On Thu, 9 May 2024, Christoph Fritz wrote:
> A LIN node can work as commander or responder, so introduce a new
> control mode (CAN_CTRLMODE_LIN_COMMANDER) for configuration.
>
> This enables e.g. the userland tool ip from iproute2 to turn on
> commander mode when the device is being brought up.
>
> Signed-off-by: Christoph Fritz <christoph.fritz@xxxxxxxxx>
> ---
> drivers/net/can/lin.c | 40 +++++++++++++++++++++++++++++++-
> include/net/lin.h | 7 ++++++
> include/uapi/linux/can/netlink.h | 1 +
> 3 files changed, 47 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/can/lin.c b/drivers/net/can/lin.c
> index f77abd7d7d21c..03ddf5d5a31b8 100644
> --- a/drivers/net/can/lin.c
> +++ b/drivers/net/can/lin.c
> @@ -262,11 +262,40 @@ static netdev_tx_t lin_start_xmit(struct sk_buff *skb,
> return NETDEV_TX_OK;
> }
>
> +static int lin_update_mode(struct net_device *ndev)
> +{
> + struct lin_device *ldev = netdev_priv(ndev);
> + u32 ctrlmode = ldev->can.ctrlmode;
> + enum lin_mode lm;
> + int ret = 0;
> +
> + lm = (ctrlmode & CAN_CTRLMODE_LIN_COMMANDER) ? LINBUS_COMMANDER :
> + LINBUS_RESPONDER;
> + if (ldev->lmode != lm) {
> + if (!ldev->ldev_ops->update_lin_mode) {
> + netdev_err(ndev, "setting lin mode unsupported\n");
In user visible messages, it would be best to use the expected
capitalization, which I suppose is LIN given you use capitals in the
commit message yourself?
> + return -EINVAL;
> + }
> + ret = ldev->ldev_ops->update_lin_mode(ldev, lm);
> + if (ret) {
> + netdev_err(ndev, "Failed to set lin mode: %d\n", ret);
Ditto.
There might be other cases in any of the patches, please check.
> + return ret;
> + }
> + ldev->lmode = lm;
> + }
> +
> + return ret;
> +}
> +
> static int lin_open(struct net_device *ndev)
> {
> struct lin_device *ldev = netdev_priv(ndev);
> int ret;
>
> + ret = lin_update_mode(ndev);
> + if (ret)
> + return ret;
> +
> ldev->tx_busy = false;
>
> ret = open_candev(ndev);
> @@ -443,7 +472,7 @@ struct lin_device *register_lin(struct device *dev,
> ndev->sysfs_groups[0] = &lin_sysfs_group;
> ldev->can.bittiming.bitrate = LIN_DEFAULT_BAUDRATE;
> ldev->can.ctrlmode = CAN_CTRLMODE_LIN;
> - ldev->can.ctrlmode_supported = 0;
> + ldev->can.ctrlmode_supported = CAN_CTRLMODE_LIN_COMMANDER;
> ldev->can.bitrate_const = lin_bitrate;
> ldev->can.bitrate_const_cnt = ARRAY_SIZE(lin_bitrate);
> ldev->can.do_set_bittiming = lin_set_bittiming;
> @@ -458,6 +487,15 @@ struct lin_device *register_lin(struct device *dev,
> goto exit_candev;
> }
>
> + ldev->lmode = LINBUS_RESPONDER;
> + if (ldev->ldev_ops->update_lin_mode) {
> + ret = ldev->ldev_ops->update_lin_mode(ldev, ldev->lmode);
> + if (ret) {
> + netdev_err(ndev, "updating lin mode failed\n");
Ditto.
> + goto exit_candev;
> + }
> + }
> +
> ret = register_candev(ndev);
> if (ret)
> goto exit_candev;
> diff --git a/include/net/lin.h b/include/net/lin.h
> index 31bb0feefd188..63ac870a0ab6f 100644
> --- a/include/net/lin.h
> +++ b/include/net/lin.h
> @@ -36,6 +36,11 @@ struct lin_attr {
> struct lin_device *ldev;
> };
>
> +enum lin_mode {
> + LINBUS_RESPONDER = 0,
> + LINBUS_COMMANDER,
> +};
> +
> struct lin_device {
> struct can_priv can; /* must be the first member */
> struct net_device *ndev;
> @@ -45,6 +50,7 @@ struct lin_device {
> struct work_struct tx_work;
> bool tx_busy;
> struct sk_buff *tx_skb;
> + enum lin_mode lmode;
> };
>
> enum lin_checksum_mode {
> @@ -71,6 +77,7 @@ struct lin_device_ops {
> int (*ldo_open)(struct lin_device *ldev);
> int (*ldo_stop)(struct lin_device *ldev);
> int (*ldo_tx)(struct lin_device *ldev, const struct lin_frame *frame);
> + int (*update_lin_mode)(struct lin_device *ldev, enum lin_mode lm);
> int (*update_bitrate)(struct lin_device *ldev, u16 bitrate);
> int (*update_responder_answer)(struct lin_device *ldev,
> const struct lin_responder_answer *answ);
> diff --git a/include/uapi/linux/can/netlink.h b/include/uapi/linux/can/netlink.h
> index a37f56d86c5f2..cc390f6444d59 100644
> --- a/include/uapi/linux/can/netlink.h
> +++ b/include/uapi/linux/can/netlink.h
> @@ -104,6 +104,7 @@ struct can_ctrlmode {
> #define CAN_CTRLMODE_TDC_AUTO 0x200 /* CAN transiver automatically calculates TDCV */
> #define CAN_CTRLMODE_TDC_MANUAL 0x400 /* TDCV is manually set up by user */
> #define CAN_CTRLMODE_LIN BIT(11) /* LIN bus mode */
> +#define CAN_CTRLMODE_LIN_COMMANDER BIT(12) /* LIN bus specific commander mode */
>
> /*
> * CAN device statistics
>
--
i.
