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  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_adjfreq - adjust the frequency of the hardware clock
 19 * @ptp: ptp clock structure
 20 * @delta: Desired frequency change in parts per billion
 21 *
 22 * Adjust the frequency of the PHC cycle counter by the indicated delta from
 23 * the base frequency.
 24 **/
 25static int e1000e_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta)
 26{
 27	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 28						     ptp_clock_info);
 29	struct e1000_hw *hw = &adapter->hw;
 30	bool neg_adj = false;
 31	unsigned long flags;
 32	u64 adjustment;
 33	u32 timinca, incvalue;
 34	s32 ret_val;
 35
 36	if ((delta > ptp->max_adj) || (delta <= -1000000000))
 37		return -EINVAL;
 38
 39	if (delta < 0) {
 40		neg_adj = true;
 41		delta = -delta;
 42	}
 43
 44	/* Get the System Time Register SYSTIM base frequency */
 45	ret_val = e1000e_get_base_timinca(adapter, &timinca);
 46	if (ret_val)
 47		return ret_val;
 48
 49	spin_lock_irqsave(&adapter->systim_lock, flags);
 50
 51	incvalue = timinca & E1000_TIMINCA_INCVALUE_MASK;
 52
 53	adjustment = incvalue;
 54	adjustment *= delta;
 55	adjustment = div_u64(adjustment, 1000000000);
 56
 57	incvalue = neg_adj ? (incvalue - adjustment) : (incvalue + adjustment);
 58
 59	timinca &= ~E1000_TIMINCA_INCVALUE_MASK;
 60	timinca |= incvalue;
 61
 62	ew32(TIMINCA, timinca);
 63
 64	adapter->ptp_delta = delta;
 65
 66	spin_unlock_irqrestore(&adapter->systim_lock, flags);
 67
 68	return 0;
 69}
 70
 71/**
 72 * e1000e_phc_adjtime - Shift the time of the hardware clock
 73 * @ptp: ptp clock structure
 74 * @delta: Desired change in nanoseconds
 75 *
 76 * Adjust the timer by resetting the timecounter structure.
 77 **/
 78static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)
 79{
 80	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
 81						     ptp_clock_info);
 82	unsigned long flags;
 83
 84	spin_lock_irqsave(&adapter->systim_lock, flags);
 85	timecounter_adjtime(&adapter->tc, delta);
 86	spin_unlock_irqrestore(&adapter->systim_lock, flags);
 87
 88	return 0;
 89}
 90
 91#ifdef CONFIG_E1000E_HWTS
 92#define MAX_HW_WAIT_COUNT (3)
 93
 94/**
 95 * e1000e_phc_get_syncdevicetime - Callback given to timekeeping code reads system/device registers
 96 * @device: current device time
 97 * @system: system counter value read synchronously with device time
 98 * @ctx: context provided by timekeeping code
 99 *
100 * Read device and system (ART) clock simultaneously and return the corrected
101 * clock values in ns.
102 **/
103static int e1000e_phc_get_syncdevicetime(ktime_t *device,
104					 struct system_counterval_t *system,
105					 void *ctx)
106{
107	struct e1000_adapter *adapter = (struct e1000_adapter *)ctx;
108	struct e1000_hw *hw = &adapter->hw;
109	unsigned long flags;
110	int i;
111	u32 tsync_ctrl;
112	u64 dev_cycles;
113	u64 sys_cycles;
114
115	tsync_ctrl = er32(TSYNCTXCTL);
116	tsync_ctrl |= E1000_TSYNCTXCTL_START_SYNC |
117		E1000_TSYNCTXCTL_MAX_ALLOWED_DLY_MASK;
118	ew32(TSYNCTXCTL, tsync_ctrl);
119	for (i = 0; i < MAX_HW_WAIT_COUNT; ++i) {
120		udelay(1);
121		tsync_ctrl = er32(TSYNCTXCTL);
122		if (tsync_ctrl & E1000_TSYNCTXCTL_SYNC_COMP)
123			break;
124	}
125
126	if (i == MAX_HW_WAIT_COUNT)
127		return -ETIMEDOUT;
128
129	dev_cycles = er32(SYSSTMPH);
130	dev_cycles <<= 32;
131	dev_cycles |= er32(SYSSTMPL);
132	spin_lock_irqsave(&adapter->systim_lock, flags);
133	*device = ns_to_ktime(timecounter_cyc2time(&adapter->tc, dev_cycles));
134	spin_unlock_irqrestore(&adapter->systim_lock, flags);
135
136	sys_cycles = er32(PLTSTMPH);
137	sys_cycles <<= 32;
138	sys_cycles |= er32(PLTSTMPL);
139	*system = convert_art_to_tsc(sys_cycles);
140
141	return 0;
142}
143
144/**
145 * e1000e_phc_getsynctime - Reads the current system/device cross timestamp
146 * @ptp: ptp clock structure
147 * @cts: structure containing timestamp
148 *
149 * Read device and system (ART) clock simultaneously and return the scaled
150 * clock values in ns.
151 **/
152static int e1000e_phc_getcrosststamp(struct ptp_clock_info *ptp,
153				     struct system_device_crosststamp *xtstamp)
154{
155	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
156						     ptp_clock_info);
157
158	return get_device_system_crosststamp(e1000e_phc_get_syncdevicetime,
159						adapter, NULL, xtstamp);
160}
161#endif/*CONFIG_E1000E_HWTS*/
162
163/**
164 * e1000e_phc_gettimex - Reads the current time from the hardware clock and
165 *                       system clock
166 * @ptp: ptp clock structure
167 * @ts: timespec structure to hold the current PHC time
168 * @sts: structure to hold the current system time
169 *
170 * Read the timecounter and return the correct value in ns after converting
171 * it into a struct timespec.
172 **/
173static int e1000e_phc_gettimex(struct ptp_clock_info *ptp,
174			       struct timespec64 *ts,
175			       struct ptp_system_timestamp *sts)
176{
177	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
178						     ptp_clock_info);
179	unsigned long flags;
180	u64 cycles, ns;
181
182	spin_lock_irqsave(&adapter->systim_lock, flags);
183
184	/* NOTE: Non-monotonic SYSTIM readings may be returned */
185	cycles = e1000e_read_systim(adapter, sts);
186	ns = timecounter_cyc2time(&adapter->tc, cycles);
187
188	spin_unlock_irqrestore(&adapter->systim_lock, flags);
189
190	*ts = ns_to_timespec64(ns);
191
192	return 0;
193}
194
195/**
196 * e1000e_phc_settime - Set the current time on the hardware clock
197 * @ptp: ptp clock structure
198 * @ts: timespec containing the new time for the cycle counter
199 *
200 * Reset the timecounter to use a new base value instead of the kernel
201 * wall timer value.
202 **/
203static int e1000e_phc_settime(struct ptp_clock_info *ptp,
204			      const struct timespec64 *ts)
205{
206	struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter,
207						     ptp_clock_info);
208	unsigned long flags;
209	u64 ns;
210
211	ns = timespec64_to_ns(ts);
212
213	/* reset the timecounter */
214	spin_lock_irqsave(&adapter->systim_lock, flags);
215	timecounter_init(&adapter->tc, &adapter->cc, ns);
216	spin_unlock_irqrestore(&adapter->systim_lock, flags);
217
218	return 0;
219}
220
221/**
222 * e1000e_phc_enable - enable or disable an ancillary feature
223 * @ptp: ptp clock structure
224 * @request: Desired resource to enable or disable
225 * @on: Caller passes one to enable or zero to disable
226 *
227 * Enable (or disable) ancillary features of the PHC subsystem.
228 * Currently, no ancillary features are supported.
229 **/
230static int e1000e_phc_enable(struct ptp_clock_info __always_unused *ptp,
231			     struct ptp_clock_request __always_unused *request,
232			     int __always_unused on)
233{
234	return -EOPNOTSUPP;
235}
236
237static void e1000e_systim_overflow_work(struct work_struct *work)
238{
239	struct e1000_adapter *adapter = container_of(work, struct e1000_adapter,
240						     systim_overflow_work.work);
241	struct e1000_hw *hw = &adapter->hw;
242	struct timespec64 ts;
243	u64 ns;
244
245	/* Update the timecounter */
246	ns = timecounter_read(&adapter->tc);
247
248	ts = ns_to_timespec64(ns);
249	e_dbg("SYSTIM overflow check at %lld.%09lu\n",
250	      (long long) ts.tv_sec, ts.tv_nsec);
251
252	schedule_delayed_work(&adapter->systim_overflow_work,
253			      E1000_SYSTIM_OVERFLOW_PERIOD);
254}
255
256static const struct ptp_clock_info e1000e_ptp_clock_info = {
257	.owner		= THIS_MODULE,
258	.n_alarm	= 0,
259	.n_ext_ts	= 0,
260	.n_per_out	= 0,
261	.n_pins		= 0,
262	.pps		= 0,
263	.adjfreq	= e1000e_phc_adjfreq,
264	.adjtime	= e1000e_phc_adjtime,
265	.gettimex64	= e1000e_phc_gettimex,
266	.settime64	= e1000e_phc_settime,
267	.enable		= e1000e_phc_enable,
268};
269
270/**
271 * e1000e_ptp_init - initialize PTP for devices which support it
272 * @adapter: board private structure
273 *
274 * This function performs the required steps for enabling PTP support.
275 * If PTP support has already been loaded it simply calls the cyclecounter
276 * init routine and exits.
277 **/
278void e1000e_ptp_init(struct e1000_adapter *adapter)
279{
280	struct e1000_hw *hw = &adapter->hw;
281
282	adapter->ptp_clock = NULL;
283
284	if (!(adapter->flags & FLAG_HAS_HW_TIMESTAMP))
285		return;
286
287	adapter->ptp_clock_info = e1000e_ptp_clock_info;
288
289	snprintf(adapter->ptp_clock_info.name,
290		 sizeof(adapter->ptp_clock_info.name), "%pm",
291		 adapter->netdev->perm_addr);
292
293	switch (hw->mac.type) {
294	case e1000_pch2lan:
295	case e1000_pch_lpt:
296	case e1000_pch_spt:
297	case e1000_pch_cnp:
298	case e1000_pch_tgp:
299	case e1000_pch_adp:
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 **/
343void 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}