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 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	char buf[64];
 40	int i;
 41
 42	i = scnprintf(buf, sizeof(buf), "%.62s\n", icc_get_name(path));
 43
 44	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
 45}
 46
 47static const struct file_operations bw_name_fops = {
 48	.open = simple_open,
 49	.read = bw_name_read,
 50	.llseek = default_llseek,
 51};
 52
 53static void opp_debug_create_bw(struct dev_pm_opp *opp,
 54				struct opp_table *opp_table,
 55				struct dentry *pdentry)
 56{
 57	struct dentry *d;
 58	char name[11];
 59	int i;
 60
 61	for (i = 0; i < opp_table->path_count; i++) {
 62		snprintf(name, sizeof(name), "icc-path-%.1d", i);
 63
 64		/* Create per-path directory */
 65		d = debugfs_create_dir(name, pdentry);
 66
 67		debugfs_create_file("name", S_IRUGO, d, opp_table->paths[i],
 68				    &bw_name_fops);
 69		debugfs_create_u32("peak_bw", S_IRUGO, d,
 70				   &opp->bandwidth[i].peak);
 71		debugfs_create_u32("avg_bw", S_IRUGO, d,
 72				   &opp->bandwidth[i].avg);
 73	}
 74}
 75
 76static void opp_debug_create_supplies(struct dev_pm_opp *opp,
 77				      struct opp_table *opp_table,
 78				      struct dentry *pdentry)
 79{
 80	struct dentry *d;
 81	int i;
 82
 83	for (i = 0; i < opp_table->regulator_count; i++) {
 84		char name[15];
 85
 86		snprintf(name, sizeof(name), "supply-%d", i);
 87
 88		/* Create per-opp directory */
 89		d = debugfs_create_dir(name, pdentry);
 90
 91		debugfs_create_ulong("u_volt_target", S_IRUGO, d,
 92				     &opp->supplies[i].u_volt);
 93
 94		debugfs_create_ulong("u_volt_min", S_IRUGO, d,
 95				     &opp->supplies[i].u_volt_min);
 96
 97		debugfs_create_ulong("u_volt_max", S_IRUGO, d,
 98				     &opp->supplies[i].u_volt_max);
 99
100		debugfs_create_ulong("u_amp", S_IRUGO, d,
101				     &opp->supplies[i].u_amp);
102	}
103}
104
105void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
106{
107	struct dentry *pdentry = opp_table->dentry;
108	struct dentry *d;
109	unsigned long id;
110	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */
111
112	/*
113	 * Get directory name for OPP.
114	 *
115	 * - Normally rate is unique to each OPP, use it to get unique opp-name.
116	 * - For some devices rate isn't available, use index instead.
117	 */
118	if (likely(opp->rate))
119		id = opp->rate;
120	else
121		id = _get_opp_count(opp_table);
122
123	snprintf(name, sizeof(name), "opp:%lu", id);
124
125	/* Create per-opp directory */
126	d = debugfs_create_dir(name, pdentry);
127
128	debugfs_create_bool("available", S_IRUGO, d, &opp->available);
129	debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
130	debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
131	debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
132	debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
133	debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
134	debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
135			     &opp->clock_latency_ns);
136
137	opp_debug_create_supplies(opp, opp_table, d);
138	opp_debug_create_bw(opp, opp_table, d);
139
140	opp->dentry = d;
141}
142
143static void opp_list_debug_create_dir(struct opp_device *opp_dev,
144				      struct opp_table *opp_table)
145{
146	const struct device *dev = opp_dev->dev;
147	struct dentry *d;
148
149	opp_set_dev_name(dev, opp_table->dentry_name);
150
151	/* Create device specific directory */
152	d = debugfs_create_dir(opp_table->dentry_name, rootdir);
153
154	opp_dev->dentry = d;
155	opp_table->dentry = d;
156}
157
158static void opp_list_debug_create_link(struct opp_device *opp_dev,
159				       struct opp_table *opp_table)
160{
161	char name[NAME_MAX];
162
163	opp_set_dev_name(opp_dev->dev, name);
164
165	/* Create device specific directory link */
166	opp_dev->dentry = debugfs_create_symlink(name, rootdir,
167						 opp_table->dentry_name);
168}
169
170/**
171 * opp_debug_register - add a device opp node to the debugfs 'opp' directory
172 * @opp_dev: opp-dev pointer for device
173 * @opp_table: the device-opp being added
174 *
175 * Dynamically adds device specific directory in debugfs 'opp' directory. If the
176 * device-opp is shared with other devices, then links will be created for all
177 * devices except the first.
178 */
179void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
180{
181	if (opp_table->dentry)
182		opp_list_debug_create_link(opp_dev, opp_table);
183	else
184		opp_list_debug_create_dir(opp_dev, opp_table);
185}
186
187static void opp_migrate_dentry(struct opp_device *opp_dev,
188			       struct opp_table *opp_table)
189{
190	struct opp_device *new_dev;
191	const struct device *dev;
192	struct dentry *dentry;
193
194	/* Look for next opp-dev */
195	list_for_each_entry(new_dev, &opp_table->dev_list, node)
196		if (new_dev != opp_dev)
197			break;
198
199	/* new_dev is guaranteed to be valid here */
200	dev = new_dev->dev;
201	debugfs_remove_recursive(new_dev->dentry);
202
203	opp_set_dev_name(dev, opp_table->dentry_name);
204
205	dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
206				opp_table->dentry_name);
207	if (!dentry) {
208		dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
209			__func__, dev_name(opp_dev->dev), dev_name(dev));
210		return;
211	}
212
213	new_dev->dentry = dentry;
214	opp_table->dentry = dentry;
215}
216
217/**
218 * opp_debug_unregister - remove a device opp node from debugfs opp directory
219 * @opp_dev: opp-dev pointer for device
220 * @opp_table: the device-opp being removed
221 *
222 * Dynamically removes device specific directory from debugfs 'opp' directory.
223 */
224void opp_debug_unregister(struct opp_device *opp_dev,
225			  struct opp_table *opp_table)
226{
227	if (opp_dev->dentry == opp_table->dentry) {
228		/* Move the real dentry object under another device */
229		if (!list_is_singular(&opp_table->dev_list)) {
230			opp_migrate_dentry(opp_dev, opp_table);
231			goto out;
232		}
233		opp_table->dentry = NULL;
234	}
235
236	debugfs_remove_recursive(opp_dev->dentry);
237
238out:
239	opp_dev->dentry = NULL;
240}
241
242static int __init opp_debug_init(void)
243{
244	/* Create /sys/kernel/debug/opp directory */
245	rootdir = debugfs_create_dir("opp", NULL);
246
247	return 0;
248}
249core_initcall(opp_debug_init);