Merge tag 'audit-pr-20180731' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoor...
[linux-2.6-microblaze.git] / drivers / opp / debugfs.c
1 /*
2  * Generic OPP debugfs interface
3  *
4  * Copyright (C) 2015-2016 Viresh Kumar <viresh.kumar@linaro.org>
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  */
10
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13 #include <linux/debugfs.h>
14 #include <linux/device.h>
15 #include <linux/err.h>
16 #include <linux/init.h>
17 #include <linux/limits.h>
18 #include <linux/slab.h>
19
20 #include "opp.h"
21
22 static struct dentry *rootdir;
23
24 static void opp_set_dev_name(const struct device *dev, char *name)
25 {
26         if (dev->parent)
27                 snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent),
28                          dev_name(dev));
29         else
30                 snprintf(name, NAME_MAX, "%s", dev_name(dev));
31 }
32
33 void opp_debug_remove_one(struct dev_pm_opp *opp)
34 {
35         debugfs_remove_recursive(opp->dentry);
36 }
37
38 static bool opp_debug_create_supplies(struct dev_pm_opp *opp,
39                                       struct opp_table *opp_table,
40                                       struct dentry *pdentry)
41 {
42         struct dentry *d;
43         int i;
44
45         for (i = 0; i < opp_table->regulator_count; i++) {
46                 char name[15];
47
48                 snprintf(name, sizeof(name), "supply-%d", i);
49
50                 /* Create per-opp directory */
51                 d = debugfs_create_dir(name, pdentry);
52
53                 if (!d)
54                         return false;
55
56                 if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d,
57                                           &opp->supplies[i].u_volt))
58                         return false;
59
60                 if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d,
61                                           &opp->supplies[i].u_volt_min))
62                         return false;
63
64                 if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d,
65                                           &opp->supplies[i].u_volt_max))
66                         return false;
67
68                 if (!debugfs_create_ulong("u_amp", S_IRUGO, d,
69                                           &opp->supplies[i].u_amp))
70                         return false;
71         }
72
73         return true;
74 }
75
76 int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
77 {
78         struct dentry *pdentry = opp_table->dentry;
79         struct dentry *d;
80         unsigned long id;
81         char name[25];  /* 20 chars for 64 bit value + 5 (opp:\0) */
82
83         /*
84          * Get directory name for OPP.
85          *
86          * - Normally rate is unique to each OPP, use it to get unique opp-name.
87          * - For some devices rate isn't available, use index instead.
88          */
89         if (likely(opp->rate))
90                 id = opp->rate;
91         else
92                 id = _get_opp_count(opp_table);
93
94         snprintf(name, sizeof(name), "opp:%lu", id);
95
96         /* Create per-opp directory */
97         d = debugfs_create_dir(name, pdentry);
98         if (!d)
99                 return -ENOMEM;
100
101         if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
102                 return -ENOMEM;
103
104         if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
105                 return -ENOMEM;
106
107         if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
108                 return -ENOMEM;
109
110         if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
111                 return -ENOMEM;
112
113         if (!debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate))
114                 return -ENOMEM;
115
116         if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
117                 return -ENOMEM;
118
119         if (!opp_debug_create_supplies(opp, opp_table, d))
120                 return -ENOMEM;
121
122         if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
123                                   &opp->clock_latency_ns))
124                 return -ENOMEM;
125
126         opp->dentry = d;
127         return 0;
128 }
129
130 static int opp_list_debug_create_dir(struct opp_device *opp_dev,
131                                      struct opp_table *opp_table)
132 {
133         const struct device *dev = opp_dev->dev;
134         struct dentry *d;
135
136         opp_set_dev_name(dev, opp_table->dentry_name);
137
138         /* Create device specific directory */
139         d = debugfs_create_dir(opp_table->dentry_name, rootdir);
140         if (!d) {
141                 dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
142                 return -ENOMEM;
143         }
144
145         opp_dev->dentry = d;
146         opp_table->dentry = d;
147
148         return 0;
149 }
150
151 static int opp_list_debug_create_link(struct opp_device *opp_dev,
152                                       struct opp_table *opp_table)
153 {
154         const struct device *dev = opp_dev->dev;
155         char name[NAME_MAX];
156         struct dentry *d;
157
158         opp_set_dev_name(opp_dev->dev, name);
159
160         /* Create device specific directory link */
161         d = debugfs_create_symlink(name, rootdir, opp_table->dentry_name);
162         if (!d) {
163                 dev_err(dev, "%s: Failed to create link\n", __func__);
164                 return -ENOMEM;
165         }
166
167         opp_dev->dentry = d;
168
169         return 0;
170 }
171
172 /**
173  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
174  * @opp_dev: opp-dev pointer for device
175  * @opp_table: the device-opp being added
176  *
177  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
178  * device-opp is shared with other devices, then links will be created for all
179  * devices except the first.
180  *
181  * Return: 0 on success, otherwise negative error.
182  */
183 int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
184 {
185         if (!rootdir) {
186                 pr_debug("%s: Uninitialized rootdir\n", __func__);
187                 return -EINVAL;
188         }
189
190         if (opp_table->dentry)
191                 return opp_list_debug_create_link(opp_dev, opp_table);
192
193         return opp_list_debug_create_dir(opp_dev, opp_table);
194 }
195
196 static void opp_migrate_dentry(struct opp_device *opp_dev,
197                                struct opp_table *opp_table)
198 {
199         struct opp_device *new_dev;
200         const struct device *dev;
201         struct dentry *dentry;
202
203         /* Look for next opp-dev */
204         list_for_each_entry(new_dev, &opp_table->dev_list, node)
205                 if (new_dev != opp_dev)
206                         break;
207
208         /* new_dev is guaranteed to be valid here */
209         dev = new_dev->dev;
210         debugfs_remove_recursive(new_dev->dentry);
211
212         opp_set_dev_name(dev, opp_table->dentry_name);
213
214         dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
215                                 opp_table->dentry_name);
216         if (!dentry) {
217                 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
218                         __func__, dev_name(opp_dev->dev), dev_name(dev));
219                 return;
220         }
221
222         new_dev->dentry = dentry;
223         opp_table->dentry = dentry;
224 }
225
226 /**
227  * opp_debug_unregister - remove a device opp node from debugfs opp directory
228  * @opp_dev: opp-dev pointer for device
229  * @opp_table: the device-opp being removed
230  *
231  * Dynamically removes device specific directory from debugfs 'opp' directory.
232  */
233 void opp_debug_unregister(struct opp_device *opp_dev,
234                           struct opp_table *opp_table)
235 {
236         if (opp_dev->dentry == opp_table->dentry) {
237                 /* Move the real dentry object under another device */
238                 if (!list_is_singular(&opp_table->dev_list)) {
239                         opp_migrate_dentry(opp_dev, opp_table);
240                         goto out;
241                 }
242                 opp_table->dentry = NULL;
243         }
244
245         debugfs_remove_recursive(opp_dev->dentry);
246
247 out:
248         opp_dev->dentry = NULL;
249 }
250
251 static int __init opp_debug_init(void)
252 {
253         /* Create /sys/kernel/debug/opp directory */
254         rootdir = debugfs_create_dir("opp", NULL);
255         if (!rootdir) {
256                 pr_err("%s: Failed to create root directory\n", __func__);
257                 return -ENOMEM;
258         }
259
260         return 0;
261 }
262 core_initcall(opp_debug_init);