Re: [PATCH v3 net-next 07/15] ptp: netc: add external trigger stamp support

[Frank Li <Frank.li@nxp.com>]

On Tue, Aug 12, 2025 at 05:46:26PM +0800, Wei Fang wrote:
> From: "F.S. Peng" <fushi.peng@nxp.com>
>
> The NETC Timer is capable of recording the timestamp on receipt of an
> external pulse on a GPIO pin. It supports two such external triggers.
> The recorded value is saved in a 16 entry FIFO accessed by
> TMR_ETTSa_H/L. An interrupt can be generated when the trigger occurs,
> when the FIFO reaches a threshold, and if the FIFO overflows.
>

Nit: when the FIFO reaches a threshold or overflows.

Reviewed-by: Frank Li <Frank.Li@nxp.com>

> Signed-off-by: F.S. Peng <fushi.peng@nxp.com>
> Signed-off-by: Wei Fang <wei.fang@nxp.com>
>
> ---
> v3 changes:
> 1. Rebase this patch and use priv->tmr_emask instead of reading
>    TMR_EMASK register
> 2. Rename related macros
> 3. Remove the switch statement from netc_timer_enable_extts() and
>    netc_timer_handle_etts_event()
> ---
>  drivers/ptp/ptp_netc.c | 85 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 85 insertions(+)
>
> diff --git a/drivers/ptp/ptp_netc.c b/drivers/ptp/ptp_netc.c
> index aa88767f8355..45d60ad46b68 100644
> --- a/drivers/ptp/ptp_netc.c
> +++ b/drivers/ptp/ptp_netc.c
> @@ -18,6 +18,7 @@
>  #define NETC_TMR_CTRL			0x0080
>  #define  TMR_CTRL_CK_SEL		GENMASK(1, 0)
>  #define  TMR_CTRL_TE			BIT(2)
> +#define  TMR_ETEP(i)			BIT(8 + (i))
>  #define  TMR_COMP_MODE			BIT(15)
>  #define  TMR_CTRL_TCLK_PERIOD		GENMASK(25, 16)
>  #define  TMR_CTRL_FS			BIT(28)
> @@ -26,12 +27,22 @@
>  #define  TMR_TEVNET_PPEN(i)		BIT(7 - (i))
>  #define  TMR_TEVENT_PPEN_ALL		GENMASK(7, 5)
>  #define  TMR_TEVENT_ALMEN(i)		BIT(16 + (i))
> +#define  TMR_TEVENT_ETS_THREN(i)	BIT(20 + (i))
> +#define  TMR_TEVENT_ETSEN(i)		BIT(24 + (i))
> +#define  TMR_TEVENT_ETS_OVEN(i)		BIT(28 + (i))
> +#define  TMR_TEVENT_ETS(i)		(TMR_TEVENT_ETS_THREN(i) | \
> +					 TMR_TEVENT_ETSEN(i) | \
> +					 TMR_TEVENT_ETS_OVEN(i))
>
>  #define NETC_TMR_TEMASK			0x0088
> +#define NETC_TMR_STAT			0x0094
> +#define  TMR_STAT_ETS_VLD(i)		BIT(24 + (i))
> +
>  #define NETC_TMR_CNT_L			0x0098
>  #define NETC_TMR_CNT_H			0x009c
>  #define NETC_TMR_ADD			0x00a0
>  #define NETC_TMR_PRSC			0x00a8
> +#define NETC_TMR_ECTRL			0x00ac
>  #define NETC_TMR_OFF_L			0x00b0
>  #define NETC_TMR_OFF_H			0x00b4
>
> @@ -49,6 +60,9 @@
>  #define  FIPER_CTRL_PW(i)		(GENMASK(4, 0) << (i) * 8)
>  #define  FIPER_CTRL_SET_PW(i, v)	(((v) & GENMASK(4, 0)) << 8 * (i))
>
> +/* i = 0, 1, i indicates the index of TMR_ETTS */
> +#define NETC_TMR_ETTS_L(i)		(0x00e0 + (i) * 8)
> +#define NETC_TMR_ETTS_H(i)		(0x00e4 + (i) * 8)
>  #define NETC_TMR_CUR_TIME_L		0x00f0
>  #define NETC_TMR_CUR_TIME_H		0x00f4
>
> @@ -65,6 +79,7 @@
>  #define NETC_TMR_DEFAULT_FIPER		GENMASK(31, 0)
>  #define NETC_TMR_FIPER_MAX_PW		GENMASK(4, 0)
>  #define NETC_TMR_ALARM_NUM		2
> +#define NETC_TMR_DEFAULT_ETTF_THR	7
>
>  /* 1588 timer reference clock source select */
>  #define NETC_TMR_CCM_TIMER1		0 /* enet_timer1_clk_root, from CCM */
> @@ -475,6 +490,64 @@ static int net_timer_enable_perout(struct netc_timer *priv,
>  	return err;
>  }
>
> +static void netc_timer_handle_etts_event(struct netc_timer *priv, int index,
> +					 bool update_event)
> +{
> +	struct ptp_clock_event event;
> +	u32 etts_l = 0, etts_h = 0;
> +
> +	while (netc_timer_rd(priv, NETC_TMR_STAT) & TMR_STAT_ETS_VLD(index)) {
> +		etts_l = netc_timer_rd(priv, NETC_TMR_ETTS_L(index));
> +		etts_h = netc_timer_rd(priv, NETC_TMR_ETTS_H(index));
> +	}
> +
> +	/* Invalid time stamp */
> +	if (!etts_l && !etts_h)
> +		return;
> +
> +	if (update_event) {
> +		event.type = PTP_CLOCK_EXTTS;
> +		event.index = index;
> +		event.timestamp = (u64)etts_h << 32;
> +		event.timestamp |= etts_l;
> +		ptp_clock_event(priv->clock, &event);
> +	}
> +}
> +
> +static int netc_timer_enable_extts(struct netc_timer *priv,
> +				   struct ptp_clock_request *rq, int on)
> +{
> +	int index = rq->extts.index;
> +	unsigned long flags;
> +	u32 tmr_ctrl;
> +
> +	/* Reject requests to enable time stamping on both edges */
> +	if ((rq->extts.flags & PTP_EXTTS_EDGES) == PTP_EXTTS_EDGES)
> +		return -EOPNOTSUPP;
> +
> +	spin_lock_irqsave(&priv->lock, flags);
> +
> +	netc_timer_handle_etts_event(priv, rq->extts.index, false);
> +	if (on) {
> +		tmr_ctrl = netc_timer_rd(priv, NETC_TMR_CTRL);
> +		if (rq->extts.flags & PTP_FALLING_EDGE)
> +			tmr_ctrl |= TMR_ETEP(index);
> +		else
> +			tmr_ctrl &= ~TMR_ETEP(index);
> +
> +		netc_timer_wr(priv, NETC_TMR_CTRL, tmr_ctrl);
> +		priv->tmr_emask |= TMR_TEVENT_ETS(index);
> +	} else {
> +		priv->tmr_emask &= ~TMR_TEVENT_ETS(index);
> +	}
> +
> +	netc_timer_wr(priv, NETC_TMR_TEMASK, priv->tmr_emask);
> +
> +	spin_unlock_irqrestore(&priv->lock, flags);
> +
> +	return 0;
> +}
> +
>  static void netc_timer_disable_fiper(struct netc_timer *priv)
>  {
>  	u32 fiper_ctrl = netc_timer_rd(priv, NETC_TMR_FIPER_CTRL);
> @@ -528,6 +601,8 @@ static int netc_timer_enable(struct ptp_clock_info *ptp,
>  		return netc_timer_enable_pps(priv, rq, on);
>  	case PTP_CLK_REQ_PEROUT:
>  		return net_timer_enable_perout(priv, rq, on);
> +	case PTP_CLK_REQ_EXTTS:
> +		return netc_timer_enable_extts(priv, rq, on);
>  	default:
>  		return -EOPNOTSUPP;
>  	}
> @@ -655,6 +730,9 @@ static const struct ptp_clock_info netc_timer_ptp_caps = {
>  	.n_alarm	= 2,
>  	.pps		= 1,
>  	.n_per_out	= 3,
> +	.n_ext_ts	= 2,
> +	.supported_extts_flags = PTP_RISING_EDGE | PTP_FALLING_EDGE |
> +				 PTP_STRICT_FLAGS,
>  	.adjfine	= netc_timer_adjfine,
>  	.adjtime	= netc_timer_adjtime,
>  	.gettimex64	= netc_timer_gettimex64,
> @@ -687,6 +765,7 @@ static void netc_timer_init(struct netc_timer *priv)
>  		fiper_ctrl &= ~FIPER_CTRL_PG(i);
>  	}
>  	netc_timer_wr(priv, NETC_TMR_FIPER_CTRL, fiper_ctrl);
> +	netc_timer_wr(priv, NETC_TMR_ECTRL, NETC_TMR_DEFAULT_ETTF_THR);
>
>  	ktime_get_real_ts64(&now);
>  	ns = timespec64_to_ns(&now);
> @@ -820,6 +899,12 @@ static irqreturn_t netc_timer_isr(int irq, void *data)
>  		ptp_clock_event(priv->clock, &event);
>  	}
>
> +	if (tmr_event & TMR_TEVENT_ETS(0))
> +		netc_timer_handle_etts_event(priv, 0, true);
> +
> +	if (tmr_event & TMR_TEVENT_ETS(1))
> +		netc_timer_handle_etts_event(priv, 1, true);
> +
>  	spin_unlock(&priv->lock);
>
>  	return IRQ_HANDLED;
> --
> 2.34.1
>