1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun #include <linux/errno.h>
3*4882a593Smuzhiyun #include <linux/miscdevice.h> /* for misc_register, and MISC_DYNAMIC_MINOR */
4*4882a593Smuzhiyun #include <linux/types.h>
5*4882a593Smuzhiyun #include <linux/uaccess.h>
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include "speakup.h"
8*4882a593Smuzhiyun #include "spk_priv.h"
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun static int misc_registered;
11*4882a593Smuzhiyun static int dev_opened;
12*4882a593Smuzhiyun
speakup_file_write(struct file * fp,const char __user * buffer,size_t nbytes,loff_t * ppos)13*4882a593Smuzhiyun static ssize_t speakup_file_write(struct file *fp, const char __user *buffer,
14*4882a593Smuzhiyun size_t nbytes, loff_t *ppos)
15*4882a593Smuzhiyun {
16*4882a593Smuzhiyun size_t count = nbytes;
17*4882a593Smuzhiyun const char __user *ptr = buffer;
18*4882a593Smuzhiyun size_t bytes;
19*4882a593Smuzhiyun unsigned long flags;
20*4882a593Smuzhiyun u_char buf[256];
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun if (!synth)
23*4882a593Smuzhiyun return -ENODEV;
24*4882a593Smuzhiyun while (count > 0) {
25*4882a593Smuzhiyun bytes = min(count, sizeof(buf));
26*4882a593Smuzhiyun if (copy_from_user(buf, ptr, bytes))
27*4882a593Smuzhiyun return -EFAULT;
28*4882a593Smuzhiyun count -= bytes;
29*4882a593Smuzhiyun ptr += bytes;
30*4882a593Smuzhiyun spin_lock_irqsave(&speakup_info.spinlock, flags);
31*4882a593Smuzhiyun synth_write(buf, bytes);
32*4882a593Smuzhiyun spin_unlock_irqrestore(&speakup_info.spinlock, flags);
33*4882a593Smuzhiyun }
34*4882a593Smuzhiyun return (ssize_t)nbytes;
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
speakup_file_read(struct file * fp,char __user * buf,size_t nbytes,loff_t * ppos)37*4882a593Smuzhiyun static ssize_t speakup_file_read(struct file *fp, char __user *buf,
38*4882a593Smuzhiyun size_t nbytes, loff_t *ppos)
39*4882a593Smuzhiyun {
40*4882a593Smuzhiyun return 0;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
speakup_file_open(struct inode * ip,struct file * fp)43*4882a593Smuzhiyun static int speakup_file_open(struct inode *ip, struct file *fp)
44*4882a593Smuzhiyun {
45*4882a593Smuzhiyun if (!synth)
46*4882a593Smuzhiyun return -ENODEV;
47*4882a593Smuzhiyun if (xchg(&dev_opened, 1))
48*4882a593Smuzhiyun return -EBUSY;
49*4882a593Smuzhiyun return 0;
50*4882a593Smuzhiyun }
51*4882a593Smuzhiyun
speakup_file_release(struct inode * ip,struct file * fp)52*4882a593Smuzhiyun static int speakup_file_release(struct inode *ip, struct file *fp)
53*4882a593Smuzhiyun {
54*4882a593Smuzhiyun dev_opened = 0;
55*4882a593Smuzhiyun return 0;
56*4882a593Smuzhiyun }
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun static const struct file_operations synth_fops = {
59*4882a593Smuzhiyun .read = speakup_file_read,
60*4882a593Smuzhiyun .write = speakup_file_write,
61*4882a593Smuzhiyun .open = speakup_file_open,
62*4882a593Smuzhiyun .release = speakup_file_release,
63*4882a593Smuzhiyun };
64*4882a593Smuzhiyun
65*4882a593Smuzhiyun static struct miscdevice synth_device = {
66*4882a593Smuzhiyun .minor = MISC_DYNAMIC_MINOR,
67*4882a593Smuzhiyun .name = "synth",
68*4882a593Smuzhiyun .fops = &synth_fops,
69*4882a593Smuzhiyun };
70*4882a593Smuzhiyun
speakup_register_devsynth(void)71*4882a593Smuzhiyun void speakup_register_devsynth(void)
72*4882a593Smuzhiyun {
73*4882a593Smuzhiyun if (misc_registered != 0)
74*4882a593Smuzhiyun return;
75*4882a593Smuzhiyun /* zero it so if register fails, deregister will not ref invalid ptrs */
76*4882a593Smuzhiyun if (misc_register(&synth_device)) {
77*4882a593Smuzhiyun pr_warn("Couldn't initialize miscdevice /dev/synth.\n");
78*4882a593Smuzhiyun } else {
79*4882a593Smuzhiyun pr_info("initialized device: /dev/synth, node (MAJOR %d, MINOR %d)\n",
80*4882a593Smuzhiyun MISC_MAJOR, synth_device.minor);
81*4882a593Smuzhiyun misc_registered = 1;
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun
speakup_unregister_devsynth(void)85*4882a593Smuzhiyun void speakup_unregister_devsynth(void)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun if (!misc_registered)
88*4882a593Smuzhiyun return;
89*4882a593Smuzhiyun pr_info("speakup: unregistering synth device /dev/synth\n");
90*4882a593Smuzhiyun misc_deregister(&synth_device);
91*4882a593Smuzhiyun misc_registered = 0;
92*4882a593Smuzhiyun }
93