xref: /linux/drivers/net/ethernet/intel/e1000e/ptp.c (revision a3a02a52bcfcbcc4a637d4b68bf1bc391c9fad02)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
3 
4 /* PTP 1588 Hardware Clock (PHC)
5  * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
6  * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
7  */
8 
9 #include "e1000.h"
10 
11 #ifdef CONFIG_E1000E_HWTS
12 #include <linux/clocksource.h>
13 #include <linux/ktime.h>
14 #include <asm/tsc.h>
15 #endif
16 
17 /**
18  * e1000e_phc_adjfine - adjust the frequency of the hardware clock
19  * @ptp: ptp clock structure
20  * @delta: Desired frequency chance in scaled parts per million
21  *
22  * Adjust the frequency of the PHC cycle counter by the indicated delta from
23  * the base frequency.
24  *
25  * Scaled parts per million is ppm but with a 16 bit binary fractional field.
26  **/
27 static int e1000e_phc_adjfine(struct ptp_clock_info *ptp, long delta)
28 {
29 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
30 						     ptp_clock_info);
31 	struct e1000_hw *hw = &adapter->hw;
32 	unsigned long flags;
33 	u64 incvalue;
34 	u32 timinca;
35 	s32 ret_val;
36 
37 	/* Get the System Time Register SYSTIM base frequency */
38 	ret_val = e1000e_get_base_timinca(adapter, &timinca);
39 	if (ret_val)
40 		return ret_val;
41 
42 	spin_lock_irqsave(&adapter->systim_lock, flags);
43 
44 	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
45 	incvalue = adjust_by_scaled_ppm(incvalue, delta);
46 
47 	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
48 	timinca |= incvalue;
49 
50 	ew32(TIMINCA, timinca);
51 
52 	adapter->ptp_delta = delta;
53 
54 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
55 
56 	return 0;
57 }
58 
59 /**
60  * e1000e_phc_adjtime - Shift the time of the hardware clock
61  * @ptp: ptp clock structure
62  * @delta: Desired change in nanoseconds
63  *
64  * Adjust the timer by resetting the timecounter structure.
65  **/
66 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
67 {
68 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
69 						     ptp_clock_info);
70 	unsigned long flags;
71 
72 	spin_lock_irqsave(&adapter->systim_lock, flags);
73 	timecounter_adjtime(&adapter->tc, delta);
74 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
75 
76 	return 0;
77 }
78 
79 #ifdef CONFIG_E1000E_HWTS
80 #define MAX_HW_WAIT_COUNT (3)
81 
82 /**
83  * e1000e_phc_get_syncdevicetime - Callback given to timekeeping code reads system/device registers
84  * @device: current device time
85  * @system: system counter value read synchronously with device time
86  * @ctx: context provided by timekeeping code
87  *
88  * Read device and system (ART) clock simultaneously and return the corrected
89  * clock values in ns.
90  **/
91 static int e1000e_phc_get_syncdevicetime(ktime_t *device,
92 					 struct system_counterval_t *system,
93 					 void *ctx)
94 {
95 	struct e1000_adapter *adapter = (struct e1000_adapter *)ctx;
96 	struct e1000_hw *hw = &adapter->hw;
97 	unsigned long flags;
98 	int i;
99 	u32 tsync_ctrl;
100 	u64 dev_cycles;
101 	u64 sys_cycles;
102 
103 	tsync_ctrl = er32(TSYNCTXCTL);
104 	tsync_ctrl |= E1000_TSYNCTXCTL_START_SYNC |
105 		E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK;
106 	ew32(TSYNCTXCTL, tsync_ctrl);
107 	for (i = 0; i < MAX_HW_WAIT_COUNT; ++i) {
108 		udelay(1);
109 		tsync_ctrl = er32(TSYNCTXCTL);
110 		if (tsync_ctrl & E1000_TSYNCTXCTL_SYNC_COMP)
111 			break;
112 	}
113 
114 	if (i == MAX_HW_WAIT_COUNT)
115 		return -ETIMEDOUT;
116 
117 	dev_cycles = er32(SYSSTMPH);
118 	dev_cycles <<= 32;
119 	dev_cycles |= er32(SYSSTMPL);
120 	spin_lock_irqsave(&adapter->systim_lock, flags);
121 	*device = ns_to_ktime(timecounter_cyc2time(&adapter->tc, dev_cycles));
122 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
123 
124 	sys_cycles = er32(PLTSTMPH);
125 	sys_cycles <<= 32;
126 	sys_cycles |= er32(PLTSTMPL);
127 	system->cycles = sys_cycles;
128 	system->cs_id = CSID_X86_ART;
129 
130 	return 0;
131 }
132 
133 /**
134  * e1000e_phc_getcrosststamp - Reads the current system/device cross timestamp
135  * @ptp: ptp clock structure
136  * @xtstamp: structure containing timestamp
137  *
138  * Read device and system (ART) clock simultaneously and return the scaled
139  * clock values in ns.
140  **/
141 static int e1000e_phc_getcrosststamp(struct ptp_clock_info *ptp,
142 				     struct system_device_crosststamp *xtstamp)
143 {
144 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
145 						     ptp_clock_info);
146 
147 	return get_device_system_crosststamp(e1000e_phc_get_syncdevicetime,
148 						adapter, NULL, xtstamp);
149 }
150 #endif/*CONFIG_E1000E_HWTS*/
151 
152 /**
153  * e1000e_phc_gettimex - Reads the current time from the hardware clock and
154  *                       system clock
155  * @ptp: ptp clock structure
156  * @ts: timespec structure to hold the current PHC time
157  * @sts: structure to hold the current system time
158  *
159  * Read the timecounter and return the correct value in ns after converting
160  * it into a struct timespec.
161  **/
162 static int e1000e_phc_gettimex(struct ptp_clock_info *ptp,
163 			       struct timespec64 *ts,
164 			       struct ptp_system_timestamp *sts)
165 {
166 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
167 						     ptp_clock_info);
168 	unsigned long flags;
169 	u64 cycles, ns;
170 
171 	spin_lock_irqsave(&adapter->systim_lock, flags);
172 
173 	/* NOTE: Non-monotonic SYSTIM readings may be returned */
174 	cycles = e1000e_read_systim(adapter, sts);
175 	ns = timecounter_cyc2time(&adapter->tc, cycles);
176 
177 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
178 
179 	*ts = ns_to_timespec64(ns);
180 
181 	return 0;
182 }
183 
184 /**
185  * e1000e_phc_settime - Set the current time on the hardware clock
186  * @ptp: ptp clock structure
187  * @ts: timespec containing the new time for the cycle counter
188  *
189  * Reset the timecounter to use a new base value instead of the kernel
190  * wall timer value.
191  **/
192 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
193 			      const struct timespec64 *ts)
194 {
195 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
196 						     ptp_clock_info);
197 	unsigned long flags;
198 	u64 ns;
199 
200 	ns = timespec64_to_ns(ts);
201 
202 	/* reset the timecounter */
203 	spin_lock_irqsave(&adapter->systim_lock, flags);
204 	timecounter_init(&adapter->tc, &adapter->cc, ns);
205 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
206 
207 	return 0;
208 }
209 
210 /**
211  * e1000e_phc_enable - enable or disable an ancillary feature
212  * @ptp: ptp clock structure
213  * @request: Desired resource to enable or disable
214  * @on: Caller passes one to enable or zero to disable
215  *
216  * Enable (or disable) ancillary features of the PHC subsystem.
217  * Currently, no ancillary features are supported.
218  **/
219 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
220 			     struct ptp_clock_request __always_unused *request,
221 			     int __always_unused on)
222 {
223 	return -EOPNOTSUPP;
224 }
225 
226 static void e1000e_systim_overflow_work(struct work_struct *work)
227 {
228 	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
229 						     systim_overflow_work.work);
230 	struct e1000_hw *hw = &adapter->hw;
231 	struct timespec64 ts;
232 	u64 ns;
233 
234 	/* Update the timecounter */
235 	ns = timecounter_read(&adapter->tc);
236 
237 	ts = ns_to_timespec64(ns);
238 	e_dbg("SYSTIM overflow check at %lld.%09lu\n",
239 	      (long long) ts.tv_sec, ts.tv_nsec);
240 
241 	schedule_delayed_work(&adapter->systim_overflow_work,
242 			      E1000_SYSTIM_OVERFLOW_PERIOD);
243 }
244 
245 static const struct ptp_clock_info e1000e_ptp_clock_info = {
246 	.owner		= THIS_MODULE,
247 	.n_alarm	= 0,
248 	.n_ext_ts	= 0,
249 	.n_per_out	= 0,
250 	.n_pins		= 0,
251 	.pps		= 0,
252 	.adjfine	= e1000e_phc_adjfine,
253 	.adjtime	= e1000e_phc_adjtime,
254 	.gettimex64	= e1000e_phc_gettimex,
255 	.settime64	= e1000e_phc_settime,
256 	.enable		= e1000e_phc_enable,
257 };
258 
259 /**
260  * e1000e_ptp_init - initialize PTP for devices which support it
261  * @adapter: board private structure
262  *
263  * This function performs the required steps for enabling PTP support.
264  * If PTP support has already been loaded it simply calls the cyclecounter
265  * init routine and exits.
266  **/
267 void e1000e_ptp_init(struct e1000_adapter *adapter)
268 {
269 	struct e1000_hw *hw = &adapter->hw;
270 
271 	adapter->ptp_clock = NULL;
272 
273 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
274 		return;
275 
276 	adapter->ptp_clock_info = e1000e_ptp_clock_info;
277 
278 	snprintf(adapter->ptp_clock_info.name,
279 		 sizeof(adapter->ptp_clock_info.name), "%pm",
280 		 adapter->netdev->perm_addr);
281 
282 	switch (hw->mac.type) {
283 	case e1000_pch2lan:
284 		adapter->ptp_clock_info.max_adj = MAX_PPB_96MHZ;
285 		break;
286 	case e1000_pch_lpt:
287 		if (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)
288 			adapter->ptp_clock_info.max_adj = MAX_PPB_96MHZ;
289 		else
290 			adapter->ptp_clock_info.max_adj = MAX_PPB_25MHZ;
291 		break;
292 	case e1000_pch_spt:
293 		adapter->ptp_clock_info.max_adj = MAX_PPB_24MHZ;
294 		break;
295 	case e1000_pch_cnp:
296 	case e1000_pch_tgp:
297 	case e1000_pch_adp:
298 	case e1000_pch_mtp:
299 	case e1000_pch_lnp:
300 	case e1000_pch_ptp:
301 	case e1000_pch_nvp:
302 		if (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)
303 			adapter->ptp_clock_info.max_adj = MAX_PPB_24MHZ;
304 		else
305 			adapter->ptp_clock_info.max_adj = MAX_PPB_38400KHZ;
306 		break;
307 	case e1000_82574:
308 	case e1000_82583:
309 		adapter->ptp_clock_info.max_adj = MAX_PPB_25MHZ;
310 		break;
311 	default:
312 		break;
313 	}
314 
315 #ifdef CONFIG_E1000E_HWTS
316 	/* CPU must have ART and GBe must be from Sunrise Point or greater */
317 	if (hw->mac.type >= e1000_pch_spt && boot_cpu_has(X86_FEATURE_ART))
318 		adapter->ptp_clock_info.getcrosststamp =
319 			e1000e_phc_getcrosststamp;
320 #endif/*CONFIG_E1000E_HWTS*/
321 
322 	INIT_DELAYED_WORK(&adapter->systim_overflow_work,
323 			  e1000e_systim_overflow_work);
324 
325 	schedule_delayed_work(&adapter->systim_overflow_work,
326 			      E1000_SYSTIM_OVERFLOW_PERIOD);
327 
328 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
329 						&adapter->pdev->dev);
330 	if (IS_ERR(adapter->ptp_clock)) {
331 		adapter->ptp_clock = NULL;
332 		e_err("ptp_clock_register failed\n");
333 	} else if (adapter->ptp_clock) {
334 		e_info("registered PHC clock\n");
335 	}
336 }
337 
338 /**
339  * e1000e_ptp_remove - disable PTP device and stop the overflow check
340  * @adapter: board private structure
341  *
342  * Stop the PTP support, and cancel the delayed work.
343  **/
344 void e1000e_ptp_remove(struct e1000_adapter *adapter)
345 {
346 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
347 		return;
348 
349 	cancel_delayed_work_sync(&adapter->systim_overflow_work);
350 
351 	if (adapter->ptp_clock) {
352 		ptp_clock_unregister(adapter->ptp_clock);
353 		adapter->ptp_clock = NULL;
354 		e_info("removed PHC\n");
355 	}
356 }
357