1 /* Intel PRO/1000 Linux driver
2  * Copyright(c) 1999 - 2014 Intel Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * The full GNU General Public License is included in this distribution in
14  * the file called "COPYING".
15  *
16  * Contact Information:
17  * Linux NICS <linux.nics@intel.com>
18  * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
19  * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
20  */
21 
22 /* PTP 1588 Hardware Clock (PHC)
23  * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
24  * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
25  */
26 
27 #include "e1000.h"
28 
29 /**
30  * e1000e_phc_adjfreq - adjust the frequency of the hardware clock
31  * @ptp: ptp clock structure
32  * @delta: Desired frequency change in parts per billion
33  *
34  * Adjust the frequency of the PHC cycle counter by the indicated delta from
35  * the base frequency.
36  **/
37 static int e1000e_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
38 {
39 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
40 						     ptp_clock_info);
41 	struct e1000_hw *hw = &adapter->hw;
42 	bool neg_adj = false;
43 	unsigned long flags;
44 	u64 adjustment;
45 	u32 timinca, incvalue;
46 	s32 ret_val;
47 
48 	if ((delta > ptp->max_adj) || (delta <= -1000000000))
49 		return -EINVAL;
50 
51 	if (delta < 0) {
52 		neg_adj = true;
53 		delta = -delta;
54 	}
55 
56 	/* Get the System Time Register SYSTIM base frequency */
57 	ret_val = e1000e_get_base_timinca(adapter, &timinca);
58 	if (ret_val)
59 		return ret_val;
60 
61 	spin_lock_irqsave(&adapter->systim_lock, flags);
62 
63 	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
64 
65 	adjustment = incvalue;
66 	adjustment *= delta;
67 	adjustment = div_u64(adjustment, 1000000000);
68 
69 	incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
70 
71 	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
72 	timinca |= incvalue;
73 
74 	ew32(TIMINCA, timinca);
75 
76 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
77 
78 	return 0;
79 }
80 
81 /**
82  * e1000e_phc_adjtime - Shift the time of the hardware clock
83  * @ptp: ptp clock structure
84  * @delta: Desired change in nanoseconds
85  *
86  * Adjust the timer by resetting the timecounter structure.
87  **/
88 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
89 {
90 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
91 						     ptp_clock_info);
92 	unsigned long flags;
93 	s64 now;
94 
95 	spin_lock_irqsave(&adapter->systim_lock, flags);
96 	now = timecounter_read(&adapter->tc);
97 	now += delta;
98 	timecounter_init(&adapter->tc, &adapter->cc, now);
99 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
100 
101 	return 0;
102 }
103 
104 /**
105  * e1000e_phc_gettime - Reads the current time from the hardware clock
106  * @ptp: ptp clock structure
107  * @ts: timespec structure to hold the current time value
108  *
109  * Read the timecounter and return the correct value in ns after converting
110  * it into a struct timespec.
111  **/
112 static int e1000e_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
113 {
114 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
115 						     ptp_clock_info);
116 	unsigned long flags;
117 	u32 remainder;
118 	u64 ns;
119 
120 	spin_lock_irqsave(&adapter->systim_lock, flags);
121 	ns = timecounter_read(&adapter->tc);
122 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
123 
124 	ts->tv_sec = div_u64_rem(ns, NSEC_PER_SEC, &remainder);
125 	ts->tv_nsec = remainder;
126 
127 	return 0;
128 }
129 
130 /**
131  * e1000e_phc_settime - Set the current time on the hardware clock
132  * @ptp: ptp clock structure
133  * @ts: timespec containing the new time for the cycle counter
134  *
135  * Reset the timecounter to use a new base value instead of the kernel
136  * wall timer value.
137  **/
138 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
139 			      const struct timespec *ts)
140 {
141 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
142 						     ptp_clock_info);
143 	unsigned long flags;
144 	u64 ns;
145 
146 	ns = timespec_to_ns(ts);
147 
148 	/* reset the timecounter */
149 	spin_lock_irqsave(&adapter->systim_lock, flags);
150 	timecounter_init(&adapter->tc, &adapter->cc, ns);
151 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
152 
153 	return 0;
154 }
155 
156 /**
157  * e1000e_phc_enable - enable or disable an ancillary feature
158  * @ptp: ptp clock structure
159  * @request: Desired resource to enable or disable
160  * @on: Caller passes one to enable or zero to disable
161  *
162  * Enable (or disable) ancillary features of the PHC subsystem.
163  * Currently, no ancillary features are supported.
164  **/
165 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
166 			     struct ptp_clock_request __always_unused *request,
167 			     int __always_unused on)
168 {
169 	return -EOPNOTSUPP;
170 }
171 
172 static void e1000e_systim_overflow_work(struct work_struct *work)
173 {
174 	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
175 						     systim_overflow_work.work);
176 	struct e1000_hw *hw = &adapter->hw;
177 	struct timespec ts;
178 
179 	adapter->ptp_clock_info.gettime(&adapter->ptp_clock_info, &ts);
180 
181 	e_dbg("SYSTIM overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
182 
183 	schedule_delayed_work(&adapter->systim_overflow_work,
184 			      E1000_SYSTIM_OVERFLOW_PERIOD);
185 }
186 
187 static const struct ptp_clock_info e1000e_ptp_clock_info = {
188 	.owner		= THIS_MODULE,
189 	.n_alarm	= 0,
190 	.n_ext_ts	= 0,
191 	.n_per_out	= 0,
192 	.n_pins		= 0,
193 	.pps		= 0,
194 	.adjfreq	= e1000e_phc_adjfreq,
195 	.adjtime	= e1000e_phc_adjtime,
196 	.gettime	= e1000e_phc_gettime,
197 	.settime	= e1000e_phc_settime,
198 	.enable		= e1000e_phc_enable,
199 };
200 
201 /**
202  * e1000e_ptp_init - initialize PTP for devices which support it
203  * @adapter: board private structure
204  *
205  * This function performs the required steps for enabling PTP support.
206  * If PTP support has already been loaded it simply calls the cyclecounter
207  * init routine and exits.
208  **/
209 void e1000e_ptp_init(struct e1000_adapter *adapter)
210 {
211 	struct e1000_hw *hw = &adapter->hw;
212 
213 	adapter->ptp_clock = NULL;
214 
215 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
216 		return;
217 
218 	adapter->ptp_clock_info = e1000e_ptp_clock_info;
219 
220 	snprintf(adapter->ptp_clock_info.name,
221 		 sizeof(adapter->ptp_clock_info.name), "%pm",
222 		 adapter->netdev->perm_addr);
223 
224 	switch (hw->mac.type) {
225 	case e1000_pch2lan:
226 	case e1000_pch_lpt:
227 		if ((hw->mac.type != e1000_pch_lpt) ||
228 		    (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
229 			adapter->ptp_clock_info.max_adj = 24000000 - 1;
230 			break;
231 		}
232 		/* fall-through */
233 	case e1000_82574:
234 	case e1000_82583:
235 		adapter->ptp_clock_info.max_adj = 600000000 - 1;
236 		break;
237 	default:
238 		break;
239 	}
240 
241 	INIT_DELAYED_WORK(&adapter->systim_overflow_work,
242 			  e1000e_systim_overflow_work);
243 
244 	schedule_delayed_work(&adapter->systim_overflow_work,
245 			      E1000_SYSTIM_OVERFLOW_PERIOD);
246 
247 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
248 						&adapter->pdev->dev);
249 	if (IS_ERR(adapter->ptp_clock)) {
250 		adapter->ptp_clock = NULL;
251 		e_err("ptp_clock_register failed\n");
252 	} else {
253 		e_info("registered PHC clock\n");
254 	}
255 }
256 
257 /**
258  * e1000e_ptp_remove - disable PTP device and stop the overflow check
259  * @adapter: board private structure
260  *
261  * Stop the PTP support, and cancel the delayed work.
262  **/
263 void e1000e_ptp_remove(struct e1000_adapter *adapter)
264 {
265 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
266 		return;
267 
268 	cancel_delayed_work_sync(&adapter->systim_overflow_work);
269 
270 	if (adapter->ptp_clock) {
271 		ptp_clock_unregister(adapter->ptp_clock);
272 		adapter->ptp_clock = NULL;
273 		e_info("removed PHC\n");
274 	}
275 }
276