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 void 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                 debugfs_create_ulong("u_volt_target", S_IRUGO, d,
  54                                      &opp->supplies[i].u_volt);
  55
  56                 debugfs_create_ulong("u_volt_min", S_IRUGO, d,
  57                                      &opp->supplies[i].u_volt_min);
  58
  59                 debugfs_create_ulong("u_volt_max", S_IRUGO, d,
  60                                      &opp->supplies[i].u_volt_max);
  61
  62                 debugfs_create_ulong("u_amp", S_IRUGO, d,
  63                                      &opp->supplies[i].u_amp);
  64         }
  65 }
  66
  67 void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
  68 {
  69         struct dentry *pdentry = opp_table->dentry;
  70         struct dentry *d;
  71         unsigned long id;
  72         char name[25];  /* 20 chars for 64 bit value + 5 (opp:\0) */
  73
  74         /*
  75          * Get directory name for OPP.
  76          *
  77          * - Normally rate is unique to each OPP, use it to get unique opp-name.
  78          * - For some devices rate isn't available, use index instead.
  79          */
  80         if (likely(opp->rate))
  81                 id = opp->rate;
  82         else
  83                 id = _get_opp_count(opp_table);
  84
  85         snprintf(name, sizeof(name), "opp:%lu", id);
  86
  87         /* Create per-opp directory */
  88         d = debugfs_create_dir(name, pdentry);
  89
  90         debugfs_create_bool("available", S_IRUGO, d, &opp->available);
  91         debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
  92         debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
  93         debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
  94         debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
  95         debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
  96         debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
  97                              &opp->clock_latency_ns);
  98
  99         opp_debug_create_supplies(opp, opp_table, d);
 100
 101         opp->dentry = d;
 102 }
 103
 104 static void opp_list_debug_create_dir(struct opp_device *opp_dev,
 105                                       struct opp_table *opp_table)
 106 {
 107         const struct device *dev = opp_dev->dev;
 108         struct dentry *d;
 109
 110         opp_set_dev_name(dev, opp_table->dentry_name);
 111
 112         /* Create device specific directory */
 113         d = debugfs_create_dir(opp_table->dentry_name, rootdir);
 114
 115         opp_dev->dentry = d;
 116         opp_table->dentry = d;
 117 }
 118
 119 static void opp_list_debug_create_link(struct opp_device *opp_dev,
 120                                        struct opp_table *opp_table)
 121 {
 122         char name[NAME_MAX];
 123
 124         opp_set_dev_name(opp_dev->dev, name);
 125
 126         /* Create device specific directory link */
 127         opp_dev->dentry = debugfs_create_symlink(name, rootdir,
 128                                                  opp_table->dentry_name);
 129 }
 130
 131 /**
 132  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
 133  * @opp_dev: opp-dev pointer for device
 134  * @opp_table: the device-opp being added
 135  *
 136  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
 137  * device-opp is shared with other devices, then links will be created for all
 138  * devices except the first.
 139  */
 140 void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
 141 {
 142         if (opp_table->dentry)
 143                 opp_list_debug_create_link(opp_dev, opp_table);
 144         else
 145                 opp_list_debug_create_dir(opp_dev, opp_table);
 146 }
 147
 148 static void opp_migrate_dentry(struct opp_device *opp_dev,
 149                                struct opp_table *opp_table)
 150 {
 151         struct opp_device *new_dev;
 152         const struct device *dev;
 153         struct dentry *dentry;
 154
 155         /* Look for next opp-dev */
 156         list_for_each_entry(new_dev, &opp_table->dev_list, node)
 157                 if (new_dev != opp_dev)
 158                         break;
 159
 160         /* new_dev is guaranteed to be valid here */
 161         dev = new_dev->dev;
 162         debugfs_remove_recursive(new_dev->dentry);
 163
 164         opp_set_dev_name(dev, opp_table->dentry_name);
 165
 166         dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
 167                                 opp_table->dentry_name);
 168         if (!dentry) {
 169                 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
 170                         __func__, dev_name(opp_dev->dev), dev_name(dev));
 171                 return;
 172         }
 173
 174         new_dev->dentry = dentry;
 175         opp_table->dentry = dentry;
 176 }
 177
 178 /**
 179  * opp_debug_unregister - remove a device opp node from debugfs opp directory
 180  * @opp_dev: opp-dev pointer for device
 181  * @opp_table: the device-opp being removed
 182  *
 183  * Dynamically removes device specific directory from debugfs 'opp' directory.
 184  */
 185 void opp_debug_unregister(struct opp_device *opp_dev,
 186                           struct opp_table *opp_table)
 187 {
 188         if (opp_dev->dentry == opp_table->dentry) {
 189                 /* Move the real dentry object under another device */
 190                 if (!list_is_singular(&opp_table->dev_list)) {
 191                         opp_migrate_dentry(opp_dev, opp_table);
 192                         goto out;
 193                 }
 194                 opp_table->dentry = NULL;
 195         }
 196
 197         debugfs_remove_recursive(opp_dev->dentry);
 198
 199 out:
 200         opp_dev->dentry = NULL;
 201 }
 202
 203 static int __init opp_debug_init(void)
 204 {
 205         /* Create /sys/kernel/debug/opp directory */
 206         rootdir = debugfs_create_dir("opp", NULL);
 207
 208         return 0;
 209 }
 210 core_initcall(opp_debug_init);