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 
14 static u64 mcp251xfd_timestamp_raw_read(const 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 
30 static 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 
42 void 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 	timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
52 
53 	INIT_DELAYED_WORK(&priv->timestamp, mcp251xfd_timestamp_work);
54 	schedule_delayed_work(&priv->timestamp,
55 			      MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
56 }
57 
58 void mcp251xfd_timestamp_stop(struct mcp251xfd_priv *priv)
59 {
60 	cancel_delayed_work_sync(&priv->timestamp);
61 }
62