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authorVincent Mailhol <mailhol.vincent@wanadoo.fr>2021-09-18 12:56:36 +0300
committerMarc Kleine-Budde <mkl@pengutronix.de>2021-10-24 17:24:29 +0300
commite8060f08cd69d1d692cfb9f0a2808477a501f35a (patch)
treeaba297da76c0be7c5cc43789868c46d8ca2cd245
parentd99755f71a80df33b981484f0d3bb956ed15a247 (diff)
downloadlinux-e8060f08cd69d1d692cfb9f0a2808477a501f35a.tar.xz
can: netlink: add can_priv::do_get_auto_tdcv() to retrieve tdcv from device
Some CAN device can measure the TDCV (Transmission Delay Compensation Value) automatically for each transmitted CAN frames. A callback function do_get_auto_tdcv() is added to retrieve that value. This function is used only if CAN_CTRLMODE_TDC_AUTO is enabled (if CAN_CTRLMODE_TDC_MANUAL is selected, the TDCV value is provided by the user). If the device does not support reporting of TDCV, do_get_auto_tdcv() should be set to NULL and TDCV will not be reported by the netlink interface. On success, do_get_auto_tdcv() shall return 0. If the value can not be measured by the device, for example because network is down or because no frames were transmitted yet, can_priv::do_get_auto_tdcv() shall return a negative error code (e.g. -EINVAL) to signify that the value is not yet available. In such cases, TDCV is not reported by the netlink interface. Link: https://lore.kernel.org/all/20210918095637.20108-6-mailhol.vincent@wanadoo.fr CC: Stefan Mätje <stefan.maetje@esd.eu> Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
-rw-r--r--drivers/net/can/dev/netlink.c15
-rw-r--r--include/linux/can/dev.h1
2 files changed, 13 insertions, 3 deletions
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c
index c77cc6ae88b6..95cca4e5251f 100644
--- a/drivers/net/can/dev/netlink.c
+++ b/drivers/net/can/dev/netlink.c
@@ -372,7 +372,8 @@ static size_t can_tdc_get_size(const struct net_device *dev)
}
if (can_tdc_is_enabled(priv)) {
- if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL)
+ if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL ||
+ priv->do_get_auto_tdcv)
size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCV */
size += nla_total_size(sizeof(u32)); /* IFLA_CAN_TDCO */
if (priv->tdc_const->tdcf_max)
@@ -445,8 +446,16 @@ static int can_tdc_fill_info(struct sk_buff *skb, const struct net_device *dev)
goto err_cancel;
if (can_tdc_is_enabled(priv)) {
- if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL &&
- nla_put_u32(skb, IFLA_CAN_TDC_TDCV, tdc->tdcv))
+ u32 tdcv;
+ int err = -EINVAL;
+
+ if (priv->ctrlmode & CAN_CTRLMODE_TDC_MANUAL) {
+ tdcv = tdc->tdcv;
+ err = 0;
+ } else if (priv->do_get_auto_tdcv) {
+ err = priv->do_get_auto_tdcv(dev, &tdcv);
+ }
+ if (!err && nla_put_u32(skb, IFLA_CAN_TDC_TDCV, tdcv))
goto err_cancel;
if (nla_put_u32(skb, IFLA_CAN_TDC_TDCO, tdc->tdco))
goto err_cancel;
diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
index 6dacbbb41e68..b4aa0f048cab 100644
--- a/include/linux/can/dev.h
+++ b/include/linux/can/dev.h
@@ -82,6 +82,7 @@ struct can_priv {
enum can_state *state);
int (*do_get_berr_counter)(const struct net_device *dev,
struct can_berr_counter *bec);
+ int (*do_get_auto_tdcv)(const struct net_device *dev, u32 *tdcv);
unsigned int echo_skb_max;
struct sk_buff **echo_skb;