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
|
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2023 Intel Corporation */
#include <linux/delay.h>
#include <linux/dev_printk.h>
#include <linux/export.h>
#include <linux/math.h>
#include <linux/minmax.h>
#include <linux/time64.h>
#include <linux/types.h>
#include <linux/units.h>
#include <asm/errno.h>
#include "adf_admin.h"
#include "adf_accel_devices.h"
#include "adf_clock.h"
#include "adf_common_drv.h"
#define MEASURE_CLOCK_RETRIES 10
#define MEASURE_CLOCK_DELAY_US 10000
#define ME_CLK_DIVIDER 16
#define MEASURE_CLOCK_DELTA_THRESHOLD_US 100
static inline u64 timespec_to_us(const struct timespec64 *ts)
{
return (u64)DIV_ROUND_CLOSEST_ULL(timespec64_to_ns(ts), NSEC_PER_USEC);
}
static inline u64 timespec_to_ms(const struct timespec64 *ts)
{
return (u64)DIV_ROUND_CLOSEST_ULL(timespec64_to_ns(ts), NSEC_PER_MSEC);
}
u64 adf_clock_get_current_time(void)
{
struct timespec64 ts;
ktime_get_real_ts64(&ts);
return timespec_to_ms(&ts);
}
static int measure_clock(struct adf_accel_dev *accel_dev, u32 *frequency)
{
struct timespec64 ts1, ts2, ts3, ts4;
u64 timestamp1, timestamp2, temp;
u32 delta_us, tries;
int ret;
tries = MEASURE_CLOCK_RETRIES;
do {
ktime_get_real_ts64(&ts1);
ret = adf_get_fw_timestamp(accel_dev, ×tamp1);
if (ret) {
dev_err(&GET_DEV(accel_dev),
"Failed to get fw timestamp\n");
return ret;
}
ktime_get_real_ts64(&ts2);
delta_us = timespec_to_us(&ts2) - timespec_to_us(&ts1);
} while (delta_us > MEASURE_CLOCK_DELTA_THRESHOLD_US && --tries);
if (!tries) {
dev_err(&GET_DEV(accel_dev), "Excessive clock measure delay\n");
return -ETIMEDOUT;
}
fsleep(MEASURE_CLOCK_DELAY_US);
tries = MEASURE_CLOCK_RETRIES;
do {
ktime_get_real_ts64(&ts3);
if (adf_get_fw_timestamp(accel_dev, ×tamp2)) {
dev_err(&GET_DEV(accel_dev),
"Failed to get fw timestamp\n");
return -EIO;
}
ktime_get_real_ts64(&ts4);
delta_us = timespec_to_us(&ts4) - timespec_to_us(&ts3);
} while (delta_us > MEASURE_CLOCK_DELTA_THRESHOLD_US && --tries);
if (!tries) {
dev_err(&GET_DEV(accel_dev), "Excessive clock measure delay\n");
return -ETIMEDOUT;
}
delta_us = timespec_to_us(&ts3) - timespec_to_us(&ts1);
if (!delta_us)
return -EINVAL;
temp = (timestamp2 - timestamp1) * ME_CLK_DIVIDER * 10;
temp = DIV_ROUND_CLOSEST_ULL(temp, delta_us);
/*
* Enclose the division to allow the preprocessor to precalculate it,
* and avoid promoting r-value to 64-bit before division.
*/
*frequency = temp * (HZ_PER_MHZ / 10);
return 0;
}
/**
* adf_dev_measure_clock() - measures device clock frequency
* @accel_dev: Pointer to acceleration device.
* @frequency: Pointer to variable where result will be stored
* @min: Minimal allowed frequency value
* @max: Maximal allowed frequency value
*
* If the measurement result will go beyond the min/max thresholds the value
* will take the value of the crossed threshold.
*
* This algorithm compares the device firmware timestamp with the kernel
* timestamp. So we can't expect too high accuracy from this measurement.
*
* Return:
* * 0 - measurement succeed
* * -ETIMEDOUT - measurement failed
*/
int adf_dev_measure_clock(struct adf_accel_dev *accel_dev,
u32 *frequency, u32 min, u32 max)
{
int ret;
u32 freq;
ret = measure_clock(accel_dev, &freq);
if (ret)
return ret;
*frequency = clamp(freq, min, max);
if (*frequency != freq)
dev_warn(&GET_DEV(accel_dev),
"Measured clock %d Hz is out of range, assuming %d\n",
freq, *frequency);
return 0;
}
EXPORT_SYMBOL_GPL(adf_dev_measure_clock);
|
