From: Paul Fertser fercerpav@gmail.com
[ Upstream commit 724e8af85854c4d3401313b6dd7d79cf792d8990 ]
Old code produces -24999 for 0b1110011100000000 input in standard format due to always rounding up rather than "away from zero".
Use the common macro for division, unify and simplify the conversion code along the way.
Fixes: 9410700b881f ("hwmon: Add driver for Texas Instruments TMP421/422/423 sensor chips") Signed-off-by: Paul Fertser fercerpav@gmail.com Link: https://lore.kernel.org/r/20210924093011.26083-3-fercerpav@gmail.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/hwmon/tmp421.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-)
diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c index c2113c00b635..cdd01a848301 100644 --- a/drivers/hwmon/tmp421.c +++ b/drivers/hwmon/tmp421.c @@ -109,23 +109,17 @@ struct tmp421_data { s16 temp[4]; };
-static int temp_from_s16(s16 reg) +static int temp_from_raw(u16 reg, bool extended) { /* Mask out status bits */ int temp = reg & ~0xf;
- return (temp * 1000 + 128) / 256; -} - -static int temp_from_u16(u16 reg) -{ - /* Mask out status bits */ - int temp = reg & ~0xf; - - /* Add offset for extended temperature range. */ - temp -= 64 * 256; + if (extended) + temp = temp - 64 * 256; + else + temp = (s16)temp;
- return (temp * 1000 + 128) / 256; + return DIV_ROUND_CLOSEST(temp * 1000, 256); }
static struct tmp421_data *tmp421_update_device(struct device *dev) @@ -162,10 +156,8 @@ static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
switch (attr) { case hwmon_temp_input: - if (tmp421->config & TMP421_CONFIG_RANGE) - *val = temp_from_u16(tmp421->temp[channel]); - else - *val = temp_from_s16(tmp421->temp[channel]); + *val = temp_from_raw(tmp421->temp[channel], + tmp421->config & TMP421_CONFIG_RANGE); return 0; case hwmon_temp_fault: /*