can_tdc_get_size() needs to access can_priv->fd making it specific to
CAN FD. Change the function parameter from struct can_priv to struct
data_bittiming_params.

can_tdc_get_size() also uses the CAN_CTRLMODE_TDC_MANUAL macro making
it specific to CAN FD. Add the tdc mask to the function parameter
list. The value of the tdc manual flag can then be derived from that
mask and stored in a local variable.

This way, the function becomes CAN FD agnostic and can be reused later
on for the CAN XL TDC.

Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
---
Changelog:

v1 -> v2:

  - Small rewrite of the patch description adding one more paragraph
    with further details.
---
 drivers/net/can/dev/netlink.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index e1a1767c0a6cfeeb06b7d53f9ec4c48d76387b62..3c0675877f5ef84a2b84d5852a0e91d23b164eeb 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -472,32 +472,32 @@ static int can_changelink(struct net_device *dev, struct nlattr *tb[],
 	return 0;
 }
 
-static size_t can_tdc_get_size(const struct net_device *dev)
+static size_t can_tdc_get_size(struct data_bittiming_params *dbt_params,
+			       u32 tdc_flags)
 {
-	struct can_priv *priv = netdev_priv(dev);
+	bool tdc_manual = tdc_flags & CAN_CTRLMODE_TDC_MANUAL_MASK;
 	size_t size;
 
-	if (!priv->fd.tdc_const)
+	if (!dbt_params->tdc_const)
 		return 0;
 
 	size = nla_total_size(0);			/* nest IFLA_CAN_TDC */
-	if (priv->ctrlmode_supported & CAN_CTRLMODE_TDC_MANUAL) {
+	if (tdc_manual) {
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCV_MIN */
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCV_MAX */
 	}
 	size += nla_total_size(sizeof(u32));		/* IFLA_CAN_TDCO_MIN */
 	size += nla_total_size(sizeof(u32));		/* IFLA_CAN_TDCO_MAX */
-	if (priv->fd.tdc_const->tdcf_max) {
+	if (dbt_params->tdc_const->tdcf_max) {
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCF_MIN */
 		size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCF_MAX */
 	}
 
-	if (can_fd_tdc_is_enabled(priv)) {
-		if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL ||
-		    priv->fd.do_get_auto_tdcv)
+	if (tdc_flags) {
+		if (tdc_manual || dbt_params->do_get_auto_tdcv)
 			size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCV */
 		size += nla_total_size(sizeof(u32));		/* IFLA_CAN_TDCO */
-		if (priv->fd.tdc_const->tdcf_max)
+		if (dbt_params->tdc_const->tdcf_max)
 			size += nla_total_size(sizeof(u32));	/* IFLA_CAN_TDCF */
 	}
 
@@ -541,7 +541,8 @@ static size_t can_get_size(const struct net_device *dev)
 		size += nla_total_size(sizeof(*priv->fd.data_bitrate_const) *
 				       priv->fd.data_bitrate_const_cnt);
 	size += sizeof(priv->bitrate_max);			/* IFLA_CAN_BITRATE_MAX */
-	size += can_tdc_get_size(dev);				/* IFLA_CAN_TDC */
+	size += can_tdc_get_size(&priv->fd,			/* IFLA_CAN_TDC */
+				 priv->ctrlmode & CAN_CTRLMODE_FD_TDC_MASK);
 	size += can_ctrlmode_ext_get_size();			/* IFLA_CAN_CTRLMODE_EXT */
 
 	return size;

-- 
2.49.1