bnxt_en: 1PPS support for 5750X family chips

1PPS (One Pulse Per Second) is a signal generated either
by the NIC PHC or an external timing source.
Integrating the support to configure and use 1PPS using
the TSIO pins along with PTP timestamps will add Grand
Master capability to the 5750X family chipsets.

This patch initializes the driver data structures and
registers the 1PPS with kernel, based on the TSIO pins'
capability in the hardware. This will create a /dev/ppsX
device which applications can use to receive PPS events.

Later patches will define functions to configure and use
the pins.

Reviewed-by: Edwin Peer <edwin.peer@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -7545,6 +7545,8 @@ static int __bnxt_hwrm_func_qcaps(struct bnxt *bp)
 	flags_ext = le32_to_cpu(resp->flags_ext);
 	if (flags_ext & FUNC_QCAPS_RESP_FLAGS_EXT_EXT_HW_STATS_SUPPORTED)
 		bp->fw_cap |= BNXT_FW_CAP_EXT_HW_STATS_SUPPORTED;
+	if (BNXT_PF(bp) && (flags_ext & FUNC_QCAPS_RESP_FLAGS_EXT_PTP_PPS_SUPPORTED))
+		bp->fw_cap |= BNXT_FW_CAP_PTP_PPS;
 
 	bp->tx_push_thresh = 0;
 	if ((flags & FUNC_QCAPS_RESP_FLAGS_PUSH_MODE_SUPPORTED) &&

drivers/net/ethernet/broadcom/bnxt/bnxt.h

@@ -1887,6 +1887,7 @@ struct bnxt {
 	#define BNXT_FW_CAP_VLAN_RX_STRIP		0x01000000
 	#define BNXT_FW_CAP_VLAN_TX_INSERT		0x02000000
 	#define BNXT_FW_CAP_EXT_HW_STATS_SUPPORTED	0x04000000
+	#define BNXT_FW_CAP_PTP_PPS			0x10000000
 	#define BNXT_FW_CAP_RING_MONITOR		0x40000000
 
 #define BNXT_NEW_RM(bp)		((bp)->fw_cap & BNXT_FW_CAP_NEW_RM)

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c

@@ -412,6 +412,80 @@ static const struct ptp_clock_info bnxt_ptp_caps = {
 	.enable		= bnxt_ptp_enable,
 };
 
+static int bnxt_ptp_verify(struct ptp_clock_info *ptp_info, unsigned int pin,
+			   enum ptp_pin_function func, unsigned int chan)
+{
+	struct bnxt_ptp_cfg *ptp = container_of(ptp_info, struct bnxt_ptp_cfg,
+						ptp_info);
+	/* Allow only PPS pin function configuration */
+	if (ptp->pps_info.pins[pin].usage <= BNXT_PPS_PIN_PPS_OUT &&
+	    func != PTP_PF_PHYSYNC)
+		return 0;
+	else
+		return -EOPNOTSUPP;
+}
+
+/* bp->hwrm_cmd_lock held by the caller */
+static int bnxt_ptp_pps_init(struct bnxt *bp)
+{
+	struct hwrm_func_ptp_pin_qcfg_output *resp = bp->hwrm_cmd_resp_addr;
+	struct hwrm_func_ptp_pin_qcfg_input req = {0};
+	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+	struct ptp_clock_info *ptp_info;
+	struct bnxt_pps *pps_info;
+	u8 *pin_usg;
+	u32 i, rc;
+
+	/* Query current/default PIN CFG */
+	bnxt_hwrm_cmd_hdr_init(bp, &req, HWRM_FUNC_PTP_PIN_QCFG, -1, -1);
+
+	rc = _hwrm_send_message(bp, &req, sizeof(req), HWRM_CMD_TIMEOUT);
+	if (rc || !resp->num_pins)
+		return -EOPNOTSUPP;
+
+	ptp_info = &ptp->ptp_info;
+	pps_info = &ptp->pps_info;
+	pps_info->num_pins = resp->num_pins;
+	ptp_info->n_pins = pps_info->num_pins;
+	ptp_info->pin_config = kcalloc(ptp_info->n_pins,
+				       sizeof(*ptp_info->pin_config),
+				       GFP_KERNEL);
+	if (!ptp_info->pin_config)
+		return -ENOMEM;
+
+	/* Report the TSIO capability to kernel */
+	pin_usg = &resp->pin0_usage;
+	for (i = 0; i < pps_info->num_pins; i++, pin_usg++) {
+		snprintf(ptp_info->pin_config[i].name,
+			 sizeof(ptp_info->pin_config[i].name), "bnxt_pps%d", i);
+		ptp_info->pin_config[i].index = i;
+		ptp_info->pin_config[i].chan = i;
+		if (*pin_usg == BNXT_PPS_PIN_PPS_IN)
+			ptp_info->pin_config[i].func = PTP_PF_EXTTS;
+		else if (*pin_usg == BNXT_PPS_PIN_PPS_OUT)
+			ptp_info->pin_config[i].func = PTP_PF_PEROUT;
+		else
+			ptp_info->pin_config[i].func = PTP_PF_NONE;
+
+		pps_info->pins[i].usage = *pin_usg;
+	}
+
+	/* Only 1 each of ext_ts and per_out pins is available in HW */
+	ptp_info->n_ext_ts = 1;
+	ptp_info->n_per_out = 1;
+	ptp_info->pps = 1;
+	ptp_info->verify = bnxt_ptp_verify;
+
+	return 0;
+}
+
+static bool bnxt_pps_config_ok(struct bnxt *bp)
+{
+	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
+
+	return !(bp->fw_cap & BNXT_FW_CAP_PTP_PPS) == !ptp->ptp_info.pin_config;
+}
+
 int bnxt_ptp_init(struct bnxt *bp)
 {
 	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
@@ -424,9 +498,15 @@ int bnxt_ptp_init(struct bnxt *bp)
 	if (rc)
 		return rc;
 
-	if (ptp->ptp_clock)
+	if (ptp->ptp_clock && bnxt_pps_config_ok(bp))
 		return 0;
 
+	if (ptp->ptp_clock) {
+		ptp_clock_unregister(ptp->ptp_clock);
+		ptp->ptp_clock = NULL;
+		kfree(ptp->ptp_info.pin_config);
+		ptp->ptp_info.pin_config = NULL;
+	}
 	atomic_set(&ptp->tx_avail, BNXT_MAX_TX_TS);
 	spin_lock_init(&ptp->ptp_lock);
 
@@ -439,6 +519,10 @@ int bnxt_ptp_init(struct bnxt *bp)
 	timecounter_init(&ptp->tc, &ptp->cc, ktime_to_ns(ktime_get_real()));
 
 	ptp->ptp_info = bnxt_ptp_caps;
+	if ((bp->fw_cap & BNXT_FW_CAP_PTP_PPS)) {
+		if (bnxt_ptp_pps_init(bp))
+			netdev_err(bp->dev, "1pps not initialized, continuing without 1pps support\n");
+	}
 	ptp->ptp_clock = ptp_clock_register(&ptp->ptp_info, &bp->pdev->dev);
 	if (IS_ERR(ptp->ptp_clock)) {
 		int err = PTR_ERR(ptp->ptp_clock);
@@ -468,6 +552,9 @@ void bnxt_ptp_clear(struct bnxt *bp)
 		ptp_clock_unregister(ptp->ptp_clock);
 
 	ptp->ptp_clock = NULL;
+	kfree(ptp->ptp_info.pin_config);
+	ptp->ptp_info.pin_config = NULL;
+
 	if (ptp->tx_skb) {
 		dev_kfree_skb_any(ptp->tx_skb);
 		ptp->tx_skb = NULL;

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h

@@ -21,11 +21,33 @@
 #define BNXT_PTP_QTS_TX_ENABLES	(PORT_TS_QUERY_REQ_ENABLES_PTP_SEQ_ID |	\
 				 PORT_TS_QUERY_REQ_ENABLES_TS_REQ_TIMEOUT)
 
+struct pps_pin {
+	u8 usage;
+};
+
+#define BNXT_PPS_PIN_DISABLE	0
+#define BNXT_PPS_PIN_ENABLE	1
+#define BNXT_PPS_PIN_NONE	0
+#define BNXT_PPS_PIN_PPS_IN	1
+#define BNXT_PPS_PIN_PPS_OUT	2
+#define BNXT_PPS_PIN_SYNC_IN	3
+#define BNXT_PPS_PIN_SYNC_OUT	4
+
+#define BNXT_PPS_EVENT_INTERNAL	1
+#define BNXT_PPS_EVENT_EXTERNAL	2
+
+struct bnxt_pps {
+	u8 num_pins;
+#define BNXT_MAX_TSIO_PINS	4
+	struct pps_pin pins[BNXT_MAX_TSIO_PINS];
+};
+
 struct bnxt_ptp_cfg {
 	struct ptp_clock_info	ptp_info;
 	struct ptp_clock	*ptp_clock;
 	struct cyclecounter	cc;
 	struct timecounter	tc;
+	struct bnxt_pps		pps_info;
 	/* serialize timecounter access */
 	spinlock_t		ptp_lock;
 	struct sk_buff		*tx_skb;