xref: /openbmc/linux/drivers/opp/debugfs.c (revision c059ee9d)
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/of.h>
14 #include <linux/init.h>
15 #include <linux/limits.h>
16 #include <linux/slab.h>
17 
18 #include "opp.h"
19 
20 static struct dentry *rootdir;
21 
22 static void opp_set_dev_name(const struct device *dev, char *name)
23 {
24 	if (dev->parent)
25 		snprintf(name, NAME_MAX, "%s-%s", dev_name(dev->parent),
26 			 dev_name(dev));
27 	else
28 		snprintf(name, NAME_MAX, "%s", dev_name(dev));
29 }
30 
31 void opp_debug_remove_one(struct dev_pm_opp *opp)
32 {
33 	debugfs_remove_recursive(opp->dentry);
34 }
35 
36 static ssize_t bw_name_read(struct file *fp, char __user *userbuf,
37 			    size_t count, loff_t *ppos)
38 {
39 	struct icc_path *path = fp->private_data;
40 	char buf[64];
41 	int i;
42 
43 	i = scnprintf(buf, sizeof(buf), "%.62s\n", icc_get_name(path));
44 
45 	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
46 }
47 
48 static const struct file_operations bw_name_fops = {
49 	.open = simple_open,
50 	.read = bw_name_read,
51 	.llseek = default_llseek,
52 };
53 
54 static void opp_debug_create_bw(struct dev_pm_opp *opp,
55 				struct opp_table *opp_table,
56 				struct dentry *pdentry)
57 {
58 	struct dentry *d;
59 	char name[11];
60 	int i;
61 
62 	for (i = 0; i < opp_table->path_count; i++) {
63 		snprintf(name, sizeof(name), "icc-path-%.1d", i);
64 
65 		/* Create per-path directory */
66 		d = debugfs_create_dir(name, pdentry);
67 
68 		debugfs_create_file("name", S_IRUGO, d, opp_table->paths[i],
69 				    &bw_name_fops);
70 		debugfs_create_u32("peak_bw", S_IRUGO, d,
71 				   &opp->bandwidth[i].peak);
72 		debugfs_create_u32("avg_bw", S_IRUGO, d,
73 				   &opp->bandwidth[i].avg);
74 	}
75 }
76 
77 static void opp_debug_create_supplies(struct dev_pm_opp *opp,
78 				      struct opp_table *opp_table,
79 				      struct dentry *pdentry)
80 {
81 	struct dentry *d;
82 	int i;
83 
84 	for (i = 0; i < opp_table->regulator_count; i++) {
85 		char name[15];
86 
87 		snprintf(name, sizeof(name), "supply-%d", i);
88 
89 		/* Create per-opp directory */
90 		d = debugfs_create_dir(name, pdentry);
91 
92 		debugfs_create_ulong("u_volt_target", S_IRUGO, d,
93 				     &opp->supplies[i].u_volt);
94 
95 		debugfs_create_ulong("u_volt_min", S_IRUGO, d,
96 				     &opp->supplies[i].u_volt_min);
97 
98 		debugfs_create_ulong("u_volt_max", S_IRUGO, d,
99 				     &opp->supplies[i].u_volt_max);
100 
101 		debugfs_create_ulong("u_amp", S_IRUGO, d,
102 				     &opp->supplies[i].u_amp);
103 
104 		debugfs_create_ulong("u_watt", S_IRUGO, d,
105 				     &opp->supplies[i].u_watt);
106 	}
107 }
108 
109 void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
110 {
111 	struct dentry *pdentry = opp_table->dentry;
112 	struct dentry *d;
113 	unsigned long id;
114 	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */
115 
116 	/*
117 	 * Get directory name for OPP.
118 	 *
119 	 * - Normally rate is unique to each OPP, use it to get unique opp-name.
120 	 * - For some devices rate isn't available, use index instead.
121 	 */
122 	if (likely(opp->rate))
123 		id = opp->rate;
124 	else
125 		id = _get_opp_count(opp_table);
126 
127 	snprintf(name, sizeof(name), "opp:%lu", id);
128 
129 	/* Create per-opp directory */
130 	d = debugfs_create_dir(name, pdentry);
131 
132 	debugfs_create_bool("available", S_IRUGO, d, &opp->available);
133 	debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
134 	debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
135 	debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
136 	debugfs_create_u32("performance_state", S_IRUGO, d, &opp->pstate);
137 	debugfs_create_ulong("rate_hz", S_IRUGO, d, &opp->rate);
138 	debugfs_create_u32("level", S_IRUGO, d, &opp->level);
139 	debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
140 			     &opp->clock_latency_ns);
141 
142 	opp->of_name = of_node_full_name(opp->np);
143 	debugfs_create_str("of_name", S_IRUGO, d, (char **)&opp->of_name);
144 
145 	opp_debug_create_supplies(opp, opp_table, d);
146 	opp_debug_create_bw(opp, opp_table, d);
147 
148 	opp->dentry = d;
149 }
150 
151 static void opp_list_debug_create_dir(struct opp_device *opp_dev,
152 				      struct opp_table *opp_table)
153 {
154 	const struct device *dev = opp_dev->dev;
155 	struct dentry *d;
156 
157 	opp_set_dev_name(dev, opp_table->dentry_name);
158 
159 	/* Create device specific directory */
160 	d = debugfs_create_dir(opp_table->dentry_name, rootdir);
161 
162 	opp_dev->dentry = d;
163 	opp_table->dentry = d;
164 }
165 
166 static void opp_list_debug_create_link(struct opp_device *opp_dev,
167 				       struct opp_table *opp_table)
168 {
169 	char name[NAME_MAX];
170 
171 	opp_set_dev_name(opp_dev->dev, name);
172 
173 	/* Create device specific directory link */
174 	opp_dev->dentry = debugfs_create_symlink(name, rootdir,
175 						 opp_table->dentry_name);
176 }
177 
178 /**
179  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
180  * @opp_dev: opp-dev pointer for device
181  * @opp_table: the device-opp being added
182  *
183  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
184  * device-opp is shared with other devices, then links will be created for all
185  * devices except the first.
186  */
187 void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
188 {
189 	if (opp_table->dentry)
190 		opp_list_debug_create_link(opp_dev, opp_table);
191 	else
192 		opp_list_debug_create_dir(opp_dev, opp_table);
193 }
194 
195 static void opp_migrate_dentry(struct opp_device *opp_dev,
196 			       struct opp_table *opp_table)
197 {
198 	struct opp_device *new_dev = NULL, *iter;
199 	const struct device *dev;
200 	struct dentry *dentry;
201 
202 	/* Look for next opp-dev */
203 	list_for_each_entry(iter, &opp_table->dev_list, node)
204 		if (iter != opp_dev) {
205 			new_dev = iter;
206 			break;
207 		}
208 
209 	BUG_ON(!new_dev);
210 
211 	/* new_dev is guaranteed to be valid here */
212 	dev = new_dev->dev;
213 	debugfs_remove_recursive(new_dev->dentry);
214 
215 	opp_set_dev_name(dev, opp_table->dentry_name);
216 
217 	dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
218 				opp_table->dentry_name);
219 	if (!dentry) {
220 		dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
221 			__func__, dev_name(opp_dev->dev), dev_name(dev));
222 		return;
223 	}
224 
225 	new_dev->dentry = dentry;
226 	opp_table->dentry = dentry;
227 }
228 
229 /**
230  * opp_debug_unregister - remove a device opp node from debugfs opp directory
231  * @opp_dev: opp-dev pointer for device
232  * @opp_table: the device-opp being removed
233  *
234  * Dynamically removes device specific directory from debugfs 'opp' directory.
235  */
236 void opp_debug_unregister(struct opp_device *opp_dev,
237 			  struct opp_table *opp_table)
238 {
239 	if (opp_dev->dentry == opp_table->dentry) {
240 		/* Move the real dentry object under another device */
241 		if (!list_is_singular(&opp_table->dev_list)) {
242 			opp_migrate_dentry(opp_dev, opp_table);
243 			goto out;
244 		}
245 		opp_table->dentry = NULL;
246 	}
247 
248 	debugfs_remove_recursive(opp_dev->dentry);
249 
250 out:
251 	opp_dev->dentry = NULL;
252 }
253 
254 static int __init opp_debug_init(void)
255 {
256 	/* Create /sys/kernel/debug/opp directory */
257 	rootdir = debugfs_create_dir("opp", NULL);
258 
259 	return 0;
260 }
261 core_initcall(opp_debug_init);
262