1
2
3
4
5
6
7
8#include <linux/debugfs.h>
9#include <linux/err.h>
10#include <linux/fs.h>
11#include <linux/io.h>
12#include <linux/kernel.h>
13#include <linux/mailbox_client.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/poll.h>
18#include <linux/slab.h>
19#include <linux/uaccess.h>
20#include <linux/sched/signal.h>
21
22#define MBOX_MAX_SIG_LEN 8
23#define MBOX_MAX_MSG_LEN 128
24#define MBOX_BYTES_PER_LINE 16
25#define MBOX_HEXDUMP_LINE_LEN ((MBOX_BYTES_PER_LINE * 4) + 2)
26#define MBOX_HEXDUMP_MAX_LEN (MBOX_HEXDUMP_LINE_LEN * \
27 (MBOX_MAX_MSG_LEN / MBOX_BYTES_PER_LINE))
28
29static bool mbox_data_ready;
30
31struct mbox_test_device {
32 struct device *dev;
33 void __iomem *tx_mmio;
34 void __iomem *rx_mmio;
35 struct mbox_chan *tx_channel;
36 struct mbox_chan *rx_channel;
37 char *rx_buffer;
38 char *signal;
39 char *message;
40 spinlock_t lock;
41 wait_queue_head_t waitq;
42 struct fasync_struct *async_queue;
43 struct dentry *root_debugfs_dir;
44};
45
46static ssize_t mbox_test_signal_write(struct file *filp,
47 const char __user *userbuf,
48 size_t count, loff_t *ppos)
49{
50 struct mbox_test_device *tdev = filp->private_data;
51
52 if (!tdev->tx_channel) {
53 dev_err(tdev->dev, "Channel cannot do Tx\n");
54 return -EINVAL;
55 }
56
57 if (count > MBOX_MAX_SIG_LEN) {
58 dev_err(tdev->dev,
59 "Signal length %zd greater than max allowed %d\n",
60 count, MBOX_MAX_SIG_LEN);
61 return -EINVAL;
62 }
63
64
65 if (!tdev->signal) {
66 tdev->signal = kzalloc(MBOX_MAX_SIG_LEN, GFP_KERNEL);
67 if (!tdev->signal)
68 return -ENOMEM;
69 }
70
71 if (copy_from_user(tdev->signal, userbuf, count)) {
72 kfree(tdev->signal);
73 tdev->signal = NULL;
74 return -EFAULT;
75 }
76
77 return count;
78}
79
80static const struct file_operations mbox_test_signal_ops = {
81 .write = mbox_test_signal_write,
82 .open = simple_open,
83 .llseek = generic_file_llseek,
84};
85
86static int mbox_test_message_fasync(int fd, struct file *filp, int on)
87{
88 struct mbox_test_device *tdev = filp->private_data;
89
90 return fasync_helper(fd, filp, on, &tdev->async_queue);
91}
92
93static ssize_t mbox_test_message_write(struct file *filp,
94 const char __user *userbuf,
95 size_t count, loff_t *ppos)
96{
97 struct mbox_test_device *tdev = filp->private_data;
98 void *data;
99 int ret;
100
101 if (!tdev->tx_channel) {
102 dev_err(tdev->dev, "Channel cannot do Tx\n");
103 return -EINVAL;
104 }
105
106 if (count > MBOX_MAX_MSG_LEN) {
107 dev_err(tdev->dev,
108 "Message length %zd greater than max allowed %d\n",
109 count, MBOX_MAX_MSG_LEN);
110 return -EINVAL;
111 }
112
113 tdev->message = kzalloc(MBOX_MAX_MSG_LEN, GFP_KERNEL);
114 if (!tdev->message)
115 return -ENOMEM;
116
117 ret = copy_from_user(tdev->message, userbuf, count);
118 if (ret) {
119 ret = -EFAULT;
120 goto out;
121 }
122
123
124
125
126
127 if (tdev->tx_mmio && tdev->signal) {
128 print_hex_dump_bytes("Client: Sending: Signal: ", DUMP_PREFIX_ADDRESS,
129 tdev->signal, MBOX_MAX_SIG_LEN);
130
131 data = tdev->signal;
132 } else
133 data = tdev->message;
134
135 print_hex_dump_bytes("Client: Sending: Message: ", DUMP_PREFIX_ADDRESS,
136 tdev->message, MBOX_MAX_MSG_LEN);
137
138 ret = mbox_send_message(tdev->tx_channel, data);
139 if (ret < 0)
140 dev_err(tdev->dev, "Failed to send message via mailbox\n");
141
142out:
143 kfree(tdev->signal);
144 kfree(tdev->message);
145 tdev->signal = NULL;
146
147 return ret < 0 ? ret : count;
148}
149
150static bool mbox_test_message_data_ready(struct mbox_test_device *tdev)
151{
152 bool data_ready;
153 unsigned long flags;
154
155 spin_lock_irqsave(&tdev->lock, flags);
156 data_ready = mbox_data_ready;
157 spin_unlock_irqrestore(&tdev->lock, flags);
158
159 return data_ready;
160}
161
162static ssize_t mbox_test_message_read(struct file *filp, char __user *userbuf,
163 size_t count, loff_t *ppos)
164{
165 struct mbox_test_device *tdev = filp->private_data;
166 unsigned long flags;
167 char *touser, *ptr;
168 int l = 0;
169 int ret;
170
171 DECLARE_WAITQUEUE(wait, current);
172
173 touser = kzalloc(MBOX_HEXDUMP_MAX_LEN + 1, GFP_KERNEL);
174 if (!touser)
175 return -ENOMEM;
176
177 if (!tdev->rx_channel) {
178 ret = snprintf(touser, 20, "<NO RX CAPABILITY>\n");
179 ret = simple_read_from_buffer(userbuf, count, ppos,
180 touser, ret);
181 goto kfree_err;
182 }
183
184 add_wait_queue(&tdev->waitq, &wait);
185
186 do {
187 __set_current_state(TASK_INTERRUPTIBLE);
188
189 if (mbox_test_message_data_ready(tdev))
190 break;
191
192 if (filp->f_flags & O_NONBLOCK) {
193 ret = -EAGAIN;
194 goto waitq_err;
195 }
196
197 if (signal_pending(current)) {
198 ret = -ERESTARTSYS;
199 goto waitq_err;
200 }
201 schedule();
202
203 } while (1);
204
205 spin_lock_irqsave(&tdev->lock, flags);
206
207 ptr = tdev->rx_buffer;
208 while (l < MBOX_HEXDUMP_MAX_LEN) {
209 hex_dump_to_buffer(ptr,
210 MBOX_BYTES_PER_LINE,
211 MBOX_BYTES_PER_LINE, 1, touser + l,
212 MBOX_HEXDUMP_LINE_LEN, true);
213
214 ptr += MBOX_BYTES_PER_LINE;
215 l += MBOX_HEXDUMP_LINE_LEN;
216 *(touser + (l - 1)) = '\n';
217 }
218 *(touser + l) = '\0';
219
220 memset(tdev->rx_buffer, 0, MBOX_MAX_MSG_LEN);
221 mbox_data_ready = false;
222
223 spin_unlock_irqrestore(&tdev->lock, flags);
224
225 ret = simple_read_from_buffer(userbuf, count, ppos, touser, MBOX_HEXDUMP_MAX_LEN);
226waitq_err:
227 __set_current_state(TASK_RUNNING);
228 remove_wait_queue(&tdev->waitq, &wait);
229kfree_err:
230 kfree(touser);
231 return ret;
232}
233
234static __poll_t
235mbox_test_message_poll(struct file *filp, struct poll_table_struct *wait)
236{
237 struct mbox_test_device *tdev = filp->private_data;
238
239 poll_wait(filp, &tdev->waitq, wait);
240
241 if (mbox_test_message_data_ready(tdev))
242 return EPOLLIN | EPOLLRDNORM;
243 return 0;
244}
245
246static const struct file_operations mbox_test_message_ops = {
247 .write = mbox_test_message_write,
248 .read = mbox_test_message_read,
249 .fasync = mbox_test_message_fasync,
250 .poll = mbox_test_message_poll,
251 .open = simple_open,
252 .llseek = generic_file_llseek,
253};
254
255static int mbox_test_add_debugfs(struct platform_device *pdev,
256 struct mbox_test_device *tdev)
257{
258 if (!debugfs_initialized())
259 return 0;
260
261 tdev->root_debugfs_dir = debugfs_create_dir(dev_name(&pdev->dev), NULL);
262 if (!tdev->root_debugfs_dir) {
263 dev_err(&pdev->dev, "Failed to create Mailbox debugfs\n");
264 return -EINVAL;
265 }
266
267 debugfs_create_file("message", 0600, tdev->root_debugfs_dir,
268 tdev, &mbox_test_message_ops);
269
270 debugfs_create_file("signal", 0200, tdev->root_debugfs_dir,
271 tdev, &mbox_test_signal_ops);
272
273 return 0;
274}
275
276static void mbox_test_receive_message(struct mbox_client *client, void *message)
277{
278 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
279 unsigned long flags;
280
281 spin_lock_irqsave(&tdev->lock, flags);
282 if (tdev->rx_mmio) {
283 memcpy_fromio(tdev->rx_buffer, tdev->rx_mmio, MBOX_MAX_MSG_LEN);
284 print_hex_dump_bytes("Client: Received [MMIO]: ", DUMP_PREFIX_ADDRESS,
285 tdev->rx_buffer, MBOX_MAX_MSG_LEN);
286 } else if (message) {
287 print_hex_dump_bytes("Client: Received [API]: ", DUMP_PREFIX_ADDRESS,
288 message, MBOX_MAX_MSG_LEN);
289 memcpy(tdev->rx_buffer, message, MBOX_MAX_MSG_LEN);
290 }
291 mbox_data_ready = true;
292 spin_unlock_irqrestore(&tdev->lock, flags);
293
294 wake_up_interruptible(&tdev->waitq);
295
296 kill_fasync(&tdev->async_queue, SIGIO, POLL_IN);
297}
298
299static void mbox_test_prepare_message(struct mbox_client *client, void *message)
300{
301 struct mbox_test_device *tdev = dev_get_drvdata(client->dev);
302
303 if (tdev->tx_mmio) {
304 if (tdev->signal)
305 memcpy_toio(tdev->tx_mmio, tdev->message, MBOX_MAX_MSG_LEN);
306 else
307 memcpy_toio(tdev->tx_mmio, message, MBOX_MAX_MSG_LEN);
308 }
309}
310
311static void mbox_test_message_sent(struct mbox_client *client,
312 void *message, int r)
313{
314 if (r)
315 dev_warn(client->dev,
316 "Client: Message could not be sent: %d\n", r);
317 else
318 dev_info(client->dev,
319 "Client: Message sent\n");
320}
321
322static struct mbox_chan *
323mbox_test_request_channel(struct platform_device *pdev, const char *name)
324{
325 struct mbox_client *client;
326 struct mbox_chan *channel;
327
328 client = devm_kzalloc(&pdev->dev, sizeof(*client), GFP_KERNEL);
329 if (!client)
330 return ERR_PTR(-ENOMEM);
331
332 client->dev = &pdev->dev;
333 client->rx_callback = mbox_test_receive_message;
334 client->tx_prepare = mbox_test_prepare_message;
335 client->tx_done = mbox_test_message_sent;
336 client->tx_block = true;
337 client->knows_txdone = false;
338 client->tx_tout = 500;
339
340 channel = mbox_request_channel_byname(client, name);
341 if (IS_ERR(channel)) {
342 dev_warn(&pdev->dev, "Failed to request %s channel\n", name);
343 return NULL;
344 }
345
346 return channel;
347}
348
349static int mbox_test_probe(struct platform_device *pdev)
350{
351 struct mbox_test_device *tdev;
352 struct resource *res;
353 resource_size_t size;
354 int ret;
355
356 tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
357 if (!tdev)
358 return -ENOMEM;
359
360
361 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
362 tdev->tx_mmio = devm_ioremap_resource(&pdev->dev, res);
363 if (PTR_ERR(tdev->tx_mmio) == -EBUSY) {
364
365 size = resource_size(res);
366 tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
367 } else if (IS_ERR(tdev->tx_mmio)) {
368 tdev->tx_mmio = NULL;
369 }
370
371
372 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
373 tdev->rx_mmio = devm_ioremap_resource(&pdev->dev, res);
374 if (PTR_ERR(tdev->rx_mmio) == -EBUSY) {
375 size = resource_size(res);
376 tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
377 } else if (IS_ERR(tdev->rx_mmio)) {
378 tdev->rx_mmio = tdev->tx_mmio;
379 }
380
381 tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
382 tdev->rx_channel = mbox_test_request_channel(pdev, "rx");
383
384 if (!tdev->tx_channel && !tdev->rx_channel)
385 return -EPROBE_DEFER;
386
387
388 if (!tdev->rx_channel && (tdev->rx_mmio != tdev->tx_mmio))
389 tdev->rx_channel = tdev->tx_channel;
390
391 tdev->dev = &pdev->dev;
392 platform_set_drvdata(pdev, tdev);
393
394 spin_lock_init(&tdev->lock);
395
396 if (tdev->rx_channel) {
397 tdev->rx_buffer = devm_kzalloc(&pdev->dev,
398 MBOX_MAX_MSG_LEN, GFP_KERNEL);
399 if (!tdev->rx_buffer)
400 return -ENOMEM;
401 }
402
403 ret = mbox_test_add_debugfs(pdev, tdev);
404 if (ret)
405 return ret;
406
407 init_waitqueue_head(&tdev->waitq);
408 dev_info(&pdev->dev, "Successfully registered\n");
409
410 return 0;
411}
412
413static int mbox_test_remove(struct platform_device *pdev)
414{
415 struct mbox_test_device *tdev = platform_get_drvdata(pdev);
416
417 debugfs_remove_recursive(tdev->root_debugfs_dir);
418
419 if (tdev->tx_channel)
420 mbox_free_channel(tdev->tx_channel);
421 if (tdev->rx_channel)
422 mbox_free_channel(tdev->rx_channel);
423
424 return 0;
425}
426
427static const struct of_device_id mbox_test_match[] = {
428 { .compatible = "mailbox-test" },
429 {},
430};
431MODULE_DEVICE_TABLE(of, mbox_test_match);
432
433static struct platform_driver mbox_test_driver = {
434 .driver = {
435 .name = "mailbox_test",
436 .of_match_table = mbox_test_match,
437 },
438 .probe = mbox_test_probe,
439 .remove = mbox_test_remove,
440};
441module_platform_driver(mbox_test_driver);
442
443MODULE_DESCRIPTION("Generic Mailbox Testing Facility");
444MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org");
445MODULE_LICENSE("GPL v2");
446
