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 	mutex_unlock(&profile_lock);
110 	if (err)
111 		return err;
112 	return count;
113 }
114 
115 static DEVICE_ATTR_RO(platform_profile_choices);
116 static DEVICE_ATTR_RW(platform_profile);
117 
118 static struct attribute *platform_profile_attrs[] = {
119 	&dev_attr_platform_profile_choices.attr,
120 	&dev_attr_platform_profile.attr,
121 	NULL
122 };
123 
124 static const struct attribute_group platform_profile_group = {
125 	.attrs = platform_profile_attrs
126 };
127 
128 void platform_profile_notify(void)
129 {
130 	if (!cur_profile)
131 		return;
132 	sysfs_notify(acpi_kobj, NULL, "platform_profile");
133 }
134 EXPORT_SYMBOL_GPL(platform_profile_notify);
135 
136 int platform_profile_register(struct platform_profile_handler *pprof)
137 {
138 	int err;
139 
140 	mutex_lock(&profile_lock);
141 	/* We can only have one active profile */
142 	if (cur_profile) {
143 		mutex_unlock(&profile_lock);
144 		return -EEXIST;
145 	}
146 
147 	/* Sanity check the profile handler field are set */
148 	if (!pprof || bitmap_empty(pprof->choices, PLATFORM_PROFILE_LAST) ||
149 		!pprof->profile_set || !pprof->profile_get) {
150 		mutex_unlock(&profile_lock);
151 		return -EINVAL;
152 	}
153 
154 	err = sysfs_create_group(acpi_kobj, &platform_profile_group);
155 	if (err) {
156 		mutex_unlock(&profile_lock);
157 		return err;
158 	}
159 
160 	cur_profile = pprof;
161 	mutex_unlock(&profile_lock);
162 	return 0;
163 }
164 EXPORT_SYMBOL_GPL(platform_profile_register);
165 
166 int platform_profile_remove(void)
167 {
168 	sysfs_remove_group(acpi_kobj, &platform_profile_group);
169 
170 	mutex_lock(&profile_lock);
171 	cur_profile = NULL;
172 	mutex_unlock(&profile_lock);
173 	return 0;
174 }
175 EXPORT_SYMBOL_GPL(platform_profile_remove);
176 
177 MODULE_AUTHOR("Mark Pearson <markpearson@lenovo.com>");
178 MODULE_LICENSE("GPL");
179