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