net: fec: ptp: Enable PPS output based on ptp clock
[linux-2.6-block.git] / drivers / net / ethernet / freescale / fec_ptp.c
index cca3617a2321fa22198658e83b1ee5d65176f298..0fdcdc9ea028426d781e0919ea440cfe45a08f54 100644 (file)
 #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
 #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;
+}