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 ssize_t bw_name_read(struct file *fp, char __user *userbuf,
  36                             size_t count, loff_t *ppos)
  37 {
  38         struct icc_path *path = fp->private_data;
  39         const char *name = icc_get_name(path);
  40         char buf[64];
  41         int i = 0;
  42
  43         if (name)
  44                 i = scnprintf(buf, sizeof(buf), "%.62s\n", name);
  45
  46         return simple_read_from_buffer(userbuf, count, ppos, buf, i);
  47 }
  48
  49 static const struct file_operations bw_name_fops = {
  50         .open = simple_open,
  51         .read = bw_name_read,
  52         .llseek = default_llseek,
  53 };
  54
  55 static void opp_debug_create_bw(struct dev_pm_opp *opp,
  56                                 struct opp_table *opp_table,
  57                                 struct dentry *pdentry)
  58 {
  59         struct dentry *d;
  60         char name[11];
  61         int i;
  62
  63         for (i = 0; i < opp_table->path_count; i++) {
  64                 snprintf(name, sizeof(name), "icc-path-%.1d", i);
  65
  66                 /* Create per-path directory */
  67                 d = debugfs_create_dir(name, pdentry);
  68
  69                 debugfs_create_file("name", S_IRUGO, d, opp_table->paths[i],
  70                                     &bw_name_fops);
  71                 debugfs_create_u32("peak_bw", S_IRUGO, d,
  72                                    &opp->bandwidth[i].peak);
  73                 debugfs_create_u32("avg_bw", S_IRUGO, d,
  74                                    &opp->bandwidth[i].avg);
  75         }
  76 }
  77
  78 static void opp_debug_create_supplies(struct dev_pm_opp *opp,
  79                                       struct opp_table *opp_table,
  80                                       struct dentry *pdentry)
  81 {
  82         struct dentry *d;
  83         int i;
  84
  85         for (i = 0; i < opp_table->regulator_count; i++) {
  86                 char name[15];
  87
  88                 snprintf(name, sizeof(name), "supply-%d", i);
  89
  90                 /* Create per-opp directory */
  91                 d = debugfs_create_dir(name, pdentry);
  92
  93                 debugfs_create_ulong("u_volt_target", S_IRUGO, d,
  94                                      &opp->supplies[i].u_volt);
  95
  96                 debugfs_create_ulong("u_volt_min", S_IRUGO, d,
  97                                      &opp->supplies[i].u_volt_min);
  98
  99                 debugfs_create_ulong("u_volt_max", S_IRUGO, d,
 100                                      &opp->supplies[i].u_volt_max);
 101
 102                 debugfs_create_ulong("u_amp", S_IRUGO, d,
 103                                      &opp->supplies[i].u_amp);
 104         }
 105 }
 106
 107 void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
 108 {
 109         struct dentry *pdentry = opp_table->dentry;
 110         struct dentry *d;
 111         unsigned long id;
 112         char name[25];  /* 20 chars for 64 bit value + 5 (opp:\0) */
 113
 114         /*
 115          * Get directory name for OPP.
 116          *
 117          * - Normally rate is unique to each OPP, use it to get unique opp-name.
 118          * - For some devices rate isn't available, use index instead.
 119          */
 120         if (likely(opp->rate))
 121                 id = opp->rate;
 122         else
 123                 id = _get_opp_count(opp_table);
 124
 125         snprintf(name, sizeof(name), "opp:%lu", id);
 126
 127         /* Create per-opp directory */
 128         d = debugfs_create_dir(name, pdentry);
 129
 130         debugfs_create_bool("available", S_IRUGO, d, &opp->available);
 131         debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
 132         debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
 133         debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
 134         debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
 135         debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
 136         debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
 137                              &opp->clock_latency_ns);
 138
 139         opp_debug_create_supplies(opp, opp_table, d);
 140         opp_debug_create_bw(opp, opp_table, d);
 141
 142         opp->dentry = d;
 143 }
 144
 145 static void opp_list_debug_create_dir(struct opp_device *opp_dev,
 146                                       struct opp_table *opp_table)
 147 {
 148         const struct device *dev = opp_dev->dev;
 149         struct dentry *d;
 150
 151         opp_set_dev_name(dev, opp_table->dentry_name);
 152
 153         /* Create device specific directory */
 154         d = debugfs_create_dir(opp_table->dentry_name, rootdir);
 155
 156         opp_dev->dentry = d;
 157         opp_table->dentry = d;
 158 }
 159
 160 static void opp_list_debug_create_link(struct opp_device *opp_dev,
 161                                        struct opp_table *opp_table)
 162 {
 163         char name[NAME_MAX];
 164
 165         opp_set_dev_name(opp_dev->dev, name);
 166
 167         /* Create device specific directory link */
 168         opp_dev->dentry = debugfs_create_symlink(name, rootdir,
 169                                                  opp_table->dentry_name);
 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 void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
 182 {
 183         if (opp_table->dentry)
 184                 opp_list_debug_create_link(opp_dev, opp_table);
 185         else
 186                 opp_list_debug_create_dir(opp_dev, opp_table);
 187 }
 188
 189 static void opp_migrate_dentry(struct opp_device *opp_dev,
 190                                struct opp_table *opp_table)
 191 {
 192         struct opp_device *new_dev;
 193         const struct device *dev;
 194         struct dentry *dentry;
 195
 196         /* Look for next opp-dev */
 197         list_for_each_entry(new_dev, &opp_table->dev_list, node)
 198                 if (new_dev != opp_dev)
 199                         break;
 200
 201         /* new_dev is guaranteed to be valid here */
 202         dev = new_dev->dev;
 203         debugfs_remove_recursive(new_dev->dentry);
 204
 205         opp_set_dev_name(dev, opp_table->dentry_name);
 206
 207         dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
 208                                 opp_table->dentry_name);
 209         if (IS_ERR(dentry)) {
 210                 dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
 211                         __func__, dev_name(opp_dev->dev), dev_name(dev));
 212                 return;
 213         }
 214
 215         new_dev->dentry = dentry;
 216         opp_table->dentry = dentry;
 217 }
 218
 219 /**
 220  * opp_debug_unregister - remove a device opp node from debugfs opp directory
 221  * @opp_dev: opp-dev pointer for device
 222  * @opp_table: the device-opp being removed
 223  *
 224  * Dynamically removes device specific directory from debugfs 'opp' directory.
 225  */
 226 void opp_debug_unregister(struct opp_device *opp_dev,
 227                           struct opp_table *opp_table)
 228 {
 229         if (opp_dev->dentry == opp_table->dentry) {
 230                 /* Move the real dentry object under another device */
 231                 if (!list_is_singular(&opp_table->dev_list)) {
 232                         opp_migrate_dentry(opp_dev, opp_table);
 233                         goto out;
 234                 }
 235                 opp_table->dentry = NULL;
 236         }
 237
 238         debugfs_remove_recursive(opp_dev->dentry);
 239
 240 out:
 241         opp_dev->dentry = NULL;
 242 }
 243
 244 static int __init opp_debug_init(void)
 245 {
 246         /* Create /sys/kernel/debug/opp directory */
 247         rootdir = debugfs_create_dir("opp", NULL);
 248
 249         return 0;
 250 }
 251 core_initcall(opp_debug_init);