1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
|
/*
* Copyright (C) 2015 ST Microelectronics
*
* Author: Lee Jones <lee.jones@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/debugfs.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_client.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#define MBOX_MAX_SIG_LEN 8
#define MBOX_MAX_MSG_LEN 128
#define MBOX_BYTES_PER_LINE 16
#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
(MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
static struct dentry *root_debugfs_dir;
struct mbox_test_device {
struct device *dev;
void __iomem *tx_mmio;
void __iomem *rx_mmio;
struct mbox_chan *tx_channel;
struct mbox_chan *rx_channel;
char *rx_buffer;
char *signal;
char *message;
spinlock_t lock;
};
static ssize_t mbox_test_signal_write(struct file *filp,
const char __user *userbuf,
size_t count, loff_t *ppos)
{
struct mbox_test_device *tdev = filp->private_data;
if (!tdev->tx_channel) {
dev_err(tdev->dev, "Channel cannot do Tx\n");
return -EINVAL;
}
if (count > MBOX_MAX_SIG_LEN) {
dev_err(tdev->dev,
"Signal length %zd greater than max allowed %d\n",
count, MBOX_MAX_SIG_LEN);
return -EINVAL;
}
/* Only allocate memory if we need to */
if (!tdev->signal) {
tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
if (!tdev->signal)
return -ENOMEM;
}
if (copy_from_user(tdev->signal, userbuf, count)) {
kfree(tdev->signal);
tdev->signal = NULL;
return -EFAULT;
}
return count;
}
static const struct file_operations mbox_test_signal_ops = {
.write = mbox_test_signal_write,
.open = simple_open,
.llseek = generic_file_llseek,
};
static ssize_t mbox_test_message_write(struct file *filp,
const char __user *userbuf,
size_t count, loff_t *ppos)
{
struct mbox_test_device *tdev = filp->private_data;
void *data;
int ret;
if (!tdev->tx_channel) {
dev_err(tdev->dev, "Channel cannot do Tx\n");
return -EINVAL;
}
if (count > MBOX_MAX_MSG_LEN) {
dev_err(tdev->dev,
"Message length %zd greater than max allowed %d\n",
count, MBOX_MAX_MSG_LEN);
return -EINVAL;
}
tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
if (!tdev->message)
return -ENOMEM;
ret = copy_from_user(tdev->message, userbuf, count);
if (ret) {
ret = -EFAULT;
goto out;
}
/*
* A separate signal is only of use if there is
* MMIO to subsequently pass the message through
*/
if (tdev->tx_mmio && tdev->signal) {
print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
tdev->signal, MBOX_MAX_SIG_LEN);
data = tdev->signal;
} else
data = tdev->message;
print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
tdev->message, MBOX_MAX_MSG_LEN);
ret = mbox_send_message(tdev->tx_channel, data);
if (ret < 0)
dev_err(tdev->dev, "Failed to send message via mailbox\n");
out:
kfree(tdev->signal);
kfree(tdev->message);
return ret < 0 ? ret : count;
}
static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct mbox_test_device *tdev = filp->private_data;
unsigned long flags;
char *touser, *ptr;
int l = 0;
int ret;
touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
if (!touser)
return -ENOMEM;
if (!tdev->rx_channel) {
ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
ret = simple_read_from_buffer(userbuf, count, ppos,
touser, ret);
goto out;
}
if (tdev->rx_buffer[0] == '\0') {
ret = snprintf(touser, 9, "<EMPTY>\n");
ret = simple_read_from_buffer(userbuf, count, ppos,
touser, ret);
goto out;
}
spin_lock_irqsave(&tdev->lock, flags);
ptr = tdev->rx_buffer;
while (l < MBOX_HEXDUMP_MAX_LEN) {
hex_dump_to_buffer(ptr,
MBOX_BYTES_PER_LINE,
MBOX_BYTES_PER_LINE, 1, touser + l,
MBOX_HEXDUMP_LINE_LEN, true);
ptr += MBOX_BYTES_PER_LINE;
l += MBOX_HEXDUMP_LINE_LEN;
*(touser + (l - 1)) = '\n';
}
*(touser + l) = '\0';
memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
spin_unlock_irqrestore(&tdev->lock, flags);
ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
out:
kfree(touser);
return ret;
}
static const struct file_operations mbox_test_message_ops = {
.write = mbox_test_message_write,
.read = mbox_test_message_read,
.open = simple_open,
.llseek = generic_file_llseek,
};
static int mbox_test_add_debugfs(struct platform_device *pdev,
struct mbox_test_device *tdev)
{
if (!debugfs_initialized())
return 0;
root_debugfs_dir = debugfs_create_dir("mailbox", NULL);
if (!root_debugfs_dir) {
dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
return -EINVAL;
}
debugfs_create_file("message", 0600, root_debugfs_dir,
tdev, &mbox_test_message_ops);
debugfs_create_file("signal", 0200, root_debugfs_dir,
tdev, &mbox_test_signal_ops);
return 0;
}
static void mbox_test_receive_message(struct mbox_client *client, void *message)
{
struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
unsigned long flags;
spin_lock_irqsave(&tdev->lock, flags);
if (tdev->rx_mmio) {
memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
tdev->rx_buffer, MBOX_MAX_MSG_LEN);
} else if (message) {
print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
message, MBOX_MAX_MSG_LEN);
memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
}
spin_unlock_irqrestore(&tdev->lock, flags);
}
static void mbox_test_prepare_message(struct mbox_client *client, void *message)
{
struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
if (tdev->tx_mmio) {
if (tdev->signal)
memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
else
memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
}
}
static void mbox_test_message_sent(struct mbox_client *client,
void *message, int r)
{
if (r)
dev_warn(client->dev,
"Client: Message could not be sent: %d\n", r);
else
dev_info(client->dev,
"Client: Message sent\n");
}
static struct mbox_chan *
mbox_test_request_channel(struct platform_device *pdev, const char *name)
{
struct mbox_client *client;
struct mbox_chan *channel;
client
|