Staging: add speakup to the staging directory

Speakup is a kernel based screen review package for the linux operating
system.  It allows blind users to interact with applications on the
linux console by means of synthetic speech.

The authors and maintainers of this code include the following:

Kirk Reiser, Andy Berdan, John Covici, Brian and
David Borowski, Christopher Brannon, Samuel Thibault and William Hubbs.

Signed-off-by: William Hubbs <w.d.hubbs@gmail.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 92 insertions, 0 deletions

diff --git a/drivers/staging/speakup/devsynth.c b/drivers/staging/speakup/devsynth.c
new file mode 100644
index 0000000..a465653
--- /dev/null
+++ b/drivers/staging/speakup/devsynth.c
@@ -0,0 +1,92 @@
+#include <linux/errno.h>
+#include <linux/miscdevice.h>	/* for misc_register, and SYNTH_MINOR */
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include "speakup.h"
+#include "spk_priv.h"
+
+#ifndef SYNTH_MINOR
+#define SYNTH_MINOR 25
+#endif
+
+static int misc_registered;
+static int dev_opened;
+
+static ssize_t speakup_file_write(struct file *fp, const char *buffer,
+		   size_t nbytes, loff_t *ppos)
+{
+	size_t count = nbytes;
+	const char *ptr = buffer;
+	int bytes;
+	unsigned long flags;
+	u_char buf[256];
+	if (synth == NULL)
+		return -ENODEV;
+	while (count > 0) {
+		bytes = min_t(size_t, count, sizeof(buf));
+		if (copy_from_user(buf, ptr, bytes))
+			return -EFAULT;
+		count -= bytes;
+		ptr += bytes;
+		spk_lock(flags);
+		synth_write(buf, bytes);
+		spk_unlock(flags);
+	}
+	return (ssize_t) nbytes;
+}
+
+static ssize_t speakup_file_read(struct file *fp, char *buf, size_t nbytes, loff_t *ppos)
+{
+	return 0;
+}
+
+static int speakup_file_open(struct inode *ip, struct file *fp)
+{
+	if (synth == NULL)
+		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 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 = SYNTH_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_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;
+}