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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: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20251030182454.182406-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Maxime Chevallier 2025-10-30 19:24:53 +01:00 committed by Jakub Kicinski
parent 22795871ed
commit 209ff7af79
2 changed files with 16 additions and 7 deletions
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21
Documentation/networking/devlink/stmmac.rst
View File

@ -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

2
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
View File

@ -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,