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// 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");
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