xref: /openbmc/linux/drivers/net/ethernet/intel/e1000e/ptp.c (revision b240b419db5d624ce7a5a397d6f62a1a686009ec)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Intel PRO/1000 Linux driver
3  * Copyright(c) 1999 - 2015 Intel Corporation.
4  *
5  * This program is free software; you can redistribute it and/or modify it
6  * under the terms and conditions of the GNU General Public License,
7  * version 2, as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  *
14  * The full GNU General Public License is included in this distribution in
15  * the file called "COPYING".
16  *
17  * Contact Information:
18  * Linux NICS <linux.nics@intel.com>
19  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
20  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
21  */
22 
23 /* PTP 1588 Hardware Clock (PHC)
24  * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
25  * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
26  */
27 
28 #include "e1000.h"
29 
30 #ifdef CONFIG_E1000E_HWTS
31 #include <linux/clocksource.h>
32 #include <linux/ktime.h>
33 #include <asm/tsc.h>
34 #endif
35 
36 /**
37  * e1000e_phc_adjfreq - adjust the frequency of the hardware clock
38  * @ptp: ptp clock structure
39  * @delta: Desired frequency change in parts per billion
40  *
41  * Adjust the frequency of the PHC cycle counter by the indicated delta from
42  * the base frequency.
43  **/
44 static int e1000e_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
45 {
46 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
47 						     ptp_clock_info);
48 	struct e1000_hw *hw = &adapter->hw;
49 	bool neg_adj = false;
50 	unsigned long flags;
51 	u64 adjustment;
52 	u32 timinca, incvalue;
53 	s32 ret_val;
54 
55 	if ((delta > ptp->max_adj) || (delta <= -1000000000))
56 		return -EINVAL;
57 
58 	if (delta < 0) {
59 		neg_adj = true;
60 		delta = -delta;
61 	}
62 
63 	/* Get the System Time Register SYSTIM base frequency */
64 	ret_val = e1000e_get_base_timinca(adapter, &timinca);
65 	if (ret_val)
66 		return ret_val;
67 
68 	spin_lock_irqsave(&adapter->systim_lock, flags);
69 
70 	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
71 
72 	adjustment = incvalue;
73 	adjustment *= delta;
74 	adjustment = div_u64(adjustment, 1000000000);
75 
76 	incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
77 
78 	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
79 	timinca |= incvalue;
80 
81 	ew32(TIMINCA, timinca);
82 
83 	adapter->ptp_delta = delta;
84 
85 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
86 
87 	return 0;
88 }
89 
90 /**
91  * e1000e_phc_adjtime - Shift the time of the hardware clock
92  * @ptp: ptp clock structure
93  * @delta: Desired change in nanoseconds
94  *
95  * Adjust the timer by resetting the timecounter structure.
96  **/
97 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
98 {
99 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
100 						     ptp_clock_info);
101 	unsigned long flags;
102 
103 	spin_lock_irqsave(&adapter->systim_lock, flags);
104 	timecounter_adjtime(&adapter->tc, delta);
105 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
106 
107 	return 0;
108 }
109 
110 #ifdef CONFIG_E1000E_HWTS
111 #define MAX_HW_WAIT_COUNT (3)
112 
113 /**
114  * e1000e_phc_get_syncdevicetime - Callback given to timekeeping code reads system/device registers
115  * @device: current device time
116  * @system: system counter value read synchronously with device time
117  * @ctx: context provided by timekeeping code
118  *
119  * Read device and system (ART) clock simultaneously and return the corrected
120  * clock values in ns.
121  **/
122 static int e1000e_phc_get_syncdevicetime(ktime_t *device,
123 					 struct system_counterval_t *system,
124 					 void *ctx)
125 {
126 	struct e1000_adapter *adapter = (struct e1000_adapter *)ctx;
127 	struct e1000_hw *hw = &adapter->hw;
128 	unsigned long flags;
129 	int i;
130 	u32 tsync_ctrl;
131 	u64 dev_cycles;
132 	u64 sys_cycles;
133 
134 	tsync_ctrl = er32(TSYNCTXCTL);
135 	tsync_ctrl |= E1000_TSYNCTXCTL_START_SYNC |
136 		E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK;
137 	ew32(TSYNCTXCTL, tsync_ctrl);
138 	for (i = 0; i < MAX_HW_WAIT_COUNT; ++i) {
139 		udelay(1);
140 		tsync_ctrl = er32(TSYNCTXCTL);
141 		if (tsync_ctrl & E1000_TSYNCTXCTL_SYNC_COMP)
142 			break;
143 	}
144 
145 	if (i == MAX_HW_WAIT_COUNT)
146 		return -ETIMEDOUT;
147 
148 	dev_cycles = er32(SYSSTMPH);
149 	dev_cycles <<= 32;
150 	dev_cycles |= er32(SYSSTMPL);
151 	spin_lock_irqsave(&adapter->systim_lock, flags);
152 	*device = ns_to_ktime(timecounter_cyc2time(&adapter->tc, dev_cycles));
153 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
154 
155 	sys_cycles = er32(PLTSTMPH);
156 	sys_cycles <<= 32;
157 	sys_cycles |= er32(PLTSTMPL);
158 	*system = convert_art_to_tsc(sys_cycles);
159 
160 	return 0;
161 }
162 
163 /**
164  * e1000e_phc_getsynctime - Reads the current system/device cross timestamp
165  * @ptp: ptp clock structure
166  * @cts: structure containing timestamp
167  *
168  * Read device and system (ART) clock simultaneously and return the scaled
169  * clock values in ns.
170  **/
171 static int e1000e_phc_getcrosststamp(struct ptp_clock_info *ptp,
172 				     struct system_device_crosststamp *xtstamp)
173 {
174 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
175 						     ptp_clock_info);
176 
177 	return get_device_system_crosststamp(e1000e_phc_get_syncdevicetime,
178 						adapter, NULL, xtstamp);
179 }
180 #endif/*CONFIG_E1000E_HWTS*/
181 
182 /**
183  * e1000e_phc_gettime - Reads the current time from the hardware clock
184  * @ptp: ptp clock structure
185  * @ts: timespec structure to hold the current time value
186  *
187  * Read the timecounter and return the correct value in ns after converting
188  * it into a struct timespec.
189  **/
190 static int e1000e_phc_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
191 {
192 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
193 						     ptp_clock_info);
194 	unsigned long flags;
195 	u64 ns;
196 
197 	spin_lock_irqsave(&adapter->systim_lock, flags);
198 	ns = timecounter_read(&adapter->tc);
199 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
200 
201 	*ts = ns_to_timespec64(ns);
202 
203 	return 0;
204 }
205 
206 /**
207  * e1000e_phc_settime - Set the current time on the hardware clock
208  * @ptp: ptp clock structure
209  * @ts: timespec containing the new time for the cycle counter
210  *
211  * Reset the timecounter to use a new base value instead of the kernel
212  * wall timer value.
213  **/
214 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
215 			      const struct timespec64 *ts)
216 {
217 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
218 						     ptp_clock_info);
219 	unsigned long flags;
220 	u64 ns;
221 
222 	ns = timespec64_to_ns(ts);
223 
224 	/* reset the timecounter */
225 	spin_lock_irqsave(&adapter->systim_lock, flags);
226 	timecounter_init(&adapter->tc, &adapter->cc, ns);
227 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
228 
229 	return 0;
230 }
231 
232 /**
233  * e1000e_phc_enable - enable or disable an ancillary feature
234  * @ptp: ptp clock structure
235  * @request: Desired resource to enable or disable
236  * @on: Caller passes one to enable or zero to disable
237  *
238  * Enable (or disable) ancillary features of the PHC subsystem.
239  * Currently, no ancillary features are supported.
240  **/
241 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
242 			     struct ptp_clock_request __always_unused *request,
243 			     int __always_unused on)
244 {
245 	return -EOPNOTSUPP;
246 }
247 
248 static void e1000e_systim_overflow_work(struct work_struct *work)
249 {
250 	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
251 						     systim_overflow_work.work);
252 	struct e1000_hw *hw = &adapter->hw;
253 	struct timespec64 ts;
254 
255 	adapter->ptp_clock_info.gettime64(&adapter->ptp_clock_info, &ts);
256 
257 	e_dbg("SYSTIM overflow check at %lld.%09lu\n",
258 	      (long long) ts.tv_sec, ts.tv_nsec);
259 
260 	schedule_delayed_work(&adapter->systim_overflow_work,
261 			      E1000_SYSTIM_OVERFLOW_PERIOD);
262 }
263 
264 static const struct ptp_clock_info e1000e_ptp_clock_info = {
265 	.owner		= THIS_MODULE,
266 	.n_alarm	= 0,
267 	.n_ext_ts	= 0,
268 	.n_per_out	= 0,
269 	.n_pins		= 0,
270 	.pps		= 0,
271 	.adjfreq	= e1000e_phc_adjfreq,
272 	.adjtime	= e1000e_phc_adjtime,
273 	.gettime64	= e1000e_phc_gettime,
274 	.settime64	= e1000e_phc_settime,
275 	.enable		= e1000e_phc_enable,
276 };
277 
278 /**
279  * e1000e_ptp_init - initialize PTP for devices which support it
280  * @adapter: board private structure
281  *
282  * This function performs the required steps for enabling PTP support.
283  * If PTP support has already been loaded it simply calls the cyclecounter
284  * init routine and exits.
285  **/
286 void e1000e_ptp_init(struct e1000_adapter *adapter)
287 {
288 	struct e1000_hw *hw = &adapter->hw;
289 
290 	adapter->ptp_clock = NULL;
291 
292 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
293 		return;
294 
295 	adapter->ptp_clock_info = e1000e_ptp_clock_info;
296 
297 	snprintf(adapter->ptp_clock_info.name,
298 		 sizeof(adapter->ptp_clock_info.name), "%pm",
299 		 adapter->netdev->perm_addr);
300 
301 	switch (hw->mac.type) {
302 	case e1000_pch2lan:
303 	case e1000_pch_lpt:
304 	case e1000_pch_spt:
305 	case e1000_pch_cnp:
306 		if ((hw->mac.type < e1000_pch_lpt) ||
307 		    (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
308 			adapter->ptp_clock_info.max_adj = 24000000 - 1;
309 			break;
310 		}
311 		/* fall-through */
312 	case e1000_82574:
313 	case e1000_82583:
314 		adapter->ptp_clock_info.max_adj = 600000000 - 1;
315 		break;
316 	default:
317 		break;
318 	}
319 
320 #ifdef CONFIG_E1000E_HWTS
321 	/* CPU must have ART and GBe must be from Sunrise Point or greater */
322 	if (hw->mac.type >= e1000_pch_spt && boot_cpu_has(X86_FEATURE_ART))
323 		adapter->ptp_clock_info.getcrosststamp =
324 			e1000e_phc_getcrosststamp;
325 #endif/*CONFIG_E1000E_HWTS*/
326 
327 	INIT_DELAYED_WORK(&adapter->systim_overflow_work,
328 			  e1000e_systim_overflow_work);
329 
330 	schedule_delayed_work(&adapter->systim_overflow_work,
331 			      E1000_SYSTIM_OVERFLOW_PERIOD);
332 
333 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
334 						&adapter->pdev->dev);
335 	if (IS_ERR(adapter->ptp_clock)) {
336 		adapter->ptp_clock = NULL;
337 		e_err("ptp_clock_register failed\n");
338 	} else if (adapter->ptp_clock) {
339 		e_info("registered PHC clock\n");
340 	}
341 }
342 
343 /**
344  * e1000e_ptp_remove - disable PTP device and stop the overflow check
345  * @adapter: board private structure
346  *
347  * Stop the PTP support, and cancel the delayed work.
348  **/
349 void e1000e_ptp_remove(struct e1000_adapter *adapter)
350 {
351 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
352 		return;
353 
354 	cancel_delayed_work_sync(&adapter->systim_overflow_work);
355 
356 	if (adapter->ptp_clock) {
357 		ptp_clock_unregister(adapter->ptp_clock);
358 		adapter->ptp_clock = NULL;
359 		e_info("removed PHC\n");
360 	}
361 }
362