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Commit 89bddcda authored by Luwei Zhou's avatar Luwei Zhou Committed by David S. Miller
Browse files

net: fec: ptp: Use hardware algorithm to adjust PTP counter. 



The FEC IP supports hardware adjustment for ptp timer. Refer to the description of
ENET_ATCOR and ENET_ATINC registers in the spec about the hardware adjustment. This
patch uses hardware support to adjust the ptp offset and frequency on the slave side.

Signed-off-by: default avatarLuwei Zhou <b45643@freescale.com>
Signed-off-by: default avatarFrank Li <Frank.Li@freescale.com>
Signed-off-by: default avatarFugang Duan <b38611@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f28460b2

drivers/net/ethernet/freescale/fec.h

+3 −0
Original line number Original line Diff line number Diff line
@@ -484,6 +484,9 @@ struct fec_enet_private { 
	unsigned int itr_clk_rate;

	unsigned int itr_clk_rate;





	u32 rx_copybreak;

	u32 rx_copybreak;



	/* ptp clock period in ns*/

	unsigned int ptp_inc;

};

};





void fec_ptp_init(struct platform_device *pdev);

void fec_ptp_init(struct platform_device *pdev);

drivers/net/ethernet/freescale/fec_ptp.c

+53 −12
Original line number Original line Diff line number Diff line
@@ -145,32 +145,59 @@ void fec_ptp_start_cyclecounter(struct net_device *ndev) 
 */

 */

static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)

static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)

{

{

	u64 diff;

	unsigned long flags;

	unsigned long flags;

	int neg_adj = 0;

	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 =

	struct fec_enet_private *fep =

	    container_of(ptp, struct fec_enet_private, ptp_caps);

	    container_of(ptp, struct fec_enet_private, ptp_caps);





	if (ppb == 0)

		return 0;



	if (ppb < 0) {

	if (ppb < 0) {

		ppb = -ppb;

		ppb = -ppb;

		neg_adj = 1;

		neg_adj = 1;

	}

	}





	diff = mult;

	/* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;

	diff *= ppb;

	 * Try to find the corr_inc  between 1 to fep->ptp_inc to

	diff = div_u64(diff, 1000000000ULL);

	 * 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);

	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);

	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
@@ -190,12 +217,19 @@ static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 
	    container_of(ptp, struct fec_enet_private, ptp_caps);

	    container_of(ptp, struct fec_enet_private, ptp_caps);

	unsigned long flags;

	unsigned long flags;

	u64 now;

	u64 now;

	u32 counter;





	spin_lock_irqsave(&fep->tmreg_lock, flags);

	spin_lock_irqsave(&fep->tmreg_lock, flags);





	now = timecounter_read(&fep->tc);

	now = timecounter_read(&fep->tc);

	now += delta;

	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 */

	/* reset the timecounter */

	timecounter_init(&fep->tc, &fep->cc, now);

	timecounter_init(&fep->tc, &fep->cc, now);
@@ -246,6 +280,7 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp, 




	u64 ns;

	u64 ns;

	unsigned long flags;

	unsigned long flags;

	u32 counter;





	mutex_lock(&fep->ptp_clk_mutex);

	mutex_lock(&fep->ptp_clk_mutex);

	/* Check the ptp clock */

	/* Check the ptp clock */
@@ -256,8 +291,13 @@ static int fec_ptp_settime(struct ptp_clock_info *ptp, 




	ns = ts->tv_sec * 1000000000ULL;

	ns = ts->tv_sec * 1000000000ULL;

	ns += ts->tv_nsec;

	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);

	spin_lock_irqsave(&fep->tmreg_lock, flags);

	writel(counter, fep->hwp + FEC_ATIME);

	timecounter_init(&fep->tc, &fep->cc, ns);

	timecounter_init(&fep->tc, &fep->cc, ns);

	spin_unlock_irqrestore(&fep->tmreg_lock, flags);

	spin_unlock_irqrestore(&fep->tmreg_lock, flags);

	mutex_unlock(&fep->ptp_clk_mutex);

	mutex_unlock(&fep->ptp_clk_mutex);
@@ -396,6 +436,7 @@ void fec_ptp_init(struct platform_device *pdev) 
	fep->ptp_caps.enable = fec_ptp_enable;

	fep->ptp_caps.enable = fec_ptp_enable;





	fep->cycle_speed = clk_get_rate(fep->clk_ptp);

	fep->cycle_speed = clk_get_rate(fep->clk_ptp);

	fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;





	spin_lock_init(&fep->tmreg_lock);

	spin_lock_init(&fep->tmreg_lock);