diff options
| author | Ahmad Fatoum <a.fatoum@pengutronix.de> | 2022-11-23 10:55:26 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2023-02-09 23:01:49 +0100 |
| commit | 19409796578c879a41e88ddbdbce50c19457658d (patch) | |
| tree | 911929bb8952bd41d869e22055058b8d096bf443 /include/linux/bcd.h | |
| parent | 04596d4b3e0d20697193341694e8c99961702259 (diff) | |
include/linux/bcd.h: provide bcd_is_valid() helper
bcd2bin(0x0A) happily returns 10, despite this being an invalid BCD
value. RTC drivers converting possibly corrupted BCD timestamps might
want to validate their input before calling bcd2bin().
Provide a macro to do so. Unlike bcd2bin and bin2bcd, out-of-line
versions are not implemented. Should the macro experience enough use,
this can be retrofitted.
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Link: https://lore.kernel.org/r/20221123095527.2771434-2-s.hauer@pengutronix.de
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'include/linux/bcd.h')
| -rw-r--r-- | include/linux/bcd.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/bcd.h b/include/linux/bcd.h index 118bea36d7d4..abbc8149178e 100644 --- a/include/linux/bcd.h +++ b/include/linux/bcd.h @@ -14,8 +14,12 @@ const_bin2bcd(x) : \ _bin2bcd(x)) +#define bcd_is_valid(x) \ + const_bcd_is_valid(x) + #define const_bcd2bin(x) (((x) & 0x0f) + ((x) >> 4) * 10) #define const_bin2bcd(x) ((((x) / 10) << 4) + (x) % 10) +#define const_bcd_is_valid(x) (((x) & 0x0f) < 10 && ((x) >> 4) < 10) unsigned _bcd2bin(unsigned char val) __attribute_const__; unsigned char _bin2bcd(unsigned val) __attribute_const__; |