A LIN node can work as commander or responder. This patch is introducing a new control mode (CAN_CTRLMODE_LIN_COMMANDER), so that e.g. the ip tool from iproute2 can 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 56492952c8588..472cadc87ad86 100644 --- a/drivers/net/can/lin.c +++ b/drivers/net/can/lin.c @@ -254,11 +254,40 @@ 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"); + return -EINVAL; + } + ret = ldev->ldev_ops->update_lin_mode(ldev, lm); + if (ret) { + netdev_err(ndev, "Failed to set lin mode: %d\n", ret); + 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); @@ -437,7 +466,7 @@ struct lin_device *register_lin(struct device *dev, ndev->mtu = CANFD_MTU; 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; @@ -452,6 +481,15 @@ 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"); + 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 3f78cfda9c657..4f064a2ce2ca8 100644 --- a/include/net/lin.h +++ b/include/net/lin.h @@ -44,6 +44,11 @@ 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; @@ -55,6 +60,7 @@ struct lin_device { struct sk_buff *tx_skb; struct kobject *lin_ids_kobj; struct lin_attr sysfs_entries[LIN_NUM_IDS]; + enum lin_mode lmode; }; enum lin_checksum_mode { @@ -79,6 +85,7 @@ struct lin_responder_answer { struct lin_device_ops { 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 51b0e2a7624e4..6c84a7666c646 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 0x800 /* LIN bus mode */ +#define CAN_CTRLMODE_LIN_COMMANDER 0x1000 /* LIN bus specific commander mode */ /* * CAN device statistics -- 2.39.2