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
|
// SPDX-License-Identifier: GPL-2.0-or-later
/* Lantiq cpu temperature sensor driver
*
* Copyright (C) 2017 Florian Eckert <fe@dev.tdt.de>
*/
#include <linux/bitops.h>
#include <linux/delay.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <lantiq_soc.h>
/* gphy1 configuration register contains cpu temperature */
#define CGU_GPHY1_CR 0x0040
#define CGU_TEMP_PD BIT(19)
static void ltq_cputemp_enable(void)
{
ltq_cgu_w32(ltq_cgu_r32(CGU_GPHY1_CR) | CGU_TEMP_PD, CGU_GPHY1_CR);
}
static void ltq_cputemp_disable(void *data)
{
ltq_cgu_w32(ltq_cgu_r32(CGU_GPHY1_CR) & ~CGU_TEMP_PD, CGU_GPHY1_CR);
}
static int ltq_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *temp)
{
int value;
switch (attr) {
case hwmon_temp_input:
/* get the temperature including one decimal place */
value = (ltq_cgu_r32(CGU_GPHY1_CR) >> 9) & 0x01FF;
value = value * 5;
/* range -38 to +154 °C, register value zero is -38.0 °C */
value -= 380;
/* scale temp to millidegree */
value = value * 100;
break;
default:
return -EOPNOTSUPP;
}
*temp = value;
return 0;
}
static umode_t ltq_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
if (type != hwmon_temp)
return 0;
switch (attr) {
case hwmon_temp_input:
return 0444;
default:
return 0;
}
}
static const struct hwmon_channel_info *ltq_info[] = {
HWMON_CHANNEL_INFO(chip,
HWMON_C_REGISTER_TZ),
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT),
NULL
};
static const struct hwmon_ops ltq_hwmon_ops = {
.is_visible = ltq_is_visible,
.read = ltq_read,
};
static const struct hwmon_chip_info ltq_chip_info = {
.ops = <q_hwmon_ops,
.info = ltq_info,
};
static int ltq_cputemp_probe(struct platform_device *pdev)
{
struct device *hwmon_dev;
int err = 0;
/* available on vr9 v1.2 SoCs only */
if (ltq_soc_type() != SOC_TYPE_VR9_2)
return -ENODEV;
err = devm_add_action(&pdev->dev, ltq_cputemp_disable, NULL);
if (err)
return err;
ltq_cputemp_enable();
hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
"ltq_cputemp",
NULL,
<q_chip_info,
NULL);
if (IS_ERR(hwmon_dev)) {
dev_err(&pdev->dev, "Failed to register as hwmon device");
return PTR_ERR(hwmon_dev);
}
return 0;
}
const struct of_device_id ltq_cputemp_match[] = {
{ .compatible = "lantiq,cputemp" },
{},
};
MODULE_DEVICE_TABLE(of, ltq_cputemp_match);
static struct platform_driver ltq_cputemp_driver = {
.probe = ltq_cputemp_probe,
.driver = {
.name = "ltq-cputemp",
.of_match_table = ltq_cputemp_match,
},
};
module_platform_driver(ltq_cputemp_driver);
MODULE_AUTHOR("Florian Eckert <fe@dev.tdt.de>");
MODULE_DESCRIPTION("Lantiq cpu temperature sensor driver");
MODULE_LICENSE("GPL");
|
