1// SPDX-License-Identifier: GPL-2.0
2//
3// mcp251xfd - Microchip MCP251xFD Family CAN controller driver
4//
5// Copyright (c) 2021 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_read(const struct cyclecounter *cc)
15{
16	const struct mcp251xfd_priv *priv;
17	u32 timestamp = 0;
18	int err;
19
20	priv = container_of(cc, struct mcp251xfd_priv, cc);
21	err = mcp251xfd_get_timestamp(priv, &timestamp);
22	if (err)
23		netdev_err(priv->ndev,
24			   "Error %d while reading timestamp. HW timestamps may be inaccurate.",
25			   err);
26
27	return timestamp;
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_skb_set_timestamp(const struct mcp251xfd_priv *priv,
43				 struct sk_buff *skb, u32 timestamp)
44{
45	struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
46	u64 ns;
47
48	ns = timecounter_cyc2time(&priv->tc, timestamp);
49	hwtstamps->hwtstamp = ns_to_ktime(ns);
50}
51
52void mcp251xfd_timestamp_init(struct mcp251xfd_priv *priv)
53{
54	struct cyclecounter *cc = &priv->cc;
55
56	cc->read = mcp251xfd_timestamp_read;
57	cc->mask = CYCLECOUNTER_MASK(32);
58	cc->shift = 1;
59	cc->mult = clocksource_hz2mult(priv->can.clock.freq, cc->shift);
60
61	timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
62
63	INIT_DELAYED_WORK(&priv->timestamp, mcp251xfd_timestamp_work);
64	schedule_delayed_work(&priv->timestamp,
65			      MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
66}
67
68void mcp251xfd_timestamp_stop(struct mcp251xfd_priv *priv)
69{
70	cancel_delayed_work_sync(&priv->timestamp);
71}
72