1// SPDX-License-Identifier: GPL-2.0-or-later
2
3/* Platform profile sysfs interface */
4
5#include <linux/acpi.h>
6#include <linux/bits.h>
7#include <linux/init.h>
8#include <linux/mutex.h>
9#include <linux/platform_profile.h>
10#include <linux/sysfs.h>
11
12static struct platform_profile_handler *cur_profile;
13static DEFINE_MUTEX(profile_lock);
14
15static const char * const profile_names[] = {
16	[PLATFORM_PROFILE_LOW_POWER] = "low-power",
17	[PLATFORM_PROFILE_COOL] = "cool",
18	[PLATFORM_PROFILE_QUIET] = "quiet",
19	[PLATFORM_PROFILE_BALANCED] = "balanced",
20	[PLATFORM_PROFILE_BALANCED_PERFORMANCE] = "balanced-performance",
21	[PLATFORM_PROFILE_PERFORMANCE] = "performance",
22};
23static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
24
25static ssize_t platform_profile_choices_show(struct device *dev,
26					struct device_attribute *attr,
27					char *buf)
28{
29	int len = 0;
30	int err, i;
31
32	err = mutex_lock_interruptible(&profile_lock);
33	if (err)
34		return err;
35
36	if (!cur_profile) {
37		mutex_unlock(&profile_lock);
38		return -ENODEV;
39	}
40
41	for_each_set_bit(i, cur_profile->choices, PLATFORM_PROFILE_LAST) {
42		if (len == 0)
43			len += sysfs_emit_at(buf, len, "%s", profile_names[i]);
44		else
45			len += sysfs_emit_at(buf, len, " %s", profile_names[i]);
46	}
47	len += sysfs_emit_at(buf, len, "\n");
48	mutex_unlock(&profile_lock);
49	return len;
50}
51
52static ssize_t platform_profile_show(struct device *dev,
53					struct device_attribute *attr,
54					char *buf)
55{
56	enum platform_profile_option profile = PLATFORM_PROFILE_BALANCED;
57	int err;
58
59	err = mutex_lock_interruptible(&profile_lock);
60	if (err)
61		return err;
62
63	if (!cur_profile) {
64		mutex_unlock(&profile_lock);
65		return -ENODEV;
66	}
67
68	err = cur_profile->profile_get(cur_profile, &profile);
69	mutex_unlock(&profile_lock);
70	if (err)
71		return err;
72
73	/* Check that profile is valid index */
74	if (WARN_ON((profile < 0) || (profile >= ARRAY_SIZE(profile_names))))
75		return -EIO;
76
77	return sysfs_emit(buf, "%s\n", profile_names[profile]);
78}
79
80static ssize_t platform_profile_store(struct device *dev,
81			    struct device_attribute *attr,
82			    const char *buf, size_t count)
83{
84	int err, i;
85
86	err = mutex_lock_interruptible(&profile_lock);
87	if (err)
88		return err;
89
90	if (!cur_profile) {
91		mutex_unlock(&profile_lock);
92		return -ENODEV;
93	}
94
95	/* Scan for a matching profile */
96	i = sysfs_match_string(profile_names, buf);
97	if (i < 0) {
98		mutex_unlock(&profile_lock);
99		return -EINVAL;
100	}
101
102	/* Check that platform supports this profile choice */
103	if (!test_bit(i, cur_profile->choices)) {
104		mutex_unlock(&profile_lock);
105		return -EOPNOTSUPP;
106	}
107
108	err = cur_profile->profile_set(cur_profile, i);
109	if (!err)
110		sysfs_notify(acpi_kobj, NULL, "platform_profile");
111
112	mutex_unlock(&profile_lock);
113	if (err)
114		return err;
115	return count;
116}
117
118static DEVICE_ATTR_RO(platform_profile_choices);
119static DEVICE_ATTR_RW(platform_profile);
120
121static struct attribute *platform_profile_attrs[] = {
122	&dev_attr_platform_profile_choices.attr,
123	&dev_attr_platform_profile.attr,
124	NULL
125};
126
127static const struct attribute_group platform_profile_group = {
128	.attrs = platform_profile_attrs
129};
130
131void platform_profile_notify(void)
132{
133	if (!cur_profile)
134		return;
135	sysfs_notify(acpi_kobj, NULL, "platform_profile");
136}
137EXPORT_SYMBOL_GPL(platform_profile_notify);
138
139int platform_profile_register(struct platform_profile_handler *pprof)
140{
141	int err;
142
143	mutex_lock(&profile_lock);
144	/* We can only have one active profile */
145	if (cur_profile) {
146		mutex_unlock(&profile_lock);
147		return -EEXIST;
148	}
149
150	/* Sanity check the profile handler field are set */
151	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
152		!pprof->profile_set || !pprof->profile_get) {
153		mutex_unlock(&profile_lock);
154		return -EINVAL;
155	}
156
157	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
158	if (err) {
159		mutex_unlock(&profile_lock);
160		return err;
161	}
162
163	cur_profile = pprof;
164	mutex_unlock(&profile_lock);
165	return 0;
166}
167EXPORT_SYMBOL_GPL(platform_profile_register);
168
169int platform_profile_remove(void)
170{
171	sysfs_remove_group(acpi_kobj, &platform_profile_group);
172
173	mutex_lock(&profile_lock);
174	cur_profile = NULL;
175	mutex_unlock(&profile_lock);
176	return 0;
177}
178EXPORT_SYMBOL_GPL(platform_profile_remove);
179
180MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
181MODULE_LICENSE("GPL");
182