mcp251xfd-timestamp.c

 1// SPDX-License-Identifier: GPL-2.0
 2//
 3// mcp251xfd - Microchip MCP251xFD Family CAN controller driver
 4//
 5// Copyright (c) 2021, 2023 Pengutronix,
 6//               Marc Kleine-Budde <kernel@pengutronix.de>
 7//
 8
 9#include <linux/clocksource.h>
10#include <linux/workqueue.h>
11
12#include "mcp251xfd.h"
13
14static u64 mcp251xfd_timestamp_raw_read(struct cyclecounter *cc)
15{
16	const struct mcp251xfd_priv *priv;
17	u32 ts_raw = 0;
18	int err;
19
20	priv = container_of(cc, struct mcp251xfd_priv, cc);
21	err = mcp251xfd_get_timestamp_raw(priv, &ts_raw);
22	if (err)
23		netdev_err(priv->ndev,
24			   "Error %d while reading timestamp. HW timestamps may be inaccurate.",
25			   err);
26
27	return ts_raw;
28}
29
30static void mcp251xfd_timestamp_work(struct work_struct *work)
31{
32	struct delayed_work *delayed_work = to_delayed_work(work);
33	struct mcp251xfd_priv *priv;
34
35	priv = container_of(delayed_work, struct mcp251xfd_priv, timestamp);
36	timecounter_read(&priv->tc);
37
38	schedule_delayed_work(&priv->timestamp,
39			      MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
40}
41
42void mcp251xfd_timestamp_init(struct mcp251xfd_priv *priv)
43{
44	struct cyclecounter *cc = &priv->cc;
45
46	cc->read = mcp251xfd_timestamp_raw_read;
47	cc->mask = CYCLECOUNTER_MASK(32);
48	cc->shift = 1;
49	cc->mult = clocksource_hz2mult(priv->can.clock.freq, cc->shift);
50
51	INIT_DELAYED_WORK(&priv->timestamp, mcp251xfd_timestamp_work);
52}
53
54void mcp251xfd_timestamp_start(struct mcp251xfd_priv *priv)
55{
56	timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
57	schedule_delayed_work(&priv->timestamp,
58			      MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
59}
60
61void mcp251xfd_timestamp_stop(struct mcp251xfd_priv *priv)
62{
63	cancel_delayed_work_sync(&priv->timestamp);
64}