1 // SPDX-License-Identifier: GPL-2.0-only
4  * serio port. Closely emulates behavior of pre-2.6 /dev/psaux device
18 #include <linux/wait.h>
36 	wait_queue_head_t wait;  member
55 static int serio_raw_fasync(int fd, struct file *file, int on)  in serio_raw_fasync()  argument
57 	struct serio_raw_client *client = file->private_data;  in serio_raw_fasync()
59 	return fasync_helper(fd, file, on, &client->fasync);  in serio_raw_fasync()
67 		if (serio_raw->dev.minor == minor)  in serio_raw_locate()
82 			return -ENODEV;  in serio_raw_open()
84 		if (serio_raw->dead)  in serio_raw_open()
85 			return -ENODEV;  in serio_raw_open()
89 			return -ENOMEM;  in serio_raw_open()
91 		client->serio_raw = serio_raw;  in serio_raw_open()
92 		file->private_data = client;  in serio_raw_open()
94 		kref_get(&serio_raw->kref);  in serio_raw_open()
96 		scoped_guard(serio_pause_rx, serio_raw->serio)  in serio_raw_open()
97 			list_add_tail(&client->node, &serio_raw->client_list);  in serio_raw_open()
102 	return -EINTR;  in serio_raw_open()
110 	put_device(&serio_raw->serio->dev);  in serio_raw_free()
116 	struct serio_raw_client *client = file->private_data;  in serio_raw_release()
117 	struct serio_raw *serio_raw = client->serio_raw;  in serio_raw_release()
119 	scoped_guard(serio_pause_rx, serio_raw->serio)  in serio_raw_release()
120 		list_del(&client->node);  in serio_raw_release()
124 	kref_put(&serio_raw->kref, serio_raw_free);  in serio_raw_release()
131 	guard(serio_pause_rx)(serio_raw->serio);  in serio_raw_fetch_byte()
133 	if (serio_raw->head == serio_raw->tail)  in serio_raw_fetch_byte()
136 	*c = serio_raw->queue[serio_raw->tail];  in serio_raw_fetch_byte()
137 	serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN;  in serio_raw_fetch_byte()
145 	struct serio_raw_client *client = file->private_data;  in serio_raw_read()
146 	struct serio_raw *serio_raw = client->serio_raw;  in serio_raw_read()
148 	ssize_t read = 0;  in serio_raw_read()  local
152 		if (serio_raw->dead)  in serio_raw_read()
153 			return -ENODEV;  in serio_raw_read()
155 		if (serio_raw->head == serio_raw->tail &&  in serio_raw_read()
156 		    (file->f_flags & O_NONBLOCK))  in serio_raw_read()
157 			return -EAGAIN;  in serio_raw_read()
162 		while (read < count && serio_raw_fetch_byte(serio_raw, &c)) {  in serio_raw_read()
164 				return -EFAULT;  in serio_raw_read()
165 			read++;  in serio_raw_read()
168 		if (read)  in serio_raw_read()
171 		if (!(file->f_flags & O_NONBLOCK)) {  in serio_raw_read()
172 			error = wait_event_interruptible(serio_raw->wait,  in serio_raw_read()
173 					serio_raw->head != serio_raw->tail ||  in serio_raw_read()
174 					serio_raw->dead);  in serio_raw_read()
180 	return read;  in serio_raw_read()
186 	struct serio_raw_client *client = file->private_data;  in serio_raw_write()
187 	struct serio_raw *serio_raw = client->serio_raw;  in serio_raw_write()
192 		if (serio_raw->dead)  in serio_raw_write()
193 			return -ENODEV;  in serio_raw_write()
198 		while (count--) {  in serio_raw_write()
200 				return -EFAULT;  in serio_raw_write()
202 			if (serio_write(serio_raw->serio, c)) {  in serio_raw_write()
204 				return written ?: -EIO;  in serio_raw_write()
213 	return -EINTR;  in serio_raw_write()
216 static __poll_t serio_raw_poll(struct file *file, poll_table *wait)  in serio_raw_poll()  argument
218 	struct serio_raw_client *client = file->private_data;  in serio_raw_poll()
219 	struct serio_raw *serio_raw = client->serio_raw;  in serio_raw_poll()
222 	poll_wait(file, &serio_raw->wait, wait);  in serio_raw_poll()
224 	mask = serio_raw->dead ? EPOLLHUP | EPOLLERR : EPOLLOUT | EPOLLWRNORM;  in serio_raw_poll()
225 	if (serio_raw->head != serio_raw->tail)  in serio_raw_poll()
235 	.read		= serio_raw_read,
252 	unsigned int head = serio_raw->head;  in serio_raw_interrupt()
254 	/* we are holding serio->lock here so we are protected */  in serio_raw_interrupt()
255 	serio_raw->queue[head] = data;  in serio_raw_interrupt()
257 	if (likely(head != serio_raw->tail)) {  in serio_raw_interrupt()
258 		serio_raw->head = head;  in serio_raw_interrupt()
259 		list_for_each_entry(client, &serio_raw->client_list, node)  in serio_raw_interrupt()
260 			kill_fasync(&client->fasync, SIGIO, POLL_IN);  in serio_raw_interrupt()
261 		wake_up_interruptible(&serio_raw->wait);  in serio_raw_interrupt()
269 	static atomic_t serio_raw_no = ATOMIC_INIT(-1);  in serio_raw_connect()
275 		dev_dbg(&serio->dev, "can't allocate memory for a device\n");  in serio_raw_connect()
276 		return -ENOMEM;  in serio_raw_connect()
279 	snprintf(serio_raw->name, sizeof(serio_raw->name),  in serio_raw_connect()
281 	kref_init(&serio_raw->kref);  in serio_raw_connect()
282 	INIT_LIST_HEAD(&serio_raw->client_list);  in serio_raw_connect()
283 	init_waitqueue_head(&serio_raw->wait);  in serio_raw_connect()
285 	serio_raw->serio = serio;  in serio_raw_connect()
286 	get_device(&serio->dev);  in serio_raw_connect()
298 	list_add_tail(&serio_raw->node, &serio_raw_list);  in serio_raw_connect()
301 	serio_raw->dev.minor = PSMOUSE_MINOR;  in serio_raw_connect()
302 	serio_raw->dev.name = serio_raw->name;  in serio_raw_connect()
303 	serio_raw->dev.parent = &serio->dev;  in serio_raw_connect()
304 	serio_raw->dev.fops = &serio_raw_fops;  in serio_raw_connect()
306 	err = misc_register(&serio_raw->dev);  in serio_raw_connect()
308 		serio_raw->dev.minor = MISC_DYNAMIC_MINOR;  in serio_raw_connect()
309 		err = misc_register(&serio_raw->dev);  in serio_raw_connect()
313 		dev_err(&serio->dev,  in serio_raw_connect()
315 			serio->phys);  in serio_raw_connect()
319 	dev_info(&serio->dev, "raw access enabled on %s (%s, minor %d)\n",  in serio_raw_connect()
320 		 serio->phys, serio_raw->name, serio_raw->dev.minor);  in serio_raw_connect()
324 	list_del_init(&serio_raw->node);  in serio_raw_connect()
329 	kref_put(&serio_raw->kref, serio_raw_free);  in serio_raw_connect()
336 	struct serio_driver *drv = serio->drv;  in serio_raw_reconnect()
339 		dev_dbg(&serio->dev,  in serio_raw_reconnect()
341 		return -1;  in serio_raw_reconnect()
359 	scoped_guard(serio_pause_rx, serio_raw->serio) {  in serio_raw_hangup()
360 		list_for_each_entry(client, &serio_raw->client_list, node)  in serio_raw_hangup()
361 			kill_fasync(&client->fasync, SIGIO, POLL_HUP);  in serio_raw_hangup()
364 	wake_up_interruptible(&serio_raw->wait);  in serio_raw_hangup()
372 	misc_deregister(&serio_raw->dev);  in serio_raw_disconnect()
375 		serio_raw->dead = true;  in serio_raw_disconnect()
376 		list_del_init(&serio_raw->node);  in serio_raw_disconnect()
382 	kref_put(&serio_raw->kref, serio_raw_free);  in serio_raw_disconnect()