wifi: iwlwifi: mvm: add support for PTP HW clock (PHC)

Add support to enable/disable PHC clock. The PHC clock includes support
for fetching the cross timestamp i.e. a non-atomic snapshot of the current
time from the hardware (WiFi device) clock and system clock (wall-clock)
simultaneously.

Signed-off-by: Krishnanand Prabhu <krishnanand.prabhu@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230320122330.ae1d64f513b9.Ib3b6ad61c9fa2fc5908f1e0d6f59f4af6eec1a77@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/Makefile b/drivers/net/wireless/intel/iwlwifi/mvm/Makefile
index b82f79ac53785b9f88c1a3eb7212b4b41f0b490d..943e8de9bc98dd32b97b3b49788822d6efc53647 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/Makefile
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/Makefile
@@ -8,6 +8,7 @@ iwlmvm-y += tt.o offloading.o tdls.o
 iwlmvm-y += ftm-responder.o ftm-initiator.o
 iwlmvm-y += rfi.o
 iwlmvm-y += mld-key.o mld-mac.o link.o mld-sta.o mld-mac80211.o
+iwlmvm-y += ptp.o
 iwlmvm-$(CONFIG_IWLWIFI_DEBUGFS) += debugfs.o debugfs-vif.o
 iwlmvm-$(CONFIG_IWLWIFI_LEDS) += led.o
 iwlmvm-$(CONFIG_PM) += d3.o

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
index fe7dfdcd531b2181d0dd1157aea485d68bbda2be..4079c0d939c1945bda8401495d4a855d467f9c50 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/fw.c
@@ -1669,6 +1669,9 @@ int iwl_mvm_up(struct iwl_mvm *mvm)
        if (test_bit(IWL_MVM_STATUS_IN_HW_RESTART, &mvm->status))
                iwl_mvm_send_recovery_cmd(mvm, ERROR_RECOVERY_UPDATE_DB);
 
+       if (!mvm->ptp_data.ptp_clock)
+               iwl_mvm_ptp_init(mvm);
+
        if (iwl_acpi_get_eckv(mvm->dev, &mvm->ext_clock_valid))
                IWL_DEBUG_INFO(mvm, "ECKV table doesn't exist in BIOS\n");
 

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index 7cc3526e78ce1388fc0c3033b0dc9c7123865b19..4d99e76811a367ff88b26a5ea26477fb22b2f032 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -16,6 +16,8 @@
 #include <linux/thermal.h>
 #endif
 
+#include <linux/ptp_clock_kernel.h>
+
 #include <linux/ktime.h>
 
 #include "iwl-op-mode.h"
@@ -770,6 +772,15 @@ struct iwl_mvm_dqa_txq_info {
        enum iwl_mvm_queue_status status;
 };
 
+struct ptp_data {
+       struct ptp_clock *ptp_clock;
+       struct ptp_clock_info ptp_clock_info;
+       /* keeps track of GP2 wrap-around */
+       u32 last_gp2;
+       u32 wrap_counter;
+       struct delayed_work dwork;
+};
+
 struct iwl_mvm {
        /* for logger access */
        struct device *dev;
@@ -1080,6 +1091,8 @@ struct iwl_mvm {
 
        struct list_head resp_pasn_list;
 
+       struct ptp_data ptp_data;
+
        struct {
                u8 range_resp;
        } cmd_ver;
@@ -2121,6 +2134,8 @@ void iwl_mvm_event_frame_timeout_callback(struct iwl_mvm *mvm,
                                          const struct ieee80211_sta *sta,
                                          u16 tid);
 
+void iwl_mvm_ptp_init(struct iwl_mvm *mvm);
+void iwl_mvm_ptp_remove(struct iwl_mvm *mvm);
 int iwl_mvm_sar_select_profile(struct iwl_mvm *mvm, int prof_a, int prof_b);
 int iwl_mvm_get_sar_geo_profile(struct iwl_mvm *mvm);
 int iwl_mvm_ppag_send_cmd(struct iwl_mvm *mvm);

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
index 03da4e53de677bf4d3976823112306e61445723f..e7def1a0f767b26ec62757d3e6229175f738d859 100644 (file)
--- a/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ops.c
@@ -1435,6 +1435,8 @@ static void iwl_op_mode_mvm_stop(struct iwl_op_mode *op_mode)
        kfree(mvm->error_recovery_buf);
        mvm->error_recovery_buf = NULL;
 
+       iwl_mvm_ptp_remove(mvm);
+
        iwl_trans_op_mode_leave(mvm->trans);
 
        iwl_phy_db_free(mvm->phy_db);

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c b/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c
new file mode 100644 (file)
index 0000000..f786f5e
--- /dev/null
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/ptp.c
@@ -0,0 +1,131 @@
+// 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>
+
+#define IWL_PTP_GP2_WRAP       0x100000000ULL
+#define IWL_PTP_WRAP_TIME      (3600 * HZ)
+
+static void iwl_mvm_ptp_update_new_read(struct iwl_mvm *mvm, u32 gp2)
+{
+       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);
+}
+
+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);
+       /* 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;
+       }
+
+       iwl_mvm_get_sync_time(mvm, CLOCK_REALTIME, &gp2, NULL, &sys_time);
+
+       iwl_mvm_ptp_update_new_read(mvm, gp2);
+
+       gp2_ns = (gp2 + (mvm->ptp_data.wrap_counter * IWL_PTP_GP2_WRAP)) *
+               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;
+
+       return 0;
+}
+
+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);
+}
+
+/* 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;
+
+       /* 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);
+       }
+}