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 
mcp251xfd_timestamp_read(const struct cyclecounter * cc)14 static 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 
mcp251xfd_timestamp_work(struct work_struct * work)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 
mcp251xfd_skb_set_timestamp(const struct mcp251xfd_priv * priv,struct sk_buff * skb,u32 timestamp)42 void 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 
mcp251xfd_timestamp_init(struct mcp251xfd_priv * priv)52 void 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 
mcp251xfd_timestamp_stop(struct mcp251xfd_priv * priv)68 void mcp251xfd_timestamp_stop(struct mcp251xfd_priv *priv)
69 {
70 	cancel_delayed_work_sync(&priv->timestamp);
71 }
72