1 files changed, 326 insertions, 0 deletions
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c b/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c
new file mode 100644
index 000000000000..e89259de6f4c
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c
@@ -0,0 +1,326 @@
+// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+/*
+ * Copyright (C) 2021 - 2023 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_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.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_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_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);
+	}
+}