xref: /freebsd/sys/contrib/dev/iwlwifi/mvm/ptp.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
2 /*
3  * Copyright (C) 2021 - 2023 Intel Corporation
4  */
5 
6 #include "mvm.h"
7 #include "iwl-debug.h"
8 #include <linux/timekeeping.h>
9 #include <linux/math64.h>
10 
11 #define IWL_PTP_GP2_WRAP	0x100000000ULL
12 #define IWL_PTP_WRAP_TIME	(3600 * HZ)
13 
14 /* The scaled_ppm parameter is ppm (parts per million) with a 16-bit fractional
15  * part, which means that a value of 1 in one of those fields actually means
16  * 2^-16 ppm, and 2^16=65536 is 1 ppm.
17  */
18 #define SCALE_FACTOR	65536000000ULL
19 #define IWL_PTP_WRAP_THRESHOLD_USEC	(5000)
20 
21 #define IWL_PTP_GET_CROSS_TS_NUM	5
22 
23 static void iwl_mvm_ptp_update_new_read(struct iwl_mvm *mvm, u32 gp2)
24 {
25 	/* If the difference is above the threshold, assume it's a wraparound.
26 	 * Otherwise assume it's an old read and ignore it.
27 	 */
28 	if (gp2 < mvm->ptp_data.last_gp2 &&
29 	    mvm->ptp_data.last_gp2 - gp2 < IWL_PTP_WRAP_THRESHOLD_USEC) {
30 		IWL_DEBUG_INFO(mvm,
31 			       "PTP: ignore old read (gp2=%u, last_gp2=%u)\n",
32 			       gp2, mvm->ptp_data.last_gp2);
33 		return;
34 	}
35 
36 	if (gp2 < mvm->ptp_data.last_gp2) {
37 		mvm->ptp_data.wrap_counter++;
38 		IWL_DEBUG_INFO(mvm,
39 			       "PTP: wraparound detected (new counter=%u)\n",
40 			       mvm->ptp_data.wrap_counter);
41 	}
42 
43 	mvm->ptp_data.last_gp2 = gp2;
44 	schedule_delayed_work(&mvm->ptp_data.dwork, IWL_PTP_WRAP_TIME);
45 }
46 
47 u64 iwl_mvm_ptp_get_adj_time(struct iwl_mvm *mvm, u64 base_time_ns)
48 {
49 	struct ptp_data *data = &mvm->ptp_data;
50 	u64 last_gp2_ns = mvm->ptp_data.scale_update_gp2 * NSEC_PER_USEC;
51 	u64 res;
52 	u64 diff;
53 
54 	iwl_mvm_ptp_update_new_read(mvm,
55 				    div64_u64(base_time_ns, NSEC_PER_USEC));
56 
57 	IWL_DEBUG_INFO(mvm, "base_time_ns=%llu, wrap_counter=%u\n",
58 		       (unsigned long long)base_time_ns, data->wrap_counter);
59 
60 	base_time_ns = base_time_ns +
61 		(data->wrap_counter * IWL_PTP_GP2_WRAP * NSEC_PER_USEC);
62 
63 	/* It is possible that a GP2 timestamp was received from fw before the
64 	 * last scale update. Since we don't know how to scale - ignore it.
65 	 */
66 	if (base_time_ns < last_gp2_ns) {
67 		IWL_DEBUG_INFO(mvm, "Time before scale update - ignore\n");
68 		return 0;
69 	}
70 
71 	diff = base_time_ns - last_gp2_ns;
72 	IWL_DEBUG_INFO(mvm, "diff ns=%llu\n", (unsigned long long)diff);
73 
74 	diff = mul_u64_u64_div_u64(diff, data->scaled_freq,
75 				   SCALE_FACTOR);
76 	IWL_DEBUG_INFO(mvm, "scaled diff ns=%llu\n", (unsigned long long)diff);
77 
78 	res = data->scale_update_adj_time_ns + data->delta + diff;
79 
80 	IWL_DEBUG_INFO(mvm, "base=%llu delta=%lld adj=%llu\n",
81 		       (unsigned long long)base_time_ns, (long long)data->delta,
82 		       (unsigned long long)res);
83 	return res;
84 }
85 
86 static int
87 iwl_mvm_get_crosstimestamp_fw(struct iwl_mvm *mvm, u32 *gp2, u64 *sys_time)
88 {
89 	struct iwl_synced_time_cmd synced_time_cmd = {
90 		.operation = cpu_to_le32(IWL_SYNCED_TIME_OPERATION_READ_BOTH)
91 	};
92 	struct iwl_host_cmd cmd = {
93 		.id = WIDE_ID(DATA_PATH_GROUP, WNM_PLATFORM_PTM_REQUEST_CMD),
94 		.flags = CMD_WANT_SKB,
95 		.data[0] = &synced_time_cmd,
96 		.len[0] = sizeof(synced_time_cmd),
97 	};
98 	struct iwl_synced_time_rsp *resp;
99 	struct iwl_rx_packet *pkt;
100 	int ret;
101 	u64 gp2_10ns;
102 
103 	ret = iwl_mvm_send_cmd(mvm, &cmd);
104 	if (ret)
105 		return ret;
106 
107 	pkt = cmd.resp_pkt;
108 
109 	if (iwl_rx_packet_payload_len(pkt) != sizeof(*resp)) {
110 		IWL_ERR(mvm, "PTP: Invalid command response\n");
111 		iwl_free_resp(&cmd);
112 		return -EIO;
113 	}
114 
115 	resp = (void *)pkt->data;
116 
117 	gp2_10ns = (u64)le32_to_cpu(resp->gp2_timestamp_hi) << 32 |
118 		le32_to_cpu(resp->gp2_timestamp_lo);
119 	*gp2 = div_u64(gp2_10ns, 100);
120 
121 	*sys_time = (u64)le32_to_cpu(resp->platform_timestamp_hi) << 32 |
122 		le32_to_cpu(resp->platform_timestamp_lo);
123 
124 	return ret;
125 }
126 
127 static void iwl_mvm_phc_get_crosstimestamp_loop(struct iwl_mvm *mvm,
128 						ktime_t *sys_time, u32 *gp2)
129 {
130 	u64 diff = 0, new_diff;
131 	u64 tmp_sys_time;
132 	u32 tmp_gp2;
133 	int i;
134 
135 	for (i = 0; i < IWL_PTP_GET_CROSS_TS_NUM; i++) {
136 		iwl_mvm_get_sync_time(mvm, CLOCK_REALTIME, &tmp_gp2, NULL,
137 				      &tmp_sys_time);
138 		new_diff = tmp_sys_time - ((u64)tmp_gp2 * NSEC_PER_USEC);
139 		if (!diff || new_diff < diff) {
140 			*sys_time = tmp_sys_time;
141 			*gp2 = tmp_gp2;
142 			diff = new_diff;
143 			IWL_DEBUG_INFO(mvm, "PTP: new times: gp2=%u sys=%lld\n",
144 				       *gp2, *sys_time);
145 		}
146 	}
147 }
148 
149 static int
150 iwl_mvm_phc_get_crosstimestamp(struct ptp_clock_info *ptp,
151 			       struct system_device_crosststamp *xtstamp)
152 {
153 	struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
154 					   ptp_data.ptp_clock_info);
155 	int ret = 0;
156 	/* Raw value read from GP2 register in usec */
157 	u32 gp2;
158 	/* GP2 value in ns*/
159 	s64 gp2_ns;
160 	/* System (wall) time */
161 	ktime_t sys_time;
162 
163 	memset(xtstamp, 0, sizeof(struct system_device_crosststamp));
164 
165 	if (!mvm->ptp_data.ptp_clock) {
166 		IWL_ERR(mvm, "No PHC clock registered\n");
167 		return -ENODEV;
168 	}
169 
170 	mutex_lock(&mvm->mutex);
171 	if (fw_has_capa(&mvm->fw->ucode_capa, IWL_UCODE_TLV_CAPA_SYNCED_TIME)) {
172 		ret = iwl_mvm_get_crosstimestamp_fw(mvm, &gp2, &sys_time);
173 
174 		if (ret)
175 			goto out;
176 	} else {
177 		iwl_mvm_phc_get_crosstimestamp_loop(mvm, &sys_time, &gp2);
178 	}
179 
180 	gp2_ns = iwl_mvm_ptp_get_adj_time(mvm, (u64)gp2 * NSEC_PER_USEC);
181 
182 	IWL_INFO(mvm, "Got Sync Time: GP2:%u, last_GP2: %u, GP2_ns: %lld, sys_time: %lld\n",
183 		 gp2, mvm->ptp_data.last_gp2, gp2_ns, (s64)sys_time);
184 
185 	/* System monotonic raw time is not used */
186 	xtstamp->device = (ktime_t)gp2_ns;
187 	xtstamp->sys_realtime = sys_time;
188 
189 out:
190 	mutex_unlock(&mvm->mutex);
191 	return ret;
192 }
193 
194 static void iwl_mvm_ptp_work(struct work_struct *wk)
195 {
196 	struct iwl_mvm *mvm = container_of(wk, struct iwl_mvm,
197 					   ptp_data.dwork.work);
198 	u32 gp2;
199 
200 	mutex_lock(&mvm->mutex);
201 	gp2 = iwl_mvm_get_systime(mvm);
202 	iwl_mvm_ptp_update_new_read(mvm, gp2);
203 	mutex_unlock(&mvm->mutex);
204 }
205 
206 static int iwl_mvm_ptp_gettime(struct ptp_clock_info *ptp,
207 			       struct timespec64 *ts)
208 {
209 	struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
210 					   ptp_data.ptp_clock_info);
211 	u64 gp2;
212 	u64 ns;
213 
214 	mutex_lock(&mvm->mutex);
215 	gp2 = iwl_mvm_get_systime(mvm);
216 	ns = iwl_mvm_ptp_get_adj_time(mvm, gp2 * NSEC_PER_USEC);
217 	mutex_unlock(&mvm->mutex);
218 
219 	*ts = ns_to_timespec64(ns);
220 	return 0;
221 }
222 
223 static int iwl_mvm_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
224 {
225 	struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
226 					   ptp_data.ptp_clock_info);
227 	struct ptp_data *data = container_of(ptp, struct ptp_data,
228 					     ptp_clock_info);
229 
230 	mutex_lock(&mvm->mutex);
231 	data->delta += delta;
232 	IWL_DEBUG_INFO(mvm, "delta=%lld, new delta=%lld\n", (long long)delta,
233 		       (long long)data->delta);
234 	mutex_unlock(&mvm->mutex);
235 	return 0;
236 }
237 
238 static int iwl_mvm_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
239 {
240 	struct iwl_mvm *mvm = container_of(ptp, struct iwl_mvm,
241 					   ptp_data.ptp_clock_info);
242 	struct ptp_data *data = &mvm->ptp_data;
243 	u32 gp2;
244 
245 	mutex_lock(&mvm->mutex);
246 
247 	/* Must call _iwl_mvm_ptp_get_adj_time() before updating
248 	 * data->scale_update_gp2 or data->scaled_freq since
249 	 * scale_update_adj_time_ns should reflect the previous scaled_freq.
250 	 */
251 	gp2 = iwl_mvm_get_systime(mvm);
252 	data->scale_update_adj_time_ns =
253 		iwl_mvm_ptp_get_adj_time(mvm, gp2 * NSEC_PER_USEC);
254 	data->scale_update_gp2 = gp2;
255 	data->wrap_counter = 0;
256 	data->delta = 0;
257 
258 	data->scaled_freq = SCALE_FACTOR + scaled_ppm;
259 	IWL_DEBUG_INFO(mvm, "adjfine: scaled_ppm=%ld new=%llu\n",
260 		       scaled_ppm, (unsigned long long)data->scaled_freq);
261 
262 	mutex_unlock(&mvm->mutex);
263 	return 0;
264 }
265 
266 /* iwl_mvm_ptp_init - initialize PTP for devices which support it.
267  * @mvm: internal mvm structure, see &struct iwl_mvm.
268  *
269  * Performs the required steps for enabling PTP support.
270  */
271 void iwl_mvm_ptp_init(struct iwl_mvm *mvm)
272 {
273 	/* Warn if the interface already has a ptp_clock defined */
274 	if (WARN_ON(mvm->ptp_data.ptp_clock))
275 		return;
276 
277 	mvm->ptp_data.ptp_clock_info.owner = THIS_MODULE;
278 	mvm->ptp_data.ptp_clock_info.max_adj = 0x7fffffff;
279 	mvm->ptp_data.ptp_clock_info.getcrosststamp =
280 					iwl_mvm_phc_get_crosstimestamp;
281 	mvm->ptp_data.ptp_clock_info.adjfine = iwl_mvm_ptp_adjfine;
282 	mvm->ptp_data.ptp_clock_info.adjtime = iwl_mvm_ptp_adjtime;
283 	mvm->ptp_data.ptp_clock_info.gettime64 = iwl_mvm_ptp_gettime;
284 	mvm->ptp_data.scaled_freq = SCALE_FACTOR;
285 
286 	/* Give a short 'friendly name' to identify the PHC clock */
287 	snprintf(mvm->ptp_data.ptp_clock_info.name,
288 		 sizeof(mvm->ptp_data.ptp_clock_info.name),
289 		 "%s", "iwlwifi-PTP");
290 
291 	INIT_DELAYED_WORK(&mvm->ptp_data.dwork, iwl_mvm_ptp_work);
292 
293 	mvm->ptp_data.ptp_clock =
294 		ptp_clock_register(&mvm->ptp_data.ptp_clock_info, mvm->dev);
295 
296 	if (IS_ERR(mvm->ptp_data.ptp_clock)) {
297 		IWL_ERR(mvm, "Failed to register PHC clock (%ld)\n",
298 			PTR_ERR(mvm->ptp_data.ptp_clock));
299 		mvm->ptp_data.ptp_clock = NULL;
300 	} else if (mvm->ptp_data.ptp_clock) {
301 		IWL_INFO(mvm, "Registered PHC clock: %s, with index: %d\n",
302 			 mvm->ptp_data.ptp_clock_info.name,
303 			 ptp_clock_index(mvm->ptp_data.ptp_clock));
304 	}
305 }
306 
307 /* iwl_mvm_ptp_remove - disable PTP device.
308  * @mvm: internal mvm structure, see &struct iwl_mvm.
309  *
310  * Disable PTP support.
311  */
312 void iwl_mvm_ptp_remove(struct iwl_mvm *mvm)
313 {
314 	if (mvm->ptp_data.ptp_clock) {
315 		IWL_INFO(mvm, "Unregistering PHC clock: %s, with index: %d\n",
316 			 mvm->ptp_data.ptp_clock_info.name,
317 			 ptp_clock_index(mvm->ptp_data.ptp_clock));
318 
319 		ptp_clock_unregister(mvm->ptp_data.ptp_clock);
320 		mvm->ptp_data.ptp_clock = NULL;
321 		memset(&mvm->ptp_data.ptp_clock_info, 0,
322 		       sizeof(mvm->ptp_data.ptp_clock_info));
323 		mvm->ptp_data.last_gp2 = 0;
324 		cancel_delayed_work_sync(&mvm->ptp_data.dwork);
325 	}
326 }
327