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
 19static struct dentry *rootdir;
 20
 21static 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
 30void opp_debug_remove_one(struct dev_pm_opp *opp)
 31{
 32	debugfs_remove_recursive(opp->dentry);
 33}
 34
 35static 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
 64void 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
101static 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
116static 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 */
137void 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
145static 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 */
182void 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
196out:
197	opp_dev->dentry = NULL;
198}
199
200static 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}
207core_initcall(opp_debug_init);