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-rw-r--r--drivers/accessibility/speakup/devsynth.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/accessibility/speakup/devsynth.c b/drivers/accessibility/speakup/devsynth.c
new file mode 100644
index 0000000000..d305716635
--- /dev/null
+++ b/drivers/accessibility/speakup/devsynth.c
@@ -0,0 +1,92 @@
+// 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 misc_registered;
+static int dev_opened;
+
+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;
+}
+
+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 struct miscdevice synth_device = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "synth",
+ .fops = &synth_fops,
+};
+
+void speakup_register_devsynth(void)
+{
+ if (misc_registered != 0)
+ return;
+/* zero it so if register fails, deregister will not ref invalid ptrs */
+ 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);
+ misc_registered = 1;
+ }
+}
+
+void speakup_unregister_devsynth(void)
+{
+ if (!misc_registered)
+ return;
+ pr_info("speakup: unregistering synth device /dev/synth\n");
+ misc_deregister(&synth_device);
+ misc_registered = 0;
+}