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authorShawn Nematbakhsh <shawnn@chromium.org>2016-03-15 16:00:09 -0700
committerchrome-bot <chrome-bot@chromium.org>2016-03-18 22:16:53 -0700
commit952b2a54e12bfbf6635a5eb225ad777814ca9c92 (patch)
tree36aeb0608546450ec382f5370d04d1142dc518ba /common/crc8.c
parentf06443e2f7020b98dbb7145bedc930327b8c25dd (diff)
downloadchrome-ec-952b2a54e12bfbf6635a5eb225ad777814ca9c92.tar.gz
crc8: Support crc calculation across non-contiguous data
Building a single buffer for crc calculation is often inefficient, so add a new function that calculates crc8 from an existing crc8. BUG=chromium:576911 BRANCH=None TEST=Manual on sentry with subsequent commit. Verify that smbus communication with battery is functional. Change-Id: I05ffedb81ffcf0c126acda5f6212b3147b1580a1 Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org> Reviewed-on: https://chromium-review.googlesource.com/333786 Commit-Ready: Shawn N <shawnn@chromium.org> Tested-by: Shawn N <shawnn@chromium.org> Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Diffstat (limited to 'common/crc8.c')
-rw-r--r--common/crc8.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/common/crc8.c b/common/crc8.c
index b752698d14..ca32d5a19c 100644
--- a/common/crc8.c
+++ b/common/crc8.c
@@ -5,9 +5,14 @@
#include "common.h"
#include "crc8.h"
-uint8_t crc8(const uint8_t *data, int len)
+inline uint8_t crc8(const uint8_t *data, int len)
{
- unsigned crc = 0;
+ return crc8_arg(data, len, 0);
+}
+
+uint8_t crc8_arg(const uint8_t *data, int len, uint8_t previous_crc)
+{
+ unsigned crc = previous_crc << 8;
int i, j;
for (j = len; j; j--, data++) {