Quelle  mcp251xfd-timestamp.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
//
// mcp251xfd - Microchip MCP251xFD Family CAN controller driver
//
// Copyright (c) 2021, 2023 Pengutronix,
//               Marc Kleine-Budde <kernel@pengutronix.de>
//

#include <linux/clocksource.h>
#include <linux/workqueue.h>

#include "mcp251xfd.h"

static u64 mcp251xfd_timestamp_raw_read(struct cyclecounter *cc)
{
 const struct mcp251xfd_priv *priv;
 u32 ts_raw = 0;
 int err;

 priv = container_of(cc, struct mcp251xfd_priv, cc);
 err = mcp251xfd_get_timestamp_raw(priv, &ts_raw);
 if (err)
  netdev_err(priv->ndev,
      "Error %d while reading timestamp. HW timestamps may be inaccurate.",
      err);

 return ts_raw;
}

static void mcp251xfd_timestamp_work(struct work_struct *work)
{
 struct delayed_work *delayed_work = to_delayed_work(work);
 struct mcp251xfd_priv *priv;

 priv = container_of(delayed_work, struct mcp251xfd_priv, timestamp);
 timecounter_read(&priv->tc);

 schedule_delayed_work(&priv->timestamp,
         MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
}

void mcp251xfd_timestamp_init(struct mcp251xfd_priv *priv)
{
 struct cyclecounter *cc = &priv->cc;

 cc->read = mcp251xfd_timestamp_raw_read;
 cc->mask = CYCLECOUNTER_MASK(32);
 cc->shift = 1;
 cc->mult = clocksource_hz2mult(priv->can.clock.freq, cc->shift);

 INIT_DELAYED_WORK(&priv->timestamp, mcp251xfd_timestamp_work);
}

void mcp251xfd_timestamp_start(struct mcp251xfd_priv *priv)
{
 timecounter_init(&priv->tc, &priv->cc, ktime_get_real_ns());
 schedule_delayed_work(&priv->timestamp,
         MCP251XFD_TIMESTAMP_WORK_DELAY_SEC * HZ);
}

void mcp251xfd_timestamp_stop(struct mcp251xfd_priv *priv)
{
 cancel_delayed_work_sync(&priv->timestamp);
}