net: stmmac: Add Flexible PPS support

This adds support for Flexible PPS output (which is equivalent
to per_out output of PTP subsystem).

Tested using an oscilloscope and the following commands:

1) Start PTP4L:
	# ptp4l -A -4 -H -m -i eth0 &
2) Set Flexible PPS frequency:
	# echo <idx> <ts> <tns> <ps> <pns> > /sys/class/ptp/ptpX/period

Where, ts/tns is start time and ps/pns is period time, and ptpX is ptp
of eth0.

Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/common.h

@@ -346,6 +346,8 @@ struct dma_features {
 	/* TX and RX number of queues */
 	unsigned int number_rx_queues;
 	unsigned int number_tx_queues;
+	/* PPS output */
+	unsigned int pps_out_num;
 	/* Alternate (enhanced) DESC mode */
 	unsigned int enh_desc;
 	/* TX and RX FIFO sizes */

drivers/net/ethernet/stmicro/stmmac/dwmac4.h

@@ -187,6 +187,7 @@ enum power_event {
 #define GMAC_HW_RXFIFOSIZE		GENMASK(4, 0)
 
 /* MAC HW features2 bitmap */
+#define GMAC_HW_FEAT_PPSOUTNUM		GENMASK(26, 24)
 #define GMAC_HW_FEAT_TXCHCNT		GENMASK(21, 18)
 #define GMAC_HW_FEAT_RXCHCNT		GENMASK(15, 12)
 #define GMAC_HW_FEAT_TXQCNT		GENMASK(9, 6)

drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c

@@ -796,6 +796,7 @@ const struct stmmac_ops dwmac510_ops = {
 	.safety_feat_irq_status = dwmac5_safety_feat_irq_status,
 	.safety_feat_dump = dwmac5_safety_feat_dump,
 	.rxp_config = dwmac5_rxp_config,
+	.flex_pps_config = dwmac5_flex_pps_config,
 };
 
 int dwmac4_setup(struct stmmac_priv *priv)

drivers/net/ethernet/stmicro/stmmac/dwmac4_dma.c

@@ -373,6 +373,8 @@ static void dwmac4_get_hw_feature(void __iomem *ioaddr,
 		((hw_cap & GMAC_HW_FEAT_RXQCNT) >> 0) + 1;
 	dma_cap->number_tx_queues =
 		((hw_cap & GMAC_HW_FEAT_TXQCNT) >> 6) + 1;
+	/* PPS output */
+	dma_cap->pps_out_num = (hw_cap & GMAC_HW_FEAT_PPSOUTNUM) >> 24;
 
 	/* IEEE 1588-2002 */
 	dma_cap->time_stamp = 0;

drivers/net/ethernet/stmicro/stmmac/dwmac5.c

@@ -8,6 +8,7 @@
 #include "dwmac4.h"
 #include "dwmac5.h"
 #include "stmmac.h"
+#include "stmmac_ptp.h"
 
 struct dwmac5_error_desc {
 	bool valid;
@@ -494,3 +495,57 @@ re_enable:
 	writel(old_val, ioaddr + GMAC_CONFIG);
 	return ret;
 }
+
+int dwmac5_flex_pps_config(void __iomem *ioaddr, int index,
+			   struct stmmac_pps_cfg *cfg, bool enable,
+			   u32 sub_second_inc, u32 systime_flags)
+{
+	u32 tnsec = readl(ioaddr + MAC_PPSx_TARGET_TIME_NSEC(index));
+	u32 val = readl(ioaddr + MAC_PPS_CONTROL);
+	u64 period;
+
+	if (!cfg->available)
+		return -EINVAL;
+	if (tnsec & TRGTBUSY0)
+		return -EBUSY;
+	if (!sub_second_inc || !systime_flags)
+		return -EINVAL;
+
+	val &= ~PPSx_MASK(index);
+
+	if (!enable) {
+		val |= PPSCMDx(index, 0x5);
+		writel(val, ioaddr + MAC_PPS_CONTROL);
+		return 0;
+	}
+
+	val |= PPSCMDx(index, 0x2);
+	val |= TRGTMODSELx(index, 0x2);
+	val |= PPSEN0;
+
+	writel(cfg->start.tv_sec, ioaddr + MAC_PPSx_TARGET_TIME_SEC(index));
+
+	if (!(systime_flags & PTP_TCR_TSCTRLSSR))
+		cfg->start.tv_nsec = (cfg->start.tv_nsec * 1000) / 465;
+	writel(cfg->start.tv_nsec, ioaddr + MAC_PPSx_TARGET_TIME_NSEC(index));
+
+	period = cfg->period.tv_sec * 1000000000;
+	period += cfg->period.tv_nsec;
+
+	do_div(period, sub_second_inc);
+
+	if (period <= 1)
+		return -EINVAL;
+
+	writel(period - 1, ioaddr + MAC_PPSx_INTERVAL(index));
+
+	period >>= 1;
+	if (period <= 1)
+		return -EINVAL;
+
+	writel(period - 1, ioaddr + MAC_PPSx_WIDTH(index));
+
+	/* Finally, activate it */
+	writel(val, ioaddr + MAC_PPS_CONTROL);
+	return 0;
+}

drivers/net/ethernet/stmicro/stmmac/dwmac5.h

@@ -11,6 +11,25 @@
 #define PRTYEN				BIT(1)
 #define TMOUTEN				BIT(0)
 
+#define MAC_PPS_CONTROL			0x00000b70
+#define PPS_MAXIDX(x)			((((x) + 1) * 8) - 1)
+#define PPS_MINIDX(x)			((x) * 8)
+#define PPSx_MASK(x)			GENMASK(PPS_MAXIDX(x), PPS_MINIDX(x))
+#define MCGRENx(x)			BIT(PPS_MAXIDX(x))
+#define TRGTMODSELx(x, val)		\
+	GENMASK(PPS_MAXIDX(x) - 1, PPS_MAXIDX(x) - 2) & \
+	((val) << (PPS_MAXIDX(x) - 2))
+#define PPSCMDx(x, val)			\
+	GENMASK(PPS_MINIDX(x) + 3, PPS_MINIDX(x)) & \
+	((val) << PPS_MINIDX(x))
+#define PPSEN0				BIT(4)
+#define MAC_PPSx_TARGET_TIME_SEC(x)	(0x00000b80 + ((x) * 0x10))
+#define MAC_PPSx_TARGET_TIME_NSEC(x)	(0x00000b84 + ((x) * 0x10))
+#define TRGTBUSY0			BIT(31)
+#define TTSL0				GENMASK(30, 0)
+#define MAC_PPSx_INTERVAL(x)		(0x00000b88 + ((x) * 0x10))
+#define MAC_PPSx_WIDTH(x)		(0x00000b8c + ((x) * 0x10))
+
 #define MTL_RXP_CONTROL_STATUS		0x00000ca0
 #define RXPI				BIT(31)
 #define NPE				GENMASK(23, 16)
@@ -61,5 +80,8 @@ int dwmac5_safety_feat_dump(struct stmmac_safety_stats *stats,
 			int index, unsigned long *count, const char **desc);
 int dwmac5_rxp_config(void __iomem *ioaddr, struct stmmac_tc_entry *entries,
 		      unsigned int count);
+int dwmac5_flex_pps_config(void __iomem *ioaddr, int index,
+			   struct stmmac_pps_cfg *cfg, bool enable,
+			   u32 sub_second_inc, u32 systime_flags);
 
 #endif /* __DWMAC5_H__ */

drivers/net/ethernet/stmicro/stmmac/hwif.h

@@ -241,6 +241,7 @@ struct net_device;
 struct rgmii_adv;
 struct stmmac_safety_stats;
 struct stmmac_tc_entry;
+struct stmmac_pps_cfg;
 
 /* Helpers to program the MAC core */
 struct stmmac_ops {
@@ -313,6 +314,10 @@ struct stmmac_ops {
 	/* Flexible RX Parser */
 	int (*rxp_config)(void __iomem *ioaddr, struct stmmac_tc_entry *entries,
 			  unsigned int count);
+	/* Flexible PPS */
+	int (*flex_pps_config)(void __iomem *ioaddr, int index,
+			       struct stmmac_pps_cfg *cfg, bool enable,
+			       u32 sub_second_inc, u32 systime_flags);
 };
 
 #define stmmac_core_init(__priv, __args...) \
@@ -379,6 +384,8 @@ struct stmmac_ops {
 	stmmac_do_callback(__priv, mac, safety_feat_dump, __args)
 #define stmmac_rxp_config(__priv, __args...) \
 	stmmac_do_callback(__priv, mac, rxp_config, __args)
+#define stmmac_flex_pps_config(__priv, __args...) \
+	stmmac_do_callback(__priv, mac, flex_pps_config, __args)
 
 /* PTP and HW Timer helpers */
 struct stmmac_hwtimestamp {

drivers/net/ethernet/stmicro/stmmac/stmmac.h

@@ -100,6 +100,13 @@ struct stmmac_tc_entry {
 	} __packed val;
 };
 
+#define STMMAC_PPS_MAX		4
+struct stmmac_pps_cfg {
+	bool available;
+	struct timespec64 start;
+	struct timespec64 period;
+};
+
 struct stmmac_priv {
 	/* Frequently used values are kept adjacent for cache effect */
 	u32 tx_count_frames;
@@ -160,6 +167,8 @@ struct stmmac_priv {
 	struct ptp_clock *ptp_clock;
 	struct ptp_clock_info ptp_clock_ops;
 	unsigned int default_addend;
+	u32 sub_second_inc;
+	u32 systime_flags;
 	u32 adv_ts;
 	int use_riwt;
 	int irq_wake;
@@ -181,6 +190,9 @@ struct stmmac_priv {
 	unsigned int tc_entries_max;
 	unsigned int tc_off_max;
 	struct stmmac_tc_entry *tc_entries;
+
+	/* Pulse Per Second output */
+	struct stmmac_pps_cfg pps[STMMAC_PPS_MAX];
 };
 
 enum stmmac_state {

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -721,6 +721,10 @@ static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
 				priv->plat->has_gmac4, &sec_inc);
 		temp = div_u64(1000000000ULL, sec_inc);
 
+		/* Store sub second increment and flags for later use */
+		priv->sub_second_inc = sec_inc;
+		priv->systime_flags = value;
+
 		/* calculate default added value:
 		 * formula is :
 		 * addend = (2^32)/freq_div_ratio;

drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c

@@ -140,17 +140,43 @@ static int stmmac_set_time(struct ptp_clock_info *ptp,
 static int stmmac_enable(struct ptp_clock_info *ptp,
 			 struct ptp_clock_request *rq, int on)
 {
-	return -EOPNOTSUPP;
+	struct stmmac_priv *priv =
+	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
+	struct stmmac_pps_cfg *cfg;
+	int ret = -EOPNOTSUPP;
+	unsigned long flags;
+
+	switch (rq->type) {
+	case PTP_CLK_REQ_PEROUT:
+		cfg = &priv->pps[rq->perout.index];
+
+		cfg->start.tv_sec = rq->perout.start.sec;
+		cfg->start.tv_nsec = rq->perout.start.nsec;
+		cfg->period.tv_sec = rq->perout.period.sec;
+		cfg->period.tv_nsec = rq->perout.period.nsec;
+
+		spin_lock_irqsave(&priv->ptp_lock, flags);
+		ret = stmmac_flex_pps_config(priv, priv->ioaddr,
+					     rq->perout.index, cfg, on,
+					     priv->sub_second_inc,
+					     priv->systime_flags);
+		spin_unlock_irqrestore(&priv->ptp_lock, flags);
+		break;
+	default:
+		break;
+	}
+
+	return ret;
 }
 
 /* structure describing a PTP hardware clock */
-static const struct ptp_clock_info stmmac_ptp_clock_ops = {
+static struct ptp_clock_info stmmac_ptp_clock_ops = {
 	.owner = THIS_MODULE,
 	.name = "stmmac_ptp_clock",
 	.max_adj = 62500000,
 	.n_alarm = 0,
 	.n_ext_ts = 0,
-	.n_per_out = 0,
+	.n_per_out = 0, /* will be overwritten in stmmac_ptp_register */
 	.n_pins = 0,
 	.pps = 0,
 	.adjfreq = stmmac_adjust_freq,
@@ -168,6 +194,16 @@ static const struct ptp_clock_info stmmac_ptp_clock_ops = {
  */
 void stmmac_ptp_register(struct stmmac_priv *priv)
 {
+	int i;
+
+	for (i = 0; i < priv->dma_cap.pps_out_num; i++) {
+		if (i >= STMMAC_PPS_MAX)
+			break;
+		priv->pps[i].available = true;
+	}
+
+	stmmac_ptp_clock_ops.n_per_out = priv->dma_cap.pps_out_num;
+
 	spin_lock_init(&priv->ptp_lock);
 	priv->ptp_clock_ops = stmmac_ptp_clock_ops;