xref: /openbmc/linux/drivers/opp/debugfs.c (revision 9470114d)
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 	const char *name = icc_get_name(path);
41 	char buf[64];
42 	int i = 0;
43 
44 	if (name)
45 		i = scnprintf(buf, sizeof(buf), "%.62s\n", name);
46 
47 	return simple_read_from_buffer(userbuf, count, ppos, buf, i);
48 }
49 
50 static const struct file_operations bw_name_fops = {
51 	.open = simple_open,
52 	.read = bw_name_read,
53 	.llseek = default_llseek,
54 };
55 
56 static void opp_debug_create_bw(struct dev_pm_opp *opp,
57 				struct opp_table *opp_table,
58 				struct dentry *pdentry)
59 {
60 	struct dentry *d;
61 	char name[11];
62 	int i;
63 
64 	for (i = 0; i < opp_table->path_count; i++) {
65 		snprintf(name, sizeof(name), "icc-path-%.1d", i);
66 
67 		/* Create per-path directory */
68 		d = debugfs_create_dir(name, pdentry);
69 
70 		debugfs_create_file("name", S_IRUGO, d, opp_table->paths[i],
71 				    &bw_name_fops);
72 		debugfs_create_u32("peak_bw", S_IRUGO, d,
73 				   &opp->bandwidth[i].peak);
74 		debugfs_create_u32("avg_bw", S_IRUGO, d,
75 				   &opp->bandwidth[i].avg);
76 	}
77 }
78 
79 static void opp_debug_create_clks(struct dev_pm_opp *opp,
80 				  struct opp_table *opp_table,
81 				  struct dentry *pdentry)
82 {
83 	char name[12];
84 	int i;
85 
86 	if (opp_table->clk_count == 1) {
87 		debugfs_create_ulong("rate_hz", S_IRUGO, pdentry, &opp->rates[0]);
88 		return;
89 	}
90 
91 	for (i = 0; i < opp_table->clk_count; i++) {
92 		snprintf(name, sizeof(name), "rate_hz_%d", i);
93 		debugfs_create_ulong(name, S_IRUGO, pdentry, &opp->rates[i]);
94 	}
95 }
96 
97 static void opp_debug_create_supplies(struct dev_pm_opp *opp,
98 				      struct opp_table *opp_table,
99 				      struct dentry *pdentry)
100 {
101 	struct dentry *d;
102 	int i;
103 
104 	for (i = 0; i < opp_table->regulator_count; i++) {
105 		char name[15];
106 
107 		snprintf(name, sizeof(name), "supply-%d", i);
108 
109 		/* Create per-opp directory */
110 		d = debugfs_create_dir(name, pdentry);
111 
112 		debugfs_create_ulong("u_volt_target", S_IRUGO, d,
113 				     &opp->supplies[i].u_volt);
114 
115 		debugfs_create_ulong("u_volt_min", S_IRUGO, d,
116 				     &opp->supplies[i].u_volt_min);
117 
118 		debugfs_create_ulong("u_volt_max", S_IRUGO, d,
119 				     &opp->supplies[i].u_volt_max);
120 
121 		debugfs_create_ulong("u_amp", S_IRUGO, d,
122 				     &opp->supplies[i].u_amp);
123 
124 		debugfs_create_ulong("u_watt", S_IRUGO, d,
125 				     &opp->supplies[i].u_watt);
126 	}
127 }
128 
129 void opp_debug_create_one(struct dev_pm_opp *opp, struct opp_table *opp_table)
130 {
131 	struct dentry *pdentry = opp_table->dentry;
132 	struct dentry *d;
133 	unsigned long id;
134 	char name[25];	/* 20 chars for 64 bit value + 5 (opp:\0) */
135 
136 	/*
137 	 * Get directory name for OPP.
138 	 *
139 	 * - Normally rate is unique to each OPP, use it to get unique opp-name.
140 	 * - For some devices rate isn't available or there are multiple, use
141 	 *   index instead for them.
142 	 */
143 	if (likely(opp_table->clk_count == 1 && opp->rates[0]))
144 		id = opp->rates[0];
145 	else
146 		id = _get_opp_count(opp_table);
147 
148 	snprintf(name, sizeof(name), "opp:%lu", id);
149 
150 	/* Create per-opp directory */
151 	d = debugfs_create_dir(name, pdentry);
152 
153 	debugfs_create_bool("available", S_IRUGO, d, &opp->available);
154 	debugfs_create_bool("dynamic", S_IRUGO, d, &opp->dynamic);
155 	debugfs_create_bool("turbo", S_IRUGO, d, &opp->turbo);
156 	debugfs_create_bool("suspend", S_IRUGO, d, &opp->suspend);
157 	debugfs_create_u32("level", S_IRUGO, d, &opp->level);
158 	debugfs_create_ulong("clock_latency_ns", S_IRUGO, d,
159 			     &opp->clock_latency_ns);
160 
161 	opp->of_name = of_node_full_name(opp->np);
162 	debugfs_create_str("of_name", S_IRUGO, d, (char **)&opp->of_name);
163 
164 	opp_debug_create_clks(opp, opp_table, d);
165 	opp_debug_create_supplies(opp, opp_table, d);
166 	opp_debug_create_bw(opp, opp_table, d);
167 
168 	opp->dentry = d;
169 }
170 
171 static void opp_list_debug_create_dir(struct opp_device *opp_dev,
172 				      struct opp_table *opp_table)
173 {
174 	const struct device *dev = opp_dev->dev;
175 	struct dentry *d;
176 
177 	opp_set_dev_name(dev, opp_table->dentry_name);
178 
179 	/* Create device specific directory */
180 	d = debugfs_create_dir(opp_table->dentry_name, rootdir);
181 
182 	opp_dev->dentry = d;
183 	opp_table->dentry = d;
184 }
185 
186 static void opp_list_debug_create_link(struct opp_device *opp_dev,
187 				       struct opp_table *opp_table)
188 {
189 	char name[NAME_MAX];
190 
191 	opp_set_dev_name(opp_dev->dev, name);
192 
193 	/* Create device specific directory link */
194 	opp_dev->dentry = debugfs_create_symlink(name, rootdir,
195 						 opp_table->dentry_name);
196 }
197 
198 /**
199  * opp_debug_register - add a device opp node to the debugfs 'opp' directory
200  * @opp_dev: opp-dev pointer for device
201  * @opp_table: the device-opp being added
202  *
203  * Dynamically adds device specific directory in debugfs 'opp' directory. If the
204  * device-opp is shared with other devices, then links will be created for all
205  * devices except the first.
206  */
207 void opp_debug_register(struct opp_device *opp_dev, struct opp_table *opp_table)
208 {
209 	if (opp_table->dentry)
210 		opp_list_debug_create_link(opp_dev, opp_table);
211 	else
212 		opp_list_debug_create_dir(opp_dev, opp_table);
213 }
214 
215 static void opp_migrate_dentry(struct opp_device *opp_dev,
216 			       struct opp_table *opp_table)
217 {
218 	struct opp_device *new_dev = NULL, *iter;
219 	const struct device *dev;
220 	struct dentry *dentry;
221 
222 	/* Look for next opp-dev */
223 	list_for_each_entry(iter, &opp_table->dev_list, node)
224 		if (iter != opp_dev) {
225 			new_dev = iter;
226 			break;
227 		}
228 
229 	BUG_ON(!new_dev);
230 
231 	/* new_dev is guaranteed to be valid here */
232 	dev = new_dev->dev;
233 	debugfs_remove_recursive(new_dev->dentry);
234 
235 	opp_set_dev_name(dev, opp_table->dentry_name);
236 
237 	dentry = debugfs_rename(rootdir, opp_dev->dentry, rootdir,
238 				opp_table->dentry_name);
239 	if (IS_ERR(dentry)) {
240 		dev_err(dev, "%s: Failed to rename link from: %s to %s\n",
241 			__func__, dev_name(opp_dev->dev), dev_name(dev));
242 		return;
243 	}
244 
245 	new_dev->dentry = dentry;
246 	opp_table->dentry = dentry;
247 }
248 
249 /**
250  * opp_debug_unregister - remove a device opp node from debugfs opp directory
251  * @opp_dev: opp-dev pointer for device
252  * @opp_table: the device-opp being removed
253  *
254  * Dynamically removes device specific directory from debugfs 'opp' directory.
255  */
256 void opp_debug_unregister(struct opp_device *opp_dev,
257 			  struct opp_table *opp_table)
258 {
259 	if (opp_dev->dentry == opp_table->dentry) {
260 		/* Move the real dentry object under another device */
261 		if (!list_is_singular(&opp_table->dev_list)) {
262 			opp_migrate_dentry(opp_dev, opp_table);
263 			goto out;
264 		}
265 		opp_table->dentry = NULL;
266 	}
267 
268 	debugfs_remove_recursive(opp_dev->dentry);
269 
270 out:
271 	opp_dev->dentry = NULL;
272 }
273 
274 static int __init opp_debug_init(void)
275 {
276 	/* Create /sys/kernel/debug/opp directory */
277 	rootdir = debugfs_create_dir("opp", NULL);
278 
279 	return 0;
280 }
281 core_initcall(opp_debug_init);
282