Commit c3606d43 authored by Marc Kleine-Budde's avatar Marc Kleine-Budde
Browse files

can: dev: can_changelink: allow to set bitrate on devices not providing {data_,}bittiming_const 



Until commit

    08da7da4 can: provide a separate bittiming_const parameter to
                 bittiming functions

it was possible to have devices not providing bittiming_const. This can
be used for hardware that only support pre-defined fixed bitrates.
Although no mainline driver is using this feature so far.

This patch re-introduces this feature for the bitrate and the data
bitrate (of CANFD controllers). The driver can specify the
{data_,}bittiming_const (if the bittiming parameters should be
calculated from the bittiming_const) as before or no
{data_,}bittiming_const but implement the do_set_{data,}bittiming
callback.

Acked-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 12a6075c

drivers/net/can/dev.c

+30 −10
Original line number Diff line number Diff line
@@ -284,10 +284,6 @@ static int can_get_bittiming(struct net_device *dev, struct can_bittiming *bt, 
{

	int err;



	/* Check if the CAN device has bit-timing parameters */

	if (!btc)

		return -EOPNOTSUPP;



	/*

	 * Depending on the given can_bittiming parameter structure the CAN

	 * timing parameters are calculated based on the provided bitrate OR
@@ -872,10 +868,22 @@ static int can_changelink(struct net_device *dev, 
		/* Do not allow changing bittiming while running */

		if (dev->flags & IFF_UP)

			return -EBUSY;



		/* Calculate bittiming parameters based on

		 * bittiming_const if set, otherwise pass bitrate

		 * directly via do_set_bitrate(). Bail out if neither

		 * is given.

		 */

		if (!priv->bittiming_const && !priv->do_set_bittiming)

			return -EOPNOTSUPP;



		memcpy(&bt, nla_data(data[IFLA_CAN_BITTIMING]), sizeof(bt));

		err = can_get_bittiming(dev, &bt, priv->bittiming_const);

		if (priv->bittiming_const) {

			err = can_get_bittiming(dev, &bt,

						priv->bittiming_const);

			if (err)

				return err;

		}

		memcpy(&priv->bittiming, &bt, sizeof(bt));



		if (priv->do_set_bittiming) {
@@ -943,11 +951,23 @@ static int can_changelink(struct net_device *dev, 
		/* Do not allow changing bittiming while running */

		if (dev->flags & IFF_UP)

			return -EBUSY;



		/* Calculate bittiming parameters based on

		 * data_bittiming_const if set, otherwise pass bitrate

		 * directly via do_set_bitrate(). Bail out if neither

		 * is given.

		 */

		if (!priv->data_bittiming_const && !priv->do_set_data_bittiming)

			return -EOPNOTSUPP;



		memcpy(&dbt, nla_data(data[IFLA_CAN_DATA_BITTIMING]),

		       sizeof(dbt));

		err = can_get_bittiming(dev, &dbt, priv->data_bittiming_const);

		if (priv->data_bittiming_const) {

			err = can_get_bittiming(dev, &dbt,

						priv->data_bittiming_const);

			if (err)

				return err;

		}

		memcpy(&priv->data_bittiming, &dbt, sizeof(dbt));



		if (priv->do_set_data_bittiming) {

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