| /* |
| * 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 |
| #define SERPORT_ACTIVE 2 |
| #define SERPORT_DEAD 3 |
| |
| struct serport { |
| struct tty_struct *tty; |
| wait_queue_head_t wait; |
| struct serio *serio; |
| struct serio_device_id id; |
| spinlock_t lock; |
| 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 int serport_serio_open(struct serio *serio) |
| { |
| struct serport *serport = serio->port_data; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&serport->lock, flags); |
| set_bit(SERPORT_ACTIVE, &serport->flags); |
| spin_unlock_irqrestore(&serport->lock, flags); |
| |
| return 0; |
| } |
| |
| |
| static void serport_serio_close(struct serio *serio) |
| { |
| struct serport *serport = serio->port_data; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&serport->lock, flags); |
| clear_bit(SERPORT_ACTIVE, &serport->flags); |
| set_bit(SERPORT_DEAD, &serport->flags); |
| spin_unlock_irqrestore(&serport->lock, flags); |
| |
| 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; |
| |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| |
| serport = kcalloc(1, sizeof(struct serport), GFP_KERNEL); |
| if (!serport) |
| return -ENOMEM; |
| |
| serport->tty = tty; |
| spin_lock_init(&serport->lock); |
| init_waitqueue_head(&serport->wait); |
| |
| tty->disc_data = serport; |
| set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); |
| |
| 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; |
| unsigned long flags; |
| int i; |
| |
| spin_lock_irqsave(&serport->lock, flags); |
| |
| if (!test_bit(SERPORT_ACTIVE, &serport->flags)) |
| goto out; |
| |
| for (i = 0; i < count; i++) |
| serio_interrupt(serport->serio, cp[i], 0, NULL); |
| |
| out: |
| spin_unlock_irqrestore(&serport->lock, flags); |
| } |
| |
| /* |
| * 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; |
| struct serio *serio; |
| char name[64]; |
| |
| if (test_and_set_bit(SERPORT_BUSY, &serport->flags)) |
| return -EBUSY; |
| |
| serport->serio = serio = kcalloc(1, sizeof(struct serio), GFP_KERNEL); |
| if (!serio) |
| return -ENOMEM; |
| |
| strlcpy(serio->name, "Serial port", sizeof(serio->name)); |
| snprintf(serio->phys, sizeof(serio->phys), "%s/serio0", tty_name(tty, name)); |
| serio->id = serport->id; |
| serio->id.type = SERIO_RS232; |
| serio->write = serport_serio_write; |
| serio->open = serport_serio_open; |
| serio->close = serport_serio_close; |
| serio->port_data = serport; |
| |
| serio_register_port(serport->serio); |
| printk(KERN_INFO "serio: Serial port %s\n", tty_name(tty, name)); |
| |
| wait_event_interruptible(serport->wait, test_bit(SERPORT_DEAD, &serport->flags)); |
| serio_unregister_port(serport->serio); |
| serport->serio = NULL; |
| |
| clear_bit(SERPORT_DEAD, &serport->flags); |
| 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; |
| unsigned long type; |
| |
| if (cmd == SPIOCSTYPE) { |
| if (get_user(type, (unsigned long __user *) arg)) |
| return -EFAULT; |
| |
| serport->id.proto = type & 0x000000ff; |
| serport->id.id = (type & 0x0000ff00) >> 8; |
| serport->id.extra = (type & 0x00ff0000) >> 16; |
| |
| return 0; |
| } |
| |
| return -EINVAL; |
| } |
| |
| static void serport_ldisc_write_wakeup(struct tty_struct * tty) |
| { |
| struct serport *serport = (struct serport *) tty->disc_data; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&serport->lock, flags); |
| if (test_bit(SERPORT_ACTIVE, &serport->flags)) |
| serio_drv_write_wakeup(serport->serio); |
| spin_unlock_irqrestore(&serport->lock, flags); |
| } |
| |
| /* |
| * 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_unregister_ldisc(N_MOUSE); |
| } |
| |
| module_init(serport_init); |
| module_exit(serport_exit); |