/*
   * IBM/3270 Driver
   *
   * Author(s):
   *   Original 3270 Code for 2.4 written by Richard Hitt (UTS Global)
   *   Rewritten for 2.5 by Martin Schwidefsky <schwidefsky@de.ibm.com>
   *     Copyright IBM Corp. 2003, 2009
   */
  
  #include <asm/idals.h>
  #include <asm/ioctl.h>
  
  /* ioctls for fullscreen 3270 */
  #define TUBICMD		_IO('3', 3)	/* set ccw command for fs reads. */
  #define TUBOCMD		_IO('3', 4)	/* set ccw command for fs writes. */
  #define TUBGETI		_IO('3', 7)	/* get ccw command for fs reads. */
  #define TUBGETO		_IO('3', 8)	/* get ccw command for fs writes. */
  #define TUBSETMOD	_IO('3',12)	/* FIXME: what does it do ?*/
  #define TUBGETMOD	_IO('3',13)	/* FIXME: what does it do ?*/
  
  /* Local Channel Commands */
  #define TC_WRITE	0x01		/* Write */
  #define TC_RDBUF	0x02		/* Read Buffer */
  #define TC_EWRITE	0x05		/* Erase write */
  #define TC_READMOD	0x06		/* Read modified */
  #define TC_EWRITEA	0x0d		/* Erase write alternate */
  #define TC_WRITESF	0x11		/* Write structured field */
  
  /* Buffer Control Orders */
  #define TO_SF		0x1d		/* Start field */
  #define TO_SBA		0x11		/* Set buffer address */
  #define TO_IC		0x13		/* Insert cursor */
  #define TO_PT		0x05		/* Program tab */
  #define TO_RA		0x3c		/* Repeat to address */
  #define TO_SFE		0x29		/* Start field extended */
  #define TO_EUA		0x12		/* Erase unprotected to address */
  #define TO_MF		0x2c		/* Modify field */
  #define TO_SA		0x28		/* Set attribute */
  
  /* Field Attribute Bytes */
  #define TF_INPUT	0x40		/* Visible input */
  #define TF_INPUTN	0x4c		/* Invisible input */
  #define TF_INMDT	0xc1		/* Visible, Set-MDT */
  #define TF_LOG		0x60
  
  /* Character Attribute Bytes */
  #define TAT_RESET	0x00
  #define TAT_FIELD	0xc0
  #define TAT_EXTHI	0x41
  #define TAT_COLOR	0x42
  #define TAT_CHARS	0x43
  #define TAT_TRANS	0x46
  
  /* Extended-Highlighting Bytes */
  #define TAX_RESET	0x00
  #define TAX_BLINK	0xf1
  #define TAX_REVER	0xf2
  #define TAX_UNDER	0xf4
  
  /* Reset value */
  #define TAR_RESET	0x00
  
  /* Color values */
  #define TAC_RESET	0x00
  #define TAC_BLUE	0xf1
  #define TAC_RED		0xf2
  #define TAC_PINK	0xf3
  #define TAC_GREEN	0xf4
  #define TAC_TURQ	0xf5
  #define TAC_YELLOW	0xf6
  #define TAC_WHITE	0xf7
  #define TAC_DEFAULT	0x00
  
  /* Write Control Characters */
  #define TW_NONE		0x40		/* No particular action */
  #define TW_KR		0xc2		/* Keyboard restore */
  #define TW_PLUSALARM	0x04		/* Add this bit for alarm */
  
  #define RAW3270_FIRSTMINOR	1	/* First minor number */
  #define RAW3270_MAXDEVS		255	/* Max number of 3270 devices */
  
  /* For TUBGETMOD and TUBSETMOD. Should include. */
  struct raw3270_iocb {
  	short model;
  	short line_cnt;
  	short col_cnt;
  	short pf_cnt;
  	short re_cnt;
  	short map;
  };
  
  struct raw3270;
  struct raw3270_view;
  extern struct class *class3270;
  
  /* 3270 CCW request */
  struct raw3270_request {
  	struct list_head list;		/* list head for request queueing. */
  	struct raw3270_view *view;	/* view of this request */
  	struct ccw1 ccw;		/* single ccw. */
  	void *buffer;			/* output buffer. */
  	size_t size;			/* size of output buffer. */
  	int rescnt;			/* residual count from devstat. */
  	int rc;				/* return code for this request. */
  
  	/* Callback for delivering final status. */
  	void (*callback)(struct raw3270_request *, void *);
  	void *callback_data;
  };
  
  struct raw3270_request *raw3270_request_alloc(size_t size);
  struct raw3270_request *raw3270_request_alloc_bootmem(size_t size);
  void raw3270_request_free(struct raw3270_request *);
  void raw3270_request_reset(struct raw3270_request *);
  void raw3270_request_set_cmd(struct raw3270_request *, u8 cmd);
  int  raw3270_request_add_data(struct raw3270_request *, void *, size_t);
  void raw3270_request_set_data(struct raw3270_request *, void *, size_t);
  void raw3270_request_set_idal(struct raw3270_request *, struct idal_buffer *);
  
  static inline int
  raw3270_request_final(struct raw3270_request *rq)
  {
  	return list_empty(&rq->list);
  }
  
  void raw3270_buffer_address(struct raw3270 *, char *, unsigned short);
  
  /* Return value of *intv (see raw3270_fn below) can be one of the following: */
  #define RAW3270_IO_DONE		0	/* request finished */
  #define RAW3270_IO_BUSY		1	/* request still active */
  #define RAW3270_IO_RETRY	2	/* retry current request */
  #define RAW3270_IO_STOP		3	/* kill current request */
  
  /*
   * Functions of a 3270 view.
   */
  struct raw3270_fn {
  	int  (*activate)(struct raw3270_view *);
  	void (*deactivate)(struct raw3270_view *);
  	int  (*intv)(struct raw3270_view *,
  		     struct raw3270_request *, struct irb *);
  	void (*release)(struct raw3270_view *);
  	void (*free)(struct raw3270_view *);
  	void (*resize)(struct raw3270_view *, int, int, int);
  };
  
  /*
   * View structure chaining. The raw3270_view structure is meant to
   * be embedded at the start of the real view data structure, e.g.:
   *   struct example {
   *     struct raw3270_view view;
   *     ...
   *   };
   */
  struct raw3270_view {
  	struct list_head list;
  	spinlock_t lock;
  	atomic_t ref_count;
  	struct raw3270 *dev;
  	struct raw3270_fn *fn;
  	unsigned int model;
  	unsigned int rows, cols;	/* # of rows & colums of the view */
  	unsigned char *ascebc;		/* ascii -> ebcdic table */
  };
  
  int raw3270_add_view(struct raw3270_view *, struct raw3270_fn *, int);
  int raw3270_activate_view(struct raw3270_view *);
  void raw3270_del_view(struct raw3270_view *);
  void raw3270_deactivate_view(struct raw3270_view *);
  struct raw3270_view *raw3270_find_view(struct raw3270_fn *, int);
  int raw3270_start(struct raw3270_view *, struct raw3270_request *);
  int raw3270_start_locked(struct raw3270_view *, struct raw3270_request *);
  int raw3270_start_irq(struct raw3270_view *, struct raw3270_request *);
  int raw3270_reset(struct raw3270_view *);
  struct raw3270_view *raw3270_view(struct raw3270_view *);
  
  /* Reference count inliner for view structures. */
  static inline void
  raw3270_get_view(struct raw3270_view *view)
  {
  	atomic_inc(&view->ref_count);
  }
  
  extern wait_queue_head_t raw3270_wait_queue;
  
  static inline void
  raw3270_put_view(struct raw3270_view *view)
  {
  	if (atomic_dec_return(&view->ref_count) == 0)
  		wake_up(&raw3270_wait_queue);
  }
  
  struct raw3270 *raw3270_setup_console(void);
  void raw3270_wait_cons_dev(struct raw3270 *);
  
  /* Notifier for device addition/removal */
  struct raw3270_notifier {
  	struct list_head list;
  	void (*create)(int minor);
  	void (*destroy)(int minor);
  };
  
  int raw3270_register_notifier(struct raw3270_notifier *);
  void raw3270_unregister_notifier(struct raw3270_notifier *);
  void raw3270_pm_unfreeze(struct raw3270_view *);
  
  /*
   * Little memory allocator for string objects. 
   */
  struct string
  {
  	struct list_head list;
  	struct list_head update;
  	unsigned long size;
  	unsigned long len;
  	char string[0];
  } __attribute__ ((aligned(8)));
  
  static inline struct string *
  alloc_string(struct list_head *free_list, unsigned long len)
  {
  	struct string *cs, *tmp;
  	unsigned long size;
  
  	size = (len + 7L) & -8L;
  	list_for_each_entry(cs, free_list, list) {
  		if (cs->size < size)
  			continue;
  		if (cs->size > size + sizeof(struct string)) {
  			char *endaddr = (char *) (cs + 1) + cs->size;
  			tmp = (struct string *) (endaddr - size) - 1;
  			tmp->size = size;
  			cs->size -= size + sizeof(struct string);
  			cs = tmp;
  		} else
  			list_del(&cs->list);
  		cs->len = len;
  		INIT_LIST_HEAD(&cs->list);
  		INIT_LIST_HEAD(&cs->update);
  		return cs;
  	}
  	return NULL;
  }
  
  static inline unsigned long
  free_string(struct list_head *free_list, struct string *cs)
  {
  	struct string *tmp;
  	struct list_head *p, *left;
  
  	/* Find out the left neighbour in free memory list. */
  	left = free_list;
  	list_for_each(p, free_list) {
  		if (list_entry(p, struct string, list) > cs)
  			break;
  		left = p;
  	}
  	/* Try to merge with right neighbour = next element from left. */
  	if (left->next != free_list) {
  		tmp = list_entry(left->next, struct string, list);
  		if ((char *) (cs + 1) + cs->size == (char *) tmp) {
  			list_del(&tmp->list);
  			cs->size += tmp->size + sizeof(struct string);
  		}
  	}
  	/* Try to merge with left neighbour. */
  	if (left != free_list) {
  		tmp = list_entry(left, struct string, list);
  		if ((char *) (tmp + 1) + tmp->size == (char *) cs) {
  			tmp->size += cs->size + sizeof(struct string);
  			return tmp->size;
  		}
  	}
  	__list_add(&cs->list, left, left->next);
  	return cs->size;
  }
  
  static inline void
  add_string_memory(struct list_head *free_list, void *mem, unsigned long size)
  {
  	struct string *cs;
  
  	cs = (struct string *) mem;
  	cs->size = size - sizeof(struct string);
  	free_string(free_list, cs);
  }