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
 22static struct dentry *rootdir;
 23
 24static 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
 33void opp_debug_remove_one(struct dev_pm_opp *opp)
 34{
 35	debugfs_remove_recursive(opp->dentry);
 36}
 37
 38static bool 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 = 0;
 44	char *name;
 45
 46	/* Always create at least supply-0 directory */
 47	do {
 48		name = kasprintf(GFP_KERNEL, "supply-%d", i);
 49
 50		/* Create per-opp directory */
 51		d = debugfs_create_dir(name, pdentry);
 52
 53		kfree(name);
 54
 55		if (!d)
 56			return false;
 57
 58		if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d,
 59					  &opp->supplies[i].u_volt))
 60			return false;
 61
 62		if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d,
 63					  &opp->supplies[i].u_volt_min))
 64			return false;
 65
 66		if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d,
 67					  &opp->supplies[i].u_volt_max))
 68			return false;
 69
 70		if (!debugfs_create_ulong("u_amp", S_IRUGO, d,
 71					  &opp->supplies[i].u_amp))
 72			return false;
 73	} while (++i < opp_table->regulator_count);
 74
 75	return true;
 76}
 77
 78int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
 79{
 80	struct dentry *pdentry = opp_table->dentry;
 81	struct dentry *d;
 82	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */
 83
 84	/* Rate is unique to each OPP, use it to give opp-name */
 85	snprintf(name, sizeof(name), "opp:%lu", opp->rate);
 86
 87	/* Create per-opp directory */
 88	d = debugfs_create_dir(name, pdentry);
 89	if (!d)
 90		return -ENOMEM;
 91
 92	if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
 93		return -ENOMEM;
 94
 95	if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
 96		return -ENOMEM;
 97
 98	if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
 99		return -ENOMEM;
100
101	if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
102		return -ENOMEM;
103
104	if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
105		return -ENOMEM;
106
107	if (!opp_debug_create_supplies(opp, opp_table, d))
108		return -ENOMEM;
109
110	if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
111				  &opp->clock_latency_ns))
112		return -ENOMEM;
113
114	opp->dentry = d;
115	return 0;
116}
117
118static int opp_list_debug_create_dir(struct opp_device *opp_dev,
119				     struct opp_table *opp_table)
120{
121	const struct device *dev = opp_dev->dev;
122	struct dentry *d;
123
124	opp_set_dev_name(dev, opp_table->dentry_name);
125
126	/* Create device specific directory */
127	d = debugfs_create_dir(opp_table->dentry_name, rootdir);
128	if (!d) {
129		dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
130		return -ENOMEM;
131	}
132
133	opp_dev->dentry = d;
134	opp_table->dentry = d;
135
136	return 0;
137}
138
139static int opp_list_debug_create_link(struct opp_device *opp_dev,
140				      struct opp_table *opp_table)
141{
142	const struct device *dev = opp_dev->dev;
143	char name[NAME_MAX];
144	struct dentry *d;
145
146	opp_set_dev_name(opp_dev->dev, name);
147
148	/* Create device specific directory link */
149	d = debugfs_create_symlink(name, rootdir, opp_table->dentry_name);
150	if (!d) {
151		dev_err(dev, "%s: Failed to create link\n", __func__);
152		return -ENOMEM;
153	}
154
155	opp_dev->dentry = d;
156
157	return 0;
158}
159
160/**
161 * opp_debug_register - add a device opp node to the debugfs 'opp' directory
162 * @opp_dev: opp-dev pointer for device
163 * @opp_table: the device-opp being added
164 *
165 * Dynamically adds device specific directory in debugfs 'opp' directory. If the
166 * device-opp is shared with other devices, then links will be created for all
167 * devices except the first.
168 *
169 * Return: 0 on success, otherwise negative error.
170 */
171int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
172{
173	if (!rootdir) {
174		pr_debug("%s: Uninitialized rootdir\n", __func__);
175		return -EINVAL;
176	}
177
178	if (opp_table->dentry)
179		return opp_list_debug_create_link(opp_dev, opp_table);
180
181	return opp_list_debug_create_dir(opp_dev, opp_table);
182}
183
184static void opp_migrate_dentry(struct opp_device *opp_dev,
185			       struct opp_table *opp_table)
186{
187	struct opp_device *new_dev;
188	const struct device *dev;
189	struct dentry *dentry;
190
191	/* Look for next opp-dev */
192	list_for_each_entry(new_dev, &opp_table->dev_list, node)
193		if (new_dev != opp_dev)
194			break;
195
196	/* new_dev is guaranteed to be valid here */
197	dev = new_dev->dev;
198	debugfs_remove_recursive(new_dev->dentry);
199
200	opp_set_dev_name(dev, opp_table->dentry_name);
201
202	dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
203				opp_table->dentry_name);
204	if (!dentry) {
205		dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
206			__func__, dev_name(opp_dev->dev), dev_name(dev));
207		return;
208	}
209
210	new_dev->dentry = dentry;
211	opp_table->dentry = dentry;
212}
213
214/**
215 * opp_debug_unregister - remove a device opp node from debugfs opp directory
216 * @opp_dev: opp-dev pointer for device
217 * @opp_table: the device-opp being removed
218 *
219 * Dynamically removes device specific directory from debugfs 'opp' directory.
220 */
221void opp_debug_unregister(struct opp_device *opp_dev,
222			  struct opp_table *opp_table)
223{
224	if (opp_dev->dentry == opp_table->dentry) {
225		/* Move the real dentry object under another device */
226		if (!list_is_singular(&opp_table->dev_list)) {
227			opp_migrate_dentry(opp_dev, opp_table);
228			goto out;
229		}
230		opp_table->dentry = NULL;
231	}
232
233	debugfs_remove_recursive(opp_dev->dentry);
234
235out:
236	opp_dev->dentry = NULL;
237}
238
239static int __init opp_debug_init(void)
240{
241	/* Create /sys/kernel/debug/opp directory */
242	rootdir = debugfs_create_dir("opp", NULL);
243	if (!rootdir) {
244		pr_err("%s: Failed to create root directory\n", __func__);
245		return -ENOMEM;
246	}
247
248	return 0;
249}
250core_initcall(opp_debug_init);