On 11/10/20 11:18 AM, Oliver Hartkopp wrote:
> can_get_cc_dlc: get the data length code for Classical CAN raw DLC access
> can_get_cc_len: get len and len8_dlc value for Classical CAN raw DLC access
The final patch needs a bit more prose, like:
This patch adds the following helper to functions to access Classical CAN DLC
values.
> Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
> ---
> include/linux/can/dev.h | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/include/linux/can/dev.h b/include/linux/can/dev.h
> index e767a96ae075..9a787f73399e 100644
> --- a/include/linux/can/dev.h
> +++ b/include/linux/can/dev.h
> @@ -168,10 +168,38 @@ static inline bool can_is_canfd_skb(const struct sk_buff *skb)
> {
> /* the CAN specific type of skb is identified by its data length */
> return skb->len == CANFD_MTU;
> }
>
> +/* helper to get the data length code (DLC) for Classical CAN raw DLC access */
> +static inline u8 can_get_cc_dlc(const u32 ctrlmode, const struct can_frame *cf)
Please make the cf the first argument.
> +{
> + /* return len8_dlc as dlc value only if all conditions apply */
> + if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) &&
> + (cf->len == CAN_MAX_DLEN) &&
> + (cf->len8_dlc > CAN_MAX_DLEN && cf->len8_dlc <= CAN_MAX_RAW_DLC))
> + return cf->len8_dlc;
> +
> + /* return the payload length as dlc value */
> + return cf->len;
> +}
> +
> +/* helper to get len and len8_dlc value for Classical CAN raw DLC access */
> +static inline u8 can_get_cc_len(const u32 ctrlmode, struct can_frame *cf,
> + u8 dlc)
Please make the cf the first argument.
> +{
> + /* the caller already ensured that dlc is a value from 0 .. 15 */
> + if ((ctrlmode & CAN_CTRLMODE_CC_LEN8_DLC) && (dlc > CAN_MAX_DLEN))
> + cf->len8_dlc = dlc;
> +
> + /* limit the payload length 'len' to CAN_MAX_DLEN */
> + if (dlc > CAN_MAX_DLEN)
> + return CAN_MAX_DLEN;
can_cc_dlc2len()
I still think, that can_frame_set_cc_len() makes more sense. See my just posted
patches for illustration.
> +
> + return dlc;
> +}
> +
> /* helper to define static CAN controller features at device creation time */
> static inline void can_set_static_ctrlmode(struct net_device *dev,
> u32 static_mode)
> {
> struct can_priv *priv = netdev_priv(dev);
>
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Embedded Linux | https://www.pengutronix.de |
Vertretung West/Dortmund | Phone: +49-231-2826-924 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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