[PATCH 3/4 v2] lib: add crc16_le helper

[Joakim Tjernlund]

>
> This patch adds a crc16_le helper function to lib/crc16.c
>
> Signed-off-by: Matthieu CASTET <matthieu.castet at parrot.com>
> Signed-off-by: Florian Fainelli <ffainelli at freebox.fr>
> --
> diff --git a/include/linux/crc16.h b/include/linux/crc16.h
> index 9443c08..6c1c61f 100644
> --- a/include/linux/crc16.h
> +++ b/include/linux/crc16.h
> @@ -26,5 +26,7 @@ static inline u16 crc16_byte(u16 crc, const u8 data)
>     return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff];
>  }
>
> +extern u16 crc16_le(u16 crc, const u8 *buffer, size_t len);
> +
>  #endif /* __CRC16_H */
>
> diff --git a/lib/crc16.c b/lib/crc16.c
> index 8737b08..ec4a95c 100644
> --- a/lib/crc16.c
> +++ b/lib/crc16.c
> @@ -62,6 +62,18 @@ u16 crc16(u16 crc, u8 const *buffer, size_t len)
>  }
>  EXPORT_SYMBOL(crc16);
>
> +u16 crc16_le(u16 crc, u8 const *p, size_t len)
> +{
> +   int i;
> +   while (len--) {
> +      crc ^= *p++ << 8;
> +      for (i = 0; i < 8; i++)
> +         crc = (crc << 1) ^ ((crc & 0x8000) ? 0x8005 : 0);
> +   }
> +   return crc;
> +}
> +EXPORT_SYMBOL(crc16_le);
> +
>  MODULE_DESCRIPTION("CRC16 calculations");
>  MODULE_LICENSE("GPL");

Don't recall much of my earlier crc32 work but the above looks wrong.
crc & 0x8000 suggests this is a big endian crc. if so, 0x8005 looks
wrong too. see CRCPOLY_LE resp. CRCPOLY_BE for an idea.
What is this crc sum used for?

       Jocke