1 // SPDX-License-Identifier: GPL-2.0
3 // Copyright (c) 2023, 2024 Pengutronix,
7 #include <linux/clocksource.h>
9 #include "rockchip_canfd.h"
11 static u64 rkcanfd_timestamp_read(const struct cyclecounter *cc)
13 const struct rkcanfd_priv *priv = container_of(cc, struct rkcanfd_priv, cc);
15 return rkcanfd_get_timestamp(priv);
18 void rkcanfd_skb_set_timestamp(const struct rkcanfd_priv *priv,
19 struct sk_buff *skb, const u32 timestamp)
21 struct skb_shared_hwtstamps *hwtstamps = skb_hwtstamps(skb);
24 ns = timecounter_cyc2time(&priv->tc, timestamp);
26 hwtstamps->hwtstamp = ns_to_ktime(ns);
29 static void rkcanfd_timestamp_work(struct work_struct *work)
31 const struct delayed_work *delayed_work = to_delayed_work(work);
32 struct rkcanfd_priv *priv;
34 priv = container_of(delayed_work, struct rkcanfd_priv, timestamp);
35 timecounter_read(&priv->tc);
37 schedule_delayed_work(&priv->timestamp, priv->work_delay_jiffies);
40 void rkcanfd_timestamp_init(struct rkcanfd_priv *priv)
42 const struct can_bittiming *dbt = &priv->can.data_bittiming;
43 const struct can_bittiming *bt = &priv->can.bittiming;
44 struct cyclecounter *cc = &priv->cc;
45 u32 bitrate, div, reg, rate;
49 /* At the standard clock rate of 300Mhz on the rk3658, the 32
50 * bit timer overflows every 14s. This means that we have to
51 * poll it quite often to avoid missing a wrap around.
53 * Divide it down to a reasonable rate, at least twice the bit
56 bitrate = max(bt->bitrate, dbt->bitrate);
57 div = min(DIV_ROUND_UP(priv->can.clock.freq, bitrate * 2),
58 FIELD_MAX(RKCANFD_REG_TIMESTAMP_CTRL_TIME_BASE_COUNTER_PRESCALE) + 1);
60 reg = FIELD_PREP(RKCANFD_REG_TIMESTAMP_CTRL_TIME_BASE_COUNTER_PRESCALE,
62 RKCANFD_REG_TIMESTAMP_CTRL_TIME_BASE_COUNTER_ENABLE;
63 rkcanfd_write(priv, RKCANFD_REG_TIMESTAMP_CTRL, reg);
65 cc->read = rkcanfd_timestamp_read;
66 cc->mask = CYCLECOUNTER_MASK(32);
68 rate = priv->can.clock.freq / div;
69 clocks_calc_mult_shift(&cc->mult, &cc->shift, rate, NSEC_PER_SEC,
70 RKCANFD_TIMESTAMP_WORK_MAX_DELAY_SEC);
72 max_cycles = div_u64(ULLONG_MAX, cc->mult);
73 max_cycles = min(max_cycles, cc->mask);
74 work_delay_ns = clocksource_cyc2ns(max_cycles, cc->mult, cc->shift);
75 priv->work_delay_jiffies = div_u64(work_delay_ns, 3u * NSEC_PER_SEC / HZ);
76 INIT_DELAYED_WORK(&priv->timestamp, rkcanfd_timestamp_work);
78 netdev_dbg(priv->ndev, "clock=%lu.%02luMHz bitrate=%lu.%02luMBit/s div=%u rate=%lu.%02luMHz mult=%u shift=%u delay=%lus\n",
79 priv->can.clock.freq / MEGA,
80 priv->can.clock.freq % MEGA / KILO / 10,
82 bitrate % MEGA / KILO / 100,
85 rate % MEGA / KILO / 10,
87 priv->work_delay_jiffies / HZ);
90 void rkcanfd_timestamp_start(struct rkcanfd_priv *priv)
92 timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
94 schedule_delayed_work(&priv->timestamp, priv->work_delay_jiffies);
97 void rkcanfd_timestamp_stop(struct rkcanfd_priv *priv)
99 cancel_delayed_work(&priv->timestamp);
102 void rkcanfd_timestamp_stop_sync(struct rkcanfd_priv *priv)
104 cancel_delayed_work_sync(&priv->timestamp);