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