Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
ce26c5bb | 2 | /* |
c701335e | 3 | * linux/drivers/devfreq/governor_userspace.c |
ce26c5bb MH |
4 | * |
5 | * Copyright (C) 2011 Samsung Electronics | |
6 | * MyungJoo Ham <myungjoo.ham@samsung.com> | |
ce26c5bb MH |
7 | */ |
8 | ||
9 | #include <linux/slab.h> | |
10 | #include <linux/device.h> | |
11 | #include <linux/devfreq.h> | |
12 | #include <linux/pm.h> | |
13 | #include <linux/mutex.h> | |
eff607fd | 14 | #include <linux/module.h> |
ce26c5bb MH |
15 | #include "governor.h" |
16 | ||
17 | struct userspace_data { | |
18 | unsigned long user_frequency; | |
19 | bool valid; | |
20 | }; | |
21 | ||
22 | static int devfreq_userspace_func(struct devfreq *df, unsigned long *freq) | |
23 | { | |
5fdded84 | 24 | struct userspace_data *data = df->governor_data; |
ce26c5bb | 25 | |
6ff66e2a MK |
26 | if (data->valid) |
27 | *freq = data->user_frequency; | |
28 | else | |
ce26c5bb | 29 | *freq = df->previous_freq; /* No user freq specified yet */ |
6ff66e2a | 30 | |
ce26c5bb MH |
31 | return 0; |
32 | } | |
33 | ||
1ad4f329 Y |
34 | static ssize_t set_freq_store(struct device *dev, struct device_attribute *attr, |
35 | const char *buf, size_t count) | |
ce26c5bb MH |
36 | { |
37 | struct devfreq *devfreq = to_devfreq(dev); | |
38 | struct userspace_data *data; | |
39 | unsigned long wanted; | |
40 | int err = 0; | |
41 | ||
ce26c5bb | 42 | mutex_lock(&devfreq->lock); |
5fdded84 | 43 | data = devfreq->governor_data; |
ce26c5bb MH |
44 | |
45 | sscanf(buf, "%lu", &wanted); | |
46 | data->user_frequency = wanted; | |
47 | data->valid = true; | |
48 | err = update_devfreq(devfreq); | |
49 | if (err == 0) | |
50 | err = count; | |
51 | mutex_unlock(&devfreq->lock); | |
52 | return err; | |
53 | } | |
54 | ||
1ad4f329 Y |
55 | static ssize_t set_freq_show(struct device *dev, |
56 | struct device_attribute *attr, char *buf) | |
ce26c5bb MH |
57 | { |
58 | struct devfreq *devfreq = to_devfreq(dev); | |
59 | struct userspace_data *data; | |
60 | int err = 0; | |
61 | ||
62 | mutex_lock(&devfreq->lock); | |
5fdded84 | 63 | data = devfreq->governor_data; |
ce26c5bb MH |
64 | |
65 | if (data->valid) | |
66 | err = sprintf(buf, "%lu\n", data->user_frequency); | |
67 | else | |
68 | err = sprintf(buf, "undefined\n"); | |
69 | mutex_unlock(&devfreq->lock); | |
70 | return err; | |
71 | } | |
72 | ||
1ad4f329 | 73 | static DEVICE_ATTR_RW(set_freq); |
ce26c5bb MH |
74 | static struct attribute *dev_entries[] = { |
75 | &dev_attr_set_freq.attr, | |
76 | NULL, | |
77 | }; | |
37d644aa | 78 | static const struct attribute_group dev_attr_group = { |
aa7c352f | 79 | .name = DEVFREQ_GOV_USERSPACE, |
ce26c5bb MH |
80 | .attrs = dev_entries, |
81 | }; | |
82 | ||
83 | static int userspace_init(struct devfreq *devfreq) | |
84 | { | |
85 | int err = 0; | |
86 | struct userspace_data *data = kzalloc(sizeof(struct userspace_data), | |
87 | GFP_KERNEL); | |
88 | ||
89 | if (!data) { | |
90 | err = -ENOMEM; | |
91 | goto out; | |
92 | } | |
93 | data->valid = false; | |
5fdded84 | 94 | devfreq->governor_data = data; |
ce26c5bb MH |
95 | |
96 | err = sysfs_create_group(&devfreq->dev.kobj, &dev_attr_group); | |
97 | out: | |
98 | return err; | |
99 | } | |
100 | ||
101 | static void userspace_exit(struct devfreq *devfreq) | |
102 | { | |
924b9111 CD |
103 | /* |
104 | * Remove the sysfs entry, unless this is being called after | |
105 | * device_del(), which should have done this already via kobject_del(). | |
106 | */ | |
107 | if (devfreq->dev.kobj.sd) | |
108 | sysfs_remove_group(&devfreq->dev.kobj, &dev_attr_group); | |
109 | ||
5fdded84 KF |
110 | kfree(devfreq->governor_data); |
111 | devfreq->governor_data = NULL; | |
ce26c5bb MH |
112 | } |
113 | ||
7e6fdd4b RV |
114 | static int devfreq_userspace_handler(struct devfreq *devfreq, |
115 | unsigned int event, void *data) | |
116 | { | |
117 | int ret = 0; | |
118 | ||
119 | switch (event) { | |
120 | case DEVFREQ_GOV_START: | |
121 | ret = userspace_init(devfreq); | |
122 | break; | |
123 | case DEVFREQ_GOV_STOP: | |
124 | userspace_exit(devfreq); | |
125 | break; | |
126 | default: | |
127 | break; | |
128 | } | |
129 | ||
130 | return ret; | |
131 | } | |
132 | ||
1b5c1be2 | 133 | static struct devfreq_governor devfreq_userspace = { |
4bb1faac | 134 | .name = DEVFREQ_GOV_USERSPACE, |
ce26c5bb | 135 | .get_target_freq = devfreq_userspace_func, |
7e6fdd4b | 136 | .event_handler = devfreq_userspace_handler, |
ce26c5bb | 137 | }; |
83116e66 NM |
138 | |
139 | static int __init devfreq_userspace_init(void) | |
140 | { | |
141 | return devfreq_add_governor(&devfreq_userspace); | |
142 | } | |
143 | subsys_initcall(devfreq_userspace_init); | |
144 | ||
145 | static void __exit devfreq_userspace_exit(void) | |
146 | { | |
147 | int ret; | |
148 | ||
149 | ret = devfreq_remove_governor(&devfreq_userspace); | |
150 | if (ret) | |
151 | pr_err("%s: failed remove governor %d\n", __func__, ret); | |
152 | ||
153 | return; | |
154 | } | |
155 | module_exit(devfreq_userspace_exit); | |
eff607fd | 156 | MODULE_LICENSE("GPL"); |