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