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         char name[25];  /* 20 chars for 64 bit value + 5 (opp:\0) */
  81
  82         /* Rate is unique to each OPP, use it to give opp-name */
  83         snprintf(name, sizeof(name), "opp:%lu", opp->rate);
  84
  85         /* Create per-opp directory */
  86         d = debugfs_create_dir(name, pdentry);
  87         if (!d)
  88                 return -ENOMEM;
  89
  90         if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
  91                 return -ENOMEM;
  92
  93         if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
  94                 return -ENOMEM;
  95
  96         if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
  97                 return -ENOMEM;
  98
  99         if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
 100                 return -ENOMEM;
 101
 102         if (!debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate))
 103                 return -ENOMEM;
 104
 105         if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
 106                 return -ENOMEM;
 107
 108         if (!opp_debug_create_supplies(opp, opp_table, d))
 109                 return -ENOMEM;
 110
 111         if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
 112                                   &opp->clock_latency_ns))
 113                 return -ENOMEM;
 114
 115         opp->dentry = d;
 116         return 0;
 117 }
 118
 119 static int opp_list_debug_create_dir(struct opp_device *opp_dev,
 120                                      struct opp_table *opp_table)
 121 {
 122         const struct device *dev = opp_dev->dev;
 123         struct dentry *d;
 124
 125         opp_set_dev_name(dev, opp_table->dentry_name);
 126
 127         /* Create device specific directory */
 128         d = debugfs_create_dir(opp_table->dentry_name, rootdir);
 129         if (!d) {
 130                 dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
 131                 return -ENOMEM;
 132         }
 133
 134         opp_dev->dentry = d;
 135         opp_table->dentry = d;
 136
 137         return 0;
 138 }
 139
 140 static int opp_list_debug_create_link(struct opp_device *opp_dev,
 141                                       struct opp_table *opp_table)
 142 {
 143         const struct device *dev = opp_dev->dev;
 144         char name[NAME_MAX];
 145         struct dentry *d;
 146
 147         opp_set_dev_name(opp_dev->dev, name);
 148
 149         /* Create device specific directory link */
 150         d = debugfs_create_symlink(name, rootdir, opp_table->dentry_name);
 151         if (!d) {
 152                 dev_err(dev, "%s: Failed to create link\n", __func__);
 153                 return -ENOMEM;
 154         }
 155
 156         opp_dev->dentry = d;
 157
 158         return 0;
 159 }
 160
 161 /**
 162  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
 163  * @opp_dev: opp-dev pointer for device
 164  * @opp_table: the device-opp being added
 165  *
 166  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
 167  * device-opp is shared with other devices, then links will be created for all
 168  * devices except the first.
 169  *
 170  * Return: 0 on success, otherwise negative error.
 171  */
 172 int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
 173 {
 174         if (!rootdir) {
 175                 pr_debug("%s: Uninitialized rootdir\n", __func__);
 176                 return -EINVAL;
 177         }
 178
 179         if (opp_table->dentry)
 180                 return opp_list_debug_create_link(opp_dev, opp_table);
 181
 182         return opp_list_debug_create_dir(opp_dev, opp_table);
 183 }
 184
 185 static void opp_migrate_dentry(struct opp_device *opp_dev,
 186                                struct opp_table *opp_table)
 187 {
 188         struct opp_device *new_dev;
 189         const struct device *dev;
 190         struct dentry *dentry;
 191
 192         /* Look for next opp-dev */
 193         list_for_each_entry(new_dev, &opp_table->dev_list, node)
 194                 if (new_dev != opp_dev)
 195                         break;
 196
 197         /* new_dev is guaranteed to be valid here */
 198         dev = new_dev->dev;
 199         debugfs_remove_recursive(new_dev->dentry);
 200
 201         opp_set_dev_name(dev, opp_table->dentry_name);
 202
 203         dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
 204                                 opp_table->dentry_name);
 205         if (!dentry) {
 206                 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
 207                         __func__, dev_name(opp_dev->dev), dev_name(dev));
 208                 return;
 209         }
 210
 211         new_dev->dentry = dentry;
 212         opp_table->dentry = dentry;
 213 }
 214
 215 /**
 216  * opp_debug_unregister - remove a device opp node from debugfs opp directory
 217  * @opp_dev: opp-dev pointer for device
 218  * @opp_table: the device-opp being removed
 219  *
 220  * Dynamically removes device specific directory from debugfs 'opp' directory.
 221  */
 222 void opp_debug_unregister(struct opp_device *opp_dev,
 223                           struct opp_table *opp_table)
 224 {
 225         if (opp_dev->dentry == opp_table->dentry) {
 226                 /* Move the real dentry object under another device */
 227                 if (!list_is_singular(&opp_table->dev_list)) {
 228                         opp_migrate_dentry(opp_dev, opp_table);
 229                         goto out;
 230                 }
 231                 opp_table->dentry = NULL;
 232         }
 233
 234         debugfs_remove_recursive(opp_dev->dentry);
 235
 236 out:
 237         opp_dev->dentry = NULL;
 238 }
 239
 240 static int __init opp_debug_init(void)
 241 {
 242         /* Create /sys/kernel/debug/opp directory */
 243         rootdir = debugfs_create_dir("opp", NULL);
 244         if (!rootdir) {
 245                 pr_err("%s: Failed to create root directory\n", __func__);
 246                 return -ENOMEM;
 247         }
 248
 249         return 0;
 250 }
 251 core_initcall(opp_debug_init);