1 /*******************************************************************************
2 
3   Intel PRO/1000 Linux driver
4   Copyright(c) 1999 - 2013 Intel Corporation.
5 
6   This program is free software; you can redistribute it and/or modify it
7   under the terms and conditions of the GNU General Public License,
8   version 2, as published by the Free Software Foundation.
9 
10   This program is distributed in the hope it will be useful, but WITHOUT
11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13   more details.
14 
15   You should have received a copy of the GNU General Public License along with
16   this program; if not, write to the Free Software Foundation, Inc.,
17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 
19   The full GNU General Public License is included in this distribution in
20   the file called "COPYING".
21 
22   Contact Information:
23   Linux NICS <linux.nics@intel.com>
24   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
25   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
26 
27 *******************************************************************************/
28 
29 /* PTP 1588 Hardware Clock (PHC)
30  * Derived from PTP Hardware Clock driver for Intel 82576 and 82580 (igb)
31  * Copyright (C) 2011 Richard Cochran <richardcochran@gmail.com>
32  */
33 
34 #include "e1000.h"
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 	u64 adjustment;
51 	u32 timinca, incvalue;
52 	s32 ret_val;
53 
54 	if ((delta > ptp->max_adj) || (delta <= -1000000000))
55 		return -EINVAL;
56 
57 	if (delta < 0) {
58 		neg_adj = true;
59 		delta = -delta;
60 	}
61 
62 	/* Get the System Time Register SYSTIM base frequency */
63 	ret_val = e1000e_get_base_timinca(adapter, &timinca);
64 	if (ret_val)
65 		return ret_val;
66 
67 	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
68 
69 	adjustment = incvalue;
70 	adjustment *= delta;
71 	adjustment = div_u64(adjustment, 1000000000);
72 
73 	incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
74 
75 	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
76 	timinca |= incvalue;
77 
78 	ew32(TIMINCA, timinca);
79 
80 	return 0;
81 }
82 
83 /**
84  * e1000e_phc_adjtime - Shift the time of the hardware clock
85  * @ptp: ptp clock structure
86  * @delta: Desired change in nanoseconds
87  *
88  * Adjust the timer by resetting the timecounter structure.
89  **/
90 static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
91 {
92 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
93 						     ptp_clock_info);
94 	unsigned long flags;
95 	s64 now;
96 
97 	spin_lock_irqsave(&adapter->systim_lock, flags);
98 	now = timecounter_read(&adapter->tc);
99 	now += delta;
100 	timecounter_init(&adapter->tc, &adapter->cc, now);
101 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
102 
103 	return 0;
104 }
105 
106 /**
107  * e1000e_phc_gettime - Reads the current time from the hardware clock
108  * @ptp: ptp clock structure
109  * @ts: timespec structure to hold the current time value
110  *
111  * Read the timecounter and return the correct value in ns after converting
112  * it into a struct timespec.
113  **/
114 static int e1000e_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
115 {
116 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
117 						     ptp_clock_info);
118 	unsigned long flags;
119 	u32 remainder;
120 	u64 ns;
121 
122 	spin_lock_irqsave(&adapter->systim_lock, flags);
123 	ns = timecounter_read(&adapter->tc);
124 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
125 
126 	ts->tv_sec = div_u64_rem(ns, NSEC_PER_SEC, &remainder);
127 	ts->tv_nsec = remainder;
128 
129 	return 0;
130 }
131 
132 /**
133  * e1000e_phc_settime - Set the current time on the hardware clock
134  * @ptp: ptp clock structure
135  * @ts: timespec containing the new time for the cycle counter
136  *
137  * Reset the timecounter to use a new base value instead of the kernel
138  * wall timer value.
139  **/
140 static int e1000e_phc_settime(struct ptp_clock_info *ptp,
141 			      const struct timespec *ts)
142 {
143 	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
144 						     ptp_clock_info);
145 	unsigned long flags;
146 	u64 ns;
147 
148 	ns = ts->tv_sec * NSEC_PER_SEC;
149 	ns += ts->tv_nsec;
150 
151 	/* reset the timecounter */
152 	spin_lock_irqsave(&adapter->systim_lock, flags);
153 	timecounter_init(&adapter->tc, &adapter->cc, ns);
154 	spin_unlock_irqrestore(&adapter->systim_lock, flags);
155 
156 	return 0;
157 }
158 
159 /**
160  * e1000e_phc_enable - enable or disable an ancillary feature
161  * @ptp: ptp clock structure
162  * @request: Desired resource to enable or disable
163  * @on: Caller passes one to enable or zero to disable
164  *
165  * Enable (or disable) ancillary features of the PHC subsystem.
166  * Currently, no ancillary features are supported.
167  **/
168 static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
169 			     struct ptp_clock_request __always_unused *request,
170 			     int __always_unused on)
171 {
172 	return -EOPNOTSUPP;
173 }
174 
175 static void e1000e_systim_overflow_work(struct work_struct *work)
176 {
177 	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
178 						     systim_overflow_work.work);
179 	struct e1000_hw *hw = &adapter->hw;
180 	struct timespec ts;
181 
182 	adapter->ptp_clock_info.gettime(&adapter->ptp_clock_info, &ts);
183 
184 	e_dbg("SYSTIM overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
185 
186 	schedule_delayed_work(&adapter->systim_overflow_work,
187 			      E1000_SYSTIM_OVERFLOW_PERIOD);
188 }
189 
190 static const struct ptp_clock_info e1000e_ptp_clock_info = {
191 	.owner		= THIS_MODULE,
192 	.n_alarm	= 0,
193 	.n_ext_ts	= 0,
194 	.n_per_out	= 0,
195 	.pps		= 0,
196 	.adjfreq	= e1000e_phc_adjfreq,
197 	.adjtime	= e1000e_phc_adjtime,
198 	.gettime	= e1000e_phc_gettime,
199 	.settime	= e1000e_phc_settime,
200 	.enable		= e1000e_phc_enable,
201 };
202 
203 /**
204  * e1000e_ptp_init - initialize PTP for devices which support it
205  * @adapter: board private structure
206  *
207  * This function performs the required steps for enabling PTP support.
208  * If PTP support has already been loaded it simply calls the cyclecounter
209  * init routine and exits.
210  **/
211 void e1000e_ptp_init(struct e1000_adapter *adapter)
212 {
213 	struct e1000_hw *hw = &adapter->hw;
214 
215 	adapter->ptp_clock = NULL;
216 
217 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
218 		return;
219 
220 	adapter->ptp_clock_info = e1000e_ptp_clock_info;
221 
222 	snprintf(adapter->ptp_clock_info.name,
223 		 sizeof(adapter->ptp_clock_info.name), "%pm",
224 		 adapter->netdev->perm_addr);
225 
226 	switch (hw->mac.type) {
227 	case e1000_pch2lan:
228 	case e1000_pch_lpt:
229 		if ((hw->mac.type != e1000_pch_lpt) ||
230 		    (er32(TSYNCRXCTL) & E1000_TSYNCRXCTL_SYSCFI)) {
231 			adapter->ptp_clock_info.max_adj = 24000000 - 1;
232 			break;
233 		}
234 		/* fall-through */
235 	case e1000_82574:
236 	case e1000_82583:
237 		adapter->ptp_clock_info.max_adj = 600000000 - 1;
238 		break;
239 	default:
240 		break;
241 	}
242 
243 	INIT_DELAYED_WORK(&adapter->systim_overflow_work,
244 			  e1000e_systim_overflow_work);
245 
246 	schedule_delayed_work(&adapter->systim_overflow_work,
247 			      E1000_SYSTIM_OVERFLOW_PERIOD);
248 
249 	adapter->ptp_clock = ptp_clock_register(&adapter->ptp_clock_info,
250 						&adapter->pdev->dev);
251 	if (IS_ERR(adapter->ptp_clock)) {
252 		adapter->ptp_clock = NULL;
253 		e_err("ptp_clock_register failed\n");
254 	} else {
255 		e_info("registered PHC clock\n");
256 	}
257 }
258 
259 /**
260  * e1000e_ptp_remove - disable PTP device and stop the overflow check
261  * @adapter: board private structure
262  *
263  * Stop the PTP support, and cancel the delayed work.
264  **/
265 void e1000e_ptp_remove(struct e1000_adapter *adapter)
266 {
267 	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
268 		return;
269 
270 	cancel_delayed_work_sync(&adapter->systim_overflow_work);
271 
272 	if (adapter->ptp_clock) {
273 		ptp_clock_unregister(adapter->ptp_clock);
274 		adapter->ptp_clock = NULL;
275 		e_info("removed PHC\n");
276 	}
277 }
278