diff options
| -rw-r--r-- | Documentation/networking/devlink/stmmac.rst | 21 | ||||
| -rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 2 |
2 files changed, 16 insertions, 7 deletions
diff --git a/Documentation/networking/devlink/stmmac.rst b/Documentation/networking/devlink/stmmac.rst index e8e33d1c7baf..47e3ff10bc08 100644 --- a/Documentation/networking/devlink/stmmac.rst +++ b/Documentation/networking/devlink/stmmac.rst @@ -19,13 +19,22 @@ The ``stmmac`` driver implements the following driver-specific parameters. - Type - Mode - Description - * - ``ts_coarse`` + * - ``phc_coarse_adj`` - Boolean - runtime - - Enable the Coarse timestamping mode. In Coarse mode, the ptp clock is - expected to be updated through an external PPS input, but the subsecond - increment used for timestamping is set to 1/ptp_clock_rate. In Fine mode - (i.e. Coarse mode == false), the ptp clock frequency is adjusted more - frequently, but the subsecond increment is set to 2/ptp_clock_rate. + - Enable the Coarse timestamping mode, as defined in the DWMAC TRM. + A detailed explanation of this timestamping mode can be found in the + Socfpga Functionnal Description [1]. + + In Coarse mode, the ptp clock is expected to be fed by a high-precision + clock that is externally adjusted, and the subsecond increment used for + timestamping is set to 1/ptp_clock_rate. + + In Fine mode (i.e. Coarse mode == false), the ptp clock frequency is + continuously adjusted, but the subsecond increment is set to + 2/ptp_clock_rate. + Coarse mode is suitable for PTP Grand Master operation. If unsure, leave the parameter to False. + + [1] https://www.intel.com/content/www/us/en/docs/programmable/683126/21-2/functional-description-of-the-emac.html diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 1e69c1a7dc6c..c2a783c8022d 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -7445,7 +7445,7 @@ static int stmmac_dl_ts_coarse_get(struct devlink *dl, u32 id, } static const struct devlink_param stmmac_devlink_params[] = { - DEVLINK_PARAM_DRIVER(STMMAC_DEVLINK_PARAM_ID_TS_COARSE, "ts_coarse", + DEVLINK_PARAM_DRIVER(STMMAC_DEVLINK_PARAM_ID_TS_COARSE, "phc_coarse_adj", DEVLINK_PARAM_TYPE_BOOL, BIT(DEVLINK_PARAM_CMODE_RUNTIME), stmmac_dl_ts_coarse_get, |