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
|
/*
* SH-Mobile Timer
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2002 - 2009 Paul Mundt
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/platform_device.h>
#include <linux/clocksource.h>
#include <linux/delay.h>
#include <linux/of_address.h>
void __init shmobile_setup_delay_hz(unsigned int max_cpu_core_hz,
unsigned int mult, unsigned int div)
{
/* calculate a worst-case loops-per-jiffy value
* based on maximum cpu core hz setting and the
* __delay() implementation in arch/arm/lib/delay.S
*
* this will result in a longer delay than expected
* when the cpu core runs on lower frequencies.
*/
unsigned int value = HZ * div / mult;
if (!preset_lpj)
preset_lpj = max_cpu_core_hz / value;
}
void __init shmobile_setup_delay(unsigned int max_cpu_core_mhz,
unsigned int mult, unsigned int div)
{
/* calculate a worst-case loops-per-jiffy value
* based on maximum cpu core mhz setting and the
* __delay() implementation in arch/arm/lib/delay.S
*
* this will result in a longer delay than expected
* when the cpu core runs on lower frequencies.
*/
unsigned int value = (1000000 * mult) / (HZ * div);
if (!preset_lpj)
preset_lpj = max_cpu_core_mhz * value;
}
void __init shmobile_init_delay(void)
{
struct device_node *np, *cpus;
bool is_a8_a9 = false;
bool is_a15 = false;
u32 max_freq = 0;
cpus = of_find_node_by_path("/cpus");
if (!cpus)
return;
for_each_child_of_node(cpus, np) {
u32 freq;
if (!of_property_read_u32(np, "clock-frequency", &freq))
max_freq = max(max_freq, freq);
if (of_device_is_compatible(np, "arm,cortex-a8") ||
of_device_is_compatible(np, "arm,cortex-a9"))
is_a8_a9 = true;
else if (of_device_is_compatible(np, "arm,cortex-a15"))
is_a15 = true;
}
of_node_put(cpus);
if (!max_freq)
return;
if (is_a8_a9)
shmobile_setup_delay_hz(max_freq, 1, 3);
else if (is_a15 && !IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
shmobile_setup_delay_hz(max_freq, 2, 4);
}
static void __init shmobile_late_time_init(void)
{
/*
* Make sure all compiled-in early timers register themselves.
*
* Run probe() for two "earlytimer" devices, these will be the
* clockevents and clocksource devices respectively. In the event
* that only a clockevents device is available, we -ENODEV on the
* clocksource and the jiffies clocksource is used transparently
* instead. No error handling is necessary here.
*/
early_platform_driver_register_all("earlytimer");
early_platform_driver_probe("earlytimer", 2, 0);
}
void __init shmobile_earlytimer_init(void)
{
late_time_init = shmobile_late_time_init;
}
|
