--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/* Microchip KSZ PTP Implementation
+ *
+ * Copyright (C) 2020 ARRI Lighting
+ * Copyright (C) 2022 Microchip Technology Inc.
+ */
+
+#include <linux/kernel.h>
+#include <linux/ptp_classify.h>
+#include <linux/ptp_clock_kernel.h>
+
+#include "ksz_common.h"
+#include "ksz_ptp.h"
+#include "ksz_ptp_reg.h"
+
+#define ptp_caps_to_data(d) container_of((d), struct ksz_ptp_data, caps)
+#define ptp_data_to_ksz_dev(d) container_of((d), struct ksz_device, ptp_data)
+
+/* Sub-nanoseconds-adj,max * sub-nanoseconds / 40ns * 1ns
+ * = (2^30-1) * (2 ^ 32) / 40 ns * 1 ns = 6249999
+ */
+#define KSZ_MAX_DRIFT_CORR 6249999
+
+#define KSZ_PTP_INC_NS 40ULL /* HW clock is incremented every 40 ns (by 40) */
+#define KSZ_PTP_SUBNS_BITS 32
+
+static int _ksz_ptp_gettime(struct ksz_device *dev, struct timespec64 *ts)
+{
+ u32 nanoseconds;
+ u32 seconds;
+ u8 phase;
+ int ret;
+
+ /* Copy current PTP clock into shadow registers and read */
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_READ_TIME, PTP_READ_TIME);
+ if (ret)
+ return ret;
+
+ ret = ksz_read8(dev, REG_PTP_RTC_SUB_NANOSEC__2, &phase);
+ if (ret)
+ return ret;
+
+ ret = ksz_read32(dev, REG_PTP_RTC_NANOSEC, &nanoseconds);
+ if (ret)
+ return ret;
+
+ ret = ksz_read32(dev, REG_PTP_RTC_SEC, &seconds);
+ if (ret)
+ return ret;
+
+ ts->tv_sec = seconds;
+ ts->tv_nsec = nanoseconds + phase * 8;
+
+ return 0;
+}
+
+static int ksz_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+ ret = _ksz_ptp_gettime(dev, ts);
+ mutex_unlock(&ptp_data->lock);
+
+ return ret;
+}
+
+static int ksz_ptp_settime(struct ptp_clock_info *ptp,
+ const struct timespec64 *ts)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ /* Write to shadow registers and Load PTP clock */
+ ret = ksz_write16(dev, REG_PTP_RTC_SUB_NANOSEC__2, PTP_RTC_0NS);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_write32(dev, REG_PTP_RTC_NANOSEC, ts->tv_nsec);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_write32(dev, REG_PTP_RTC_SEC, ts->tv_sec);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_LOAD_TIME, PTP_LOAD_TIME);
+
+unlock:
+ mutex_unlock(&ptp_data->lock);
+
+ return ret;
+}
+
+static int ksz_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ u64 base, adj;
+ bool negative;
+ u32 data32;
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ if (scaled_ppm) {
+ base = KSZ_PTP_INC_NS << KSZ_PTP_SUBNS_BITS;
+ negative = diff_by_scaled_ppm(base, scaled_ppm, &adj);
+
+ data32 = (u32)adj;
+ data32 &= PTP_SUBNANOSEC_M;
+ if (!negative)
+ data32 |= PTP_RATE_DIR;
+
+ ret = ksz_write32(dev, REG_PTP_SUBNANOSEC_RATE, data32);
+ if (ret)
+ goto unlock;
+
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ADJ_ENABLE,
+ PTP_CLK_ADJ_ENABLE);
+ if (ret)
+ goto unlock;
+ } else {
+ ret = ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ADJ_ENABLE, 0);
+ if (ret)
+ goto unlock;
+ }
+
+unlock:
+ mutex_unlock(&ptp_data->lock);
+ return ret;
+}
+
+static int ksz_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ struct ksz_ptp_data *ptp_data = ptp_caps_to_data(ptp);
+ struct ksz_device *dev = ptp_data_to_ksz_dev(ptp_data);
+ s32 sec, nsec;
+ u16 data16;
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ /* do not use ns_to_timespec64(),
+ * both sec and nsec are subtracted by hw
+ */
+ sec = div_s64_rem(delta, NSEC_PER_SEC, &nsec);
+
+ ret = ksz_write32(dev, REG_PTP_RTC_NANOSEC, abs(nsec));
+ if (ret)
+ goto unlock;
+
+ ret = ksz_write32(dev, REG_PTP_RTC_SEC, abs(sec));
+ if (ret)
+ goto unlock;
+
+ ret = ksz_read16(dev, REG_PTP_CLK_CTRL, &data16);
+ if (ret)
+ goto unlock;
+
+ data16 |= PTP_STEP_ADJ;
+
+ /* PTP_STEP_DIR -- 0: subtract, 1: add */
+ if (delta < 0)
+ data16 &= ~PTP_STEP_DIR;
+ else
+ data16 |= PTP_STEP_DIR;
+
+ ret = ksz_write16(dev, REG_PTP_CLK_CTRL, data16);
+
+unlock:
+ mutex_unlock(&ptp_data->lock);
+ return ret;
+}
+
+static int ksz_ptp_start_clock(struct ksz_device *dev)
+{
+ return ksz_rmw16(dev, REG_PTP_CLK_CTRL, PTP_CLK_ENABLE, PTP_CLK_ENABLE);
+}
+
+int ksz_ptp_clock_register(struct dsa_switch *ds)
+{
+ struct ksz_device *dev = ds->priv;
+ struct ksz_ptp_data *ptp_data;
+ int ret;
+
+ ptp_data = &dev->ptp_data;
+ mutex_init(&ptp_data->lock);
+
+ ptp_data->caps.owner = THIS_MODULE;
+ snprintf(ptp_data->caps.name, 16, "Microchip Clock");
+ ptp_data->caps.max_adj = KSZ_MAX_DRIFT_CORR;
+ ptp_data->caps.gettime64 = ksz_ptp_gettime;
+ ptp_data->caps.settime64 = ksz_ptp_settime;
+ ptp_data->caps.adjfine = ksz_ptp_adjfine;
+ ptp_data->caps.adjtime = ksz_ptp_adjtime;
+
+ ret = ksz_ptp_start_clock(dev);
+ if (ret)
+ return ret;
+
+ /* Currently only P2P mode is supported. When 802_1AS bit is set, it
+ * forwards all PTP packets to host port and none to other ports.
+ */
+ ret = ksz_rmw16(dev, REG_PTP_MSG_CONF1, PTP_TC_P2P | PTP_802_1AS,
+ PTP_TC_P2P | PTP_802_1AS);
+ if (ret)
+ return ret;
+
+ ptp_data->clock = ptp_clock_register(&ptp_data->caps, dev->dev);
+ if (IS_ERR_OR_NULL(ptp_data->clock))
+ return PTR_ERR(ptp_data->clock);
+
+ return 0;
+}
+
+void ksz_ptp_clock_unregister(struct dsa_switch *ds)
+{
+ struct ksz_device *dev = ds->priv;
+ struct ksz_ptp_data *ptp_data;
+
+ ptp_data = &dev->ptp_data;
+
+ if (ptp_data->clock)
+ ptp_clock_unregister(ptp_data->clock);
+}
+
+MODULE_AUTHOR("Christian Eggers <ceggers@arri.de>");
+MODULE_AUTHOR("Arun Ramadoss <arun.ramadoss@microchip.com>");
+MODULE_DESCRIPTION("PTP support for KSZ switch");
+MODULE_LICENSE("GPL");
--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip KSZ PTP register definitions
+ * Copyright (C) 2022 Microchip Technology Inc.
+ */
+
+#ifndef __KSZ_PTP_REGS_H
+#define __KSZ_PTP_REGS_H
+
+/* 5 - PTP Clock */
+#define REG_PTP_CLK_CTRL 0x0500
+
+#define PTP_STEP_ADJ BIT(6)
+#define PTP_STEP_DIR BIT(5)
+#define PTP_READ_TIME BIT(4)
+#define PTP_LOAD_TIME BIT(3)
+#define PTP_CLK_ADJ_ENABLE BIT(2)
+#define PTP_CLK_ENABLE BIT(1)
+#define PTP_CLK_RESET BIT(0)
+
+#define REG_PTP_RTC_SUB_NANOSEC__2 0x0502
+
+#define PTP_RTC_SUB_NANOSEC_M 0x0007
+#define PTP_RTC_0NS 0x00
+
+#define REG_PTP_RTC_NANOSEC 0x0504
+
+#define REG_PTP_RTC_SEC 0x0508
+
+#define REG_PTP_SUBNANOSEC_RATE 0x050C
+
+#define PTP_SUBNANOSEC_M 0x3FFFFFFF
+#define PTP_RATE_DIR BIT(31)
+#define PTP_TMP_RATE_ENABLE BIT(30)
+
+#define REG_PTP_SUBNANOSEC_RATE_L 0x050E
+
+#define REG_PTP_RATE_DURATION 0x0510
+#define REG_PTP_RATE_DURATION_H 0x0510
+#define REG_PTP_RATE_DURATION_L 0x0512
+
+#define REG_PTP_MSG_CONF1 0x0514
+
+#define PTP_802_1AS BIT(7)
+#define PTP_ENABLE BIT(6)
+#define PTP_ETH_ENABLE BIT(5)
+#define PTP_IPV4_UDP_ENABLE BIT(4)
+#define PTP_IPV6_UDP_ENABLE BIT(3)
+#define PTP_TC_P2P BIT(2)
+#define PTP_MASTER BIT(1)
+#define PTP_1STEP BIT(0)
+
+#endif