[U-Boot] [PATCH 2/3] lib/crc16.c: Rename cyg_crc16() to crc16_ccitt() and add crc start value

[Stefan Roese]

The original name of this function is unclear. This patch renames this
CRC16 function to crc16_ccitt() matching its name with its
implementation.

To make the usage of this function more flexible, lets add the CRC start
value as parameter to this function. This way it can be used by other
functions requiring different start values than 0 as well.

Signed-off-by: Stefan Roese <sr at denx.de>
---
 common/xyzModem.c     | 2 +-
 drivers/mmc/mmc_spi.c | 4 ++--
 include/crc.h         | 4 ++--
 lib/crc16.c           | 4 ++--
 4 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/common/xyzModem.c b/common/xyzModem.c
index 56f4bca..5656aac 100644
--- a/common/xyzModem.c
+++ b/common/xyzModem.c
@@ -446,7 +446,7 @@ xyzModem_get_hdr (void)
   /* Verify checksum/CRC */
   if (xyz.crc_mode)
     {
-      cksum = cyg_crc16 (xyz.pkt, xyz.len);
+      cksum = crc16_ccitt(0, xyz.pkt, xyz.len);
       if (cksum != ((xyz.crc1 << 8) | xyz.crc2))
 	{
 	  ZM_DEBUG (zm_dprintf ("CRC error - recvd: %02x%02x, computed: %x\n",
diff --git a/drivers/mmc/mmc_spi.c b/drivers/mmc/mmc_spi.c
index 9032a73..7547e1a 100644
--- a/drivers/mmc/mmc_spi.c
+++ b/drivers/mmc/mmc_spi.c
@@ -91,7 +91,7 @@ static uint mmc_spi_readdata(struct mmc *mmc, void *xbuf,
 			spi_xfer(spi, bsize * 8, NULL, buf, 0);
 			spi_xfer(spi, 2 * 8, NULL, &crc, 0);
 #ifdef CONFIG_MMC_SPI_CRC_ON
-			if (be_to_cpu16(cyg_crc16(buf, bsize)) != crc) {
+			if (be_to_cpu16(crc16_ccitt(0, buf, bsize)) != crc) {
 				debug("%s: CRC error\n", mmc->cfg->name);
 				r1 = R1_SPI_COM_CRC;
 				break;
@@ -120,7 +120,7 @@ static uint mmc_spi_writedata(struct mmc *mmc, const void *xbuf,
 	tok[1] = multi ? SPI_TOKEN_MULTI_WRITE : SPI_TOKEN_SINGLE;
 	while (bcnt--) {
 #ifdef CONFIG_MMC_SPI_CRC_ON
-		crc = cpu_to_be16(cyg_crc16((u8 *)buf, bsize));
+		crc = cpu_to_be16(crc16_ccitt(0, (u8 *)buf, bsize));
 #endif
 		spi_xfer(spi, 2 * 8, tok, NULL, 0);
 		spi_xfer(spi, bsize * 8, buf, NULL, 0);
diff --git a/include/crc.h b/include/crc.h
index 5085d4e..b0031b2 100644
--- a/include/crc.h
+++ b/include/crc.h
@@ -62,8 +62,8 @@ cyg_ether_crc32(unsigned char *s, int len);
 extern uint32_t
 cyg_ether_crc32_accumulate(uint32_t crc, unsigned char *s, int len);
 
-/* 16 bit CRC with polynomial x^16+x^12+x^5+1 */
+/* 16 bit CRC with polynomial x^16+x^12+x^5+1 (CRC-CCITT) */
 
-extern uint16_t cyg_crc16(unsigned char *s, int len);
+uint16_t crc16_ccitt(uint16_t crc_start, unsigned char *s, int len);
 
 #endif /* _SERVICES_CRC_CRC_H_ */
diff --git a/lib/crc16.c b/lib/crc16.c
index 57e46f8..753b987 100644
--- a/lib/crc16.c
+++ b/lib/crc16.c
@@ -61,12 +61,12 @@ static const uint16_t crc16_tab[] = {
 	0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0,
 };
 
-uint16_t cyg_crc16(unsigned char *buf, int len)
+uint16_t crc16_ccitt(uint16_t crc_start, unsigned char *buf, int len)
 {
 	int i;
 	uint16_t cksum;
 
-	cksum = 0;
+	cksum = crc_start;
 	for (i = 0;  i < len;  i++)
 		cksum = crc16_tab[((cksum>>8) ^ *buf++) & 0xff] ^ (cksum << 8);
 
-- 
2.7.2