Commit 209ff7af authored by Maxime Chevallier's avatar Maxime Chevallier Committed by Jakub Kicinski
Browse files

net: stmmac: rename devlink parameter ts_coarse into phc_coarse_adj 



The devlink param "ts_coarse" doesn't indicate that we get coarse
timestamps, but rather that the PHC clock adjusments are coarse as the
frequency won't be continuously adjusted. Adjust the devlink parameter
name to reflect that.

The Coarse terminlogy comes from the dwmac register naming, update the
documentation to better explain what the parameter is about.

With this change, the parameter can now be adjusted using:
  devlink dev param set <dev> name phc_coarse_adj value true cmode runtime

Signed-off-by: default avatarMaxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20251030182454.182406-1-maxime.chevallier@bootlin.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 22795871

Documentation/networking/devlink/stmmac.rst

+15 −6
Original line number Diff line number Diff line
@@ -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

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

+1 −1
Original line number Diff line number Diff line
@@ -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,