hwmon: (max31827) Modify conversion wait time

There is nothing in the datasheet indicating that the 1ms error is
needed and I didn't encounter any error during testing with 140ms wait
time.

Signed-off-by: Daniel Matyas <daniel.matyas@analog.com>
Link: https://lore.kernel.org/r/20230919093456.10592-2-daniel.matyas@analog.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/hwmon/max31827.rst b/Documentation/hwmon/max31827.rst
index b0971d0..9a1055a 100644 (file)
--- a/Documentation/hwmon/max31827.rst
+++ b/Documentation/hwmon/max31827.rst
@@ -73,8 +73,8 @@ the conversion frequency to 1 conv/s. The conversion time varies depending on
 the resolution. The conversion time doubles with every bit of increased
 resolution. For 10 bit resolution 35ms are needed, while for 12 bit resolution
 (default) 140ms. When chip is in shutdown mode and a read operation is
-requested, one-shot is triggered, the device waits for 140 (conversion time) + 1
-(error) ms, and only after that is the temperature value register read.
+requested, one-shot is triggered, the device waits for 140 (conversion time) ms,
+and only after that is the temperature value register read.
 
 The LSB of the temperature values is 0.0625 degrees Celsius, but the values of
 the temperatures are displayed in milli-degrees. This means, that some data is

diff --git a/drivers/hwmon/max31827.c b/drivers/hwmon/max31827.c
index 6e3e034..614bbf5 100644 (file)
--- a/drivers/hwmon/max31827.c
+++ b/drivers/hwmon/max31827.c
@@ -25,7 +25,7 @@
 #define MAX31827_CONFIGURATION_U_TEMP_STAT_MASK        BIT(14)
 #define MAX31827_CONFIGURATION_O_TEMP_STAT_MASK        BIT(15)
 
-#define MAX31827_12_BIT_CNV_TIME       141
+#define MAX31827_12_BIT_CNV_TIME       140
 
 #define MAX31827_16_BIT_TO_M_DGR(x)    (sign_extend32(x, 15) * 1000 / 16)
 #define MAX31827_M_DGR_TO_16_BIT(x)    (((x) << 4) / 1000)