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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@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 { =20 static struct dummy_can *dummy_can; =20 +static const u16 dummy_can_termination_const[] =3D { + CAN_TERMINATION_DISABLED, /* 0 =3D off */ + 120, /* 120 Ohms */ +}; + +static int dummy_can_set_termination(struct net_device *dev, u16 term) +{ + struct dummy_can *priv =3D netdev_priv(dev); + + netdev_dbg(dev, "set termination to %u Ohms\n", term); + priv->can.termination =3D term; + + return 0; +} + static const struct can_bittiming_const dummy_can_bittiming_const =3D { .name =3D "dummy_can CC", .tseg1_min =3D 2, @@ -250,6 +265,12 @@ static int __init dummy_can_init(void) priv->can.xl.data_bittiming_const =3D &dummy_can_xl_databittiming_const; priv->can.xl.tdc_const =3D &dummy_can_xl_tdc_const; priv->can.xl.pwm_const =3D &dummy_can_pwm_const; +=09 + /* Advertise software termination support */ + priv->can.termination_const =3D dummy_can_termination_const; + priv->can.termination_const_cnt =3D ARRAY_SIZE(dummy_can_termination_cons= t); + priv->can.do_set_termination =3D dummy_can_set_termination; + priv->can.ctrlmode_supported =3D CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD | CAN_CTRLMODE_TDC_AUTO | CAN_CTRLMODE_RESTRICTED | CAN_CTRLMODE_XL | --=20 2.51.0