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authorDavid S. Miller <davem@davemloft.net>2014-10-14 14:45:17 -0400
committerDavid S. Miller <davem@davemloft.net>2014-10-14 14:45:17 -0400
commitf787d6c8dd52ded9874cbbc447a32515c80fa2bf (patch)
tree57cb9578e7e20ab6700a715e67834d08b399a11a /drivers
parent02ea80741a25435123e8a5ca40cac6a0bcf0c9f1 (diff)
parent278d24047891a1bf4a98128eaa8ecafd019e58c2 (diff)
Merge branch 'fec-ptp'
Luwei Zhou says: ==================== Enable FEC pps feather Change from v2 to v3: -Using the default channel 0 to be PPS channel not PTP_PIN_SET/GETFUNC interface. -Using the linux definition of NSEC_PER_SEC. Change from v1 to v2: - Fix the potential 32-bit multiplication overflow issue. - Optimize the hareware adjustment code to improve efficiency as Richard suggested - Use ptp PTP_PIN_SET/GETFUNC interface to set PPS channel not device tree and add PTP_PF_PPS enumeration - Modify comments style ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/ethernet/freescale/fec.h10
-rw-r--r--drivers/net/ethernet/freescale/fec_main.c2
-rw-r--r--drivers/net/ethernet/freescale/fec_ptp.c272
3 files changed, 267 insertions, 17 deletions
diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h
index 1d5e1822bb2c..1e65917a9381 100644
--- a/drivers/net/ethernet/freescale/fec.h
+++ b/drivers/net/ethernet/freescale/fec.h
@@ -484,12 +484,22 @@ struct fec_enet_private {
unsigned int itr_clk_rate;
u32 rx_copybreak;
+
+ /* ptp clock period in ns*/
+ unsigned int ptp_inc;
+
+ /* pps */
+ int pps_channel;
+ unsigned int reload_period;
+ int pps_enable;
+ unsigned int next_counter;
};
void fec_ptp_init(struct platform_device *pdev);
void fec_ptp_start_cyclecounter(struct net_device *ndev);
int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr);
int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr);
+uint fec_ptp_check_pps_event(struct fec_enet_private *fep);
/****************************************************************************/
#endif /* FEC_H */
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 7a8209e73199..e364d1fc7bdc 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -1622,6 +1622,8 @@ fec_enet_interrupt(int irq, void *dev_id)
complete(&fep->mdio_done);
}
+ fec_ptp_check_pps_event(fep);
+
return ret;
}
diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c
index cca3617a2321..0fdcdc9ea028 100644
--- a/drivers/net/ethernet/freescale/fec_ptp.c
+++ b/drivers/net/ethernet/freescale/fec_ptp.c
@@ -61,6 +61,24 @@
#define FEC_T_INC_CORR_MASK 0x00007f00
#define FEC_T_INC_CORR_OFFSET 8
+#define FEC_T_CTRL_PINPER 0x00000080
+#define FEC_T_TF0_MASK 0x00000001
+#define FEC_T_TF0_OFFSET 0
+#define FEC_T_TF1_MASK 0x00000002
+#define FEC_T_TF1_OFFSET 1
+#define FEC_T_TF2_MASK 0x00000004
+#define FEC_T_TF2_OFFSET 2
+#define FEC_T_TF3_MASK 0x00000008
+#define FEC_T_TF3_OFFSET 3
+#define FEC_T_TDRE_MASK 0x00000001
+#define FEC_T_TDRE_OFFSET 0
+#define FEC_T_TMODE_MASK 0x0000003C
+#define FEC_T_TMODE_OFFSET 2
+#define FEC_T_TIE_MASK 0x00000040
+#define FEC_T_TIE_OFFSET 6
+#define FEC_T_TF_MASK 0x00000080
+#define FEC_T_TF_OFFSET 7
+
#define FEC_ATIME_CTRL 0x400
#define FEC_ATIME 0x404
#define FEC_ATIME_EVT_OFFSET 0x408
@@ -69,7 +87,143 @@
#define FEC_ATIME_INC 0x414
#define FEC_TS_TIMESTAMP 0x418
+#define FEC_TGSR 0x604
+#define FEC_TCSR(n) (0x608 + n * 0x08)
+#define FEC_TCCR(n) (0x60C + n * 0x08)
+#define MAX_TIMER_CHANNEL 3
+#define FEC_TMODE_TOGGLE 0x05
+#define FEC_HIGH_PULSE 0x0F
+
#define FEC_CC_MULT (1 << 31)
+#define FEC_COUNTER_PERIOD (1 << 31)
+#define PPS_OUPUT_RELOAD_PERIOD NSEC_PER_SEC
+#define FEC_CHANNLE_0 0
+#define DEFAULT_PPS_CHANNEL FEC_CHANNLE_0
+
+/**
+ * fec_ptp_enable_pps
+ * @fep: the fec_enet_private structure handle
+ * @enable: enable the channel pps output
+ *
+ * This function enble the PPS ouput on the timer channel.
+ */
+static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
+{
+ unsigned long flags;
+ u32 val, tempval;
+ int inc;
+ struct timespec ts;
+ u64 ns;
+ u32 remainder;
+ val = 0;
+
+ if (!(fep->hwts_tx_en || fep->hwts_rx_en)) {
+ dev_err(&fep->pdev->dev, "No ptp stack is running\n");
+ return -EINVAL;
+ }
+
+ if (fep->pps_enable == enable)
+ return 0;
+
+ fep->pps_channel = DEFAULT_PPS_CHANNEL;
+ fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
+ inc = fep->ptp_inc;
+
+ spin_lock_irqsave(&fep->tmreg_lock, flags);
+
+ if (enable) {
+ /* clear capture or output compare interrupt status if have.
+ */
+ writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
+
+ /* It is recommended to doulbe check the TMODE field in the
+ * TCSR register to be cleared before the first compare counter
+ * is written into TCCR register. Just add a double check.
+ */
+ val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
+ do {
+ val &= ~(FEC_T_TMODE_MASK);
+ writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
+ val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
+ } while (val & FEC_T_TMODE_MASK);
+
+ /* Dummy read counter to update the counter */
+ timecounter_read(&fep->tc);
+ /* We want to find the first compare event in the next
+ * second point. So we need to know what the ptp time
+ * is now and how many nanoseconds is ahead to get next second.
+ * The remaining nanosecond ahead before the next second would be
+ * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
+ * to current timer would be next second.
+ */
+ tempval = readl(fep->hwp + FEC_ATIME_CTRL);
+ tempval |= FEC_T_CTRL_CAPTURE;
+ writel(tempval, fep->hwp + FEC_ATIME_CTRL);
+
+ tempval = readl(fep->hwp + FEC_ATIME);
+ /* Convert the ptp local counter to 1588 timestamp */
+ ns = timecounter_cyc2time(&fep->tc, tempval);
+ ts.tv_sec = div_u64_rem(ns, 1000000000ULL, &remainder);
+ ts.tv_nsec = remainder;
+
+ /* The tempval is less than 3 seconds, and so val is less than
+ * 4 seconds. No overflow for 32bit calculation.
+ */
+ val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
+
+ /* Need to consider the situation that the current time is
+ * very close to the second point, which means NSEC_PER_SEC
+ * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
+ * is still running when we calculate the first compare event, it is
+ * possible that the remaining nanoseonds run out before the compare
+ * counter is calculated and written into TCCR register. To avoid
+ * this possibility, we will set the compare event to be the next
+ * of next second. The current setting is 31-bit timer and wrap
+ * around over 2 seconds. So it is okay to set the next of next
+ * seond for the timer.
+ */
+ val += NSEC_PER_SEC;
+
+ /* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
+ * ptp counter, which maybe cause 32-bit wrap. Since the
+ * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
+ * We can ensure the wrap will not cause issue. If the offset
+ * is bigger than fep->cc.mask would be a error.
+ */
+ val &= fep->cc.mask;
+ writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
+
+ /* Calculate the second the compare event timestamp */
+ fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
+
+ /* * Enable compare event when overflow */
+ val = readl(fep->hwp + FEC_ATIME_CTRL);
+ val |= FEC_T_CTRL_PINPER;
+ writel(val, fep->hwp + FEC_ATIME_CTRL);
+
+ /* Compare channel setting. */
+ val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
+ val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
+ val &= ~(1 << FEC_T_TDRE_OFFSET);
+ val &= ~(FEC_T_TMODE_MASK);
+ val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
+ writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
+
+ /* Write the second compare event timestamp and calculate
+ * the third timestamp. Refer the TCCR register detail in the spec.
+ */
+ writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
+ fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
+ } else {
+ writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
+ }
+
+ fep->pps_enable = enable;
+ spin_unlock_irqrestore(&fep->tmreg_lock, flags);
+
+ return 0;
+}
+
/**
* fec_ptp_read - read raw cycle counter (to be used by time counter)
* @cc: the cyclecounter structure
@@ -113,14 +267,15 @@ void fec_ptp_start_cyclecounter(struct net_device *ndev)
/* 1ns counter */
writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
- /* use free running count */
- writel(0, fep->hwp + FEC_ATIME_EVT_PERIOD);
+ /* use 31-bit timer counter */
+ writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
- writel(FEC_T_CTRL_ENABLE, fep->hwp + FEC_ATIME_CTRL);
+ writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
+ fep->hwp + FEC_ATIME_CTRL);
memset(&fep->cc, 0, sizeof(fep->cc));
fep->cc.read = fec_ptp_read;
- fep->cc.mask = CLOCKSOURCE_MASK(32);
+ fep->cc.mask = CLOCKSOURCE_MASK(31);
fep->cc.shift = 31;
fep->cc.mult = FEC_CC_MULT;
@@ -143,32 +298,59 @@ void fec_ptp_start_cyclecounter(struct net_device *ndev)
*/
static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
- u64 diff;
unsigned long flags;
int neg_adj = 0;
- u32 mult = FEC_CC_MULT;
+ u32 i, tmp;
+ u32 corr_inc, corr_period;
+ u32 corr_ns;
+ u64 lhs, rhs;
struct fec_enet_private *fep =
container_of(ptp, struct fec_enet_private, ptp_caps);
+ if (ppb == 0)
+ return 0;
+
if (ppb < 0) {
ppb = -ppb;
neg_adj = 1;
}
- diff = mult;
- diff *= ppb;
- diff = div_u64(diff, 1000000000ULL);
+ /* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
+ * Try to find the corr_inc between 1 to fep->ptp_inc to
+ * meet adjustment requirement.
+ */
+ lhs = NSEC_PER_SEC;
+ rhs = (u64)ppb * (u64)fep->ptp_inc;
+ for (i = 1; i <= fep->ptp_inc; i++) {
+ if (lhs >= rhs) {
+ corr_inc = i;
+ corr_period = div_u64(lhs, rhs);
+ break;
+ }
+ lhs += NSEC_PER_SEC;
+ }
+ /* Not found? Set it to high value - double speed
+ * correct in every clock step.
+ */
+ if (i > fep->ptp_inc) {
+ corr_inc = fep->ptp_inc;
+ corr_period = 1;
+ }
+
+ if (neg_adj)
+ corr_ns = fep->ptp_inc - corr_inc;
+ else
+ corr_ns = fep->ptp_inc + corr_inc;
spin_lock_irqsave(&fep->tmreg_lock, flags);
- /*
- * dummy read to set cycle_last in tc to now.
- * So use adjusted mult to calculate when next call
- * timercounter_read.
- */
- timecounter_read(&fep->tc);
- fep->cc.mult = neg_adj ? mult - diff : mult + diff;
+ tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
+ tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
+ writel(tmp, fep->hwp + FEC_ATIME_INC);
+ writel(corr_period, fep->hwp + FEC_ATIME_CORR);
+ /* dummy read to update the timer. */
+ timecounter_read(&fep->tc);
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
@@ -188,12 +370,19 @@ static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
container_of(ptp, struct fec_enet_private, ptp_caps);
unsigned long flags;
u64 now;
+ u32 counter;
spin_lock_irqsave(&fep->tmreg_lock, flags);
now = timecounter_read(&fep->tc);
now += delta;
+ /* Get the timer value based on adjusted timestamp.
+ * Update the counter with the masked value.
+ */
+ counter = now & fep->cc.mask;
+ writel(counter, fep->hwp + FEC_ATIME);
+
/* reset the timecounter */
timecounter_init(&fep->tc, &fep->cc, now);
@@ -244,6 +433,7 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp,
u64 ns;
unsigned long flags;
+ u32 counter;
mutex_lock(&fep->ptp_clk_mutex);
/* Check the ptp clock */
@@ -254,8 +444,13 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp,
ns = ts->tv_sec * 1000000000ULL;
ns += ts->tv_nsec;
+ /* Get the timer value based on timestamp.
+ * Update the counter with the masked value.
+ */
+ counter = ns & fep->cc.mask;
spin_lock_irqsave(&fep->tmreg_lock, flags);
+ writel(counter, fep->hwp + FEC_ATIME);
timecounter_init(&fep->tc, &fep->cc, ns);
spin_unlock_irqrestore(&fep->tmreg_lock, flags);
mutex_unlock(&fep->ptp_clk_mutex);
@@ -272,6 +467,15 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp,
static int fec_ptp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
+ struct fec_enet_private *fep =
+ container_of(ptp, struct fec_enet_private, ptp_caps);
+ int ret = 0;
+
+ if (rq->type == PTP_CLK_REQ_PPS) {
+ ret = fec_ptp_enable_pps(fep, on);
+
+ return ret;
+ }
return -EOPNOTSUPP;
}
@@ -386,7 +590,7 @@ void fec_ptp_init(struct platform_device *pdev)
fep->ptp_caps.n_ext_ts = 0;
fep->ptp_caps.n_per_out = 0;
fep->ptp_caps.n_pins = 0;
- fep->ptp_caps.pps = 0;
+ fep->ptp_caps.pps = 1;
fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
fep->ptp_caps.adjtime = fec_ptp_adjtime;
fep->ptp_caps.gettime = fec_ptp_gettime;
@@ -394,6 +598,7 @@ void fec_ptp_init(struct platform_device *pdev)
fep->ptp_caps.enable = fec_ptp_enable;
fep->cycle_speed = clk_get_rate(fep->clk_ptp);
+ fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
spin_lock_init(&fep->tmreg_lock);
@@ -409,3 +614,36 @@ void fec_ptp_init(struct platform_device *pdev)
schedule_delayed_work(&fep->time_keep, HZ);
}
+
+/**
+ * fec_ptp_check_pps_event
+ * @fep: the fec_enet_private structure handle
+ *
+ * This function check the pps event and reload the timer compare counter.
+ */
+uint fec_ptp_check_pps_event(struct fec_enet_private *fep)
+{
+ u32 val;
+ u8 channel = fep->pps_channel;
+ struct ptp_clock_event event;
+
+ val = readl(fep->hwp + FEC_TCSR(channel));
+ if (val & FEC_T_TF_MASK) {
+ /* Write the next next compare(not the next according the spec)
+ * value to the register
+ */
+ writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
+ do {
+ writel(val, fep->hwp + FEC_TCSR(channel));
+ } while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
+
+ /* Update the counter; */
+ fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
+
+ event.type = PTP_CLOCK_PPS;
+ ptp_clock_event(fep->ptp_clock, &event);
+ return 1;
+ }
+
+ return 0;
+}