Subject: [PATCH net-next 0/4] igb: support PEROUT and EXTTS PTP pin functions on 82580/i354/i350

From: Ruud Bos <[email-masked]>
Date: Wed, 6 Oct 2021 14:58:21 +0200

The igb driver provides support for PEROUT and EXTTS pin functions that
allow adapter external use of timing signals. At Hottinger Bruel & Kjaer we
are using the PEROUT function to feed a PTP corrected 1pps signal into an
FPGA as cross system synchronized time source.

Support for the PEROUT and EXTTS SDP functions is currently limited to
i210/i211 based adapters. This patch series enables these functions also
for 82580/i354/i350 based ones. Because the time registers of these
adapters do not have the nice split in second rollovers as the i210 has,
the implementation is slightly more complex compared to the i210
implementation.

The PEROUT function has been successfully tested on an i350 based ethernet
adapter. Using the following user space code excerpt, the driver outputs a
PTP corrected 1pps signal on the SDP0 pin of an i350:

    struct ptp_pin_desc desc;
    memset(&desc, 0, sizeof(desc));
    desc.index = 0;
    desc.func = PTP_PF_PEROUT;
    desc.chan = 0;
    if (ioctl(fd, PTP_PIN_SETFUNC, &desc) == 0) {
        struct timespec ts;
        if (clock_gettime(clkid, &ts) == 0) {
            struct ptp_perout_request rq;
            memset(&rq, 0, sizeof(rq));
            rq.index = 0;
            rq.start.sec = ts.tv_sec + 1;
            rq.start.nsec = 500000000;
            rq.period.sec  = 1;
            rq.period.nsec = 0;
            if (ioctl(fd, PTP_PEROUT_REQUEST, &rq) == 0) {
                /* 1pps signal is now available on SDP0 */
            }
        }
    }

The added EXTTS function has not been tested. However, looking at the data
sheets, the layout of the registers involved match the i210 exactly except
for the time registers mentioned before. Hence the almost identical
implementation.

Ruud Bos (4):
  igb: move SDP config initialization to separate function
  igb: move PEROUT and EXTTS isr logic to separate functions
  igb: support PEROUT on 82580/i354/i350
  support EXTTS on 82580/i354/i350

 drivers/net/ethernet/intel/igb/igb_main.c | 141 ++++++++++++-----
 drivers/net/ethernet/intel/igb/igb_ptp.c  | 183 ++++++++++++++++++++--
 2 files changed, 279 insertions(+), 45 deletions(-)

-- 
2.30.2