diff options
| author | James Calligeros <jcalligeros99@gmail.com> | 2026-04-25 10:44:05 +1000 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2026-04-27 06:58:07 +0900 |
| commit | c7ecb6a61908c2604dda6e42da66724d256de7b9 (patch) | |
| tree | 7120bb4f6f9053218eaf801c2d83e442fbfe032c /sound | |
| parent | 4cfb5971c2fbfac061c23fb4224a3a008199de81 (diff) | |
ASoC: tas2770: Fix order of operations for temperature calculation
The order of operations to derive the temperature from the temp
register values was wrong, since 1000 / 16 is not an integer. This
resulted in the calculated temperature value deviating from the
value represented by the registers slightly, which was most obvious
when the registers were zeroed (-92.265 *C vs the expected -93.000 *C).
Scale the reading before dividing the whole thing by 16 to correct
this.
Fixes: ff73e2780169 ("ASoC: tas2770: expose die temp to hwmon")
Signed-off-by: James Calligeros <jcalligeros99@gmail.com>
Link: https://patch.msgid.link/20260425-tas27xx-hwmon-fixes-v1-3-83c13b8e8f54@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/soc/codecs/tas2770.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sound/soc/codecs/tas2770.c b/sound/soc/codecs/tas2770.c index d4d7d056141b..50501bcbe916 100644 --- a/sound/soc/codecs/tas2770.c +++ b/sound/soc/codecs/tas2770.c @@ -624,7 +624,7 @@ static int tas2770_read_die_temp(struct tas2770_priv *tas2770, long *result) /* * As per datasheet: divide register by 16 and subtract 93 to get * degrees Celsius. hwmon requires millidegrees. Let's avoid rounding - * errors by subtracting 93 * 16 then multiplying by 1000 / 16. + * errors by subtracting 93 * 16 and scaling before dividing. * * NOTE: The ADC registers are initialised to 0 on reset. This means * that the temperature will read -93 *C until the chip is brought out @@ -633,7 +633,7 @@ static int tas2770_read_die_temp(struct tas2770_priv *tas2770, long *result) * value read back from its registers will be the last value sampled * before entering software shutdown. */ - *result = (reading - (93 * 16)) * (1000 / 16); + *result = (reading - (93 * 16)) * 1000 / 16; return 0; } |