1 #include <linux/errno.h>
2 #include <linux/miscdevice.h> /* for misc_register, and SYNTH_MINOR */
3 #include <linux/types.h>
4 #include <linux/uaccess.h>
10 #define SYNTH_MINOR 25
13 static int misc_registered;
14 static int dev_opened;
16 static ssize_t speakup_file_write(struct file *fp, const char *buffer,
17 size_t nbytes, loff_t *ppos)
19 size_t count = nbytes;
20 const char *ptr = buffer;
27 bytes = min_t(size_t, count, sizeof(buf));
28 if (copy_from_user(buf, ptr, bytes))
33 synth_write(buf, bytes);
36 return (ssize_t) nbytes;
39 static ssize_t speakup_file_read(struct file *fp, char *buf, size_t nbytes, loff_t *ppos)
44 static int speakup_file_open(struct inode *ip, struct file *fp)
48 if (xchg(&dev_opened, 1))
53 static int speakup_file_release(struct inode *ip, struct file *fp)
59 static struct file_operations synth_fops = {
60 .read = speakup_file_read,
61 .write = speakup_file_write,
62 .open = speakup_file_open,
63 .release = speakup_file_release,
66 static struct miscdevice synth_device = {
72 void speakup_register_devsynth(void)
74 if (misc_registered != 0)
76 /* zero it so if register fails, deregister will not ref invalid ptrs */
77 if (misc_register(&synth_device))
78 pr_warn("Couldn't initialize miscdevice /dev/synth.\n");
80 pr_info("initialized device: /dev/synth, node (MAJOR %d, MINOR %d)\n", MISC_MAJOR, SYNTH_MINOR);
85 void speakup_unregister_devsynth(void)
89 pr_info("speakup: unregistering synth device /dev/synth\n");
90 misc_deregister(&synth_device);