1 files changed, 226 insertions, 0 deletions

diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
new file mode 100644
index 000000000000..22f73683952b
--- /dev/null
+++ b/drivers/input/serio/serport.c
@@ -0,0 +1,226 @@
+/*
+ * Input device TTY line discipline
+ *
+ * Copyright (c) 1999-2002 Vojtech Pavlik
+ *
+ * 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 version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <asm/uaccess.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/serio.h>
+#include <linux/tty.h>
+
+MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
+MODULE_DESCRIPTION("Input device TTY line discipline");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_LDISC(N_MOUSE);
+
+#define SERPORT_BUSY    1
+
+struct serport {
+        struct tty_struct *tty;
+        wait_queue_head_t wait;
+        struct serio *serio;
+        unsigned long flags;
+};
+
+/*
+ * Callback functions from the serio code.
+ */
+
+static int serport_serio_write(struct serio *serio, unsigned char data)
+{
+        struct serport *serport = serio->port_data;
+        return -(serport->tty->driver->write(serport->tty, &data, 1) != 1);
+}
+
+static void serport_serio_close(struct serio *serio)
+{
+        struct serport *serport = serio->port_data;
+
+        serport->serio->id.type = 0;
+        wake_up_interruptible(&serport->wait);
+}
+
+/*
+ * serport_ldisc_open() is the routine that is called upon setting our line
+ * discipline on a tty. It prepares the serio struct.
+ */
+
+static int serport_ldisc_open(struct tty_struct *tty)
+{
+        struct serport *serport;
+        struct serio *serio;
+        char name[64];
+
+        if (!capable(CAP_SYS_ADMIN))
+                return -EPERM;
+
+        serport = kmalloc(sizeof(struct serport), GFP_KERNEL);
+        serio = kmalloc(sizeof(struct serio), GFP_KERNEL);
+        if (unlikely(!serport || !serio)) {
+                kfree(serport);
+                kfree(serio);
+                return -ENOMEM;
+        }
+
+        memset(serport, 0, sizeof(struct serport));
+        serport->serio = serio;
+        set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
+        serport->tty = tty;
+        tty->disc_data = serport;
+
+        memset(serio, 0, sizeof(struct serio));
+        strlcpy(serio->name, "Serial port", sizeof(serio->name));
+        snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name));
+        serio->id.type = SERIO_RS232;
+        serio->write = serport_serio_write;
+        serio->close = serport_serio_close;
+        serio->port_data = 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);
+}
+
+/*
+ * 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.
+ *
+ * FIXME: We should get pt_regs from the tty layer and forward them to
+ *        serio_interrupt here.
+ */
+
+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++)
+                serio_interrupt(serport->serio, cp[i], 0, NULL);
+}
+
+/*
+ * 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 __user * buf, size_t nr)
+{
+        struct serport *serport = (struct serport*) tty->disc_data;
+        char name[64];
+
+        if (test_and_set_bit(SERPORT_BUSY, &serport->flags))
+                return -EBUSY;
+
+        serio_register_port(serport->serio);
+        printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name));
+        wait_event_interruptible(serport->wait, !serport->serio->id.type);
+        serio_unregister_port(serport->serio);
+
+        clear_bit(SERPORT_BUSY, &serport->flags);
+
+        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;
+        struct serio *serio = serport->serio;
+        unsigned long type;
+
+        if (cmd == SPIOCSTYPE) {
+                if (get_user(type, (unsigned long __user *) arg))
+                        return -EFAULT;
+
+                serio->id.proto = type & 0x000000ff;
+                serio->id.id    = (type & 0x0000ff00) >> 8;
+                serio->id.extra = (type & 0x00ff0000) >> 16;
+
+                return 0;
+        }
+
+        return -EINVAL;
+}
+
+static void serport_ldisc_write_wakeup(struct tty_struct * tty)
+{
+        struct serport *sp = (struct serport *) tty->disc_data;
+
+        serio_drv_write_wakeup(sp->serio);
+}
+
+/*
+ * The line discipline structure.
+ */
+
+static struct tty_ldisc serport_ldisc = {
+        .owner =        THIS_MODULE,
+        .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,
+        .write_wakeup = serport_ldisc_write_wakeup
+};
+
+/*
+ * The functions for insering/removing us as a module.
+ */
+
+static int __init serport_init(void)
+{
+        int retval;
+        retval = tty_register_ldisc(N_MOUSE, &serport_ldisc);
+        if (retval)
+                printk(KERN_ERR "serport.c: Error registering line discipline.\n");
+
+        return  retval;
+}
+
+static void __exit serport_exit(void)
+{
+        tty_register_ldisc(N_MOUSE, NULL);
+}
+
+module_init(serport_init);
+module_exit(serport_exit);