// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Generic OPP debugfs interface
   *
   * Copyright (C) 2015-2016 Viresh Kumar <viresh.kumar@linaro.org>

   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/debugfs.h>
  #include <linux/device.h>
  #include <linux/err.h>
  #include <linux/init.h>
  #include <linux/limits.h>

  #include <linux/slab.h>

  
  #include "opp.h"
  
  static struct dentry *rootdir;
  
  static void opp_set_dev_name(const struct device *dev, char *name)
  {
  	if (dev->parent)
  		snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent),
  			 dev_name(dev));
  	else
  		snprintf(name, NAME_MAX, "%s", dev_name(dev));
  }
  
  void opp_debug_remove_one(struct dev_pm_opp *opp)
  {
  	debugfs_remove_recursive(opp->dentry);
  }

  static void opp_debug_create_supplies(struct dev_pm_opp *opp,

  				      struct opp_table *opp_table,
  				      struct dentry *pdentry)
  {
  	struct dentry *d;

  	int i;

  	for (i = 0; i < opp_table->regulator_count; i++) {

  		char name[15];
  
  		snprintf(name, sizeof(name), "supply-%d", i);

  
  		/* Create per-opp directory */
  		d = debugfs_create_dir(name, pdentry);

  		debugfs_create_ulong("u_volt_target", S_IRUGO, d,
  				     &opp->supplies[i].u_volt);

  		debugfs_create_ulong("u_volt_min", S_IRUGO, d,
  				     &opp->supplies[i].u_volt_min);

  		debugfs_create_ulong("u_volt_max", S_IRUGO, d,
  				     &opp->supplies[i].u_volt_max);

  		debugfs_create_ulong("u_amp", S_IRUGO, d,
  				     &opp->supplies[i].u_amp);

  	}

  }

  void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)

  {

  	struct dentry *pdentry = opp_table->dentry;

  	struct dentry *d;

  	unsigned long id;

  	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */

  	/*
  	 * Get directory name for OPP.
  	 *
  	 * - Normally rate is unique to each OPP, use it to get unique opp-name.
  	 * - For some devices rate isn't available, use index instead.
  	 */
  	if (likely(opp->rate))
  		id = opp->rate;
  	else
  		id = _get_opp_count(opp_table);
  
  	snprintf(name, sizeof(name), "opp:%lu", id);

  
  	/* Create per-opp directory */
  	d = debugfs_create_dir(name, pdentry);

  	debugfs_create_bool("available", S_IRUGO, d, &opp->available);
  	debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
  	debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
  	debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
  	debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
  	debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
  	debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
  			     &opp->clock_latency_ns);

  	opp_debug_create_supplies(opp, opp_table, d);

  
  	opp->dentry = d;

  }

  static void opp_list_debug_create_dir(struct opp_device *opp_dev,
  				      struct opp_table *opp_table)

  {

  	const struct device *dev = opp_dev->dev;

  	struct dentry *d;

  	opp_set_dev_name(dev, opp_table->dentry_name);

  
  	/* Create device specific directory */

  	d = debugfs_create_dir(opp_table->dentry_name, rootdir);

  	opp_dev->dentry = d;
  	opp_table->dentry = d;

  }

  static void opp_list_debug_create_link(struct opp_device *opp_dev,
  				       struct opp_table *opp_table)

  {

  	char name[NAME_MAX];

  	opp_set_dev_name(opp_dev->dev, name);

  
  	/* Create device specific directory link */

  	opp_dev->dentry = debugfs_create_symlink(name, rootdir,
  						 opp_table->dentry_name);

  }
  
  /**
   * opp_debug_register - add a device opp node to the debugfs 'opp' directory

   * @opp_dev: opp-dev pointer for device
   * @opp_table: the device-opp being added

   *
   * Dynamically adds device specific directory in debugfs 'opp' directory. If the
   * device-opp is shared with other devices, then links will be created for all
   * devices except the first.

   */

  void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)

  {

  	if (opp_table->dentry)

  		opp_list_debug_create_link(opp_dev, opp_table);
  	else
  		opp_list_debug_create_dir(opp_dev, opp_table);

  }

  static void opp_migrate_dentry(struct opp_device *opp_dev,
  			       struct opp_table *opp_table)

  {

  	struct opp_device *new_dev;

  	const struct device *dev;
  	struct dentry *dentry;

  	/* Look for next opp-dev */
  	list_for_each_entry(new_dev, &opp_table->dev_list, node)
  		if (new_dev != opp_dev)

  			break;
  
  	/* new_dev is guaranteed to be valid here */
  	dev = new_dev->dev;
  	debugfs_remove_recursive(new_dev->dentry);

  	opp_set_dev_name(dev, opp_table->dentry_name);

  	dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
  				opp_table->dentry_name);

  	if (!dentry) {
  		dev_err(dev, "%s: Failed to rename link from: %s to %s
  ",

  			__func__, dev_name(opp_dev->dev), dev_name(dev));

  		return;
  	}
  
  	new_dev->dentry = dentry;

  	opp_table->dentry = dentry;

  }
  
  /**
   * opp_debug_unregister - remove a device opp node from debugfs opp directory

   * @opp_dev: opp-dev pointer for device
   * @opp_table: the device-opp being removed

   *
   * Dynamically removes device specific directory from debugfs 'opp' directory.
   */

  void opp_debug_unregister(struct opp_device *opp_dev,
  			  struct opp_table *opp_table)

  {

  	if (opp_dev->dentry == opp_table->dentry) {

  		/* Move the real dentry object under another device */

  		if (!list_is_singular(&opp_table->dev_list)) {
  			opp_migrate_dentry(opp_dev, opp_table);

  			goto out;
  		}

  		opp_table->dentry = NULL;

  	}

  	debugfs_remove_recursive(opp_dev->dentry);

  
  out:

  	opp_dev->dentry = NULL;

  }
  
  static int __init opp_debug_init(void)
  {
  	/* Create /sys/kernel/debug/opp directory */
  	rootdir = debugfs_create_dir("opp", NULL);

  
  	return 0;
  }
  core_initcall(opp_debug_init);