On Fri, Oct 17, 2025 at 02:03:34PM +0200, Marco Felsch wrote: > Port the Linux CRC16 implementation. > > Signed-off-by: Marco Felsch <[email protected]>
I was faster ;) We already have this in master Sascha > --- > include/linux/crc16.h | 28 +++++++++++++++++++ > lib/Kconfig | 8 ++++++ > lib/Makefile | 1 + > lib/crc16.c | 65 +++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 102 insertions(+) > create mode 100644 include/linux/crc16.h > create mode 100644 lib/crc16.c > > diff --git a/include/linux/crc16.h b/include/linux/crc16.h > new file mode 100644 > index 000000000000..9fa74529b317 > --- /dev/null > +++ b/include/linux/crc16.h > @@ -0,0 +1,28 @@ > +/* SPDX-License-Identifier: GPL-2.0-only */ > +/* > + * crc16.h - CRC-16 routine > + * > + * Implements the standard CRC-16: > + * Width 16 > + * Poly 0x8005 (x^16 + x^15 + x^2 + 1) > + * Init 0 > + * > + * Copyright (c) 2005 Ben Gardner <[email protected]> > + */ > + > +#ifndef __CRC16_H > +#define __CRC16_H > + > +#include <linux/types.h> > + > +extern u16 const crc16_table[256]; > + > +extern u16 crc16(u16 crc, const u8 *buffer, size_t len); > + > +static inline u16 crc16_byte(u16 crc, const u8 data) > +{ > + return (crc >> 8) ^ crc16_table[(crc ^ data) & 0xff]; > +} > + > +#endif /* __CRC16_H */ > + > diff --git a/lib/Kconfig b/lib/Kconfig > index d07e2f3b6959..153a07ec8f4d 100644 > --- a/lib/Kconfig > +++ b/lib/Kconfig > @@ -155,6 +155,14 @@ config CRC_CCITT > the kernel tree does. Such modules that use library CRC-CCITT > functions require M here. > > +config CRC16 > + tristate "CRC16 functions" > + help > + This option is provided for the case where no in-kernel-tree > + modules require CRC16 functions, but a module built outside > + the kernel tree does. Such modules that use library CRC16 > + functions require M here. > + > config CRC8 > bool "CRC8 function" > help > diff --git a/lib/Makefile b/lib/Makefile > index 13f1de142008..e9f152b21dad 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -85,6 +85,7 @@ obj-y += parseopt.o > obj-y += clz_ctz.o > obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o > obj-$(CONFIG_CRC8) += crc8.o > +obj-$(CONFIG_CRC16) += crc16.o > obj-$(CONFIG_NLS) += nls_base.o > obj-$(CONFIG_FSL_QE_FIRMWARE) += fsl-qe-firmware.o > obj-$(CONFIG_UBSAN_STANDALONE) += ubsan.o > diff --git a/lib/crc16.c b/lib/crc16.c > new file mode 100644 > index 000000000000..5c3a803c01e0 > --- /dev/null > +++ b/lib/crc16.c > @@ -0,0 +1,65 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * crc16.c > + */ > + > +#include <linux/types.h> > +#include <linux/module.h> > +#include <linux/crc16.h> > + > +/** CRC table for the CRC-16. The poly is 0x8005 (x^16 + x^15 + x^2 + 1) */ > +u16 const crc16_table[256] = { > + 0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, > + 0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440, > + 0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, > + 0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, > + 0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40, > + 0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, > + 0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641, > + 0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, > + 0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, > + 0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441, > + 0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, > + 0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, > + 0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41, > + 0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, > + 0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640, > + 0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, > + 0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, > + 0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441, > + 0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, > + 0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840, > + 0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, > + 0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, > + 0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640, > + 0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, > + 0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, > + 0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440, > + 0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, > + 0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841, > + 0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, > + 0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, > + 0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641, > + 0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040 > +}; > +EXPORT_SYMBOL(crc16_table); > + > +/** > + * crc16 - compute the CRC-16 for the data buffer > + * @crc: previous CRC value > + * @buffer: data pointer > + * @len: number of bytes in the buffer > + * > + * Returns the updated CRC value. > + */ > +u16 crc16(u16 crc, u8 const *buffer, size_t len) > +{ > + while (len--) > + crc = crc16_byte(crc, *buffer++); > + return crc; > +} > +EXPORT_SYMBOL(crc16); > + > +MODULE_DESCRIPTION("CRC16 calculations"); > +MODULE_LICENSE("GPL"); > + > -- > 2.47.3 > > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
