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  **/
e1000e_phc_adjfine(struct ptp_clock_info * ptp,long delta)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 	bool neg_adj = false;
33 	unsigned long flags;
34 	u64 adjustment;
35 	u32 timinca, incvalue;
36 	s32 ret_val;
37 
38 	if (delta < 0) {
39 		neg_adj = true;
40 		delta = -delta;
41 	}
42 
43 	/* Get the System Time Register SYSTIM base frequency */
44 	ret_val = e1000e_get_base_timinca(adapter, &timinca);
45 	if (ret_val)
46 		return ret_val;
47 
48 	spin_lock_irqsave(&adapter->systim_lock, flags);
49 
50 	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
51 
52 	adjustment = mul_u64_u64_div_u64(incvalue, (u64)delta,
53 					 1000000ULL << 16);
54 
55 	incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
56 
57 	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
58 	timinca |= incvalue;
59 
60 	ew32(TIMINCA, timinca);
61 
62 	adapter->ptp_delta = delta;
63 
64 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
65 
66 	return 0;
67 }
68 
69 /**
70  * e1000e_phc_adjtime - Shift the time of the hardware clock
71  * @ptp: ptp clock structure
72  * @delta: Desired change in nanoseconds
73  *
74  * Adjust the timer by resetting the timecounter structure.
75  **/
e1000e_phc_adjtime(struct ptp_clock_info * ptp,s64 delta)76 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
77 {
78 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
79 						     ptp_clock_info);
80 	unsigned long flags;
81 
82 	spin_lock_irqsave(&adapter->systim_lock, flags);
83 	timecounter_adjtime(&adapter->tc, delta);
84 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
85 
86 	return 0;
87 }
88 
89 #ifdef CONFIG_E1000E_HWTS
90 #define MAX_HW_WAIT_COUNT (3)
91 
92 /**
93  * e1000e_phc_get_syncdevicetime - Callback given to timekeeping code reads system/device registers
94  * @device: current device time
95  * @system: system counter value read synchronously with device time
96  * @ctx: context provided by timekeeping code
97  *
98  * Read device and system (ART) clock simultaneously and return the corrected
99  * clock values in ns.
100  **/
e1000e_phc_get_syncdevicetime(ktime_t * device,struct system_counterval_t * system,void * ctx)101 static int e1000e_phc_get_syncdevicetime(ktime_t *device,
102 					 struct system_counterval_t *system,
103 					 void *ctx)
104 {
105 	struct e1000_adapter *adapter = (struct e1000_adapter *)ctx;
106 	struct e1000_hw *hw = &adapter->hw;
107 	unsigned long flags;
108 	int i;
109 	u32 tsync_ctrl;
110 	u64 dev_cycles;
111 	u64 sys_cycles;
112 
113 	tsync_ctrl = er32(TSYNCTXCTL);
114 	tsync_ctrl |= E1000_TSYNCTXCTL_START_SYNC |
115 		E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK;
116 	ew32(TSYNCTXCTL, tsync_ctrl);
117 	for (i = 0; i < MAX_HW_WAIT_COUNT; ++i) {
118 		udelay(1);
119 		tsync_ctrl = er32(TSYNCTXCTL);
120 		if (tsync_ctrl & E1000_TSYNCTXCTL_SYNC_COMP)
121 			break;
122 	}
123 
124 	if (i == MAX_HW_WAIT_COUNT)
125 		return -ETIMEDOUT;
126 
127 	dev_cycles = er32(SYSSTMPH);
128 	dev_cycles <<= 32;
129 	dev_cycles |= er32(SYSSTMPL);
130 	spin_lock_irqsave(&adapter->systim_lock, flags);
131 	*device = ns_to_ktime(timecounter_cyc2time(&adapter->tc, dev_cycles));
132 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
133 
134 	sys_cycles = er32(PLTSTMPH);
135 	sys_cycles <<= 32;
136 	sys_cycles |= er32(PLTSTMPL);
137 	*system = convert_art_to_tsc(sys_cycles);
138 
139 	return 0;
140 }
141 
142 /**
143  * e1000e_phc_getcrosststamp - Reads the current system/device cross timestamp
144  * @ptp: ptp clock structure
145  * @xtstamp: structure containing timestamp
146  *
147  * Read device and system (ART) clock simultaneously and return the scaled
148  * clock values in ns.
149  **/
e1000e_phc_getcrosststamp(struct ptp_clock_info * ptp,struct system_device_crosststamp * xtstamp)150 static int e1000e_phc_getcrosststamp(struct ptp_clock_info *ptp,
151 				     struct system_device_crosststamp *xtstamp)
152 {
153 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
154 						     ptp_clock_info);
155 
156 	return get_device_system_crosststamp(e1000e_phc_get_syncdevicetime,
157 						adapter, NULL, xtstamp);
158 }
159 #endif/*CONFIG_E1000E_HWTS*/
160 
161 /**
162  * e1000e_phc_gettimex - Reads the current time from the hardware clock and
163  *                       system clock
164  * @ptp: ptp clock structure
165  * @ts: timespec structure to hold the current PHC time
166  * @sts: structure to hold the current system time
167  *
168  * Read the timecounter and return the correct value in ns after converting
169  * it into a struct timespec.
170  **/
e1000e_phc_gettimex(struct ptp_clock_info * ptp,struct timespec64 * ts,struct ptp_system_timestamp * sts)171 static int e1000e_phc_gettimex(struct ptp_clock_info *ptp,
172 			       struct timespec64 *ts,
173 			       struct ptp_system_timestamp *sts)
174 {
175 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
176 						     ptp_clock_info);
177 	unsigned long flags;
178 	u64 cycles, ns;
179 
180 	spin_lock_irqsave(&adapter->systim_lock, flags);
181 
182 	/* NOTE: Non-monotonic SYSTIM readings may be returned */
183 	cycles = e1000e_read_systim(adapter, sts);
184 	ns = timecounter_cyc2time(&adapter->tc, cycles);
185 
186 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
187 
188 	*ts = ns_to_timespec64(ns);
189 
190 	return 0;
191 }
192 
193 /**
194  * e1000e_phc_settime - Set the current time on the hardware clock
195  * @ptp: ptp clock structure
196  * @ts: timespec containing the new time for the cycle counter
197  *
198  * Reset the timecounter to use a new base value instead of the kernel
199  * wall timer value.
200  **/
e1000e_phc_settime(struct ptp_clock_info * ptp,const struct timespec64 * ts)201 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
202 			      const struct timespec64 *ts)
203 {
204 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
205 						     ptp_clock_info);
206 	unsigned long flags;
207 	u64 ns;
208 
209 	ns = timespec64_to_ns(ts);
210 
211 	/* reset the timecounter */
212 	spin_lock_irqsave(&adapter->systim_lock, flags);
213 	timecounter_init(&adapter->tc, &adapter->cc, ns);
214 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
215 
216 	return 0;
217 }
218 
219 /**
220  * e1000e_phc_enable - enable or disable an ancillary feature
221  * @ptp: ptp clock structure
222  * @request: Desired resource to enable or disable
223  * @on: Caller passes one to enable or zero to disable
224  *
225  * Enable (or disable) ancillary features of the PHC subsystem.
226  * Currently, no ancillary features are supported.
227  **/
e1000e_phc_enable(struct ptp_clock_info __always_unused * ptp,struct ptp_clock_request __always_unused * request,int __always_unused on)228 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
229 			     struct ptp_clock_request __always_unused *request,
230 			     int __always_unused on)
231 {
232 	return -EOPNOTSUPP;
233 }
234 
e1000e_systim_overflow_work(struct work_struct * work)235 static void e1000e_systim_overflow_work(struct work_struct *work)
236 {
237 	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
238 						     systim_overflow_work.work);
239 	struct e1000_hw *hw = &adapter->hw;
240 	struct timespec64 ts;
241 	u64 ns;
242 
243 	/* Update the timecounter */
244 	ns = timecounter_read(&adapter->tc);
245 
246 	ts = ns_to_timespec64(ns);
247 	e_dbg("SYSTIM overflow check at %lld.%09lu\n",
248 	      (long long) ts.tv_sec, ts.tv_nsec);
249 
250 	schedule_delayed_work(&adapter->systim_overflow_work,
251 			      E1000_SYSTIM_OVERFLOW_PERIOD);
252 }
253 
254 static const struct ptp_clock_info e1000e_ptp_clock_info = {
255 	.owner		= THIS_MODULE,
256 	.n_alarm	= 0,
257 	.n_ext_ts	= 0,
258 	.n_per_out	= 0,
259 	.n_pins		= 0,
260 	.pps		= 0,
261 	.adjfine	= e1000e_phc_adjfine,
262 	.adjtime	= e1000e_phc_adjtime,
263 	.gettimex64	= e1000e_phc_gettimex,
264 	.settime64	= e1000e_phc_settime,
265 	.enable		= e1000e_phc_enable,
266 };
267 
268 /**
269  * e1000e_ptp_init - initialize PTP for devices which support it
270  * @adapter: board private structure
271  *
272  * This function performs the required steps for enabling PTP support.
273  * If PTP support has already been loaded it simply calls the cyclecounter
274  * init routine and exits.
275  **/
e1000e_ptp_init(struct e1000_adapter * adapter)276 void e1000e_ptp_init(struct e1000_adapter *adapter)
277 {
278 	struct e1000_hw *hw = &adapter->hw;
279 
280 	adapter->ptp_clock = NULL;
281 
282 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
283 		return;
284 
285 	adapter->ptp_clock_info = e1000e_ptp_clock_info;
286 
287 	snprintf(adapter->ptp_clock_info.name,
288 		 sizeof(adapter->ptp_clock_info.name), "%pm",
289 		 adapter->netdev->perm_addr);
290 
291 	switch (hw->mac.type) {
292 	case e1000_pch2lan:
293 	case e1000_pch_lpt:
294 	case e1000_pch_spt:
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 		if ((hw->mac.type < e1000_pch_lpt) ||
301 		    (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
302 			adapter->ptp_clock_info.max_adj = 24000000 - 1;
303 			break;
304 		}
305 		fallthrough;
306 	case e1000_82574:
307 	case e1000_82583:
308 		adapter->ptp_clock_info.max_adj = 600000000 - 1;
309 		break;
310 	default:
311 		break;
312 	}
313 
314 #ifdef CONFIG_E1000E_HWTS
315 	/* CPU must have ART and GBe must be from Sunrise Point or greater */
316 	if (hw->mac.type >= e1000_pch_spt && boot_cpu_has(X86_FEATURE_ART))
317 		adapter->ptp_clock_info.getcrosststamp =
318 			e1000e_phc_getcrosststamp;
319 #endif/*CONFIG_E1000E_HWTS*/
320 
321 	INIT_DELAYED_WORK(&adapter->systim_overflow_work,
322 			  e1000e_systim_overflow_work);
323 
324 	schedule_delayed_work(&adapter->systim_overflow_work,
325 			      E1000_SYSTIM_OVERFLOW_PERIOD);
326 
327 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
328 						&adapter->pdev->dev);
329 	if (IS_ERR(adapter->ptp_clock)) {
330 		adapter->ptp_clock = NULL;
331 		e_err("ptp_clock_register failed\n");
332 	} else if (adapter->ptp_clock) {
333 		e_info("registered PHC clock\n");
334 	}
335 }
336 
337 /**
338  * e1000e_ptp_remove - disable PTP device and stop the overflow check
339  * @adapter: board private structure
340  *
341  * Stop the PTP support, and cancel the delayed work.
342  **/
e1000e_ptp_remove(struct e1000_adapter * adapter)343 void e1000e_ptp_remove(struct e1000_adapter *adapter)
344 {
345 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
346 		return;
347 
348 	cancel_delayed_work_sync(&adapter->systim_overflow_work);
349 
350 	if (adapter->ptp_clock) {
351 		ptp_clock_unregister(adapter->ptp_clock);
352 		adapter->ptp_clock = NULL;
353 		e_info("removed PHC\n");
354 	}
355 }
356