summaryrefslogtreecommitdiffstats
path: root/drivers/acpi/platform_profile.c
blob: 4a59c5993bde432b482f85d6bf7c345b6467b3dd (plain)
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
// SPDX-License-Identifier: GPL-2.0-or-later

/* Platform profile sysfs interface */

#include <linux/acpi.h>
#include <linux/bits.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/platform_profile.h>
#include <linux/sysfs.h>

static struct platform_profile_handler *cur_profile;
static DEFINE_MUTEX(profile_lock);

static const char * const profile_names[] = {
	[PLATFORM_PROFILE_LOW_POWER] = "low-power",
	[PLATFORM_PROFILE_COOL] = "cool",
	[PLATFORM_PROFILE_QUIET] = "quiet",
	[PLATFORM_PROFILE_BALANCED] = "balanced",
	[PLATFORM_PROFILE_PERFORMANCE] = "performance",
};
static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);

static ssize_t platform_profile_choices_show(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	int len = 0;
	int err, i;

	err = mutex_lock_interruptible(&profile_lock);
	if (err)
		return err;

	if (!cur_profile) {
		mutex_unlock(&profile_lock);
		return -ENODEV;
	}

	for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
		if (len == 0)
			len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
		else
			len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
	}
	len += sysfs_emit_at(buf, len, "\n");
	mutex_unlock(&profile_lock);
	return len;
}

static ssize_t platform_profile_show(struct device *dev,
					struct device_attribute *attr,
					char *buf)
{
	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
	int err;

	err = mutex_lock_interruptible(&profile_lock);
	if (err)
		return err;

	if (!cur_profile) {
		mutex_unlock(&profile_lock);
		return -ENODEV;
	}

	err = cur_profile->profile_get(cur_profile, &profile);
	mutex_unlock(&profile_lock);
	if (err)
		return err;

	/* Check that profile is valid index */
	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
		return -EIO;

	return sysfs_emit(buf, "%s\n", profile_names[profile]);
}

static ssize_t platform_profile_store(struct device *dev,
			    struct device_attribute *attr,
			    const char *buf, size_t count)
{
	int err, i;

	err = mutex_lock_interruptible(&profile_lock);
	if (err)
		return err;

	if (!cur_profile) {
		mutex_unlock(&profile_lock);
		return -ENODEV;
	}

	/* Scan for a matching profile */
	i = sysfs_match_string(profile_names, buf);
	if (i < 0) {
		mutex_unlock(&profile_lock);
		return -EINVAL;
	}

	/* Check that platform supports this profile choice */
	if (!test_bit(i, cur_profile->choices)) {
		mutex_unlock(&profile_lock);
		return -EOPNOTSUPP;
	}

	err = cur_profile->profile_set(cur_profile, i);
	mutex_unlock(&profile_lock);
	if (err)
		return err;
	return count;
}

static DEVICE_ATTR_RO(platform_profile_choices);
static DEVICE_ATTR_RW(platform_profile);

static struct attribute *platform_profile_attrs[] = {
	&dev_attr_platform_profile_choices.attr,
	&dev_attr_platform_profile.attr,
	NULL
};

static const struct attribute_group platform_profile_group = {
	.attrs = platform_profile_attrs
};

void platform_profile_notify(void)
{
	if (!cur_profile)
		return;
	sysfs_notify(acpi_kobj, NULL, "platform_profile");
}
EXPORT_SYMBOL_GPL(platform_profile_notify);

int platform_profile_register(struct platform_profile_handler *pprof)
{
	int err;

	mutex_lock(&profile_lock);
	/* We can only have one active profile */
	if (cur_profile) {
		mutex_unlock(&profile_lock);
		return -EEXIST;
	}

	/* Sanity check the profile handler field are set */
	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
		!pprof->profile_set || !pprof->profile_get) {
		mutex_unlock(&profile_lock);
		return -EINVAL;
	}

	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
	if (err) {
		mutex_unlock(&profile_lock);
		return err;
	}

	cur_profile = pprof;
	mutex_unlock(&profile_lock);
	return 0;
}
EXPORT_SYMBOL_GPL(platform_profile_register);

int platform_profile_remove(void)
{
	sysfs_remove_group(acpi_kobj, &platform_profile_group);

	mutex_lock(&profile_lock);
	cur_profile = NULL;
	mutex_unlock(&profile_lock);
	return 0;
}
EXPORT_SYMBOL_GPL(platform_profile_remove);

MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
MODULE_LICENSE("GPL");