hwmon: (lm70) Fix rounding of negative temperatures

temp1_input_show() drops the low bits of the temperature register by
dividing the raw value (raw / 32 on the LM70). These bits are not part
of the temperature: the LM70, LM71, LM74 and TMP122/TMP124 always
return some of them as 1, and the TMP125 fills them with copies of the
temperature LSB. Division rounds toward zero, so a negative temperature
with any of these bits set is reported one LSB too high.

For example, the TMP122 returns 0xffff for -0.0625 degrees C, which the
driver reports as 0. The LM70 returns 0xf39f for -25 degrees C, which
the driver reports as -24750.

Use an arithmetic right shift instead, which drops the low bits and
rounds down.

Fixes: e1a8e913f97e ("[PATCH] lm70: New hardware monitoring driver")
Fixes: a86e94dc946d ("hwmon: (lm70) Add support for LM71 and LM74")
Fixes: cd929672a9ef ("hwmon: (lm70) Add ti,tmp125 support")
Cc: stable@vger.kernel.org
Signed-off-by: Ridham Khurana <khurana.ridham222@gmail.com>
Link: https://patch.msgid.link/20260924205326.1739229-1-khurana.ridham222@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

0 files changed, 0 insertions, 0 deletions