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);