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| author | Larry Johnson <lrj@acm.org> | 2008-02-21 13:58:16 -0500 |
|---|---|---|
| committer | Wolfgang Denk <wd@denx.de> | 2008-02-22 16:33:09 +0100 |
| commit | d01b847c5cd070895c4ba178c85cd068a95cf7cd (patch) | |
| tree | a5a4bcff6943bf094173e7355183ca987c8e96aa /drivers/hwmon | |
| parent | 5a910c224b13e413bda41922379add6d75c32da3 (diff) | |
| download | u-boot-imx-d01b847c5cd070895c4ba178c85cd068a95cf7cd.zip u-boot-imx-d01b847c5cd070895c4ba178c85cd068a95cf7cd.tar.gz u-boot-imx-d01b847c5cd070895c4ba178c85cd068a95cf7cd.tar.bz2 | |
LM75 bug fix for negative temperatures
When the LM75 temperature sensor measures a temperature below 0 C, the
current driver does not perform sign extension, so the result returned is
256 C too high. This patch fixes the problem.
Signed-off-by: Larry Johnson <lrj@acm.org>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/lm75.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c index 63f3b75..e29b294 100644 --- a/drivers/hwmon/lm75.c +++ b/drivers/hwmon/lm75.c @@ -179,7 +179,13 @@ int dtt_init (void) int dtt_get_temp(int sensor) { - return (dtt_read(sensor, DTT_READ_TEMP) / 256); + int const ret = dtt_read(sensor, DTT_READ_TEMP); + + if (ret < 0) { + printf("DTT temperature read failed.\n"); + return 0; + } + return (int)((int16_t) ret / 256); } /* dtt_get_temp() */ #endif /* CONFIG_DTT_LM75 */ |