drivers/base/power/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 = 0;
  44         char *name;
  45
  46         /* Always create at least supply-0 directory */
  47         do {
  48                 name = kasprintf(GFP_KERNEL, "supply-%d", i);
  49
  50                 /* Create per-opp directory */
  51                 d = debugfs_create_dir(name, pdentry);
  52
  53                 kfree(name);
  54
  55                 if (!d)
  56                         return false;
  57
  58                 if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d,
  59                                           &opp->supplies[i].u_volt))
  60                         return false;
  61
  62                 if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d,
  63                                           &opp->supplies[i].u_volt_min))
  64                         return false;
  65
  66                 if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d,
  67                                           &opp->supplies[i].u_volt_max))
  68                         return false;
  69
  70                 if (!debugfs_create_ulong("u_amp", S_IRUGO, d,
  71                                           &opp->supplies[i].u_amp))
  72                         return false;
  73         } while (++i < opp_table->regulator_count);
  74
  75         return true;
  76 }
  77
  78 int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
  79 {
  80         struct dentry *pdentry = opp_table->dentry;
  81         struct dentry *d;
  82         char name[25];  /* 20 chars for 64 bit value + 5 (opp:\0) */
  83
  84         /* Rate is unique to each OPP, use it to give opp-name */
  85         snprintf(name, sizeof(name), "opp:%lu", opp->rate);
  86
  87         /* Create per-opp directory */
  88         d = debugfs_create_dir(name, pdentry);
  89         if (!d)
  90                 return -ENOMEM;
  91
  92         if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
  93                 return -ENOMEM;
  94
  95         if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
  96                 return -ENOMEM;
  97
  98         if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
  99                 return -ENOMEM;
 100
 101         if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
 102                 return -ENOMEM;
 103
 104         if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
 105                 return -ENOMEM;
 106
 107         if (!opp_debug_create_supplies(opp, opp_table, d))
 108                 return -ENOMEM;
 109
 110         if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
 111                                   &opp->clock_latency_ns))
 112                 return -ENOMEM;
 113
 114         opp->dentry = d;
 115         return 0;
 116 }
 117
 118 static int opp_list_debug_create_dir(struct opp_device *opp_dev,
 119                                      struct opp_table *opp_table)
 120 {
 121         const struct device *dev = opp_dev->dev;
 122         struct dentry *d;
 123
 124         opp_set_dev_name(dev, opp_table->dentry_name);
 125
 126         /* Create device specific directory */
 127         d = debugfs_create_dir(opp_table->dentry_name, rootdir);
 128         if (!d) {
 129                 dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
 130                 return -ENOMEM;
 131         }
 132
 133         opp_dev->dentry = d;
 134         opp_table->dentry = d;
 135
 136         return 0;
 137 }
 138
 139 static int opp_list_debug_create_link(struct opp_device *opp_dev,
 140                                       struct opp_table *opp_table)
 141 {
 142         const struct device *dev = opp_dev->dev;
 143         char name[NAME_MAX];
 144         struct dentry *d;
 145
 146         opp_set_dev_name(opp_dev->dev, name);
 147
 148         /* Create device specific directory link */
 149         d = debugfs_create_symlink(name, rootdir, opp_table->dentry_name);
 150         if (!d) {
 151                 dev_err(dev, "%s: Failed to create link\n", __func__);
 152                 return -ENOMEM;
 153         }
 154
 155         opp_dev->dentry = d;
 156
 157         return 0;
 158 }
 159
 160 /**
 161  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
 162  * @opp_dev: opp-dev pointer for device
 163  * @opp_table: the device-opp being added
 164  *
 165  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
 166  * device-opp is shared with other devices, then links will be created for all
 167  * devices except the first.
 168  *
 169  * Return: 0 on success, otherwise negative error.
 170  */
 171 int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
 172 {
 173         if (!rootdir) {
 174                 pr_debug("%s: Uninitialized rootdir\n", __func__);
 175                 return -EINVAL;
 176         }
 177
 178         if (opp_table->dentry)
 179                 return opp_list_debug_create_link(opp_dev, opp_table);
 180
 181         return opp_list_debug_create_dir(opp_dev, opp_table);
 182 }
 183
 184 static void opp_migrate_dentry(struct opp_device *opp_dev,
 185                                struct opp_table *opp_table)
 186 {
 187         struct opp_device *new_dev;
 188         const struct device *dev;
 189         struct dentry *dentry;
 190
 191         /* Look for next opp-dev */
 192         list_for_each_entry(new_dev, &opp_table->dev_list, node)
 193                 if (new_dev != opp_dev)
 194                         break;
 195
 196         /* new_dev is guaranteed to be valid here */
 197         dev = new_dev->dev;
 198         debugfs_remove_recursive(new_dev->dentry);
 199
 200         opp_set_dev_name(dev, opp_table->dentry_name);
 201
 202         dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
 203                                 opp_table->dentry_name);
 204         if (!dentry) {
 205                 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
 206                         __func__, dev_name(opp_dev->dev), dev_name(dev));
 207                 return;
 208         }
 209
 210         new_dev->dentry = dentry;
 211         opp_table->dentry = dentry;
 212 }
 213
 214 /**
 215  * opp_debug_unregister - remove a device opp node from debugfs opp directory
 216  * @opp_dev: opp-dev pointer for device
 217  * @opp_table: the device-opp being removed
 218  *
 219  * Dynamically removes device specific directory from debugfs 'opp' directory.
 220  */
 221 void opp_debug_unregister(struct opp_device *opp_dev,
 222                           struct opp_table *opp_table)
 223 {
 224         if (opp_dev->dentry == opp_table->dentry) {
 225                 /* Move the real dentry object under another device */
 226                 if (!list_is_singular(&opp_table->dev_list)) {
 227                         opp_migrate_dentry(opp_dev, opp_table);
 228                         goto out;
 229                 }
 230                 opp_table->dentry = NULL;
 231         }
 232
 233         debugfs_remove_recursive(opp_dev->dentry);
 234
 235 out:
 236         opp_dev->dentry = NULL;
 237 }
 238
 239 static int __init opp_debug_init(void)
 240 {
 241         /* Create /sys/kernel/debug/opp directory */
 242         rootdir = debugfs_create_dir("opp", NULL);
 243         if (!rootdir) {
 244                 pr_err("%s: Failed to create root directory\n", __func__);
 245                 return -ENOMEM;
 246         }
 247
 248         return 0;
 249 }
 250 core_initcall(opp_debug_init);