xref: /openbmc/linux/drivers/opp/debugfs.c (revision 842ed298)
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 
19 static struct dentry *rootdir;
20 
21 static 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 
30 void opp_debug_remove_one(struct dev_pm_opp *opp)
31 {
32 	debugfs_remove_recursive(opp->dentry);
33 }
34 
35 static 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 
47 static const struct file_operations bw_name_fops = {
48 	.open = simple_open,
49 	.read = bw_name_read,
50 	.llseek = default_llseek,
51 };
52 
53 static 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 
76 static 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 
105 void 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 
143 static 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 
158 static 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  */
179 void 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 
187 static 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  */
224 void 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 
238 out:
239 	opp_dev->dentry = NULL;
240 }
241 
242 static 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 }
249 core_initcall(opp_debug_init);
250