path: root/drivers/net/ethernet/microchip/lan966x/lan966x_ptp.c

// SPDX-License-Identifier: GPL-2.0+

#include <linux/ptp_classify.h>

#include "lan966x_main.h"
#include "vcap_api.h"
#include "vcap_api_client.h"

#define LAN966X_MAX_PTP_ID	512

/* Represents 1ppm adjustment in 2^59 format with 6.037735849ns as reference
 * The value is calculated as following: (1/1000000)/((2^-59)/6.037735849)
 */
#define LAN966X_1PPM_FORMAT		3480517749723LL

/* Represents 1ppb adjustment in 2^29 format with 6.037735849ns as reference
 * The value is calculated as following: (1/1000000000)/((2^59)/6.037735849)
 */
#define LAN966X_1PPB_FORMAT		3480517749LL

#define TOD_ACC_PIN		0x7

/* This represents the base rule ID for the PTP rules that are added in the
 * VCAP to trap frames to CPU. This number needs to be bigger than the maximum
 * number of entries that can exist in the VCAP.
 */
#define LAN966X_VCAP_PTP_RULE_ID	1000000
#define LAN966X_VCAP_L2_PTP_TRAP	(LAN966X_VCAP_PTP_RULE_ID + 0)
#define LAN966X_VCAP_IPV4_EV_PTP_TRAP	(LAN966X_VCAP_PTP_RULE_ID + 1)
#define LAN966X_VCAP_IPV4_GEN_PTP_TRAP	(LAN966X_VCAP_PTP_RULE_ID + 2)
#define LAN966X_VCAP_IPV6_EV_PTP_TRAP	(LAN966X_VCAP_PTP_RULE_ID + 3)
#define LAN966X_VCAP_IPV6_GEN_PTP_TRAP	(LAN966X_VCAP_PTP_RULE_ID + 4)

enum {
	PTP_PIN_ACTION_IDLE = 0,
	PTP_PIN_ACTION_LOAD,
	PTP_PIN_ACTION_SAVE,
	PTP_PIN_ACTION_CLOCK,
	PTP_PIN_ACTION_DELTA,
	PTP_PIN_ACTION_TOD
};

static u64 lan966x_ptp_get_nominal_value(void)
{
	/* This is the default value that for each system clock, the time of day
	 * is increased. It has the format 5.59 nanosecond.
	 */
	return 0x304d4873ecade305;
}

static int lan966x_ptp_add_trap(struct lan966x_port *port,
				int (*add_ptp_key)(struct vcap_rule *vrule,
						   struct lan966x_port*),
				u32 rule_id,
				u16 proto)
{
	struct lan966x *lan966x = port->lan966x;
	struct vcap_rule *vrule;
	int err;

	vrule = vcap_get_rule(lan966x->vcap_ctrl, rule_id);
	if (!IS_ERR(vrule)) {
		u32 value, mask;

		/* Just modify the ingress port mask and exit */
		vcap_rule_get_key_u32(vrule, VCAP_KF_IF_IGR_PORT_MASK,
				      &value, &mask);
		mask &= ~BIT(port->chip_port);
		vcap_rule_mod_key_u32(vrule, VCAP_KF_IF_IGR_PORT_MASK,
				      value, mask);

		err = vcap_mod_rule(vrule);
		goto free_rule;
	}

	vrule = vcap_alloc_rule(lan966x->vcap_ctrl, port->dev,
				LAN966X_VCAP_CID_IS2_L0,
				VCAP_USER_PTP, 0, rule_id);
	if (IS_ERR(vrule))
		return PTR_ERR(vrule);

	err = add_ptp_key(vrule, port);
	if (err)
		goto free_rule;

	err = vcap_rule_add_action_bit(vrule, VCAP_AF_CPU_COPY_ENA, VCAP_BIT_1);
	err |= vcap_rule_add_action_u32(vrule, VCAP_AF_MASK_MODE, LAN966X_PMM_REPLACE);
	err |= vcap_val_rule(vrule, proto);
	if (err)
		goto free_rule;

	err = vcap_add_rule(vrule);

free_rule:
	/* Free the local copy of the rule */
	vcap_free_rule(vrule);
	return err;
}

static int lan966x_ptp_del_trap(struct lan966x_port *port,
				u32 rule_id)
{
	struct lan966x *lan966x = port->lan966x;
	struct vcap_rule *vrule;
	u32 value, mask;
	int err;

	vrule = vcap_get_rule(lan966x->vcap_ctrl, rule_id);
	if (IS_ERR(vrule))
		return -EEXIST;

	vcap_rule_get_key_u32(vrule, VCAP_KF_IF_IGR_PORT_MASK, &value, &mask);
	mask |= BIT(port->chip_port);

	/* No other port requires this trap, so it is safe to remove it */
	if (mask == GENMASK(lan966x->num_phys_ports, 0)) {
		err = vcap_del_rule(lan966x->vcap_ctrl, port->dev, rule_id);
		goto free_rule;
	}

	vcap_rule_mod_key_u32(vrule, VCAP_KF_IF_IGR_PORT_MASK, value, mask);
	err = vcap_mod_rule(vrule);

free_rule:
	vcap_free_rule(vrule);
	return err;
}

static int lan966x_ptp_add_l2_key(struct vcap_rule *vrule,
				  struct lan966x_port *port)
{
	return vcap_rule_add_key_u32(vrule, VCAP_KF_ETYPE, ETH_P_1588, ~0);
}

static int lan966x_ptp_add_ip_event_key(struct vcap_rule *vrule,
					struct lan966x_port *port)
{
	return vcap_rule_add_key_u32(vrule, VCAP_KF_L4_DPORT, PTP_EV_PORT, ~0) ||
	       vcap_rule_add_key_bit(vrule, VCAP_KF_TCP_IS, VCAP_BIT_0);
}

static int lan966x_ptp_add_ip_general_key(struct vcap_rule *vrule,
					  struct lan966x_port *port)
{
	return vcap_rule_add_key_u32(vrule, VCAP_KF_L4_DPORT, PTP_GEN_PORT, ~0) ||
	       vcap_rule_add_key_bit(vrule, VCAP_KF_TCP_IS, VCAP_BIT_0);
}

static int lan966x_ptp_add_l2_rule(struct lan966x_port *port)
{
	return lan966x_ptp_add_trap(port, lan966x_ptp_add_l2_key,
				    LAN966X_VCAP_L2_PTP_TRAP, ETH_P_ALL);
}

static int lan966x_ptp_add_ipv4_rules(struct lan966x_port *port)
{
	int err;

	err = lan966x_ptp_add_trap(port, lan966x_ptp_add_ip_event_key,
				   LAN966X_VCAP_IPV4_EV_PTP_TRAP, ETH_P_IP);
	if (err)
		return err;

	err = lan966x_ptp_add_trap(port, lan966x_ptp_add_ip_general_key,
				   LAN966X_VCAP_IPV4_GEN_PTP_TRAP, ETH_P_IP);
	if (err)
		lan966x_ptp_del_trap(port, LAN966X_VCAP_IPV4_EV_PTP_TRAP);

	return err;
}

static int l