On Tue Aug 18 2020, Russell King wrote:
> On Tue, Aug 18, 2020 at 12:32:44PM +0200, Kurt Kanzenbach wrote:
>> The message type is located at different offsets within the ptp header
>> depending
>> on the ptp version (v1 or v2). Therefore, drivers which also deal with ptp v1
>> have some code for it.
>>
>> Extract this into a helper function for drivers to be used.
>>
>> Signed-off-by: Kurt Kanzenbach <k...@linutronix.de>
>> Reviewed-by: Richard Cochran <richardcoch...@gmail.com>
>> Reviewed-by: Florian Fainelli <f.faine...@gmail.com>
>> ---
>> include/linux/ptp_classify.h | 25 +++++++++++++++++++++++++
>> 1 file changed, 25 insertions(+)
>>
>> diff --git a/include/linux/ptp_classify.h b/include/linux/ptp_classify.h
>> index 996f31e8f35d..39bad015d1d6 100644
>> --- a/include/linux/ptp_classify.h
>> +++ b/include/linux/ptp_classify.h
>> @@ -96,6 +96,31 @@ unsigned int ptp_classify_raw(const struct sk_buff *skb);
>> */
>> struct ptp_header *ptp_parse_header(struct sk_buff *skb, unsigned int type);
>>
>> +/**
>> + * ptp_get_msgtype - Extract ptp message type from given header
>> + * @hdr: ptp header
>> + * @type: type of the packet (see ptp_classify_raw())
>> + *
>> + * This function returns the message type for a given ptp header. It takes
>> care
>> + * of the different ptp header versions (v1 or v2).
>> + *
>> + * Return: The message type
>> + */
>> +static inline u8 ptp_get_msgtype(const struct ptp_header *hdr,
>> + unsigned int type)
>> +{
>> + u8 msgtype;
>> +
>> + if (unlikely(type & PTP_CLASS_V1)) {
>> + /* msg type is located at the control field for ptp v1 */
>> + msgtype = hdr->control;
>> + } else {
>> + msgtype = hdr->tsmt & 0x0f;
>> + }
>> +
>> + return msgtype;
>> +}
>
> Are there 256 different message types in V1?There are only a few messages in PTP V1. But, the control field which indicates the message type is a byte whereas in PTP v2 it's a nibble. Thanks, Kurt
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