Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2)  * userio kernel serio device emulation module
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright (C) 2015 Red Hat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Copyright (C) 2015 Stephen Chandler Paul <thatslyude@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * This program is free software; you can redistribute it and/or modify it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * under the terms of the GNU Lesser General Public License as published by
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * the Free Software Foundation; either version 2 of the License, or (at
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * your option) any later version.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  * This program is distributed in the hope that it will be useful, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  * WITHOUT ANY WARRANTY; without even the implied warranty of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  * General Public License for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/circ_buf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/serio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/poll.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <uapi/linux/userio.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #define USERIO_NAME		"userio"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #define USERIO_BUFSIZE		16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) static struct miscdevice userio_misc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) struct userio_device {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct serio *serio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct mutex mutex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	bool running;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 	u8 head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	u8 tail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	spinlock_t buf_lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 	unsigned char buf[USERIO_BUFSIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 	wait_queue_head_t waitq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51)  * userio_device_write - Write data from serio to a userio device in userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52)  * @id: The serio port for the userio device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53)  * @val: The data to write to the device
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) static int userio_device_write(struct serio *id, unsigned char val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	struct userio_device *userio = id->port_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	spin_lock_irqsave(&userio->buf_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	userio->buf[userio->head] = val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	userio->head = (userio->head + 1) % USERIO_BUFSIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	if (userio->head == userio->tail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 		dev_warn(userio_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 			 "Buffer overflowed, userio client isn't keeping up");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	spin_unlock_irqrestore(&userio->buf_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	wake_up_interruptible(&userio->waitq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) static int userio_char_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	struct userio_device *userio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	userio = kzalloc(sizeof(struct userio_device), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (!userio)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	mutex_init(&userio->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	spin_lock_init(&userio->buf_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	init_waitqueue_head(&userio->waitq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	userio->serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	if (!userio->serio) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		kfree(userio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	userio->serio->write = userio_device_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	userio->serio->port_data = userio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	file->private_data = userio;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) static int userio_char_release(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	struct userio_device *userio = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	if (userio->running) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 		 * Don't free the serio port here, serio_unregister_port()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		 * does it for us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		serio_unregister_port(userio->serio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		kfree(userio->serio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	kfree(userio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) static ssize_t userio_char_read(struct file *file, char __user *user_buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 				size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	struct userio_device *userio = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	size_t nonwrap_len, copylen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	unsigned char buf[USERIO_BUFSIZE];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	 * By the time we get here, the data that was waiting might have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	 * been taken by another thread. Grab the buffer lock and check if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	 * there's still any data waiting, otherwise repeat this process
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	 * until we have data (unless the file descriptor is non-blocking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	 * of course).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 		spin_lock_irqsave(&userio->buf_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		nonwrap_len = CIRC_CNT_TO_END(userio->head,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 					      userio->tail,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 					      USERIO_BUFSIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 		copylen = min(nonwrap_len, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 		if (copylen) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 			memcpy(buf, &userio->buf[userio->tail], copylen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 			userio->tail = (userio->tail + copylen) %
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 							USERIO_BUFSIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 		spin_unlock_irqrestore(&userio->buf_lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		if (nonwrap_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 		/* buffer was/is empty */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		if (file->f_flags & O_NONBLOCK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 			return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		 * count == 0 is special - no IO is done but we check
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		 * for error conditions (see above).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 		if (count == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		error = wait_event_interruptible(userio->waitq,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 						 userio->head != userio->tail);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		if (error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 			return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	if (copylen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 		if (copy_to_user(user_buffer, buf, copylen))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 			return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	return copylen;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) static ssize_t userio_char_write(struct file *file, const char __user *buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 				 size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	struct userio_device *userio = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	struct userio_cmd cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	int error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	if (count != sizeof(cmd)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		dev_warn(userio_misc.this_device, "Invalid payload size\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	if (copy_from_user(&cmd, buffer, sizeof(cmd)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 		return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	error = mutex_lock_interruptible(&userio->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 	if (error)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 		return error;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	switch (cmd.type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	case USERIO_CMD_REGISTER:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 		if (!userio->serio->id.type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 			dev_warn(userio_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 				 "No port type given on /dev/userio\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 			error = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		if (userio->running) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 			dev_warn(userio_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 				 "Begin command sent, but we're already running\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 			error = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 		userio->running = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 		serio_register_port(userio->serio);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	case USERIO_CMD_SET_PORT_TYPE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		if (userio->running) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			dev_warn(userio_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 				 "Can't change port type on an already running userio instance\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 			error = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		userio->serio->id.type = cmd.data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	case USERIO_CMD_SEND_INTERRUPT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		if (!userio->running) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 			dev_warn(userio_misc.this_device,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 				 "The device must be registered before sending interrupts\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 			error = -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 		serio_interrupt(userio->serio, cmd.data, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 		error = -EOPNOTSUPP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	mutex_unlock(&userio->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	return error ?: count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) static __poll_t userio_char_poll(struct file *file, poll_table *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	struct userio_device *userio = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	poll_wait(file, &userio->waitq, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	if (userio->head != userio->tail)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 		return EPOLLIN | EPOLLRDNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) static const struct file_operations userio_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	.open		= userio_char_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	.release	= userio_char_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	.read		= userio_char_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	.write		= userio_char_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	.poll		= userio_char_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	.llseek		= no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) static struct miscdevice userio_misc = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	.fops	= &userio_fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 	.minor	= USERIO_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	.name	= USERIO_NAME,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) module_driver(userio_misc, misc_register, misc_deregister);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) MODULE_ALIAS_MISCDEV(USERIO_MINOR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) MODULE_ALIAS("devname:" USERIO_NAME);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) MODULE_AUTHOR("Stephen Chandler Paul <thatslyude@gmail.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) MODULE_DESCRIPTION("Virtual Serio Device Support");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) MODULE_LICENSE("GPL");