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9#include <linux/kref.h>
10#include <linux/sched.h>
11#include <linux/slab.h>
12#include <linux/poll.h>
13#include <linux/module.h>
14#include <linux/serio.h>
15#include <linux/major.h>
16#include <linux/device.h>
17#include <linux/miscdevice.h>
18#include <linux/wait.h>
19#include <linux/mutex.h>
20
21#define DRIVER_DESC "Raw serio driver"
22
23MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
24MODULE_DESCRIPTION(DRIVER_DESC);
25MODULE_LICENSE("GPL");
26
27#define SERIO_RAW_QUEUE_LEN 64
28struct serio_raw {
29 unsigned char queue[SERIO_RAW_QUEUE_LEN];
30 unsigned int tail, head;
31
32 char name[16];
33 struct kref kref;
34 struct serio *serio;
35 struct miscdevice dev;
36 wait_queue_head_t wait;
37 struct list_head client_list;
38 struct list_head node;
39 bool dead;
40};
41
42struct serio_raw_client {
43 struct fasync_struct *fasync;
44 struct serio_raw *serio_raw;
45 struct list_head node;
46};
47
48static DEFINE_MUTEX(serio_raw_mutex);
49static LIST_HEAD(serio_raw_list);
50
51
52
53
54
55static int serio_raw_fasync(int fd, struct file *file, int on)
56{
57 struct serio_raw_client *client = file->private_data;
58
59 return fasync_helper(fd, file, on, &client->fasync);
60}
61
62static struct serio_raw *serio_raw_locate(int minor)
63{
64 struct serio_raw *serio_raw;
65
66 list_for_each_entry(serio_raw, &serio_raw_list, node) {
67 if (serio_raw->dev.minor == minor)
68 return serio_raw;
69 }
70
71 return NULL;
72}
73
74static int serio_raw_open(struct inode *inode, struct file *file)
75{
76 struct serio_raw *serio_raw;
77 struct serio_raw_client *client;
78 int retval;
79
80 retval = mutex_lock_interruptible(&serio_raw_mutex);
81 if (retval)
82 return retval;
83
84 serio_raw = serio_raw_locate(iminor(inode));
85 if (!serio_raw) {
86 retval = -ENODEV;
87 goto out;
88 }
89
90 if (serio_raw->dead) {
91 retval = -ENODEV;
92 goto out;
93 }
94
95 client = kzalloc(sizeof(struct serio_raw_client), GFP_KERNEL);
96 if (!client) {
97 retval = -ENOMEM;
98 goto out;
99 }
100
101 client->serio_raw = serio_raw;
102 file->private_data = client;
103
104 kref_get(&serio_raw->kref);
105
106 serio_pause_rx(serio_raw->serio);
107 list_add_tail(&client->node, &serio_raw->client_list);
108 serio_continue_rx(serio_raw->serio);
109
110out:
111 mutex_unlock(&serio_raw_mutex);
112 return retval;
113}
114
115static void serio_raw_free(struct kref *kref)
116{
117 struct serio_raw *serio_raw =
118 container_of(kref, struct serio_raw, kref);
119
120 put_device(&serio_raw->serio->dev);
121 kfree(serio_raw);
122}
123
124static int serio_raw_release(struct inode *inode, struct file *file)
125{
126 struct serio_raw_client *client = file->private_data;
127 struct serio_raw *serio_raw = client->serio_raw;
128
129 serio_pause_rx(serio_raw->serio);
130 list_del(&client->node);
131 serio_continue_rx(serio_raw->serio);
132
133 kfree(client);
134
135 kref_put(&serio_raw->kref, serio_raw_free);
136
137 return 0;
138}
139
140static bool serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
141{
142 bool empty;
143
144 serio_pause_rx(serio_raw->serio);
145
146 empty = serio_raw->head == serio_raw->tail;
147 if (!empty) {
148 *c = serio_raw->queue[serio_raw->tail];
149 serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN;
150 }
151
152 serio_continue_rx(serio_raw->serio);
153
154 return !empty;
155}
156
157static ssize_t serio_raw_read(struct file *file, char __user *buffer,
158 size_t count, loff_t *ppos)
159{
160 struct serio_raw_client *client = file->private_data;
161 struct serio_raw *serio_raw = client->serio_raw;
162 char c;
163 ssize_t read = 0;
164 int error;
165
166 for (;;) {
167 if (serio_raw->dead)
168 return -ENODEV;
169
170 if (serio_raw->head == serio_raw->tail &&
171 (file->f_flags & O_NONBLOCK))
172 return -EAGAIN;
173
174 if (count == 0)
175 break;
176
177 while (read < count && serio_raw_fetch_byte(serio_raw, &c)) {
178 if (put_user(c, buffer++))
179 return -EFAULT;
180 read++;
181 }
182
183 if (read)
184 break;
185
186 if (!(file->f_flags & O_NONBLOCK)) {
187 error = wait_event_interruptible(serio_raw->wait,
188 serio_raw->head != serio_raw->tail ||
189 serio_raw->dead);
190 if (error)
191 return error;
192 }
193 }
194
195 return read;
196}
197
198static ssize_t serio_raw_write(struct file *file, const char __user *buffer,
199 size_t count, loff_t *ppos)
200{
201 struct serio_raw_client *client = file->private_data;
202 struct serio_raw *serio_raw = client->serio_raw;
203 int retval = 0;
204 unsigned char c;
205
206 retval = mutex_lock_interruptible(&serio_raw_mutex);
207 if (retval)
208 return retval;
209
210 if (serio_raw->dead) {
211 retval = -ENODEV;
212 goto out;
213 }
214
215 if (count > 32)
216 count = 32;
217
218 while (count--) {
219 if (get_user(c, buffer++)) {
220 retval = -EFAULT;
221 goto out;
222 }
223
224 if (serio_write(serio_raw->serio, c)) {
225
226 if (retval == 0)
227 retval = -EIO;
228 goto out;
229 }
230
231 retval++;
232 }
233
234out:
235 mutex_unlock(&serio_raw_mutex);
236 return retval;
237}
238
239static __poll_t serio_raw_poll(struct file *file, poll_table *wait)
240{
241 struct serio_raw_client *client = file->private_data;
242 struct serio_raw *serio_raw = client->serio_raw;
243 __poll_t mask;
244
245 poll_wait(file, &serio_raw->wait, wait);
246
247 mask = serio_raw->dead ? EPOLLHUP | EPOLLERR : EPOLLOUT | EPOLLWRNORM;
248 if (serio_raw->head != serio_raw->tail)
249 mask |= EPOLLIN | EPOLLRDNORM;
250
251 return mask;
252}
253
254static const struct file_operations serio_raw_fops = {
255 .owner = THIS_MODULE,
256 .open = serio_raw_open,
257 .release = serio_raw_release,
258 .read = serio_raw_read,
259 .write = serio_raw_write,
260 .poll = serio_raw_poll,
261 .fasync = serio_raw_fasync,
262 .llseek = noop_llseek,
263};
264
265
266
267
268
269
270static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data,
271 unsigned int dfl)
272{
273 struct serio_raw *serio_raw = serio_get_drvdata(serio);
274 struct serio_raw_client *client;
275 unsigned int head = serio_raw->head;
276
277
278 serio_raw->queue[head] = data;
279 head = (head + 1) % SERIO_RAW_QUEUE_LEN;
280 if (likely(head != serio_raw->tail)) {
281 serio_raw->head = head;
282 list_for_each_entry(client, &serio_raw->client_list, node)
283 kill_fasync(&client->fasync, SIGIO, POLL_IN);
284 wake_up_interruptible(&serio_raw->wait);
285 }
286
287 return IRQ_HANDLED;
288}
289
290static int serio_raw_connect(struct serio *serio, struct serio_driver *drv)
291{
292 static atomic_t serio_raw_no = ATOMIC_INIT(-1);
293 struct serio_raw *serio_raw;
294 int err;
295
296 serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL);
297 if (!serio_raw) {
298 dev_dbg(&serio->dev, "can't allocate memory for a device\n");
299 return -ENOMEM;
300 }
301
302 snprintf(serio_raw->name, sizeof(serio_raw->name),
303 "serio_raw%ld", (long)atomic_inc_return(&serio_raw_no));
304 kref_init(&serio_raw->kref);
305 INIT_LIST_HEAD(&serio_raw->client_list);
306 init_waitqueue_head(&serio_raw->wait);
307
308 serio_raw->serio = serio;
309 get_device(&serio->dev);
310
311 serio_set_drvdata(serio, serio_raw);
312
313 err = serio_open(serio, drv);
314 if (err)
315 goto err_free;
316
317 err = mutex_lock_killable(&serio_raw_mutex);
318 if (err)
319 goto err_close;
320
321 list_add_tail(&serio_raw->node, &serio_raw_list);
322 mutex_unlock(&serio_raw_mutex);
323
324 serio_raw->dev.minor = PSMOUSE_MINOR;
325 serio_raw->dev.name = serio_raw->name;
326 serio_raw->dev.parent = &serio->dev;
327 serio_raw->dev.fops = &serio_raw_fops;
328
329 err = misc_register(&serio_raw->dev);
330 if (err) {
331 serio_raw->dev.minor = MISC_DYNAMIC_MINOR;
332 err = misc_register(&serio_raw->dev);
333 }
334
335 if (err) {
336 dev_err(&serio->dev,
337 "failed to register raw access device for %s\n",
338 serio->phys);
339 goto err_unlink;
340 }
341
342 dev_info(&serio->dev, "raw access enabled on %s (%s, minor %d)\n",
343 serio->phys, serio_raw->name, serio_raw->dev.minor);
344 return 0;
345
346err_unlink:
347 list_del_init(&serio_raw->node);
348err_close:
349 serio_close(serio);
350err_free:
351 serio_set_drvdata(serio, NULL);
352 kref_put(&serio_raw->kref, serio_raw_free);
353 return err;
354}
355
356static int serio_raw_reconnect(struct serio *serio)
357{
358 struct serio_raw *serio_raw = serio_get_drvdata(serio);
359 struct serio_driver *drv = serio->drv;
360
361 if (!drv || !serio_raw) {
362 dev_dbg(&serio->dev,
363 "reconnect request, but serio is disconnected, ignoring...\n");
364 return -1;
365 }
366
367
368
369
370
371 return 0;
372}
373
374
375
376
377
378static void serio_raw_hangup(struct serio_raw *serio_raw)
379{
380 struct serio_raw_client *client;
381
382 serio_pause_rx(serio_raw->serio);
383 list_for_each_entry(client, &serio_raw->client_list, node)
384 kill_fasync(&client->fasync, SIGIO, POLL_HUP);
385 serio_continue_rx(serio_raw->serio);
386
387 wake_up_interruptible(&serio_raw->wait);
388}
389
390
391static void serio_raw_disconnect(struct serio *serio)
392{
393 struct serio_raw *serio_raw = serio_get_drvdata(serio);
394
395 misc_deregister(&serio_raw->dev);
396
397 mutex_lock(&serio_raw_mutex);
398 serio_raw->dead = true;
399 list_del_init(&serio_raw->node);
400 mutex_unlock(&serio_raw_mutex);
401
402 serio_raw_hangup(serio_raw);
403
404 serio_close(serio);
405 kref_put(&serio_raw->kref, serio_raw_free);
406
407 serio_set_drvdata(serio, NULL);
408}
409
410static const struct serio_device_id serio_raw_serio_ids[] = {
411 {
412 .type = SERIO_8042,
413 .proto = SERIO_ANY,
414 .id = SERIO_ANY,
415 .extra = SERIO_ANY,
416 },
417 {
418 .type = SERIO_8042_XL,
419 .proto = SERIO_ANY,
420 .id = SERIO_ANY,
421 .extra = SERIO_ANY,
422 },
423 { 0 }
424};
425
426MODULE_DEVICE_TABLE(serio, serio_raw_serio_ids);
427
428static struct serio_driver serio_raw_drv = {
429 .driver = {
430 .name = "serio_raw",
431 },
432 .description = DRIVER_DESC,
433 .id_table = serio_raw_serio_ids,
434 .interrupt = serio_raw_interrupt,
435 .connect = serio_raw_connect,
436 .reconnect = serio_raw_reconnect,
437 .disconnect = serio_raw_disconnect,
438 .manual_bind = true,
439};
440
441module_serio_driver(serio_raw_drv);
442
