Commit | Line | Data |
---|---|---|
ce26c5bb | 1 | /* |
c701335e | 2 | * linux/drivers/devfreq/governor_userspace.c |
ce26c5bb MH |
3 | * |
4 | * Copyright (C) 2011 Samsung Electronics | |
5 | * MyungJoo Ham <myungjoo.ham@samsung.com> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | */ | |
11 | ||
12 | #include <linux/slab.h> | |
13 | #include <linux/device.h> | |
14 | #include <linux/devfreq.h> | |
15 | #include <linux/pm.h> | |
16 | #include <linux/mutex.h> | |
eff607fd | 17 | #include <linux/module.h> |
ce26c5bb MH |
18 | #include "governor.h" |
19 | ||
20 | struct userspace_data { | |
21 | unsigned long user_frequency; | |
22 | bool valid; | |
23 | }; | |
24 | ||
25 | static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq) | |
26 | { | |
27 | struct userspace_data *data = df->data; | |
28 | ||
6ff66e2a MK |
29 | if (data->valid) |
30 | *freq = data->user_frequency; | |
31 | else | |
ce26c5bb | 32 | *freq = df->previous_freq; /* No user freq specified yet */ |
6ff66e2a | 33 | |
ce26c5bb MH |
34 | return 0; |
35 | } | |
36 | ||
37 | static ssize_t store_freq(struct device *dev, struct device_attribute *attr, | |
38 | const char *buf, size_t count) | |
39 | { | |
40 | struct devfreq *devfreq = to_devfreq(dev); | |
41 | struct userspace_data *data; | |
42 | unsigned long wanted; | |
43 | int err = 0; | |
44 | ||
ce26c5bb MH |
45 | mutex_lock(&devfreq->lock); |
46 | data = devfreq->data; | |
47 | ||
48 | sscanf(buf, "%lu", &wanted); | |
49 | data->user_frequency = wanted; | |
50 | data->valid = true; | |
51 | err = update_devfreq(devfreq); | |
52 | if (err == 0) | |
53 | err = count; | |
54 | mutex_unlock(&devfreq->lock); | |
55 | return err; | |
56 | } | |
57 | ||
58 | static ssize_t show_freq(struct device *dev, struct device_attribute *attr, | |
59 | char *buf) | |
60 | { | |
61 | struct devfreq *devfreq = to_devfreq(dev); | |
62 | struct userspace_data *data; | |
63 | int err = 0; | |
64 | ||
65 | mutex_lock(&devfreq->lock); | |
66 | data = devfreq->data; | |
67 | ||
68 | if (data->valid) | |
69 | err = sprintf(buf, "%lu\n", data->user_frequency); | |
70 | else | |
71 | err = sprintf(buf, "undefined\n"); | |
72 | mutex_unlock(&devfreq->lock); | |
73 | return err; | |
74 | } | |
75 | ||
76 | static DEVICE_ATTR(set_freq, 0644, show_freq, store_freq); | |
77 | static struct attribute *dev_entries[] = { | |
78 | &dev_attr_set_freq.attr, | |
79 | NULL, | |
80 | }; | |
37d644aa | 81 | static const struct attribute_group dev_attr_group = { |
aa7c352f | 82 | .name = DEVFREQ_GOV_USERSPACE, |
ce26c5bb MH |
83 | .attrs = dev_entries, |
84 | }; | |
85 | ||
86 | static int userspace_init(struct devfreq *devfreq) | |
87 | { | |
88 | int err = 0; | |
89 | struct userspace_data *data = kzalloc(sizeof(struct userspace_data), | |
90 | GFP_KERNEL); | |
91 | ||
92 | if (!data) { | |
93 | err = -ENOMEM; | |
94 | goto out; | |
95 | } | |
96 | data->valid = false; | |
97 | devfreq->data = data; | |
98 | ||
99 | err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group); | |
100 | out: | |
101 | return err; | |
102 | } | |
103 | ||
104 | static void userspace_exit(struct devfreq *devfreq) | |
105 | { | |
924b9111 CD |
106 | /* |
107 | * Remove the sysfs entry, unless this is being called after | |
108 | * device_del(), which should have done this already via kobject_del(). | |
109 | */ | |
110 | if (devfreq->dev.kobj.sd) | |
111 | sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group); | |
112 | ||
ce26c5bb MH |
113 | kfree(devfreq->data); |
114 | devfreq->data = NULL; | |
115 | } | |
116 | ||
7e6fdd4b RV |
117 | static int devfreq_userspace_handler(struct devfreq *devfreq, |
118 | unsigned int event, void *data) | |
119 | { | |
120 | int ret = 0; | |
121 | ||
122 | switch (event) { | |
123 | case DEVFREQ_GOV_START: | |
124 | ret = userspace_init(devfreq); | |
125 | break; | |
126 | case DEVFREQ_GOV_STOP: | |
127 | userspace_exit(devfreq); | |
128 | break; | |
129 | default: | |
130 | break; | |
131 | } | |
132 | ||
133 | return ret; | |
134 | } | |
135 | ||
1b5c1be2 | 136 | static struct devfreq_governor devfreq_userspace = { |
ce26c5bb MH |
137 | .name = "userspace", |
138 | .get_target_freq = devfreq_userspace_func, | |
7e6fdd4b | 139 | .event_handler = devfreq_userspace_handler, |
ce26c5bb | 140 | }; |
83116e66 NM |
141 | |
142 | static int __init devfreq_userspace_init(void) | |
143 | { | |
144 | return devfreq_add_governor(&devfreq_userspace); | |
145 | } | |
146 | subsys_initcall(devfreq_userspace_init); | |
147 | ||
148 | static void __exit devfreq_userspace_exit(void) | |
149 | { | |
150 | int ret; | |
151 | ||
152 | ret = devfreq_remove_governor(&devfreq_userspace); | |
153 | if (ret) | |
154 | pr_err("%s: failed remove governor %d\n", __func__, ret); | |
155 | ||
156 | return; | |
157 | } | |
158 | module_exit(devfreq_userspace_exit); | |
eff607fd | 159 | MODULE_LICENSE("GPL"); |