#define SJA1105_MAX_ADJ_PPB 32000000
#define SJA1105_SIZE_PTP_CMD 4
-/* Timestamps are in units of 8 ns clock ticks (equivalent to a fixed
- * 125 MHz clock) so the scale factor (MULT / SHIFT) needs to be 8.
- * Furthermore, wisely pick SHIFT as 28 bits, which translates
- * MULT into 2^31 (0x80000000). This is the same value around which
- * the hardware PTPCLKRATE is centered, so the same ppb conversion
- * arithmetic can be reused.
- */
-#define SJA1105_CC_SHIFT 28
-#define SJA1105_CC_MULT (8 << SJA1105_CC_SHIFT)
-
-/* Having 33 bits of cycle counter left until a 64-bit overflow during delta
- * conversion, we multiply this by the 8 ns counter resolution and arrive at
- * a comfortable 68.71 second refresh interval until the delta would cause
- * an integer overflow, in absence of any other readout.
- * Approximate to 1 minute.
- */
-#define SJA1105_REFRESH_INTERVAL (HZ * 60)
-
/* This range is actually +/- SJA1105_MAX_ADJ_PPB
* divided by 1000 (ppb -> ppm) and with a 16-bit
* "fractional" part (actually fixed point).
*
* This forgoes a "ppb" numeric representation (up to NSEC_PER_SEC)
* and defines the scaling factor between scaled_ppm and the actual
- * frequency adjustments (both cycle counter and hardware).
+ * frequency adjustments of the PHC.
*
* ptpclkrate = scaled_ppm * 2^31 / (10^6 * 2^16)
* simplifies to
*/
#define SJA1105_CC_MULT_NUM (1 << 9)
#define SJA1105_CC_MULT_DEM 15625
+#define SJA1105_CC_MULT 0x80000000
+
+enum sja1105_ptp_clk_mode {
+ PTP_ADD_MODE = 1,
+ PTP_SET_MODE = 0,
+};
#define ptp_caps_to_data(d) \
container_of((d), struct sja1105_ptp_data, caps)
-#define cc_to_ptp_data(d) \
- container_of((d), struct sja1105_ptp_data, tstamp_cc)
-#define dw_to_ptp_data(d) \
- container_of((d), struct sja1105_ptp_data, refresh_work)
#define ptp_data_to_sja1105(d) \
container_of((d), struct sja1105_private, ptp_data)
sja1105_pack(buf, &valid, 31, 31, size);
sja1105_pack(buf, &cmd->resptp, 2, 2, size);
+ sja1105_pack(buf, &cmd->corrclk4ts, 1, 1, size);
+ sja1105_pack(buf, &cmd->ptpclkadd, 0, 0, size);
return sja1105_xfer_buf(priv, SPI_WRITE, regs->ptp_control, buf,
SJA1105_SIZE_PTP_CMD);
sja1105_pack(buf, &valid, 31, 31, size);
sja1105_pack(buf, &cmd->resptp, 3, 3, size);
+ sja1105_pack(buf, &cmd->corrclk4ts, 2, 2, size);
+ sja1105_pack(buf, &cmd->ptpclkadd, 0, 0, size);
return sja1105_xfer_buf(priv, SPI_WRITE, regs->ptp_control, buf,
SJA1105_SIZE_PTP_CMD);
return 0;
}
+/* Caller must hold ptp_data->lock */
+static int sja1105_ptpclkval_read(struct sja1105_private *priv, u64 *ticks)
+{
+ const struct sja1105_regs *regs = priv->info->regs;
+
+ return sja1105_xfer_u64(priv, SPI_READ, regs->ptpclkval, ticks);
+}
+
+/* Caller must hold ptp_data->lock */
+static int sja1105_ptpclkval_write(struct sja1105_private *priv, u64 ticks)
+{
+ const struct sja1105_regs *regs = priv->info->regs;
+
+ return sja1105_xfer_u64(priv, SPI_WRITE, regs->ptpclkval, &ticks);
+}
+
#define rxtstamp_to_tagger(d) \
container_of((d), struct sja1105_tagger_data, rxtstamp_work)
#define tagger_to_sja1105(d) \
while ((skb = skb_dequeue(&tagger_data->skb_rxtstamp_queue)) != NULL) {
struct skb_shared_hwtstamps *shwt = skb_hwtstamps(skb);
- u64 now, ts;
+ u64 ticks, ts;
+ int rc;
- now = ptp_data->tstamp_cc.read(&ptp_data->tstamp_cc);
+ rc = sja1105_ptpclkval_read(priv, &ticks);
+ if (rc < 0) {
+ dev_err(ds->dev, "Failed to read PTP clock: %d\n", rc);
+ kfree_skb(skb);
+ continue;
+ }
*shwt = (struct skb_shared_hwtstamps) {0};
ts = SJA1105_SKB_CB(skb)->meta_tstamp;
- ts = sja1105_tstamp_reconstruct(ds, now, ts);
- ts = timecounter_cyc2time(&ptp_data->tstamp_tc, ts);
+ ts = sja1105_tstamp_reconstruct(ds, ticks, ts);
- shwt->hwtstamp = ns_to_ktime(ts);
+ shwt->hwtstamp = ns_to_ktime(sja1105_ticks_to_ns(ts));
netif_rx_ni(skb);
}
dev_dbg(ds->dev, "Resetting PTP clock\n");
rc = priv->info->ptp_cmd(ds, &cmd);
- timecounter_init(&ptp_data->tstamp_tc, &ptp_data->tstamp_cc,
- ktime_to_ns(ktime_get_real()));
-
mutex_unlock(&ptp_data->lock);
return rc;
struct timespec64 *ts)
{
struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
- u64 ns;
+ struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
+ u64 ticks = 0;
+ int rc;
mutex_lock(&ptp_data->lock);
- ns = timecounter_read(&ptp_data->tstamp_tc);
+
+ rc = sja1105_ptpclkval_read(priv, &ticks);
+ *ts = ns_to_timespec64(sja1105_ticks_to_ns(ticks));
+
mutex_unlock(&ptp_data->lock);
- *ts = ns_to_timespec64(ns);
+ return rc;
+}
- return 0;
+/* Caller must hold ptp_data->lock */
+static int sja1105_ptp_mode_set(struct sja1105_private *priv,
+ enum sja1105_ptp_clk_mode mode)
+{
+ struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
+
+ if (ptp_data->cmd.ptpclkadd == mode)
+ return 0;
+
+ ptp_data->cmd.ptpclkadd = mode;
+
+ return priv->info->ptp_cmd(priv->ds, &ptp_data->cmd);
}
+/* Write to PTPCLKVAL while PTPCLKADD is 0 */
static int sja1105_ptp_settime(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
- u64 ns = timespec64_to_ns(ts);
+ struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
+ u64 ticks = ns_to_sja1105_ticks(timespec64_to_ns(ts));
+ int rc;
mutex_lock(&ptp_data->lock);
- timecounter_init(&ptp_data->tstamp_tc, &ptp_data->tstamp_cc, ns);
+
+ rc = sja1105_ptp_mode_set(priv, PTP_SET_MODE);
+ if (rc < 0) {
+ dev_err(priv->ds->dev, "Failed to put PTPCLK in set mode\n");
+ goto out;
+ }
+
+ rc = sja1105_ptpclkval_write(priv, ticks);
+out:
mutex_unlock(&ptp_data->lock);
- return 0;
+ return rc;
}
static int sja1105_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
+ const struct sja1105_regs *regs = priv->info->regs;
+ u32 clkrate32;
s64 clkrate;
+ int rc;
clkrate = (s64)scaled_ppm * SJA1105_CC_MULT_NUM;
clkrate = div_s64(clkrate, SJA1105_CC_MULT_DEM);
- mutex_lock(&ptp_data->lock);
+ /* Take a +/- value and re-center it around 2^31. */
+ clkrate = SJA1105_CC_MULT + clkrate;
+ WARN_ON(abs(clkrate) >= GENMASK_ULL(31, 0));
+ clkrate32 = clkrate;
- /* Force a readout to update the timer *before* changing its frequency.
- *
- * This way, its corrected time curve can at all times be modeled
- * as a linear "A * x + B" function, where:
- *
- * - B are past frequency adjustments and offset shifts, all
- * accumulated into the cycle_last variable.
- *
- * - A is the new frequency adjustments we're just about to set.
- *
- * Reading now makes B accumulate the correct amount of time,
- * corrected at the old rate, before changing it.
- *
- * Hardware timestamps then become simple points on the curve and
- * are approximated using the above function. This is still better
- * than letting the switch take the timestamps using the hardware
- * rate-corrected clock (PTPCLKVAL) - the comparison in this case would
- * be that we're shifting the ruler at the same time as we're taking
- * measurements with it.
- *
- * The disadvantage is that it's possible to receive timestamps when
- * a frequency adjustment took place in the near past.
- * In this case they will be approximated using the new ppb value
- * instead of a compound function made of two segments (one at the old
- * and the other at the new rate) - introducing some inaccuracy.
- */
- timecounter_read(&ptp_data->tstamp_tc);
+ mutex_lock(&ptp_data->lock);
- ptp_data->tstamp_cc.mult = SJA1105_CC_MULT + clkrate;
+ rc = sja1105_xfer_u32(priv, SPI_WRITE, regs->ptpclkrate, &clkrate32);
mutex_unlock(&ptp_data->lock);
- return 0;
+ return rc;
}
+/* Write to PTPCLKVAL while PTPCLKADD is 1 */
static int sja1105_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
-
- mutex_lock(&ptp_data->lock);
- timecounter_adjtime(&ptp_data->tstamp_tc, delta);
- mutex_unlock(&ptp_data->lock);
-
- return 0;
-}
-
-static u64 sja1105_ptptsclk_read(const struct cyclecounter *cc)
-{
- struct sja1105_ptp_data *ptp_data = cc_to_ptp_data(cc);
struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
- const struct sja1105_regs *regs = priv->info->regs;
- u64 ptptsclk = 0;
+ s64 ticks = ns_to_sja1105_ticks(delta);
int rc;
- rc = sja1105_xfer_u64(priv, SPI_READ, regs->ptptsclk, &ptptsclk);
- if (rc < 0)
- dev_err_ratelimited(priv->ds->dev,
- "failed to read ptp cycle counter: %d\n",
- rc);
- return ptptsclk;
-}
+ mutex_lock(&ptp_data->lock);
-static void sja1105_ptp_overflow_check(struct work_struct *work)
-{
- struct delayed_work *dw = to_delayed_work(work);
- struct sja1105_ptp_data *ptp_data = dw_to_ptp_data(dw);
- struct timespec64 ts;
+ rc = sja1105_ptp_mode_set(priv, PTP_ADD_MODE);
+ if (rc < 0) {
+ dev_err(priv->ds->dev, "Failed to put PTPCLK in add mode\n");
+ goto out;
+ }
- sja1105_ptp_gettime(&ptp_data->caps, &ts);
+ rc = sja1105_ptpclkval_write(priv, ticks);
- schedule_delayed_work(&ptp_data->refresh_work,
- SJA1105_REFRESH_INTERVAL);
+out:
+ mutex_unlock(&ptp_data->lock);
+
+ return rc;
}
int sja1105_ptp_clock_register(struct dsa_switch *ds)
struct sja1105_tagger_data *tagger_data = &priv->tagger_data;
struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
- /* Set up the cycle counter */
- ptp_data->tstamp_cc = (struct cyclecounter) {
- .read = sja1105_ptptsclk_read,
- .mask = CYCLECOUNTER_MASK(64),
- .shift = SJA1105_CC_SHIFT,
- .mult = SJA1105_CC_MULT,
- };
ptp_data->caps = (struct ptp_clock_info) {
.owner = THIS_MODULE,
.name = "SJA1105 PHC",
if (IS_ERR_OR_NULL(ptp_data->clock))
return PTR_ERR(ptp_data->clock);
- INIT_DELAYED_WORK(&ptp_data->refresh_work, sja1105_ptp_overflow_check);
- schedule_delayed_work(&ptp_data->refresh_work, SJA1105_REFRESH_INTERVAL);
+ ptp_data->cmd.corrclk4ts = true;
+ ptp_data->cmd.ptpclkadd = PTP_SET_MODE;
return sja1105_ptp_reset(ds);
}
cancel_work_sync(&priv->tagger_data.rxtstamp_work);
skb_queue_purge(&priv->tagger_data.skb_rxtstamp_queue);
- cancel_delayed_work_sync(&ptp_data->refresh_work);
ptp_clock_unregister(ptp_data->clock);
ptp_data->clock = NULL;
}
struct sja1105_private *priv = ds->priv;
struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
struct skb_shared_hwtstamps shwt = {0};
- u64 now, ts;
+ u64 ticks, ts;
int rc;
skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
mutex_lock(&ptp_data->lock);
- now = ptp_data->tstamp_cc.read(&ptp_data->tstamp_cc);
+ rc = sja1105_ptpclkval_read(priv, &ticks);
+ if (rc < 0) {
+ dev_err(ds->dev, "Failed to read PTP clock: %d\n", rc);
+ kfree_skb(skb);
+ goto out;
+ }
rc = sja1105_ptpegr_ts_poll(ds, slot, &ts);
if (rc < 0) {
goto out;
}
- ts = sja1105_tstamp_reconstruct(ds, now, ts);
- ts = timecounter_cyc2time(&ptp_data->tstamp_tc, ts);
+ ts = sja1105_tstamp_reconstruct(ds, ticks, ts);
- shwt.hwtstamp = ns_to_ktime(ts);
+ shwt.hwtstamp = ns_to_ktime(sja1105_ticks_to_ns(ts));
skb_complete_tx_timestamp(skb, &shwt);
out:
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