Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
19#include "opp.h"
20
21static struct dentry *rootdir;
22
23static void opp_set_dev_name(const struct device *dev, char *name)
24{
25 if (dev->parent)
26 snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent),
27 dev_name(dev));
28 else
29 snprintf(name, NAME_MAX, "%s", dev_name(dev));
30}
31
32void opp_debug_remove_one(struct dev_pm_opp *opp)
33{
34 debugfs_remove_recursive(opp->dentry);
35}
36
37int opp_debug_create_one(struct dev_pm_opp *opp, struct device_opp *dev_opp)
38{
39 struct dentry *pdentry = dev_opp->dentry;
40 struct dentry *d;
41 char name[25]; /* 20 chars for 64 bit value + 5 (opp:\0) */
42
43 /* Rate is unique to each OPP, use it to give opp-name */
44 snprintf(name, sizeof(name), "opp:%lu", opp->rate);
45
46 /* Create per-opp directory */
47 d = debugfs_create_dir(name, pdentry);
48 if (!d)
49 return -ENOMEM;
50
51 if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
52 return -ENOMEM;
53
54 if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
55 return -ENOMEM;
56
57 if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
58 return -ENOMEM;
59
60 if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
61 return -ENOMEM;
62
63 if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
64 return -ENOMEM;
65
66 if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d, &opp->u_volt))
67 return -ENOMEM;
68
69 if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d, &opp->u_volt_min))
70 return -ENOMEM;
71
72 if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d, &opp->u_volt_max))
73 return -ENOMEM;
74
75 if (!debugfs_create_ulong("u_amp", S_IRUGO, d, &opp->u_amp))
76 return -ENOMEM;
77
78 if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
79 &opp->clock_latency_ns))
80 return -ENOMEM;
81
82 opp->dentry = d;
83 return 0;
84}
85
86static int device_opp_debug_create_dir(struct device_list_opp *list_dev,
87 struct device_opp *dev_opp)
88{
89 const struct device *dev = list_dev->dev;
90 struct dentry *d;
91
92 opp_set_dev_name(dev, dev_opp->dentry_name);
93
94 /* Create device specific directory */
95 d = debugfs_create_dir(dev_opp->dentry_name, rootdir);
96 if (!d) {
97 dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
98 return -ENOMEM;
99 }
100
101 list_dev->dentry = d;
102 dev_opp->dentry = d;
103
104 return 0;
105}
106
107static int device_opp_debug_create_link(struct device_list_opp *list_dev,
108 struct device_opp *dev_opp)
109{
110 const struct device *dev = list_dev->dev;
111 char name[NAME_MAX];
112 struct dentry *d;
113
114 opp_set_dev_name(list_dev->dev, name);
115
116 /* Create device specific directory link */
117 d = debugfs_create_symlink(name, rootdir, dev_opp->dentry_name);
118 if (!d) {
119 dev_err(dev, "%s: Failed to create link\n", __func__);
120 return -ENOMEM;
121 }
122
123 list_dev->dentry = d;
124
125 return 0;
126}
127
128/**
129 * opp_debug_register - add a device opp node to the debugfs 'opp' directory
130 * @list_dev: list-dev pointer for device
131 * @dev_opp: the device-opp being added
132 *
133 * Dynamically adds device specific directory in debugfs 'opp' directory. If the
134 * device-opp is shared with other devices, then links will be created for all
135 * devices except the first.
136 *
137 * Return: 0 on success, otherwise negative error.
138 */
139int opp_debug_register(struct device_list_opp *list_dev,
140 struct device_opp *dev_opp)
141{
142 if (!rootdir) {
143 pr_debug("%s: Uninitialized rootdir\n", __func__);
144 return -EINVAL;
145 }
146
147 if (dev_opp->dentry)
148 return device_opp_debug_create_link(list_dev, dev_opp);
149
150 return device_opp_debug_create_dir(list_dev, dev_opp);
151}
152
153static void opp_migrate_dentry(struct device_list_opp *list_dev,
154 struct device_opp *dev_opp)
155{
156 struct device_list_opp *new_dev;
157 const struct device *dev;
158 struct dentry *dentry;
159
160 /* Look for next list-dev */
161 list_for_each_entry(new_dev, &dev_opp->dev_list, node)
162 if (new_dev != list_dev)
163 break;
164
165 /* new_dev is guaranteed to be valid here */
166 dev = new_dev->dev;
167 debugfs_remove_recursive(new_dev->dentry);
168
169 opp_set_dev_name(dev, dev_opp->dentry_name);
170
171 dentry = debugfs_rename(rootdir, list_dev->dentry, rootdir,
172 dev_opp->dentry_name);
173 if (!dentry) {
174 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
175 __func__, dev_name(list_dev->dev), dev_name(dev));
176 return;
177 }
178
179 new_dev->dentry = dentry;
180 dev_opp->dentry = dentry;
181}
182
183/**
184 * opp_debug_unregister - remove a device opp node from debugfs opp directory
185 * @list_dev: list-dev pointer for device
186 * @dev_opp: the device-opp being removed
187 *
188 * Dynamically removes device specific directory from debugfs 'opp' directory.
189 */
190void opp_debug_unregister(struct device_list_opp *list_dev,
191 struct device_opp *dev_opp)
192{
193 if (list_dev->dentry == dev_opp->dentry) {
194 /* Move the real dentry object under another device */
195 if (!list_is_singular(&dev_opp->dev_list)) {
196 opp_migrate_dentry(list_dev, dev_opp);
197 goto out;
198 }
199 dev_opp->dentry = NULL;
200 }
201
202 debugfs_remove_recursive(list_dev->dentry);
203
204out:
205 list_dev->dentry = NULL;
206}
207
208static int __init opp_debug_init(void)
209{
210 /* Create /sys/kernel/debug/opp directory */
211 rootdir = debugfs_create_dir("opp", NULL);
212 if (!rootdir) {
213 pr_err("%s: Failed to create root directory\n", __func__);
214 return -ENOMEM;
215 }
216
217 return 0;
218}
219core_initcall(opp_debug_init);