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;
 44
 45	for (i = 0; i < opp_table->regulator_count; i++) {
 46		char name[15];
 47
 48		snprintf(name, sizeof(name), "supply-%d", i);
 49
 50		/* Create per-opp directory */
 51		d = debugfs_create_dir(name, pdentry);
 52
 53		if (!d)
 54			return false;
 55
 56		if (!debugfs_create_ulong("u_volt_target", S_IRUGO, d,
 57					  &opp->supplies[i].u_volt))
 58			return false;
 59
 60		if (!debugfs_create_ulong("u_volt_min", S_IRUGO, d,
 61					  &opp->supplies[i].u_volt_min))
 62			return false;
 63
 64		if (!debugfs_create_ulong("u_volt_max", S_IRUGO, d,
 65					  &opp->supplies[i].u_volt_max))
 66			return false;
 67
 68		if (!debugfs_create_ulong("u_amp", S_IRUGO, d,
 69					  &opp->supplies[i].u_amp))
 70			return false;
 71	}
 72
 73	return true;
 74}
 75
 76int opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
 77{
 78	struct dentry *pdentry = opp_table->dentry;
 79	struct dentry *d;
 80	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */
 81
 82	/* Rate is unique to each OPP, use it to give opp-name */
 83	snprintf(name, sizeof(name), "opp:%lu", opp->rate);
 84
 85	/* Create per-opp directory */
 86	d = debugfs_create_dir(name, pdentry);
 87	if (!d)
 88		return -ENOMEM;
 89
 90	if (!debugfs_create_bool("available", S_IRUGO, d, &opp->available))
 91		return -ENOMEM;
 92
 93	if (!debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic))
 94		return -ENOMEM;
 95
 96	if (!debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo))
 97		return -ENOMEM;
 98
 99	if (!debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend))
100		return -ENOMEM;
101
102	if (!debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate))
103		return -ENOMEM;
104
105	if (!debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate))
106		return -ENOMEM;
107
108	if (!opp_debug_create_supplies(opp, opp_table, d))
109		return -ENOMEM;
110
111	if (!debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
112				  &opp->clock_latency_ns))
113		return -ENOMEM;
114
115	opp->dentry = d;
116	return 0;
117}
118
119static int opp_list_debug_create_dir(struct opp_device *opp_dev,
120				     struct opp_table *opp_table)
121{
122	const struct device *dev = opp_dev->dev;
123	struct dentry *d;
124
125	opp_set_dev_name(dev, opp_table->dentry_name);
126
127	/* Create device specific directory */
128	d = debugfs_create_dir(opp_table->dentry_name, rootdir);
129	if (!d) {
130		dev_err(dev, "%s: Failed to create debugfs dir\n", __func__);
131		return -ENOMEM;
132	}
133
134	opp_dev->dentry = d;
135	opp_table->dentry = d;
136
137	return 0;
138}
139
140static int opp_list_debug_create_link(struct opp_device *opp_dev,
141				      struct opp_table *opp_table)
142{
143	const struct device *dev = opp_dev->dev;
144	char name[NAME_MAX];
145	struct dentry *d;
146
147	opp_set_dev_name(opp_dev->dev, name);
148
149	/* Create device specific directory link */
150	d = debugfs_create_symlink(name, rootdir, opp_table->dentry_name);
151	if (!d) {
152		dev_err(dev, "%s: Failed to create link\n", __func__);
153		return -ENOMEM;
154	}
155
156	opp_dev->dentry = d;
157
158	return 0;
159}
160
161/**
162 * opp_debug_register - add a device opp node to the debugfs 'opp' directory
163 * @opp_dev: opp-dev pointer for device
164 * @opp_table: the device-opp being added
165 *
166 * Dynamically adds device specific directory in debugfs 'opp' directory. If the
167 * device-opp is shared with other devices, then links will be created for all
168 * devices except the first.
169 *
170 * Return: 0 on success, otherwise negative error.
171 */
172int opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
173{
174	if (!rootdir) {
175		pr_debug("%s: Uninitialized rootdir\n", __func__);
176		return -EINVAL;
177	}
178
179	if (opp_table->dentry)
180		return opp_list_debug_create_link(opp_dev, opp_table);
181
182	return opp_list_debug_create_dir(opp_dev, opp_table);
183}
184
185static void opp_migrate_dentry(struct opp_device *opp_dev,
186			       struct opp_table *opp_table)
187{
188	struct opp_device *new_dev;
189	const struct device *dev;
190	struct dentry *dentry;
191
192	/* Look for next opp-dev */
193	list_for_each_entry(new_dev, &opp_table->dev_list, node)
194		if (new_dev != opp_dev)
195			break;
196
197	/* new_dev is guaranteed to be valid here */
198	dev = new_dev->dev;
199	debugfs_remove_recursive(new_dev->dentry);
200
201	opp_set_dev_name(dev, opp_table->dentry_name);
202
203	dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
204				opp_table->dentry_name);
205	if (!dentry) {
206		dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
207			__func__, dev_name(opp_dev->dev), dev_name(dev));
208		return;
209	}
210
211	new_dev->dentry = dentry;
212	opp_table->dentry = dentry;
213}
214
215/**
216 * opp_debug_unregister - remove a device opp node from debugfs opp directory
217 * @opp_dev: opp-dev pointer for device
218 * @opp_table: the device-opp being removed
219 *
220 * Dynamically removes device specific directory from debugfs 'opp' directory.
221 */
222void opp_debug_unregister(struct opp_device *opp_dev,
223			  struct opp_table *opp_table)
224{
225	if (opp_dev->dentry == opp_table->dentry) {
226		/* Move the real dentry object under another device */
227		if (!list_is_singular(&opp_table->dev_list)) {
228			opp_migrate_dentry(opp_dev, opp_table);
229			goto out;
230		}
231		opp_table->dentry = NULL;
232	}
233
234	debugfs_remove_recursive(opp_dev->dentry);
235
236out:
237	opp_dev->dentry = NULL;
238}
239
240static int __init opp_debug_init(void)
241{
242	/* Create /sys/kernel/debug/opp directory */
243	rootdir = debugfs_create_dir("opp", NULL);
244	if (!rootdir) {
245		pr_err("%s: Failed to create root directory\n", __func__);
246		return -ENOMEM;
247	}
248
249	return 0;
250}
251core_initcall(opp_debug_init);