1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
|
// SPDX-License-Identifier: (GPL-2.0 OR MIT)
/*
* DSA driver for:
* Hirschmann Hellcreek TSN switch.
*
* Copyright (C) 2019,2020 Hochschule Offenburg
* Copyright (C) 2019,2020 Linutronix GmbH
* Authors: Kamil Alkhouri <kamil.alkhouri@hs-offenburg.de>
* Kurt Kanzenbach <kurt@linutronix.de>
*/
#include <linux/ptp_clock_kernel.h>
#include "hellcreek.h"
#include "hellcreek_ptp.h"
static u16 hellcreek_ptp_read(struct hellcreek *hellcreek, unsigned int offset)
{
return readw(hellcreek->ptp_base + offset);
}
static void hellcreek_ptp_write(struct hellcreek *hellcreek, u16 data,
unsigned int offset)
{
writew(data, hellcreek->ptp_base + offset);
}
/* Get nanoseconds from PTP clock */
static u64 hellcreek_ptp_clock_read(struct hellcreek *hellcreek)
{
u16 nsl, nsh;
/* Take a snapshot */
hellcreek_ptp_write(hellcreek, PR_COMMAND_C_SS, PR_COMMAND_C);
/* The time of the day is saved as 96 bits. However, due to hardware
* limitations the seconds are not or only partly kept in the PTP
* core. Currently only three bits for the seconds are available. That's
* why only the nanoseconds are used and the seconds are tracked in
* software. Anyway due to internal locking all five registers should be
* read.
*/
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsh = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
nsl = hellcreek_ptp_read(hellcreek, PR_SS_SYNC_DATA_C);
return (u64)nsl | ((u64)nsh << 16);
}
static u64 __hellcreek_ptp_gettime(struct hellcreek *hellcreek)
{
u64 ns;
ns = hellcreek_ptp_clock_read(hellcreek);
if (ns < hellcreek->last_ts)
hellcreek->seconds++;
hellcreek->last_ts = ns;
ns += hellcreek->seconds * NSEC_PER_SEC;
return ns;
}
static int hellcreek_ptp_gettime(struct ptp_clock_info *ptp,
struct timespec64 *ts)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u64 ns;
mutex_lock(&hellcreek->ptp_lock);
ns = __hellcreek_ptp_gettime(hellcreek);
mutex_unlock(&hellcreek->ptp_lock);
*ts = ns_to_timespec64(ns);
return 0;
}
static int hellcreek_ptp_settime(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u16 secl, nsh, nsl;
secl = ts->tv_sec & 0xffff;
nsh = ((u32)ts->tv_nsec & 0xffff0000) >> 16;
nsl = ts->tv_nsec & 0xffff;
mutex_lock(&hellcreek->ptp_lock);
/* Update overflow data structure */
hellcreek->seconds = ts->tv_sec;
hellcreek->last_ts = ts->tv_nsec;
/* Set time in clock */
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, secl, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, nsh, PR_CLOCK_WRITE_C);
hellcreek_ptp_write(hellcreek, nsl, PR_CLOCK_WRITE_C);
mutex_unlock(&hellcreek->ptp_lock);
return 0;
}
static int hellcreek_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u16 negative = 0, addendh, addendl;
u32 addend;
u64 adj;
if (scaled_ppm < 0) {
negative = 1;
scaled_ppm = -scaled_ppm;
}
/* IP-Core adjusts the nominal frequency by adding or subtracting 1 ns
* from the 8 ns (period of the oscillator) every time the accumulator
* register overflows. The value stored in the addend register is added
* to the accumulator register every 8 ns.
*
* addend value = (2^30 * accumulator_overflow_rate) /
* oscillator_frequency
* where:
*
* oscillator_frequency = 125 MHz
* accumulator_overflow_rate = 125 MHz * scaled_ppm * 2^-16 * 10^-6 * 8
*/
adj = scaled_ppm;
adj <<= 11;
addend = (u32)div_u64(adj, 15625);
addendh = (addend & 0xffff0000) >> 16;
addendl = addend & 0xffff;
negative = (negative << 15) & 0x8000;
mutex_lock(&hellcreek->ptp_lock);
/* Set drift register */
hellcreek_ptp_write(hellcreek, negative, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, 0x00, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, addendh, PR_CLOCK_DRIFT_C);
hellcreek_ptp_write(hellcreek, addendl, PR_CLOCK_DRIFT_C);
mutex_unlock(&hellcreek->ptp_lock);
return 0;
}
static int hellcreek_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
struct hellcreek *hellcreek = ptp_to_hellcreek(ptp);
u16 negative = 0, counth, countl;
u32 count_val;
/* If the offset is larger than IP-Core slow offset resources. Don't
* consider slow adjustment. Rather, add the offset directly to the
* current time
*/
if (abs(delta) > MAX_SLOW_OFFSET_ADJ) {
struct timespec64 now, then = ns_to_timespec64(delta);
hellcreek_ptp_gettime(ptp, &now);
now = timespec64_add(now, then);
hellcreek_ptp_settime(ptp, &now);
return 0;
}
if (delta < 0) {
negative = 1;
delta = -delta;
}
/* 'count_val' does not exceed the maximum register size (2^30) */
count_val = div_s64(delta, MAX_NS_PER_STEP);
counth = (count_val & 0xffff0000) >> 16;
countl = count_val & 0xffff;
negative = (negative << 15) & 0x8000;
mutex_lock(&hellcreek->ptp_lock);
/* Set offset write register */
hellcreek_ptp_write(hellcreek, negative, PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, MAX_NS_PER_STEP, PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, MIN_CLK_CYCLES_BETWEEN_STEPS,
PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, countl, PR_CLOCK_OFFSET_C);
hellcreek_ptp_write(hellcreek, counth, PR_CLOCK_OFFSET_C);
mutex_unlock(&hellcreek->ptp_lock);
return 0;
}
static int hellcreek_ptp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
return -EOPNOTSUPP;
}
static void hellcreek_ptp_overflow_check(struct work_struct *work)
{
struct delayed_work *dw = to_delayed_work(work);
struct hellcreek *hellcreek;
hellcreek = dw_overflow_to_hellcreek(dw);
mutex_lock(&hellcreek->ptp_lock);
__hellcreek_ptp_gettime(hellcreek);
mutex_unlock(&hellcreek->ptp_lock);
schedule_delayed_work(&hellcreek->overflow_work,
HELLCREEK_OVERFLOW_PERIOD);
}
int hellcreek_ptp_setup(struct hellcreek *hellcreek)
{
u16 status;
/* Set up the overflow work */
INIT_DELAYED_WORK(&hellcreek->overflow_work,
hellcreek_ptp_overflow_check);
/* Setup PTP clock */
hellcreek->ptp_clock_info.owner = THIS_MODULE;
snprintf(hellcreek->ptp_clock_info.name,
sizeof(hellcreek->ptp_clock_info.name),
dev_name(hellcreek->dev));
/* IP-Core can add up to 0.5 ns per 8 ns cycle, which means
* accumulator_overflow_rate shall not exceed 62.5 MHz (which adjusts
* the nominal frequency by 6.25%)
*/
hellcreek->ptp_clock_info.max_adj = 62500000;
hellcreek->ptp_clock_info.n_alarm = 0;
hellcreek->ptp_clock_info.n_pins = 0;
hellcreek->ptp_clock_info.n_ext_ts = 0;
hellcreek->ptp_clock_info.n_per_out = 0;
hellcreek->ptp_clock_info.pps = 0;
hellcreek->ptp_clock_info.adjfine = hellcreek_ptp_adjfine;
hellcreek->ptp_clock_info.adjtime = hellcreek_ptp_adjtime;
hellcreek->ptp_clock_info.gettime64 = hellcreek_ptp_gettime;
hellcreek->ptp_clock_info.settime64 = hellcreek_ptp_settime;
hellcreek->ptp_clock_info.enable = hellcreek_ptp_enable;
hellcreek->ptp_clock = ptp_clock_register(&hellcreek->ptp_clock_info,
hellcreek->dev);
if (IS_ERR(hellcreek->ptp_clock))
return PTR_ERR(hellcreek->ptp_clock);
/* Enable the offset correction process, if no offset correction is
* already taking place
*/
status = hellcreek_ptp_read(hellcreek, PR_CLOCK_STATUS_C);
if (!(status & PR_CLOCK_STATUS_C_OFS_ACT))
hellcreek_ptp_write(hellcreek,
status | PR_CLOCK_STATUS_C_ENA_OFS,
PR_CLOCK_STATUS_C);
/* Enable the drift correction process */
hellcreek_ptp_write(hellcreek, status | PR_CLOCK_STATUS_C_ENA_DRIFT,
PR_CLOCK_STATUS_C);
schedule_delayed_work(&hellcreek->overflow_work,
HELLCREEK_OVERFLOW_PERIOD);
return 0;
}
void hellcreek_ptp_free(struct hellcreek *hellcreek)
{
cancel_delayed_work_sync(&hellcreek->overflow_work);
if (hellcreek->ptp_clock)
ptp_clock_unregister(hellcreek->ptp_clock);
hellcreek->ptp_clock = NULL;
}
|