1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Debug support for HID Nintendo Wii / Wii U peripherals
4  * Copyright (c) 2011-2013 David Herrmann <dh.herrmann@gmail.com>
5  */
6 
7 /*
8  */
9 
10 #include <linux/debugfs.h>
11 #include <linux/module.h>
12 #include <linux/seq_file.h>
13 #include <linux/spinlock.h>
14 #include <linux/uaccess.h>
15 #include "hid-wiimote.h"
16 
17 struct wiimote_debug {
18 	struct wiimote_data *wdata;
19 	struct dentry *eeprom;
20 	struct dentry *drm;
21 };
22 
23 static ssize_t wiidebug_eeprom_read(struct file *f, char __user *u, size_t s,
24 								loff_t *off)
25 {
26 	struct wiimote_debug *dbg = f->private_data;
27 	struct wiimote_data *wdata = dbg->wdata;
28 	unsigned long flags;
29 	ssize_t ret;
30 	char buf[16];
31 	__u16 size = 0;
32 
33 	if (s == 0)
34 		return -EINVAL;
35 	if (*off > 0xffffff)
36 		return 0;
37 	if (s > 16)
38 		s = 16;
39 
40 	ret = wiimote_cmd_acquire(wdata);
41 	if (ret)
42 		return ret;
43 
44 	spin_lock_irqsave(&wdata->state.lock, flags);
45 	wdata->state.cmd_read_size = s;
46 	wdata->state.cmd_read_buf = buf;
47 	wiimote_cmd_set(wdata, WIIPROTO_REQ_RMEM, *off & 0xffff);
48 	wiiproto_req_reeprom(wdata, *off, s);
49 	spin_unlock_irqrestore(&wdata->state.lock, flags);
50 
51 	ret = wiimote_cmd_wait(wdata);
52 	if (!ret)
53 		size = wdata->state.cmd_read_size;
54 
55 	spin_lock_irqsave(&wdata->state.lock, flags);
56 	wdata->state.cmd_read_buf = NULL;
57 	spin_unlock_irqrestore(&wdata->state.lock, flags);
58 
59 	wiimote_cmd_release(wdata);
60 
61 	if (ret)
62 		return ret;
63 	else if (size == 0)
64 		return -EIO;
65 
66 	if (copy_to_user(u, buf, size))
67 		return -EFAULT;
68 
69 	*off += size;
70 	ret = size;
71 
72 	return ret;
73 }
74 
75 static const struct file_operations wiidebug_eeprom_fops = {
76 	.owner = THIS_MODULE,
77 	.open = simple_open,
78 	.read = wiidebug_eeprom_read,
79 	.llseek = generic_file_llseek,
80 };
81 
82 static const char *wiidebug_drmmap[] = {
83 	[WIIPROTO_REQ_NULL] = "NULL",
84 	[WIIPROTO_REQ_DRM_K] = "K",
85 	[WIIPROTO_REQ_DRM_KA] = "KA",
86 	[WIIPROTO_REQ_DRM_KE] = "KE",
87 	[WIIPROTO_REQ_DRM_KAI] = "KAI",
88 	[WIIPROTO_REQ_DRM_KEE] = "KEE",
89 	[WIIPROTO_REQ_DRM_KAE] = "KAE",
90 	[WIIPROTO_REQ_DRM_KIE] = "KIE",
91 	[WIIPROTO_REQ_DRM_KAIE] = "KAIE",
92 	[WIIPROTO_REQ_DRM_E] = "E",
93 	[WIIPROTO_REQ_DRM_SKAI1] = "SKAI1",
94 	[WIIPROTO_REQ_DRM_SKAI2] = "SKAI2",
95 	[WIIPROTO_REQ_MAX] = NULL
96 };
97 
98 static int wiidebug_drm_show(struct seq_file *f, void *p)
99 {
100 	struct wiimote_debug *dbg = f->private;
101 	const char *str = NULL;
102 	unsigned long flags;
103 	__u8 drm;
104 
105 	spin_lock_irqsave(&dbg->wdata->state.lock, flags);
106 	drm = dbg->wdata->state.drm;
107 	spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);
108 
109 	if (drm < WIIPROTO_REQ_MAX)
110 		str = wiidebug_drmmap[drm];
111 	if (!str)
112 		str = "unknown";
113 
114 	seq_printf(f, "%s\n", str);
115 
116 	return 0;
117 }
118 
119 static int wiidebug_drm_open(struct inode *i, struct file *f)
120 {
121 	return single_open(f, wiidebug_drm_show, i->i_private);
122 }
123 
124 static ssize_t wiidebug_drm_write(struct file *f, const char __user *u,
125 							size_t s, loff_t *off)
126 {
127 	struct seq_file *sf = f->private_data;
128 	struct wiimote_debug *dbg = sf->private;
129 	unsigned long flags;
130 	char buf[16];
131 	ssize_t len;
132 	int i;
133 
134 	if (s == 0)
135 		return -EINVAL;
136 
137 	len = min((size_t) 15, s);
138 	if (copy_from_user(buf, u, len))
139 		return -EFAULT;
140 
141 	buf[len] = 0;
142 
143 	for (i = 0; i < WIIPROTO_REQ_MAX; ++i) {
144 		if (!wiidebug_drmmap[i])
145 			continue;
146 		if (!strcasecmp(buf, wiidebug_drmmap[i]))
147 			break;
148 	}
149 
150 	if (i == WIIPROTO_REQ_MAX)
151 		i = simple_strtoul(buf, NULL, 16);
152 
153 	spin_lock_irqsave(&dbg->wdata->state.lock, flags);
154 	dbg->wdata->state.flags &= ~WIIPROTO_FLAG_DRM_LOCKED;
155 	wiiproto_req_drm(dbg->wdata, (__u8) i);
156 	if (i != WIIPROTO_REQ_NULL)
157 		dbg->wdata->state.flags |= WIIPROTO_FLAG_DRM_LOCKED;
158 	spin_unlock_irqrestore(&dbg->wdata->state.lock, flags);
159 
160 	return len;
161 }
162 
163 static const struct file_operations wiidebug_drm_fops = {
164 	.owner = THIS_MODULE,
165 	.open = wiidebug_drm_open,
166 	.read = seq_read,
167 	.llseek = seq_lseek,
168 	.write = wiidebug_drm_write,
169 	.release = single_release,
170 };
171 
172 int wiidebug_init(struct wiimote_data *wdata)
173 {
174 	struct wiimote_debug *dbg;
175 	unsigned long flags;
176 	int ret = -ENOMEM;
177 
178 	dbg = kzalloc(sizeof(*dbg), GFP_KERNEL);
179 	if (!dbg)
180 		return -ENOMEM;
181 
182 	dbg->wdata = wdata;
183 
184 	dbg->eeprom = debugfs_create_file("eeprom", S_IRUSR,
185 		dbg->wdata->hdev->debug_dir, dbg, &wiidebug_eeprom_fops);
186 	if (!dbg->eeprom)
187 		goto err;
188 
189 	dbg->drm = debugfs_create_file("drm", S_IRUSR,
190 			dbg->wdata->hdev->debug_dir, dbg, &wiidebug_drm_fops);
191 	if (!dbg->drm)
192 		goto err_drm;
193 
194 	spin_lock_irqsave(&wdata->state.lock, flags);
195 	wdata->debug = dbg;
196 	spin_unlock_irqrestore(&wdata->state.lock, flags);
197 
198 	return 0;
199 
200 err_drm:
201 	debugfs_remove(dbg->eeprom);
202 err:
203 	kfree(dbg);
204 	return ret;
205 }
206 
207 void wiidebug_deinit(struct wiimote_data *wdata)
208 {
209 	struct wiimote_debug *dbg = wdata->debug;
210 	unsigned long flags;
211 
212 	if (!dbg)
213 		return;
214 
215 	spin_lock_irqsave(&wdata->state.lock, flags);
216 	wdata->debug = NULL;
217 	spin_unlock_irqrestore(&wdata->state.lock, flags);
218 
219 	debugfs_remove(dbg->drm);
220 	debugfs_remove(dbg->eeprom);
221 	kfree(dbg);
222 }
223