/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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);
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);

/*
 * Functions of a 3270 view.
 */
struct raw3270_fn {
        int  (*activate)(struct raw3270_view *);
        void (*deactivate)(struct raw3270_view *);
        void (*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;
#define RAW3270_VIEW_LOCK_IRQ   0
#define RAW3270_VIEW_LOCK_BH    1
        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);
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 *);
int raw3270_view_active(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 *);

/*
 * Little memory allocator for string objects. 
 */
struct string
{
        struct list_head list;
        struct list_head update;
        unsigned long size;
        unsigned long len;
        char string[];
} __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);
}