net: lan966x: Add offload support for taprio

Lan966x switch supports time-based egress shaping in hardware
according to IEEE 802.1Qbv. Add support for TAS configuration on
egress port of lan966x switch.
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/microchip/lan966x/Makefile

@@ -9,4 +9,4 @@ lan966x-switch-objs  := lan966x_main.o lan966x_phylink.o lan966x_port.o \
 			lan966x_mac.o lan966x_ethtool.o lan966x_switchdev.o \
 			lan966x_vlan.o lan966x_fdb.o lan966x_mdb.o \
 			lan966x_ptp.o lan966x_fdma.o lan966x_lag.o \
-			lan966x_tc.o lan966x_mqprio.o
+			lan966x_tc.o lan966x_mqprio.o lan966x_taprio.o

drivers/net/ethernet/microchip/lan966x/lan966x_main.c

@@ -963,6 +963,8 @@ static void lan966x_init(struct lan966x *lan966x)
 		lan966x, ANA_ANAINTR);
 
 	spin_lock_init(&lan966x->tx_lock);
+
+	lan966x_taprio_init(lan966x);
 }
 
 static int lan966x_ram_init(struct lan966x *lan966x)
@@ -1172,6 +1174,7 @@ static int lan966x_remove(struct platform_device *pdev)
 {
 	struct lan966x *lan966x = platform_get_drvdata(pdev);
 
+	lan966x_taprio_deinit(lan966x);
 	lan966x_fdma_deinit(lan966x);
 	lan966x_cleanup_ports(lan966x);
 

drivers/net/ethernet/microchip/lan966x/lan966x_main.h

@@ -9,6 +9,7 @@
 #include <linux/phy.h>
 #include <linux/phylink.h>
 #include <linux/ptp_clock_kernel.h>
+#include <net/pkt_sched.h>
 #include <net/switchdev.h>
 
 #include "lan966x_regs.h"
@@ -410,6 +411,8 @@ void lan966x_ptp_txtstamp_release(struct lan966x_port *port,
 				  struct sk_buff *skb);
 irqreturn_t lan966x_ptp_irq_handler(int irq, void *args);
 irqreturn_t lan966x_ptp_ext_irq_handler(int irq, void *args);
+u32 lan966x_ptp_get_period_ps(void);
+int lan966x_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts);
 
 int lan966x_fdma_xmit(struct sk_buff *skb, __be32 *ifh, struct net_device *dev);
 int lan966x_fdma_change_mtu(struct lan966x *lan966x);
@@ -452,6 +455,13 @@ int lan966x_tc_setup(struct net_device *dev, enum tc_setup_type type,
 int lan966x_mqprio_add(struct lan966x_port *port, u8 num_tc);
 int lan966x_mqprio_del(struct lan966x_port *port);
 
+void lan966x_taprio_init(struct lan966x *lan966x);
+void lan966x_taprio_deinit(struct lan966x *lan966x);
+int lan966x_taprio_add(struct lan966x_port *port,
+		       struct tc_taprio_qopt_offload *qopt);
+int lan966x_taprio_del(struct lan966x_port *port);
+int lan966x_taprio_speed_set(struct lan966x_port *port, int speed);
+
 static inline void __iomem *lan_addr(void __iomem *base[],
 				     int id, int tinst, int tcnt,
 				     int gbase, int ginst,

drivers/net/ethernet/microchip/lan966x/lan966x_port.c

@@ -165,6 +165,8 @@ static void lan966x_port_link_up(struct lan966x_port *port)
 		break;
 	}
 
+	lan966x_taprio_speed_set(port, config->speed);
+
 	/* Also the GIGA_MODE_ENA(1) needs to be set regardless of the
 	 * port speed for QSGMII ports.
 	 */

drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c

@@ -464,8 +464,7 @@ static int lan966x_ptp_settime64(struct ptp_clock_info *ptp,
 	return 0;
 }
 
-static int lan966x_ptp_gettime64(struct ptp_clock_info *ptp,
-				 struct timespec64 *ts)
+int lan966x_ptp_gettime64(struct ptp_clock_info *ptp, struct timespec64 *ts)
 {
 	struct lan966x_phc *phc = container_of(ptp, struct lan966x_phc, info);
 	struct lan966x *lan966x = phc->lan966x;
@@ -890,3 +889,9 @@ void lan966x_ptp_rxtstamp(struct lan966x *lan966x, struct sk_buff *skb,
 	shhwtstamps = skb_hwtstamps(skb);
 	shhwtstamps->hwtstamp = full_ts_in_ns;
 }
+
+u32 lan966x_ptp_get_period_ps(void)
+{
+	/* This represents the system clock period in picoseconds */
+	return 15125;
+}

drivers/net/ethernet/microchip/lan966x/lan966x_tc.c

@@ -15,6 +15,13 @@ static int lan966x_tc_setup_qdisc_mqprio(struct lan966x_port *port,
 			lan966x_mqprio_del(port);
 }
 
+static int lan966x_tc_setup_qdisc_taprio(struct lan966x_port *port,
+					 struct tc_taprio_qopt_offload *taprio)
+{
+	return taprio->enable ? lan966x_taprio_add(port, taprio) :
+				lan966x_taprio_del(port);
+}
+
 int lan966x_tc_setup(struct net_device *dev, enum tc_setup_type type,
 		     void *type_data)
 {
@@ -23,6 +30,8 @@ int lan966x_tc_setup(struct net_device *dev, enum tc_setup_type type,
 	switch (type) {
 	case TC_SETUP_QDISC_MQPRIO:
 		return lan966x_tc_setup_qdisc_mqprio(port, type_data);
+	case TC_SETUP_QDISC_TAPRIO:
+		return lan966x_tc_setup_qdisc_taprio(port, type_data);
 	default:
 		return -EOPNOTSUPP;
 	}