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
