xref: /linux/Documentation/networking/devlink/stmmac.rst (revision 4d07797faaa19aa8e80e10a04ca1a72c643ef5cf)
1.. SPDX-License-Identifier: GPL-2.0
2
3=======================================
4stmmac (synopsys dwmac) devlink support
5=======================================
6
7This document describes the devlink features implemented by the ``stmmac``
8device driver.
9
10Parameters
11==========
12
13The ``stmmac`` driver implements the following driver-specific parameters.
14
15.. list-table:: Driver-specific parameters implemented
16   :widths: 5 5 5 85
17
18   * - Name
19     - Type
20     - Mode
21     - Description
22   * - ``ts_coarse``
23     - Boolean
24     - runtime
25     - Enable the Coarse timestamping mode. In Coarse mode, the ptp clock is
26       expected to be updated through an external PPS input, but the subsecond
27       increment used for timestamping is set to 1/ptp_clock_rate. In Fine mode
28       (i.e. Coarse mode == false), the ptp clock frequency is adjusted more
29       frequently, but the subsecond increment is set to 2/ptp_clock_rate.
30       Coarse mode is suitable for PTP Grand Master operation. If unsure, leave
31       the parameter to False.
32