patch-2.4.0-test2 linux/drivers/char/joystick/serport.c

• Lines: 221
• Date: Wed Jun 21 08:22:21 2000
• Orig file: v2.4.0-test1/linux/drivers/char/joystick/serport.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.0-test1/linux/drivers/char/joystick/serport.c linux/drivers/char/joystick/serport.c
@@ -0,0 +1,220 @@
+/*
+ * $Id: serport.c,v 1.4 2000/05/29 10:54:53 vojtech Exp $
+ *
+ *  Copyright (c) 1999-2000 Vojtech Pavlik
+ *
+ *  Sponsored by SuSE
+ */
+
+/*
+ * This is a module that converts a tty line into a much simpler
+ * 'serial io port' abstraction that the input device drivers use.
+ */
+
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or 
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * 
+ *  Should you need to contact me, the author, you can do so either by
+ * e-mail - mail your message to <vojtech@ucw.cz>, or by paper mail:
+ * Vojtech Pavlik, Ucitelska 1576, Prague 8, 182 00 Czech Republic
+ */
+
+#include <asm/uaccess.h>
+#include <linux/kernel.h>
+#include <linux/malloc.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serio.h>
+#include <linux/tty.h>
+
+struct serport {
+	struct tty_struct *tty;
+	wait_queue_head_t wait;
+	struct serio serio;
+};
+
+/*
+ * Callback functions from the serio code.
+ */
+
+static int serport_serio_write(struct serio *serio, unsigned char data)
+{
+	struct serport *serport = serio->driver;
+	return -(serport->tty->driver.write(serport->tty, 0, &data, 1) != 1);
+}
+
+static int serport_serio_open(struct serio *serio)
+{
+        return 0;
+}
+
+static void serport_serio_close(struct serio *serio)
+{
+	struct serport *serport = serio->driver;
+	wake_up_interruptible(&serport->wait);
+}
+
+/*
+ * serport_ldisc_open() is the routine that is called upon setting our line
+ * discipline on a tty. It looks for the Mag, and if found, registers
+ * it as a joystick device.
+ */
+
+static int serport_ldisc_open(struct tty_struct *tty)
+{
+	struct serport *serport;
+
+	MOD_INC_USE_COUNT;
+
+	if (!(serport = kmalloc(sizeof(struct serport), GFP_KERNEL))) {
+		MOD_DEC_USE_COUNT;
+		return -ENOMEM;
+	}
+
+	memset(serport, 0, sizeof(struct serport));
+
+	serport->tty = tty;
+	tty->disc_data = serport;
+
+	serport->serio.type = SERIO_RS232;
+	serport->serio.write = serport_serio_write;
+	serport->serio.open = serport_serio_open;
+	serport->serio.close = serport_serio_close;
+	serport->serio.driver = serport;
+
+	init_waitqueue_head(&serport->wait);
+
+	return 0;
+}
+
+/*
+ * serport_ldisc_close() is the opposite of serport_ldisc_open()
+ */
+
+static void serport_ldisc_close(struct tty_struct *tty)
+{
+	struct serport *serport = (struct serport*) tty->disc_data;
+	kfree(serport);
+	MOD_DEC_USE_COUNT;
+}
+
+/*
+ * serport_ldisc_receive() is called by the low level tty driver when characters
+ * are ready for us. We forward the characters, one by one to the 'interrupt'
+ * routine.
+ */
+
+static void serport_ldisc_receive(struct tty_struct *tty, const unsigned char *cp, char *fp, int count)
+{
+	struct serport *serport = (struct serport*) tty->disc_data;
+	int i;
+	for (i = 0; i < count; i++)
+		if (serport->serio.dev)
+			serport->serio.dev->interrupt(&serport->serio, cp[i], 0);
+}
+
+/*
+ * serport_ldisc_room() reports how much room we do have for receiving data.
+ * Although we in fact have infinite room, we need to specify some value
+ * here, and 256 seems to be reasonable.
+ */
+
+static int serport_ldisc_room(struct tty_struct *tty)
+{
+	return 256;
+}
+
+/*
+ * serport_ldisc_read() just waits indefinitely if everything goes well. 
+ * However, when the serio driver closes the serio port, it finishes,
+ * returning 0 characters.
+ */
+
+static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char * buf, size_t nr)
+{
+	struct serport *serport = (struct serport*) tty->disc_data;
+	DECLARE_WAITQUEUE(wait, current);
+	char name[32];
+
+	sprintf(name, tty->driver.name, MINOR(tty->device) - tty->driver.minor_start);
+
+	serio_register_port(&serport->serio);
+
+	printk(KERN_INFO "serio%d: Serial port %s\n", serport->serio.number, name);
+
+	add_wait_queue(&serport->wait, &wait);
+	current->state = TASK_INTERRUPTIBLE;
+
+	while(serport->serio.type && !signal_pending(current)) schedule();
+
+	current->state = TASK_RUNNING;
+	remove_wait_queue(&serport->wait, &wait);
+
+	serio_unregister_port(&serport->serio);
+
+	return 0;
+}
+
+/*
+ * serport_ldisc_ioctl() allows to set the port protocol, and device ID
+ */
+
+static int serport_ldisc_ioctl(struct tty_struct * tty, struct file * file, unsigned int cmd, unsigned long arg)
+{
+	struct serport *serport = (struct serport*) tty->disc_data;
+	
+	switch (cmd) {
+		case SPIOCSTYPE:
+			return get_user(serport->serio.type, (unsigned long *) arg);
+	}
+
+	return -EINVAL;
+}
+
+/*
+ * The line discipline structure.
+ */
+
+static struct tty_ldisc serport_ldisc = {
+	name:		"input",
+	open:		serport_ldisc_open,
+	close:		serport_ldisc_close,
+	read:		serport_ldisc_read,
+	ioctl:		serport_ldisc_ioctl,
+	receive_buf:	serport_ldisc_receive,
+	receive_room:	serport_ldisc_room,
+};
+
+/*
+ * The functions for insering/removing us as a module.
+ */
+
+int __init serport_init(void)
+{
+        if (tty_register_ldisc(N_MOUSE, &serport_ldisc)) {
+                printk(KERN_ERR "serport.c: Error registering line discipline.\n");
+		return -ENODEV;
+	}
+
+	return  0;
+}
+
+void __exit serport_exit(void)
+{
+	tty_register_ldisc(N_MOUSE, NULL);
+}
+
+module_init(serport_init);
+module_exit(serport_exit);