// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright (C) 2021 - 2023, 2025 Intel Corporation
 */

#include "mvm.h"
#include "iwl-debug.h"
#include <linux/timekeeping.h>
#include <linux/math64.h>

#define IWL_PTP_GP2_WRAP        0x100000000ULL
#define IWL_PTP_WRAP_TIME       (3600 * HZ)

/* The scaled_ppm parameter is ppm (parts per million) with a 16-bit fractional
 * part, which means that a value of 1 in one of those fields actually means
 * 2^-16 ppm, and 2^16=65536 is 1 ppm.
 */
#define SCALE_FACTOR    65536000000ULL
#define IWL_PTP_WRAP_THRESHOLD_USEC     (5000)

#define IWL_PTP_GET_CROSS_TS_NUM        5

static void iwl_mvm_ptp_update_new_read(struct iwl_mvm *mvm, u32 gp2)
{
        /* If the difference is above the threshold, assume it's a wraparound.
         * Otherwise assume it's an old read and ignore it.
         */
        if (gp2 < mvm->ptp_data.last_gp2 &&
            mvm->ptp_data.last_gp2 - gp2 < IWL_PTP_WRAP_THRESHOLD_USEC) {
                IWL_DEBUG_INFO(mvm,
                               "PTP: ignore old read (gp2=%u, last_gp2=%u)\n",
                               gp2, mvm->ptp_data.last_gp2);
                return;
        }

        if (gp2 < mvm->ptp_data.last_gp2) {
                mvm->ptp_data.wrap_counter++;
                IWL_DEBUG_INFO(mvm,
                               "PTP: wraparound detected (new counter=%u)\n",
                               mvm->ptp_data.wrap_counter);
        }

        mvm->ptp_data.last_gp2 = gp2;
        schedule_delayed_work(&mvm->ptp_data.dwork, IWL_PTP_WRAP_TIME);
}

u64 iwl_mvm_ptp_get_adj_time(struct iwl_mvm *mvm, u64 base_time_ns)
{
        struct ptp_data *data = &mvm->ptp_data;
        u64 last_gp2_ns = mvm->ptp_data.scale_update_gp2 * NSEC_PER_USEC;
        u64 res;
        u64 diff;

        iwl_mvm_ptp_update_new_read(mvm,
                                    div64_u64(base_time_ns, NSEC_PER_USEC));

        IWL_DEBUG_INFO(mvm, "base_time_ns=%llu, wrap_counter=%u\n",
                       (unsigned long long)base_time_ns, data->wrap_counter);

        base_time_ns = base_time_ns +
                (data->wrap_counter * IWL_PTP_GP2_WRAP * NSEC_PER_USEC);

        /* It is possible that a GP2 timestamp was received from fw before the
         * last scale update. Since we don't know how to scale - ignore it.
         */
        if (base_time_ns < last_gp2_ns) {
                IWL_DEBUG_INFO(mvm, "Time before scale update - ignore\n");
                return 0;
        }

        diff = base_time_ns - last_gp2_ns;
        IWL_DEBUG_INFO(mvm, "diff ns=%llu\n", (unsigned long long)diff);

        diff = mul_u64_u64_div_u64(diff, data->scaled_freq,
                                   SCALE_FACTOR);
        IWL_DEBUG_INFO(mvm, "scaled diff ns=%llu\n", (unsigned long long)diff);

        res = data->scale_update_adj_time_ns + data->delta + diff;

        IWL_DEBUG_INFO(mvm, "base=%llu delta=%lld adj=%llu\n",
                       (unsigned long long)base_time_ns, (long long)data->delta,
                       (unsigned long long)res);
        return res;
}

static int
iwl_mvm_get_crosstimestamp_fw(struct iwl_mvm *mvm, u32 *gp2, u64 *sys_time)
{
        struct iwl_synced_time_cmd synced_time_cmd = {
                .operation = cpu_to_le32(IWL_SYNCED_TIME_OPERATION_READ_BOTH)
        };
        struct iwl_host_cmd cmd = {
                .id = WIDE_ID(DATA_PATH_GROUP, WNM_PLATFORM_PTM_REQUEST_CMD),
                .flags = CMD_WANT_SKB,
                .data[0] = &synced_time_cmd,
                .len[0] = sizeof(synced_time_cmd),
        };
        struct iwl_synced_time_rsp *resp;
        struct iwl_rx_packet *pkt;
        int ret;
        u64 gp2_10ns;

        ret = iwl_mvm_send_cmd(mvm, &cmd);
        if (ret)
                return ret;

        pkt = cmd.resp_pkt;

        if (iwl_rx_packet_payload_len(pkt) != sizeof(*resp)) {
                IWL_ERR(mvm, "PTP: Invalid command response\n");
                iwl_free_resp(&cmd);
                return -EIO;
        }

        resp = (void *)pkt->data;

        gp2_10ns = (u64)le32_to_cpu(resp->gp2_timestamp_hi) << 32 |
                le32_to_cpu(resp->gp2_timestamp_lo);
        *gp2 = div_u64(gp2_10ns, 100);

        *sys_time = (u64)le32_to_cpu(resp->platform_timestamp_hi) << 32 |
                le32_to_cpu(resp->platform_timestamp_lo);

        return ret;
}

static void iwl_mvm_phc_get_crosstimestamp_loop(struct iwl_mvm *mvm,
                                                ktime_t *sys_time, u32 *gp2)
{
        u64 diff = 0, new_diff;
        u64 tmp_sys_time;
        u32 tmp_gp2;
        int i;

        for (i = 0; i < IWL_PTP_GET_CROSS_TS_NUM; i++) {
                iwl_mvm_get_sync_time(mvm, CLOCK_REALTIME, &tmp_gp2, NULL,
                                      &tmp_sys_time);
                new_diff = tmp_sys_time - ((u64)tmp_gp2 * NSEC_PER_USEC);
                if (!diff || new_diff < diff) {
                        *sys_time = tmp_sys_time;
                        *gp2 = tmp_gp2;
                        diff = new_diff;
                        IWL_DEBUG_INFO(mvm, "PTP: new times: gp2=%u sys=%lld\n",
                                       *gp2, *sys_time);
                }
        }
}

static int
iwl_mvm_phc_get_crosstimestamp(struct ptp_clock_info *ptp,
                               struct system_device_crosststamp *xtstamp)
{
        struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
                                           ptp_data.ptp_clock_info);
        int ret = 0;
        /* Raw value read from GP2 register in usec */
        u32 gp2;
        /* GP2 value in ns*/
        s64 gp2_ns;
        /* System (wall) time */
        ktime_t sys_time;

        memset(xtstamp, 0, sizeof(struct system_device_crosststamp));

        if (!mvm->ptp_data.ptp_clock) {
                IWL_ERR(mvm, "No PHC clock registered\n");
                return -ENODEV;
        }

        mutex_lock(&mvm->mutex);
        if (fw_has_capa(&mvm->fw->ucode_capa, IWL_UCODE_TLV_CAPA_SYNCED_TIME)) {
                ret = iwl_mvm_get_crosstimestamp_fw(mvm, &gp2, &sys_time);

                if (ret)
                        goto out;
        } else {
                iwl_mvm_phc_get_crosstimestamp_loop(mvm, &sys_time, &gp2);
        }

        gp2_ns = iwl_mvm_ptp_get_adj_time(mvm, (u64)gp2 * NSEC_PER_USEC);

        IWL_INFO(mvm, "Got Sync Time: GP2:%u, last_GP2: %u, GP2_ns: %lld, sys_time: %lld\n",
                 gp2, mvm->ptp_data.last_gp2, gp2_ns, (s64)sys_time);

        /* System monotonic raw time is not used */
        xtstamp->device = (ktime_t)gp2_ns;
        xtstamp->sys_realtime = sys_time;

out:
        mutex_unlock(&mvm->mutex);
        return ret;
}

static void iwl_mvm_ptp_work(struct work_struct *wk)
{
        struct iwl_mvm *mvm = container_of(wk, struct iwl_mvm,
                                           ptp_data.dwork.work);
        u32 gp2;

        mutex_lock(&mvm->mutex);
        gp2 = iwl_mvm_get_systime(mvm);
        iwl_mvm_ptp_update_new_read(mvm, gp2);
        mutex_unlock(&mvm->mutex);
}

static int iwl_mvm_ptp_gettime(struct ptp_clock_info *ptp,
                               struct timespec64 *ts)
{
        struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
                                           ptp_data.ptp_clock_info);
        u64 gp2;
        u64 ns;

        mutex_lock(&mvm->mutex);
        gp2 = iwl_mvm_get_systime(mvm);
        ns = iwl_mvm_ptp_get_adj_time(mvm, gp2 * NSEC_PER_USEC);
        mutex_unlock(&mvm->mutex);

        *ts = ns_to_timespec64(ns);
        return 0;
}

static int iwl_mvm_ptp_settime(struct ptp_clock_info *ptp,
                               const struct timespec64 *ts)
{
        return -EOPNOTSUPP;
}

static int iwl_mvm_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
        struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
                                           ptp_data.ptp_clock_info);
        struct ptp_data *data = container_of(ptp, struct ptp_data,
                                             ptp_clock_info);

        mutex_lock(&mvm->mutex);
        data->delta += delta;
        IWL_DEBUG_INFO(mvm, "delta=%lld, new delta=%lld\n", (long long)delta,
                       (long long)data->delta);
        mutex_unlock(&mvm->mutex);
        return 0;
}

static int iwl_mvm_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
        struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
                                           ptp_data.ptp_clock_info);
        struct ptp_data *data = &mvm->ptp_data;
        u32 gp2;

        mutex_lock(&mvm->mutex);

        /* Must call _iwl_mvm_ptp_get_adj_time() before updating
         * data->scale_update_gp2 or data->scaled_freq since
         * scale_update_adj_time_ns should reflect the previous scaled_freq.
         */
        gp2 = iwl_mvm_get_systime(mvm);
        data->scale_update_adj_time_ns =
                iwl_mvm_ptp_get_adj_time(mvm, gp2 * NSEC_PER_USEC);
        data->scale_update_gp2 = gp2;
        data->wrap_counter = 0;
        data->delta = 0;

        data->scaled_freq = SCALE_FACTOR + scaled_ppm;
        IWL_DEBUG_INFO(mvm, "adjfine: scaled_ppm=%ld new=%llu\n",
                       scaled_ppm, (unsigned long long)data->scaled_freq);

        mutex_unlock(&mvm->mutex);
        return 0;
}

/* iwl_mvm_ptp_init - initialize PTP for devices which support it.
 * @mvm: internal mvm structure, see &struct iwl_mvm.
 *
 * Performs the required steps for enabling PTP support.
 */
void iwl_mvm_ptp_init(struct iwl_mvm *mvm)
{
        /* Warn if the interface already has a ptp_clock defined */
        if (WARN_ON(mvm->ptp_data.ptp_clock))
                return;

        mvm->ptp_data.ptp_clock_info.owner = THIS_MODULE;
        mvm->ptp_data.ptp_clock_info.max_adj = 0x7fffffff;
        mvm->ptp_data.ptp_clock_info.getcrosststamp =
                                        iwl_mvm_phc_get_crosstimestamp;
        mvm->ptp_data.ptp_clock_info.adjfine = iwl_mvm_ptp_adjfine;
        mvm->ptp_data.ptp_clock_info.adjtime = iwl_mvm_ptp_adjtime;
        mvm->ptp_data.ptp_clock_info.gettime64 = iwl_mvm_ptp_gettime;
        mvm->ptp_data.ptp_clock_info.settime64 = iwl_mvm_ptp_settime;
        mvm->ptp_data.scaled_freq = SCALE_FACTOR;

        /* Give a short 'friendly name' to identify the PHC clock */
        snprintf(mvm->ptp_data.ptp_clock_info.name,
                 sizeof(mvm->ptp_data.ptp_clock_info.name),
                 "%s", "iwlwifi-PTP");

        INIT_DELAYED_WORK(&mvm->ptp_data.dwork, iwl_mvm_ptp_work);

        mvm->ptp_data.ptp_clock =
                ptp_clock_register(&mvm->ptp_data.ptp_clock_info, mvm->dev);

        if (IS_ERR(mvm->ptp_data.ptp_clock)) {
                IWL_ERR(mvm, "Failed to register PHC clock (%ld)\n",
                        PTR_ERR(mvm->ptp_data.ptp_clock));
                mvm->ptp_data.ptp_clock = NULL;
        } else if (mvm->ptp_data.ptp_clock) {
                IWL_DEBUG_INFO(mvm, "Registered PHC clock: %s, with index: %d\n",
                               mvm->ptp_data.ptp_clock_info.name,
                               ptp_clock_index(mvm->ptp_data.ptp_clock));
        }
}

/* iwl_mvm_ptp_remove - disable PTP device.
 * @mvm: internal mvm structure, see &struct iwl_mvm.
 *
 * Disable PTP support.
 */
void iwl_mvm_ptp_remove(struct iwl_mvm *mvm)
{
        if (mvm->ptp_data.ptp_clock) {
                IWL_DEBUG_INFO(mvm, "Unregistering PHC clock: %s, with index: %d\n",
                               mvm->ptp_data.ptp_clock_info.name,
                               ptp_clock_index(mvm->ptp_data.ptp_clock));

                ptp_clock_unregister(mvm->ptp_data.ptp_clock);
                mvm->ptp_data.ptp_clock = NULL;
                memset(&mvm->ptp_data.ptp_clock_info, 0,
                       sizeof(mvm->ptp_data.ptp_clock_info));
                mvm->ptp_data.last_gp2 = 0;
                cancel_delayed_work_sync(&mvm->ptp_data.dwork);
        }
}