iio: adc: qcom-vadc-common: use <linux/units.h> helpers

This switches the qcom-vadc-common to use milli_kelvin_to_millicelsius()
in <linux/units.h>.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Akinobu Mita <[email protected]>
Acked-by: Jonathan Cameron <[email protected]>
Reviewed-by: Andy Shevchenko <[email protected]>
Cc: Hartmut Knaack <[email protected]>
Cc: Lars-Peter Clausen <[email protected]>
Cc: Peter Meerwald-Stadler <[email protected]>
Cc: Amit Kucheria <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Emmanuel Grumbach <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jean Delvare <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Johannes Berg <[email protected]>
Cc: Jonathan Cameron <[email protected]>
Cc: Kalle Valo <[email protected]>
Cc: Keith Busch <[email protected]>
Cc: Luca Coelho <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Cc: Stanislaw Gruszka <[email protected]>
Cc: Sujith Thomas <[email protected]>
Cc: Zhang Rui <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>

drivers/iio/adc/qcom-vadc-common.c

@@ -6,6 +6,7 @@
 #include <linux/log2.h>
 #include <linux/err.h>
 #include <linux/module.h>
+#include <linux/units.h>
 
 #include "qcom-vadc-common.h"
 
@@ -236,8 +237,7 @@ static int qcom_vadc_scale_die_temp(const struct vadc_linear_graph *calib_graph,
 		voltage = 0;
 	}
 
-	voltage -= KELVINMIL_CELSIUSMIL;
-	*result_mdec = voltage;
+	*result_mdec = milli_kelvin_to_millicelsius(voltage);
 
 	return 0;
 }
@@ -325,7 +325,7 @@ static int qcom_vadc_scale_hw_calib_die_temp(
 {
 	*result_mdec = qcom_vadc_scale_code_voltage_factor(adc_code,
 				prescale, data, 2);
-	*result_mdec -= KELVINMIL_CELSIUSMIL;
+	*result_mdec = milli_kelvin_to_millicelsius(*result_mdec);
 
 	return 0;
 }

drivers/iio/adc/qcom-vadc-common.h

@@ -38,7 +38,6 @@
 #define VADC_AVG_SAMPLES_MAX			512
 #define ADC5_AVG_SAMPLES_MAX			16
 
-#define KELVINMIL_CELSIUSMIL			273150
 #define PMIC5_CHG_TEMP_SCALE_FACTOR		377500
 #define PMIC5_SMB_TEMP_CONSTANT			419400
 #define PMIC5_SMB_TEMP_SCALE_FACTOR		356