path: root/drivers/s390/char/sclp_tty.c

/*
 *  drivers/s390/char/sclp_tty.c
 *    SCLP line mode terminal driver.
 *
 *  S390 version
 *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Peschke <mpeschke@de.ibm.com>
 *		 Martin Schwidefsky <schwidefsky@de.ibm.com>
 */

#include <linux/module.h>
#include <linux/kmod.h>
#include <linux/tty.h>
#include <linux/tty_driver.h>
#include <linux/tty_flip.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/uaccess.h>

#include "ctrlchar.h"
#include "sclp.h"
#include "sclp_rw.h"
#include "sclp_tty.h"

#define SCLP_TTY_PRINT_HEADER "sclp tty driver: "

/*
 * size of a buffer that collects single characters coming in
 * via sclp_tty_put_char()
 */
#define SCLP_TTY_BUF_SIZE 512

/*
 * There is exactly one SCLP terminal, so we can keep things simple
 * and allocate all variables statically.
 */

/* Lock to guard over changes to global variables. */
static spinlock_t sclp_tty_lock;
/* List of free pages that can be used for console output buffering. */
static struct list_head sclp_tty_pages;
/* List of full struct sclp_buffer structures ready for output. */
static struct list_head sclp_tty_outqueue;
/* Counter how many buffers are emitted. */
static int sclp_tty_buffer_count;
/* Pointer to current console buffer. */
static struct sclp_buffer *sclp_ttybuf;
/* Timer for delayed output of console messages. */
static struct timer_list sclp_tty_timer;
/* Waitqueue to wait for buffers to get empty. */
static wait_queue_head_t sclp_tty_waitq;

static struct tty_struct *sclp_tty;
static unsigned char sclp_tty_chars[SCLP_TTY_BUF_SIZE];
static unsigned short int sclp_tty_chars_count;

struct tty_driver *sclp_tty_driver;

static struct sclp_ioctls sclp_ioctls;
static struct sclp_ioctls sclp_ioctls_init =
{
	8,			/* 1 hor. tab. = 8 spaces */
	0,			/* no echo of input by this driver */
	80,			/* 80 characters/line */
	1,			/* write after 1/10 s without final new line */
	MAX_KMEM_PAGES,		/* quick fix: avoid __alloc_pages */
	MAX_KMEM_PAGES,		/* take 32/64 pages from kernel memory, */
	0,			/* do not convert to lower case */
	0x6c			/* to seprate upper and lower case */
				/* ('%' in EBCDIC) */
};

/* This routine is called whenever we try to open a SCLP terminal. */
static int
sclp_tty_open(struct tty_struct *tty, struct file *filp)
{
	sclp_tty = tty;
	tty->driver_data = NULL;
	tty->low_latency = 0;
	return 0;
}

/* This routine is called when the SCLP terminal is closed. */
static void
sclp_tty_close(struct tty_struct *tty, struct file *filp)
{
	if (tty->count > 1)
		return;
	sclp_tty = NULL;
}

/* execute commands to control the i/o behaviour of the SCLP tty at runtime */
static int
sclp_tty_ioctl(struct tty_struct *tty, struct file * file,
	       unsigned int cmd, unsigned long arg)
{
	unsigned long flags;
	unsigned int obuf;
	int check;
	int rc;

	if (tty->flags & (1 << TTY_IO_ERROR))
		return -EIO;
	rc = 0;
	check = 0;
	switch (cmd) {
	case TIOCSCLPSHTAB:
		/* set width of horizontal tab	*/
		if (get_user(sclp_ioctls.htab, (unsigned short __user *) arg))
			rc = -EFAULT;
		else
			check = 1;
		break;
	case TIOCSCLPGHTAB:
		/* get width of horizontal tab	*/
		if (put_user(sclp_ioctls.htab, (unsigned short __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPSECHO:
		/* enable/disable echo of input */
		if (get_user(sclp_ioctls.echo, (unsigned char __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPGECHO:
		/* Is echo of input enabled ?  */
		if (put_user(sclp_ioctls.echo, (unsigned char __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPSCOLS:
		/* set number of columns for output  */
		if (get_user(sclp_ioctls.columns, (unsigned short __user *) arg))
			rc = -EFAULT;
		else
			check = 1;
		break;
	case TIOCSCLPGCOLS:
		/* get number of columns for output  */
		if (put_user(sclp_ioctls.columns, (unsigned short __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPSNL:
		/* enable/disable writing without final new line character  */
		if (get_user(sclp_ioctls.final_nl, (signed char __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPGNL:
		/* Is writing without final new line character enabled ?  */
		if (put_user(sclp_ioctls.final_nl, (signed char __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPSOBUF:
		/*
		 * set the maximum buffers size for output, will be rounded
		 * up to next 4kB boundary and stored as number of SCCBs
		 * (4kB Buffers) limitation: 256 x 4kB
		 */
		if (get_user(obuf, (unsigned int __user *) arg) == 0) {
			if (obuf & 0xFFF)
				sclp_ioctls.max_sccb = (obuf >> 12) + 1;
			else
				sclp_ioctls.max_sccb = (obuf >> 12);
		} else
			rc = -EFAULT;
		break;
	case TIOCSCLPGOBUF:
		/* get the maximum buffers size for output  */
		obuf = sclp_ioctls.max_sccb << 12;
		if (put_user(obuf, (unsigned int __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPGKBUF:
		/* get the number of buffers got from kernel at startup */
		if (put_user(sclp_ioctls.kmem_sccb, (unsigned short __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPSCASE:
		/* enable/disable conversion from upper to lower case */
		if (get_user(sclp_ioctls.tolower, (unsigned char __user *) arg))
			rc = -EFAULT;
		break;
	case TIOCSCLPGCASE:
		/* Is conversion from upper to lower case of input enabled? */
		if (put_user(sclp_ioctls.tolower, (unsigned char __user *)