net: add support for Cavium PTP coprocessor

This patch adds support for the Precision Time Protocol
Clocks and Timestamping hardware found on Cavium ThunderX
processors.

Signed-off-by: Radoslaw Biernacki <rad@semihalf.com>
Signed-off-by: Aleksey Makarov <aleksey.makarov@cavium.com>
Acked-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 70 insertions, 0 deletions

diff --git a/drivers/net/ethernet/cavium/common/cavium_ptp.h b/drivers/net/ethernet/cavium/common/cavium_ptp.h
new file mode 100644
index 000000000000..be2bafc7beeb
--- /dev/null
+++ b/drivers/net/ethernet/cavium/common/cavium_ptp.h
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+/* cavium_ptp.h - PTP 1588 clock on Cavium hardware
+ * Copyright (c) 2003-2015, 2017 Cavium, Inc.
+ */
+
+#ifndef CAVIUM_PTP_H
+#define CAVIUM_PTP_H
+
+#include <linux/ptp_clock_kernel.h>
+#include <linux/timecounter.h>
+
+struct cavium_ptp {
+	struct pci_dev *pdev;
+
+	/* Serialize access to cycle_counter, time_counter and hw_registers */
+	spinlock_t spin_lock;
+	struct cyclecounter cycle_counter;
+	struct timecounter time_counter;
+	void __iomem *reg_base;
+
+	u32 clock_rate;
+
+	struct ptp_clock_info ptp_info;
+	struct ptp_clock *ptp_clock;
+};
+
+#if IS_ENABLED(CONFIG_CAVIUM_PTP)
+
+struct cavium_ptp *cavium_ptp_get(void);
+void cavium_ptp_put(struct cavium_ptp *ptp);
+
+static inline u64 cavium_ptp_tstamp2time(struct cavium_ptp *ptp, u64 tstamp)
+{
+	unsigned long flags;
+	u64 ret;
+
+	spin_lock_irqsave(&ptp->spin_lock, flags);
+	ret = timecounter_cyc2time(&ptp->time_counter, tstamp);
+	spin_unlock_irqrestore(&ptp->spin_lock, flags);
+
+	return ret;
+}
+
+static inline int cavium_ptp_clock_index(struct cavium_ptp *clock)
+{
+	return ptp_clock_index(clock->ptp_clock);
+}
+
+#else
+
+static inline struct cavium_ptp *cavium_ptp_get(void)
+{
+	return ERR_PTR(-ENODEV);
+}
+
+static inline void cavium_ptp_put(struct cavium_ptp *ptp) {}
+
+static inline u64 cavium_ptp_tstamp2time(struct cavium_ptp *ptp, u64 tstamp)
+{
+	return 0;
+}
+
+static inline int cavium_ptp_clock_index(struct cavium_ptp *clock)
+{
+	return -1;
+}
+
+#endif
+
+#endif