path: root/drivers/s390/char/con3215.c

/*
 *  drivers/s390/char/con3215.c
 *    3215 line mode terminal driver.
 *
 *  S390 version
 *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
 *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
 *
 *  Updated:
 *   Aug-2000: Added tab support
 *	       Dan Morrison, IBM Corporation (dmorriso@cse.buffalo.edu)
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/vt_kern.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/reboot.h>

#include <linux/slab.h>
#include <linux/bootmem.h>

#include <asm/ccwdev.h>
#include <asm/cio.h>
#include <asm/io.h>
#include <asm/ebcdic.h>
#include <asm/uaccess.h>
#include <asm/delay.h>
#include <asm/cpcmd.h>
#include <asm/setup.h>

#include "ctrlchar.h"

#define NR_3215		    1
#define NR_3215_REQ	    (4*NR_3215)
#define RAW3215_BUFFER_SIZE 65536     /* output buffer size */
#define RAW3215_INBUF_SIZE  256	      /* input buffer size */
#define RAW3215_MIN_SPACE   128	      /* minimum free space for wakeup */
#define RAW3215_MIN_WRITE   1024      /* min. length for immediate output */
#define RAW3215_MAX_BYTES   3968      /* max. bytes to write with one ssch */
#define RAW3215_MAX_NEWLINE 50	      /* max. lines to write with one ssch */
#define RAW3215_NR_CCWS	    3
#define RAW3215_TIMEOUT	    HZ/10     /* time for delayed output */

#define RAW3215_FIXED	    1	      /* 3215 console device is not be freed */
#define RAW3215_ACTIVE	    2	      /* set if the device is in use */
#define RAW3215_WORKING	    4	      /* set if a request is being worked on */
#define RAW3215_THROTTLED   8	      /* set if reading is disabled */
#define RAW3215_STOPPED	    16	      /* set if writing is disabled */
#define RAW3215_CLOSING	    32	      /* set while in close process */
#define RAW3215_TIMER_RUNS  64	      /* set if the output delay timer is on */
#define RAW3215_FLUSHING    128	      /* set to flush buffer (no delay) */

#define TAB_STOP_SIZE	    8	      /* tab stop size */

/*
 * Request types for a 3215 device
 */
enum raw3215_type {
	RAW3215_FREE, RAW3215_READ, RAW3215_WRITE
};

/*
 * Request structure for a 3215 device
 */
struct raw3215_req {
	enum raw3215_type type;	      /* type of the request */
	int start, len;		      /* start index & len in output buffer */
	int delayable;		      /* indication to wait for more data */
	int residual;		      /* residual count for read request */
	struct ccw1 ccws[RAW3215_NR_CCWS]; /* space for the channel program */
	struct raw3215_info *info;    /* pointer to main structure */
	struct raw3215_req *next;     /* pointer to next request */
} __attribute__ ((aligned(8)));

struct raw3215_info {
	struct ccw_device *cdev;      /* device for tty driver */
	spinlock_t *lock;	      /* pointer to irq lock */
	int flags;		      /* state flags */
	char *buffer;		      /* pointer to output buffer */
	char *inbuf;		      /* pointer to input buffer */
	int head;		      /* first free byte in output buffer */
	int count;		      /* number of bytes in output buffer */
	int written;		      /* number of bytes in write requests */
	struct tty_struct *tty;	      /* pointer to tty structure if present */
	struct raw3215_req *queued_read; /* pointer to queued read requests */
	struct raw3215_req *queued_write;/* pointer to queued write requests */
	wait_queue_head_t empty_wait; /* wait queue for flushing */
	struct timer_list timer;      /* timer for delayed output */
	int line_pos;		      /* position on the line (for tabs) */
	char ubuffer[80];	      /* copy_from_user buffer */
};

/* array of 3215 devices structures */
static struct raw3215_info *raw3215[NR_3215];
/* spinlock to protect the raw3215 array */
static DEFINE_SPINLOCK(raw3215_device_lock);
/* list of free request structures */
static struct raw3215_req *raw3215_freelist;
/* spinlock to protect free list */
static spinlock_t raw3215_freelist_lock;

static struct tty_driver *tty3215_driver;

/*
 * Get a request structure from the free list
 */
static inline struct raw3215_req *
raw3215_alloc_req(void) {
	struct raw3215_req *req;
	unsigned long flags;

	spin_lock_irqsave(&raw3215_freelist_lock, flags);
	req = raw3215_freelist;
	raw3215_freelist = req->next;
	spin_unlock_irqrestore(&raw3215_freelist_lock, flags);
	return req;
}

/*
 * Put a request structure back to the free list
 */
static inline void
raw3215_free_req(struct raw3215_req *req) {
	unsigned long flags;

	if (req->type == RAW3215_FREE)
		return;		/* don't free a free request */
	req->type = RAW3215_FREE;
	spin_lock_irqsave(&raw3215_freelist_lock, flags);
	req->next = raw3215_freelist;
	raw3215_freelist = req