kYo6GLuwZ5wQDhmgtWMzlWhYrsBdabR4yLg8A3LOB6u+axCmbqkHyuIxm2PlRFlVBE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764271177; c=relaxed/simple; bh=QiQubMv26zYAKcBaIcJDXjIhFZMBqqNoxcxStSi01jQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=WC9CdxlTCoa8L6wAOT3FJ7ifdFdxRvvhS+n/G91LVYkDNwaIAEeooC1vSwLNk3b1ko3l+zZO9oGcpYf/D3gelp9PNhwidsKRVYm3NorzZQTrZMJe7APNkNIDcdSz56+Z5fSKDy6nmBJie/cwldoWtBE1E+1SL2xktoeGyuuzk8U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=IMjfJ0Bg; arc=none smtp.client-ip=209.85.210.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IMjfJ0Bg" Received: by mail-pf1-f173.google.com with SMTP id d2e1a72fcca58-7b8eff36e3bso1622488b3a.2 for ; Thu, 27 Nov 2025 11:19:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1764271176; x=1764875976; darn=lists.linux.dev; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=Bc1zInQPA3mOeFCysXnI54YAVIuQEcNbca5dzFQtVUQ=; b=IMjfJ0BgON/Rsz6Nz77o9gERV821e2Ln40RRWoyTSu4UEbXT//RdlgbSUmyEcFlmZ+ MYPoYsAuW2wHwQ0pFfvHg2HXD4jIzjWFbWzDu70zJovLnfSHQHo6RjnnXGdR5ntuNXma avYX0Cglm8ZTTZiBd4QkLnuLAHTPzVi3BnhRtiOiERw+aVeGfIe9I8iwpCFz7p+MHtOk be21hU6wV6KjcsG2+3MQs+y4g/qbDwwM/GefYV9zZUDg7a+5q7cXFNCFbhT0rcF8CnwO vJqqGTZQqHQJeJXT82V0mPr9qosYlMMK7ZcPX1RrnCxHZNheGAKhl80aLKHd3zLFKFH0 TFKA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764271176; x=1764875976; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=Bc1zInQPA3mOeFCysXnI54YAVIuQEcNbca5dzFQtVUQ=; b=JUlurbB81naZDwDx4d8kRK7OnTTOG1khX9RCJzg7RZqvaT8NmgDS2Dn3gpdO4Uk90I lA0Iw4fftCoexo31qza96PCPajDnaFVjCY74H4uM353RUWwp9LxV5bByb607HRQb9K3c sV/ZuN2AFj6qA3tkypsFVgu7okWRtOrieCxJ9+Jie5w4WO0NWY7HzbP6+2FJfo/8gNmv 8TgLYtBXHZL11sCWYoO1MSnL/dbOXYNJh4QzrrtZaPTTtOmfxVBcKT9lpUBPlztSIaXb kf8n2urQGvrpc9Ap1w3nA9qRY7xzseICpm3c8kTGDUpz3DXTF1YJVpTAOPnzbLjkyOMU egWQ== X-Forwarded-Encrypted: i=1; AJvYcCVFtFLLlqK6HiaP4zaMPt/p9E5+CTGdcNDrBxNQdKYtVEEwaX8oDmgu5KLCQQs6C75uUzZTIQDt7+Bjv6JvqyScU6Vn6g==@lists.linux.dev X-Gm-Message-State: AOJu0YwNaR5v5xErKxtemIqpKowJvhvx6YZ1qncmIcldlQIRtnlCgOm+ /xKjPhYC0AAzUeod+XPEmX0MfXo6JFNqsw3iI23Wv02w3A278K+1fofZ X-Gm-Gg: ASbGnctROrHaPe4wTvsKmgrwbX5Quh3Jn9nzWqXKC9Zq8XoNeti8VFvSlE3CzwO1HLA H0BbnE9Jp2O5iL7uzWkWIMhp8kQymzDiLZ17coRR7gxCGwz9THEF+JxDUQB3c8Z2BQiVMni74kr Z6J5oOgEu688z6obxi1CgZR7GGwJSI74hACCp/eF3Qr4g0Nqwh/KXS1jx2NmpB30lNFtOrjKY/o 8saMsqBowD2oAwOBtA7aH5JeZWA+epq9HDezmFf3DJqDpSG/In4g+ozYczQCx/VUpcpxKhy7ida f9u548+nqaBs4LDgVEktSMLrbEr0N64B6iCEIzXTxA1mZdzEZhRbEc0mSisqguqgAyYYHGJHPwl O2ngYnbhe/Na+u871J/gS9Ri4FdN3hSsA3Bl81fCr41gpIbq1INPNJVtUdXhK2x8kPg8FKEHRPJ g/d9zIYGHOzYJ0lANt X-Google-Smtp-Source: AGHT+IGhP0W8lcI8uELg/tQPQCKcVo14Va1mvj+bMVqnMs/DZ2d195Ll0cMh0zJjIMvRCX2xb6uVyg== X-Received: by 2002:a05:6a00:2d9a:b0:7b6:363b:c678 with SMTP id d2e1a72fcca58-7ca8760d166mr14107945b3a.6.1764271175664; Thu, 27 Nov 2025 11:19:35 -0800 (PST) Received: from rakuram-MSI ([2409:40f4:211f:b50d:1190:e256:8b21:a462]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-7d15f176096sm2620703b3a.57.2025.11.27.11.19.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 27 Nov 2025 11:19:35 -0800 (PST) From: Rakuram Eswaran To: linux-can@vger.kernel.org Cc: mkl@pengutronix.de, socketcan@hartkopp.net, mailhol@kernel.org, khalid@kernel.org, skhan@linuxfoundation.org, linux-kernel@vger.kernel.org, rakuram.e96@gmail.com, david.hunter.linux@gmail.com, linux-kernel-mentees@lists.linux.dev Subject: [RFC PATCH 1/2] can: dummy_can: add CAN termination support Date: Fri, 28 Nov 2025 00:48:07 +0530 Message-ID: <20251127191808.144723-2-rakuram.e96@gmail.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251127191808.144723-1-rakuram.e96@gmail.com> References: <20251127191808.144723-1-rakuram.e96@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel-mentees@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Add support for configuring bus termination in the dummy_can driver. This allows users to emulate a properly terminated CAN bus when setting up virtual test environments. Signed-off-by: Rakuram Eswaran --- Tested the termination setting using below iproute commands: ip link set can0 type can termination 120 ip link set can0 type can termination off drivers/net/can/dummy_can.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/net/can/dummy_can.c b/drivers/net/can/dummy_can.c index 41953655e3d3..2949173547e6 100644 --- a/drivers/net/can/dummy_can.c +++ b/drivers/net/can/dummy_can.c @@ -23,6 +23,21 @@ struct dummy_can { static struct dummy_can *dummy_can; +static const u16 dummy_can_termination_const[] = { + CAN_TERMINATION_DISABLED, /* 0 = off */ + 120, /* 120 Ohms */ +}; + +static int dummy_can_set_termination(struct net_device *dev, u16 term) +{ + struct dummy_can *priv = netdev_priv(dev); + + netdev_dbg(dev, "set termination to %u Ohms\n", term); + priv->can.termination = term; + + return 0; +} + static const struct can_bittiming_const dummy_can_bittiming_const = { .name = "dummy_can CC", .tseg1_min = 2, @@ -250,6 +265,12 @@ static int __init dummy_can_init(void) priv->can.xl.data_bittiming_const = &dummy_can_xl_databittiming_const; priv->can.xl.tdc_const = &dummy_can_xl_tdc_const; priv->can.xl.pwm_const = &dummy_can_pwm_const; + + /* Advertise software termination support */ + priv->can.termination_const = dummy_can_termination_const; + priv->can.termination_const_cnt = ARRAY_SIZE(dummy_can_termination_const); + priv->can.do_set_termination = dummy_can_set_termination; + priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD | CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_RESTRICTED | CAN_CTRLMODE_XL | -- 2.51.0