Quelle  devsynth.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
#include <linux/errno.h>
#include <linux/miscdevice.h> /* for misc_register, and MISC_DYNAMIC_MINOR */
#include <linux/types.h>
#include <linux/uaccess.h>

#include "speakup.h"
#include "spk_priv.h"

static int synth_registered, synthu_registered;
static int dev_opened;

/* Latin1 version */
static ssize_t speakup_file_write(struct file *fp, const char __user *buffer,
      size_t nbytes, loff_t *ppos)
{
 size_t count = nbytes;
 const char __user *ptr = buffer;
 size_t bytes;
 unsigned long flags;
 u_char buf[256];

 if (!synth)
  return -ENODEV;
 while (count > 0) {
  bytes = min(count, sizeof(buf));
  if (copy_from_user(buf, ptr, bytes))
   return -EFAULT;
  count -= bytes;
  ptr += bytes;
  spin_lock_irqsave(&speakup_info.spinlock, flags);
  synth_write(buf, bytes);
  spin_unlock_irqrestore(&speakup_info.spinlock, flags);
 }
 return (ssize_t)nbytes;
}

/* UTF-8 version */
static ssize_t speakup_file_writeu(struct file *fp, const char __user *buffer,
       size_t nbytes, loff_t *ppos)
{
 size_t count = nbytes, consumed, want;
 const char __user *ptr = buffer;
 size_t bytes;
 unsigned long flags;
 unsigned char buf[256];
 u16 ubuf[256];
 size_t in, out;

 if (!synth)
  return -ENODEV;

 want = 1;
 while (count >= want) {
  /* Copy some UTF-8 piece from userland */
  bytes = min(count, sizeof(buf));
  if (copy_from_user(buf, ptr, bytes))
   return -EFAULT;

  /* Convert to u16 */
  for (in = 0, out = 0; in < bytes; in += consumed) {
   s32 value;

   value = synth_utf8_get(buf + in, bytes - in, &consumed, &want);
   if (value == -1) {
    /* Invalid or incomplete */

    if (want > bytes - in)
     /* We don't have it all yet, stop here
 * and wait for the rest
 */
     bytes = in;

    continue;
   }

   if (value < 0x10000)
    ubuf[out++] = value;
  }

  count -= bytes;
  ptr += bytes;

  /* And speak this up */
  if (out) {
   spin_lock_irqsave(&speakup_info.spinlock, flags);
   for (in = 0; in < out; in++)
    synth_buffer_add(ubuf[in]);
   synth_start();
   spin_unlock_irqrestore(&speakup_info.spinlock, flags);
  }
 }

 return (ssize_t)(nbytes - count);
}

static ssize_t speakup_file_read(struct file *fp, char __user *buf,
     size_t nbytes, loff_t *ppos)
{
 return 0;
}

static int speakup_file_open(struct inode *ip, struct file *fp)
{
 if (!synth)
  return -ENODEV;
 if (xchg(&dev_opened, 1))
  return -EBUSY;
 return 0;
}

static int speakup_file_release(struct inode *ip, struct file *fp)
{
 dev_opened = 0;
 return 0;
}

static const struct file_operations synth_fops = {
 .read = speakup_file_read,
 .write = speakup_file_write,
 .open = speakup_file_open,
 .release = speakup_file_release,
};

static const struct file_operations synthu_fops = {
 .read = speakup_file_read,
 .write = speakup_file_writeu,
 .open = speakup_file_open,
 .release = speakup_file_release,
};

static struct miscdevice synth_device = {
 .minor = MISC_DYNAMIC_MINOR,
 .name = "synth",
 .fops = &synth_fops,
};

static struct miscdevice synthu_device = {
 .minor = MISC_DYNAMIC_MINOR,
 .name = "synthu",
 .fops = &synthu_fops,
};

void speakup_register_devsynth(void)
{
 if (!synth_registered) {
  if (misc_register(&synth_device)) {
   pr_warn("Couldn't initialize miscdevice /dev/synth.\n");
  } else {
   pr_info("initialized device: /dev/synth, node (MAJOR %d, MINOR %d)\n",
    MISC_MAJOR, synth_device.minor);
   synth_registered = 1;
  }
 }
 if (!synthu_registered) {
  if (misc_register(&synthu_device)) {
   pr_warn("Couldn't initialize miscdevice /dev/synthu.\n");
  } else {
   pr_info("initialized device: /dev/synthu, node (MAJOR %d, MINOR %d)\n",
    MISC_MAJOR, synthu_device.minor);
   synthu_registered = 1;
  }
 }
}

void speakup_unregister_devsynth(void)
{
 if (synth_registered) {
  pr_info("speakup: unregistering synth device /dev/synth\n");
  misc_deregister(&synth_device);
  synth_registered = 0;
 }
 if (synthu_registered) {
  pr_info("speakup: unregistering synth device /dev/synthu\n");
  misc_deregister(&synthu_device);
  synthu_registered = 0;
 }
}