linux-imx

/*

 * linux/fs/nls/nls_base.c

 *

 * Native language support--charsets and unicode translations.

 * By Gordon Chaffee 1996, 1997

 *

 * Unicode based case conversion 1999 by Wolfram Pienkoss

 *

 */

​

#include <linux/module.h>

#include <linux/string.h>

#include <linux/nls.h>

#include <linux/kernel.h>

#include <linux/errno.h>

#include <linux/kmod.h>

#include <linux/spinlock.h>

#include <asm/byteorder.h>

​

static struct nls_table default_table;

static struct nls_table *tables = &default_table;

static DEFINE_SPINLOCK(nls_lock);

​

/*

 * Sample implementation from Unicode home page.

 * http://www.stonehand.com/unicode/standard/fss-utf.html

 */

struct utf8_table {

    int     cmask;

    int     cval;

    int     shift;

    long    lmask;

    long    lval;

};

​

static const struct utf8_table utf8_table[] =

{

    {0x80,  0x00,   0*6,    0x7F,           0,         /* 1 byte sequence */},

    {0xE0,  0xC0,   1*6,    0x7FF,          0x80,      /* 2 byte sequence */},

    {0xF0,  0xE0,   2*6,    0xFFFF,         0x800,     /* 3 byte sequence */},

    {0xF8,  0xF0,   3*6,    0x1FFFFF,       0x10000,   /* 4 byte sequence */},

    {0xFC,  0xF8,   4*6,    0x3FFFFFF,      0x200000,  /* 5 byte sequence */},

    {0xFE,  0xFC,   5*6,    0x7FFFFFFF,     0x4000000, /* 6 byte sequence */},

    {0,                            /* end of table    */}

};

​

#define UNICODE_MAX 0x0010ffff

#define PLANE_SIZE  0x00010000

​

#define SURROGATE_MASK  0xfffff800

#define SURROGATE_PAIR  0x0000d800

#define SURROGATE_LOW   0x00000400

#define SURROGATE_BITS  0x000003ff

​

int utf8_to_utf32(const u8 *s, int inlen, unicode_t *pu)

{

    unsigned long l;

    int c0, c, nc;

    const struct utf8_table *t;

    nc = 0;

    c0 = *s;

    l = c0;

    for (t = utf8_table; t->cmask; t++) {

        nc++;

        if ((c0 & t->cmask) == t->cval) {

            l &= t->lmask;

            if (l < t->lval || l > UNICODE_MAX ||

                    (l & SURROGATE_MASK) == SURROGATE_PAIR)

                return -1;

            *pu = (unicode_t) l;

            return nc;

        }

        if (inlen <= nc)

            return -1;

        s++;

        c = (*s ^ 0x80) & 0xFF;

        if (c & 0xC0)

            return -1;

        l = (l << 6) | c;

    }

    return -1;

}

EXPORT_SYMBOL(utf8_to_utf32);

​

int utf32_to_utf8(unicode_t u, u8 *s, int maxout)

{

    unsigned long l;

    int c, nc;

    const struct utf8_table *t;

​

    if (!s)