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 
12 static struct platform_profile_handler *cur_profile;
13 static DEFINE_MUTEX(profile_lock);
14 
15 static 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 };
23 static_assert(ARRAY_SIZE(profile_names) == PLATFORM_PROFILE_LAST);
24 
25 static 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 
52 static 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 
80 static 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 
118 static DEVICE_ATTR_RO(platform_profile_choices);
119 static DEVICE_ATTR_RW(platform_profile);
120 
121 static struct attribute *platform_profile_attrs[] = {
122 	&dev_attr_platform_profile_choices.attr,
123 	&dev_attr_platform_profile.attr,
124 	NULL
125 };
126 
127 static const struct attribute_group platform_profile_group = {
128 	.attrs = platform_profile_attrs
129 };
130 
131 void platform_profile_notify(void)
132 {
133 	if (!cur_profile)
134 		return;
135 	sysfs_notify(acpi_kobj, NULL, "platform_profile");
136 }
137 EXPORT_SYMBOL_GPL(platform_profile_notify);
138 
139 int 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 }
167 EXPORT_SYMBOL_GPL(platform_profile_register);
168 
169 int 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 }
178 EXPORT_SYMBOL_GPL(platform_profile_remove);
179 
180 MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
181 MODULE_LICENSE("GPL");
182