drivers/opp/debugfs.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Generic OPP debugfs interface
   4  *
   5  * Copyright (C) 2015-2016 Viresh Kumar <viresh.kumar@linaro.org>
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/debugfs.h>
  11 #include <linux/device.h>
  12 #include <linux/err.h>
  13 #include <linux/init.h>
  14 #include <linux/limits.h>
  15 #include <linux/slab.h>
  16
  17 #include "opp.h"
  18
  19 static struct dentry *rootdir;
  20
  21 static void opp_set_dev_name(const struct device *dev, char *name)
  22 {
  23         if (dev->parent)
  24                 snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent),
  25                          dev_name(dev));
  26         else
  27                 snprintf(name, NAME_MAX, "%s", dev_name(dev));
  28 }
  29
  30 void opp_debug_remove_one(struct dev_pm_opp *opp)
  31 {
  32         debugfs_remove_recursive(opp->dentry);
  33 }
  34
  35 static void opp_debug_create_supplies(struct dev_pm_opp *opp,
  36                                       struct opp_table *opp_table,
  37                                       struct dentry *pdentry)
  38 {
  39         struct dentry *d;
  40         int i;
  41
  42         for (i = 0; i < opp_table->regulator_count; i++) {
  43                 char name[15];
  44
  45                 snprintf(name, sizeof(name), "supply-%d", i);
  46
  47                 /* Create per-opp directory */
  48                 d = debugfs_create_dir(name, pdentry);
  49
  50                 debugfs_create_ulong("u_volt_target", S_IRUGO, d,
  51                                      &opp->supplies[i].u_volt);
  52
  53                 debugfs_create_ulong("u_volt_min", S_IRUGO, d,
  54                                      &opp->supplies[i].u_volt_min);
  55
  56                 debugfs_create_ulong("u_volt_max", S_IRUGO, d,
  57                                      &opp->supplies[i].u_volt_max);
  58
  59                 debugfs_create_ulong("u_amp", S_IRUGO, d,
  60                                      &opp->supplies[i].u_amp);
  61         }
  62 }
  63
  64 void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
  65 {
  66         struct dentry *pdentry = opp_table->dentry;
  67         struct dentry *d;
  68         unsigned long id;
  69         char name[25];  /* 20 chars for 64 bit value + 5 (opp:\0) */
  70
  71         /*
  72          * Get directory name for OPP.
  73          *
  74          * - Normally rate is unique to each OPP, use it to get unique opp-name.
  75          * - For some devices rate isn't available, use index instead.
  76          */
  77         if (likely(opp->rate))
  78                 id = opp->rate;
  79         else
  80                 id = _get_opp_count(opp_table);
  81
  82         snprintf(name, sizeof(name), "opp:%lu", id);
  83
  84         /* Create per-opp directory */
  85         d = debugfs_create_dir(name, pdentry);
  86
  87         debugfs_create_bool("available", S_IRUGO, d, &opp->available);
  88         debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
  89         debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
  90         debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
  91         debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
  92         debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
  93         debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
  94                              &opp->clock_latency_ns);
  95
  96         opp_debug_create_supplies(opp, opp_table, d);
  97
  98         opp->dentry = d;
  99 }
 100
 101 static void opp_list_debug_create_dir(struct opp_device *opp_dev,
 102                                       struct opp_table *opp_table)
 103 {
 104         const struct device *dev = opp_dev->dev;
 105         struct dentry *d;
 106
 107         opp_set_dev_name(dev, opp_table->dentry_name);
 108
 109         /* Create device specific directory */
 110         d = debugfs_create_dir(opp_table->dentry_name, rootdir);
 111
 112         opp_dev->dentry = d;
 113         opp_table->dentry = d;
 114 }
 115
 116 static void opp_list_debug_create_link(struct opp_device *opp_dev,
 117                                        struct opp_table *opp_table)
 118 {
 119         char name[NAME_MAX];
 120
 121         opp_set_dev_name(opp_dev->dev, name);
 122
 123         /* Create device specific directory link */
 124         opp_dev->dentry = debugfs_create_symlink(name, rootdir,
 125                                                  opp_table->dentry_name);
 126 }
 127
 128 /**
 129  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
 130  * @opp_dev: opp-dev pointer for device
 131  * @opp_table: the device-opp being added
 132  *
 133  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
 134  * device-opp is shared with other devices, then links will be created for all
 135  * devices except the first.
 136  */
 137 void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
 138 {
 139         if (opp_table->dentry)
 140                 opp_list_debug_create_link(opp_dev, opp_table);
 141         else
 142                 opp_list_debug_create_dir(opp_dev, opp_table);
 143 }
 144
 145 static void opp_migrate_dentry(struct opp_device *opp_dev,
 146                                struct opp_table *opp_table)
 147 {
 148         struct opp_device *new_dev;
 149         const struct device *dev;
 150         struct dentry *dentry;
 151
 152         /* Look for next opp-dev */
 153         list_for_each_entry(new_dev, &opp_table->dev_list, node)
 154                 if (new_dev != opp_dev)
 155                         break;
 156
 157         /* new_dev is guaranteed to be valid here */
 158         dev = new_dev->dev;
 159         debugfs_remove_recursive(new_dev->dentry);
 160
 161         opp_set_dev_name(dev, opp_table->dentry_name);
 162
 163         dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
 164                                 opp_table->dentry_name);
 165         if (!dentry) {
 166                 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
 167                         __func__, dev_name(opp_dev->dev), dev_name(dev));
 168                 return;
 169         }
 170
 171         new_dev->dentry = dentry;
 172         opp_table->dentry = dentry;
 173 }
 174
 175 /**
 176  * opp_debug_unregister - remove a device opp node from debugfs opp directory
 177  * @opp_dev: opp-dev pointer for device
 178  * @opp_table: the device-opp being removed
 179  *
 180  * Dynamically removes device specific directory from debugfs 'opp' directory.
 181  */
 182 void opp_debug_unregister(struct opp_device *opp_dev,
 183                           struct opp_table *opp_table)
 184 {
 185         if (opp_dev->dentry == opp_table->dentry) {
 186                 /* Move the real dentry object under another device */
 187                 if (!list_is_singular(&opp_table->dev_list)) {
 188                         opp_migrate_dentry(opp_dev, opp_table);
 189                         goto out;
 190                 }
 191                 opp_table->dentry = NULL;
 192         }
 193
 194         debugfs_remove_recursive(opp_dev->dentry);
 195
 196 out:
 197         opp_dev->dentry = NULL;
 198 }
 199
 200 static int __init opp_debug_init(void)
 201 {
 202         /* Create /sys/kernel/debug/opp directory */
 203         rootdir = debugfs_create_dir("opp", NULL);
 204
 205         return 0;
 206 }
 207 core_initcall(opp_debug_init);