/*
   *    ebcdic keycode functions for s390 console drivers
   *
   *  S390 version
   *    Copyright IBM Corp. 2003
   *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
   */
  
  #include <linux/module.h>
  #include <linux/sched.h>
  #include <linux/slab.h>
  #include <linux/sysrq.h>
  
  #include <linux/consolemap.h>
  #include <linux/kbd_kern.h>
  #include <linux/kbd_diacr.h>
  #include <asm/uaccess.h>
  
  #include "keyboard.h"
  
  /*
   * Handler Tables.
   */
  #define K_HANDLERS\
  	k_self,		k_fn,		k_spec,		k_ignore,\
  	k_dead,		k_ignore,	k_ignore,	k_ignore,\
  	k_ignore,	k_ignore,	k_ignore,	k_ignore,\
  	k_ignore,	k_ignore,	k_ignore,	k_ignore
  
  typedef void (k_handler_fn)(struct kbd_data *, unsigned char);
  static k_handler_fn K_HANDLERS;
  static k_handler_fn *k_handler[16] = { K_HANDLERS };
  
  /* maximum values each key_handler can handle */
  static const int kbd_max_vals[] = {
  	255, ARRAY_SIZE(func_table) - 1, NR_FN_HANDLER - 1, 0,
  	NR_DEAD - 1, 0, 0, 0, 0, 0, 0, 0, 0, 0
  };
  static const int KBD_NR_TYPES = ARRAY_SIZE(kbd_max_vals);
  
  static unsigned char ret_diacr[NR_DEAD] = {
  	'`', '\'', '^', '~', '"', ','
  };
  
  /*
   * Alloc/free of kbd_data structures.
   */
  struct kbd_data *
  kbd_alloc(void) {
  	struct kbd_data *kbd;
  	int i;
  
  	kbd = kzalloc(sizeof(struct kbd_data), GFP_KERNEL);
  	if (!kbd)
  		goto out;
  	kbd->key_maps = kzalloc(sizeof(key_maps), GFP_KERNEL);
  	if (!kbd->key_maps)
  		goto out_kbd;
  	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
  		if (key_maps[i]) {
  			kbd->key_maps[i] = kmemdup(key_maps[i],
  						   sizeof(u_short) * NR_KEYS,
  						   GFP_KERNEL);
  			if (!kbd->key_maps[i])
  				goto out_maps;
  		}
  	}
  	kbd->func_table = kzalloc(sizeof(func_table), GFP_KERNEL);
  	if (!kbd->func_table)
  		goto out_maps;
  	for (i = 0; i < ARRAY_SIZE(func_table); i++) {
  		if (func_table[i]) {
  			kbd->func_table[i] = kstrdup(func_table[i],
  						     GFP_KERNEL);
  			if (!kbd->func_table[i])
  				goto out_func;
  		}
  	}
  	kbd->fn_handler =
  		kzalloc(sizeof(fn_handler_fn *) * NR_FN_HANDLER, GFP_KERNEL);
  	if (!kbd->fn_handler)
  		goto out_func;
  	kbd->accent_table = kmemdup(accent_table,
  				    sizeof(struct kbdiacruc) * MAX_DIACR,
  				    GFP_KERNEL);
  	if (!kbd->accent_table)
  		goto out_fn_handler;
  	kbd->accent_table_size = accent_table_size;
  	return kbd;
  
  out_fn_handler:
  	kfree(kbd->fn_handler);
  out_func:
  	for (i = 0; i < ARRAY_SIZE(func_table); i++)
  		kfree(kbd->func_table[i]);
  	kfree(kbd->func_table);
  out_maps:
  	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
  		kfree(kbd->key_maps[i]);
  	kfree(kbd->key_maps);
  out_kbd:
  	kfree(kbd);
  out:
  	return NULL;
  }
  
  void
  kbd_free(struct kbd_data *kbd)
  {
  	int i;
  
  	kfree(kbd->accent_table);
  	kfree(kbd->fn_handler);
  	for (i = 0; i < ARRAY_SIZE(func_table); i++)
  		kfree(kbd->func_table[i]);
  	kfree(kbd->func_table);
  	for (i = 0; i < ARRAY_SIZE(key_maps); i++)
  		kfree(kbd->key_maps[i]);
  	kfree(kbd->key_maps);
  	kfree(kbd);
  }
  
  /*
   * Generate ascii -> ebcdic translation table from kbd_data.
   */
  void
  kbd_ascebc(struct kbd_data *kbd, unsigned char *ascebc)
  {
  	unsigned short *keymap, keysym;
  	int i, j, k;
  
  	memset(ascebc, 0x40, 256);
  	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
  		keymap = kbd->key_maps[i];
  		if (!keymap)
  			continue;
  		for (j = 0; j < NR_KEYS; j++) {
  			k = ((i & 1) << 7) + j;
  			keysym = keymap[j];
  			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
  			    KTYP(keysym) == (KT_LETTER | 0xf0))
  				ascebc[KVAL(keysym)] = k;
  			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
  				ascebc[ret_diacr[KVAL(keysym)]] = k;
  		}
  	}
  }
  
  #if 0
  /*
   * Generate ebcdic -> ascii translation table from kbd_data.
   */
  void
  kbd_ebcasc(struct kbd_data *kbd, unsigned char *ebcasc)
  {
  	unsigned short *keymap, keysym;
  	int i, j, k;
  
  	memset(ebcasc, ' ', 256);
  	for (i = 0; i < ARRAY_SIZE(key_maps); i++) {
  		keymap = kbd->key_maps[i];
  		if (!keymap)
  			continue;
  		for (j = 0; j < NR_KEYS; j++) {
  			keysym = keymap[j];
  			k = ((i & 1) << 7) + j;
  			if (KTYP(keysym) == (KT_LATIN | 0xf0) ||
  			    KTYP(keysym) == (KT_LETTER | 0xf0))
  				ebcasc[k] = KVAL(keysym);
  			else if (KTYP(keysym) == (KT_DEAD | 0xf0))
  				ebcasc[k] = ret_diacr[KVAL(keysym)];
  		}
  	}
  }
  #endif
  
  /*
   * We have a combining character DIACR here, followed by the character CH.
   * If the combination occurs in the table, return the corresponding value.
   * Otherwise, if CH is a space or equals DIACR, return DIACR.
   * Otherwise, conclude that DIACR was not combining after all,
   * queue it and return CH.
   */
  static unsigned int
  handle_diacr(struct kbd_data *kbd, unsigned int ch)
  {
  	int i, d;
  
  	d = kbd->diacr;
  	kbd->diacr = 0;
  
  	for (i = 0; i < kbd->accent_table_size; i++) {
  		if (kbd->accent_table[i].diacr == d &&
  		    kbd->accent_table[i].base == ch)
  			return kbd->accent_table[i].result;
  	}
  
  	if (ch == ' ' || ch == d)
  		return d;
  
  	kbd_put_queue(kbd->port, d);
  	return ch;
  }
  
  /*
   * Handle dead key.
   */
  static void
  k_dead(struct kbd_data *kbd, unsigned char value)
  {
  	value = ret_diacr[value];
  	kbd->diacr = (kbd->diacr ? handle_diacr(kbd, value) : value);
  }
  
  /*
   * Normal character handler.
   */
  static void
  k_self(struct kbd_data *kbd, unsigned char value)
  {
  	if (kbd->diacr)
  		value = handle_diacr(kbd, value);
  	kbd_put_queue(kbd->port, value);
  }
  
  /*
   * Special key handlers
   */
  static void
  k_ignore(struct kbd_data *kbd, unsigned char value)
  {
  }
  
  /*
   * Function key handler.
   */
  static void
  k_fn(struct kbd_data *kbd, unsigned char value)
  {
  	if (kbd->func_table[value])
  		kbd_puts_queue(kbd->port, kbd->func_table[value]);
  }
  
  static void
  k_spec(struct kbd_data *kbd, unsigned char value)
  {
  	if (value >= NR_FN_HANDLER)
  		return;
  	if (kbd->fn_handler[value])
  		kbd->fn_handler[value](kbd);
  }
  
  /*
   * Put utf8 character to tty flip buffer.
   * UTF-8 is defined for words of up to 31 bits,
   * but we need only 16 bits here
   */
  static void
  to_utf8(struct tty_port *port, ushort c)
  {
  	if (c < 0x80)
  		/*  0******* */
  		kbd_put_queue(port, c);
  	else if (c < 0x800) {
  		/* 110***** 10****** */
  		kbd_put_queue(port, 0xc0 | (c >> 6));
  		kbd_put_queue(port, 0x80 | (c & 0x3f));
  	} else {
  		/* 1110**** 10****** 10****** */
  		kbd_put_queue(port, 0xe0 | (c >> 12));
  		kbd_put_queue(port, 0x80 | ((c >> 6) & 0x3f));
  		kbd_put_queue(port, 0x80 | (c & 0x3f));
  	}
  }
  
  /*
   * Process keycode.
   */
  void
  kbd_keycode(struct kbd_data *kbd, unsigned int keycode)
  {
  	unsigned short keysym;
  	unsigned char type, value;
  
  	if (!kbd)
  		return;
  
  	if (keycode >= 384)
  		keysym = kbd->key_maps[5][keycode - 384];
  	else if (keycode >= 256)
  		keysym = kbd->key_maps[4][keycode - 256];
  	else if (keycode >= 128)
  		keysym = kbd->key_maps[1][keycode - 128];
  	else
  		keysym = kbd->key_maps[0][keycode];
  
  	type = KTYP(keysym);
  	if (type >= 0xf0) {
  		type -= 0xf0;
  		if (type == KT_LETTER)
  			type = KT_LATIN;
  		value = KVAL(keysym);
  #ifdef CONFIG_MAGIC_SYSRQ	       /* Handle the SysRq Hack */
  		if (kbd->sysrq) {
  			if (kbd->sysrq == K(KT_LATIN, '-')) {
  				kbd->sysrq = 0;
  				handle_sysrq(value);
  				return;
  			}
  			if (value == '-') {
  				kbd->sysrq = K(KT_LATIN, '-');
  				return;
  			}
  			/* Incomplete sysrq sequence. */
  			(*k_handler[KTYP(kbd->sysrq)])(kbd, KVAL(kbd->sysrq));
  			kbd->sysrq = 0;
  		} else if ((type == KT_LATIN && value == '^') ||
  			   (type == KT_DEAD && ret_diacr[value] == '^')) {
  			kbd->sysrq = K(type, value);
  			return;
  		}
  #endif
  		(*k_handler[type])(kbd, value);
  	} else
  		to_utf8(kbd->port, keysym);
  }
  
  /*
   * Ioctl stuff.
   */
  static int
  do_kdsk_ioctl(struct kbd_data *kbd, struct kbentry __user *user_kbe,
  	      int cmd, int perm)
  {
  	struct kbentry tmp;
  	ushort *key_map, val, ov;
  
  	if (copy_from_user(&tmp, user_kbe, sizeof(struct kbentry)))
  		return -EFAULT;
  #if NR_KEYS < 256
  	if (tmp.kb_index >= NR_KEYS)
  		return -EINVAL;
  #endif
  #if MAX_NR_KEYMAPS < 256
  	if (tmp.kb_table >= MAX_NR_KEYMAPS)
  		return -EINVAL;	
  #endif
  
  	switch (cmd) {
  	case KDGKBENT:
  		key_map = kbd->key_maps[tmp.kb_table];
  		if (key_map) {
  		    val = U(key_map[tmp.kb_index]);
  		    if (KTYP(val) >= KBD_NR_TYPES)
  			val = K_HOLE;
  		} else
  		    val = (tmp.kb_index ? K_HOLE : K_NOSUCHMAP);
  		return put_user(val, &user_kbe->kb_value);
  	case KDSKBENT:
  		if (!perm)
  			return -EPERM;
  		if (!tmp.kb_index && tmp.kb_value == K_NOSUCHMAP) {
  			/* disallocate map */
  			key_map = kbd->key_maps[tmp.kb_table];
  			if (key_map) {
  			    kbd->key_maps[tmp.kb_table] = NULL;
  			    kfree(key_map);
  			}
  			break;
  		}
  
  		if (KTYP(tmp.kb_value) >= KBD_NR_TYPES)
  			return -EINVAL;
  		if (KVAL(tmp.kb_value) > kbd_max_vals[KTYP(tmp.kb_value)])
  			return -EINVAL;
  
  		if (!(key_map = kbd->key_maps[tmp.kb_table])) {
  			int j;
  
  			key_map = kmalloc(sizeof(plain_map),
  						     GFP_KERNEL);
  			if (!key_map)
  				return -ENOMEM;
  			kbd->key_maps[tmp.kb_table] = key_map;
  			for (j = 0; j < NR_KEYS; j++)
  				key_map[j] = U(K_HOLE);
  		}
  		ov = U(key_map[tmp.kb_index]);
  		if (tmp.kb_value == ov)
  			break;	/* nothing to do */
  		/*
  		 * Attention Key.
  		 */
  		if (((ov == K_SAK) || (tmp.kb_value == K_SAK)) &&
  		    !capable(CAP_SYS_ADMIN))
  			return -EPERM;
  		key_map[tmp.kb_index] = U(tmp.kb_value);
  		break;
  	}
  	return 0;
  }
  
  static int
  do_kdgkb_ioctl(struct kbd_data *kbd, struct kbsentry __user *u_kbs,
  	       int cmd, int perm)
  {
  	unsigned char kb_func;
  	char *p;
  	int len;
  
  	/* Get u_kbs->kb_func. */
  	if (get_user(kb_func, &u_kbs->kb_func))
  		return -EFAULT;
  #if MAX_NR_FUNC < 256
  	if (kb_func >= MAX_NR_FUNC)
  		return -EINVAL;
  #endif
  
  	switch (cmd) {
  	case KDGKBSENT:
  		p = kbd->func_table[kb_func];
  		if (p) {
  			len = strlen(p);
  			if (len >= sizeof(u_kbs->kb_string))
  				len = sizeof(u_kbs->kb_string) - 1;
  			if (copy_to_user(u_kbs->kb_string, p, len))
  				return -EFAULT;
  		} else
  			len = 0;
  		if (put_user('\0', u_kbs->kb_string + len))
  			return -EFAULT;
  		break;
  	case KDSKBSENT:
  		if (!perm)
  			return -EPERM;
  		len = strnlen_user(u_kbs->kb_string,
  				   sizeof(u_kbs->kb_string) - 1);
  		if (!len)
  			return -EFAULT;
  		if (len > sizeof(u_kbs->kb_string) - 1)
  			return -EINVAL;
  		p = kmalloc(len + 1, GFP_KERNEL);
  		if (!p)
  			return -ENOMEM;
  		if (copy_from_user(p, u_kbs->kb_string, len)) {
  			kfree(p);
  			return -EFAULT;
  		}
  		p[len] = 0;
  		kfree(kbd->func_table[kb_func]);
  		kbd->func_table[kb_func] = p;
  		break;
  	}
  	return 0;
  }
  
  int kbd_ioctl(struct kbd_data *kbd, unsigned int cmd, unsigned long arg)
  {
  	struct tty_struct *tty;
  	void __user *argp;
  	unsigned int ct;
  	int perm;
  
  	argp = (void __user *)arg;
  
  	/*
  	 * To have permissions to do most of the vt ioctls, we either have
  	 * to be the owner of the tty, or have CAP_SYS_TTY_CONFIG.
  	 */
  	tty = tty_port_tty_get(kbd->port);
  	/* FIXME this test is pretty racy */
  	perm = current->signal->tty == tty || capable(CAP_SYS_TTY_CONFIG);
  	tty_kref_put(tty);
  	switch (cmd) {
  	case KDGKBTYPE:
  		return put_user(KB_101, (char __user *)argp);
  	case KDGKBENT:
  	case KDSKBENT:
  		return do_kdsk_ioctl(kbd, argp, cmd, perm);
  	case KDGKBSENT:
  	case KDSKBSENT:
  		return do_kdgkb_ioctl(kbd, argp, cmd, perm);
  	case KDGKBDIACR:
  	{
  		struct kbdiacrs __user *a = argp;
  		struct kbdiacr diacr;
  		int i;
  
  		if (put_user(kbd->accent_table_size, &a->kb_cnt))
  			return -EFAULT;
  		for (i = 0; i < kbd->accent_table_size; i++) {
  			diacr.diacr = kbd->accent_table[i].diacr;
  			diacr.base = kbd->accent_table[i].base;
  			diacr.result = kbd->accent_table[i].result;
  			if (copy_to_user(a->kbdiacr + i, &diacr, sizeof(struct kbdiacr)))
  			return -EFAULT;
  		}
  		return 0;
  	}
  	case KDGKBDIACRUC:
  	{
  		struct kbdiacrsuc __user *a = argp;
  
  		ct = kbd->accent_table_size;
  		if (put_user(ct, &a->kb_cnt))
  			return -EFAULT;
  		if (copy_to_user(a->kbdiacruc, kbd->accent_table,
  				 ct * sizeof(struct kbdiacruc)))
  			return -EFAULT;
  		return 0;
  	}
  	case KDSKBDIACR:
  	{
  		struct kbdiacrs __user *a = argp;
  		struct kbdiacr diacr;
  		int i;
  
  		if (!perm)
  			return -EPERM;
  		if (get_user(ct, &a->kb_cnt))
  			return -EFAULT;
  		if (ct >= MAX_DIACR)
  			return -EINVAL;
  		kbd->accent_table_size = ct;
  		for (i = 0; i < ct; i++) {
  			if (copy_from_user(&diacr, a->kbdiacr + i, sizeof(struct kbdiacr)))
  				return -EFAULT;
  			kbd->accent_table[i].diacr = diacr.diacr;
  			kbd->accent_table[i].base = diacr.base;
  			kbd->accent_table[i].result = diacr.result;
  		}
  		return 0;
  	}
  	case KDSKBDIACRUC:
  	{
  		struct kbdiacrsuc __user *a = argp;
  
  		if (!perm)
  			return -EPERM;
  		if (get_user(ct, &a->kb_cnt))
  			return -EFAULT;
  		if (ct >= MAX_DIACR)
  			return -EINVAL;
  		kbd->accent_table_size = ct;
  		if (copy_from_user(kbd->accent_table, a->kbdiacruc,
  				   ct * sizeof(struct kbdiacruc)))
  			return -EFAULT;
  		return 0;
  	}
  	default:
  		return -ENOIOCTLCMD;
  	}
  }
  
  EXPORT_SYMBOL(kbd_ioctl);
  EXPORT_SYMBOL(kbd_ascebc);
  EXPORT_SYMBOL(kbd_free);
  EXPORT_SYMBOL(kbd_alloc);
  EXPORT_SYMBOL(kbd_keycode);