tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ACPI / LPAT: Common table processing functions
Since LPAT table processing is also required for other thermal drivers,
moved LPAT table related functions from intel PMIC driver (intel_pmic.c)
to a stand alonge module with exported interfaces.
In this way there will be no code duplication.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
authored by
Srinivas Pandruvada
and committed by
Zhang Rui
c55d6282
acebf7ee
+227
+1
drivers/acpi/Makefile
+1
drivers/acpi/Makefile
+161
drivers/acpi/acpi_lpat.c
+161
drivers/acpi/acpi_lpat.c
···
1
+
/*
2
+
* acpi_lpat.c - LPAT table processing functions
3
+
*
4
+
* Copyright (C) 2015 Intel Corporation. All rights reserved.
5
+
*
6
+
* This program is free software; you can redistribute it and/or
7
+
* modify it under the terms of the GNU General Public License version
8
+
* 2 as published by the Free Software Foundation.
9
+
*
10
+
* This program is distributed in the hope that it will be useful,
11
+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
12
+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13
+
* GNU General Public License for more details.
14
+
*/
15
+
16
+
#include <linux/module.h>
17
+
#include <linux/acpi.h>
18
+
#include <acpi/acpi_lpat.h>
19
+
20
+
/**
21
+
* acpi_lpat_raw_to_temp(): Return temperature from raw value through
22
+
* LPAT conversion table
23
+
*
24
+
* @lpat_table: the temperature_raw mapping table structure
25
+
* @raw: the raw value, used as a key to get the temerature from the
26
+
* above mapping table
27
+
*
28
+
* A positive converted temperarure value will be returned on success,
29
+
* a negative errno will be returned in error cases.
30
+
*/
31
+
int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
32
+
int raw)
33
+
{
34
+
int i, delta_temp, delta_raw, temp;
35
+
struct acpi_lpat *lpat = lpat_table->lpat;
36
+
37
+
for (i = 0; i < lpat_table->lpat_count - 1; i++) {
38
+
if ((raw >= lpat[i].raw && raw <= lpat[i+1].raw) ||
39
+
(raw <= lpat[i].raw && raw >= lpat[i+1].raw))
40
+
break;
41
+
}
42
+
43
+
if (i == lpat_table->lpat_count - 1)
44
+
return -ENOENT;
45
+
46
+
delta_temp = lpat[i+1].temp - lpat[i].temp;
47
+
delta_raw = lpat[i+1].raw - lpat[i].raw;
48
+
temp = lpat[i].temp + (raw - lpat[i].raw) * delta_temp / delta_raw;
49
+
50
+
return temp;
51
+
}
52
+
EXPORT_SYMBOL_GPL(acpi_lpat_raw_to_temp);
53
+
54
+
/**
55
+
* acpi_lpat_temp_to_raw(): Return raw value from temperature through
56
+
* LPAT conversion table
57
+
*
58
+
* @lpat: the temperature_raw mapping table
59
+
* @temp: the temperature, used as a key to get the raw value from the
60
+
* above mapping table
61
+
*
62
+
* A positive converted temperature value will be returned on success,
63
+
* a negative errno will be returned in error cases.
64
+
*/
65
+
int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
66
+
int temp)
67
+
{
68
+
int i, delta_temp, delta_raw, raw;
69
+
struct acpi_lpat *lpat = lpat_table->lpat;
70
+
71
+
for (i = 0; i < lpat_table->lpat_count - 1; i++) {
72
+
if (temp >= lpat[i].temp && temp <= lpat[i+1].temp)
73
+
break;
74
+
}
75
+
76
+
if (i == lpat_table->lpat_count - 1)
77
+
return -ENOENT;
78
+
79
+
delta_temp = lpat[i+1].temp - lpat[i].temp;
80
+
delta_raw = lpat[i+1].raw - lpat[i].raw;
81
+
raw = lpat[i].raw + (temp - lpat[i].temp) * delta_raw / delta_temp;
82
+
83
+
return raw;
84
+
}
85
+
EXPORT_SYMBOL_GPL(acpi_lpat_temp_to_raw);
86
+
87
+
/**
88
+
* acpi_lpat_get_conversion_table(): Parse ACPI LPAT table if present.
89
+
*
90
+
* @handle: Handle to acpi device
91
+
*
92
+
* Parse LPAT table to a struct of type acpi_lpat_table. On success
93
+
* it returns a pointer to newly allocated table. This table must
94
+
* be freed by the caller when finished processing, using a call to
95
+
* acpi_lpat_free_conversion_table.
96
+
*/
97
+
struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(acpi_handle
98
+
handle)
99
+
{
100
+
struct acpi_lpat_conversion_table *lpat_table = NULL;
101
+
struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
102
+
union acpi_object *obj_p, *obj_e;
103
+
int *lpat, i;
104
+
acpi_status status;
105
+
106
+
status = acpi_evaluate_object(handle, "LPAT", NULL, &buffer);
107
+
if (ACPI_FAILURE(status))
108
+
return NULL;
109
+
110
+
obj_p = (union acpi_object *)buffer.pointer;
111
+
if (!obj_p || (obj_p->type != ACPI_TYPE_PACKAGE) ||
112
+
(obj_p->package.count % 2) || (obj_p->package.count < 4))
113
+
goto out;
114
+
115
+
lpat = kcalloc(obj_p->package.count, sizeof(int), GFP_KERNEL);
116
+
if (!lpat)
117
+
goto out;
118
+
119
+
for (i = 0; i < obj_p->package.count; i++) {
120
+
obj_e = &obj_p->package.elements[i];
121
+
if (obj_e->type != ACPI_TYPE_INTEGER) {
122
+
kfree(lpat);
123
+
goto out;
124
+
}
125
+
lpat[i] = (s64)obj_e->integer.value;
126
+
}
127
+
128
+
lpat_table = kzalloc(sizeof(*lpat_table), GFP_KERNEL);
129
+
if (!lpat_table) {
130
+
kfree(lpat);
131
+
goto out;
132
+
}
133
+
134
+
lpat_table->lpat = (struct acpi_lpat *)lpat;
135
+
lpat_table->lpat_count = obj_p->package.count / 2;
136
+
137
+
out:
138
+
kfree(buffer.pointer);
139
+
return lpat_table;
140
+
}
141
+
EXPORT_SYMBOL_GPL(acpi_lpat_get_conversion_table);
142
+
143
+
/**
144
+
* acpi_lpat_free_conversion_table(): Free LPAT table.
145
+
*
146
+
* @lpat_table: the temperature_raw mapping table structure
147
+
*
148
+
* Frees the LPAT table previously allocated by a call to
149
+
* acpi_lpat_get_conversion_table.
150
+
*/
151
+
void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
152
+
*lpat_table)
153
+
{
154
+
if (lpat_table) {
155
+
kfree(lpat_table->lpat);
156
+
kfree(lpat_table);
157
+
}
158
+
}
159
+
EXPORT_SYMBOL_GPL(acpi_lpat_free_conversion_table);
160
+
161
+
MODULE_LICENSE("GPL");
+65
include/acpi/acpi_lpat.h
+65
include/acpi/acpi_lpat.h
···
1
+
/*
2
+
* acpi_lpat.h - LPAT table processing functions
3
+
*
4
+
* Copyright (C) 2015 Intel Corporation. All rights reserved.
5
+
*
6
+
* This program is free software; you can redistribute it and/or
7
+
* modify it under the terms of the GNU General Public License version
8
+
* 2 as published by the Free Software Foundation.
9
+
*
10
+
* This program is distributed in the hope that it will be useful,
11
+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
12
+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13
+
* GNU General Public License for more details.
14
+
*/
15
+
16
+
#ifndef ACPI_LPAT_H
17
+
#define ACPI_LPAT_H
18
+
19
+
struct acpi_lpat {
20
+
int temp;
21
+
int raw;
22
+
};
23
+
24
+
struct acpi_lpat_conversion_table {
25
+
struct acpi_lpat *lpat;
26
+
int lpat_count;
27
+
};
28
+
29
+
#ifdef CONFIG_ACPI
30
+
31
+
int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
32
+
int raw);
33
+
int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
34
+
int temp);
35
+
struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(acpi_handle
36
+
handle);
37
+
void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
38
+
*lpat_table);
39
+
40
+
#else
41
+
static int acpi_lpat_raw_to_temp(struct acpi_lpat_conversion_table *lpat_table,
42
+
int raw)
43
+
{
44
+
return 0;
45
+
}
46
+
47
+
static int acpi_lpat_temp_to_raw(struct acpi_lpat_conversion_table *lpat_table,
48
+
int temp)
49
+
{
50
+
return 0;
51
+
}
52
+
53
+
static struct acpi_lpat_conversion_table *acpi_lpat_get_conversion_table(
54
+
acpi_handle handle)
55
+
{
56
+
return NULL;
57
+
}
58
+
59
+
static void acpi_lpat_free_conversion_table(struct acpi_lpat_conversion_table
60
+
*lpat_table)
61
+
{
62
+
}
63
+
64
+
#endif
65
+
#endif