There are several helper macros to convert kelvin to/from Celsius in
<linux/thermal.h> for thermal drivers. These are useful for any other
drivers or subsystems, but it's odd to include <linux/thermal.h> just for
the helpers.
This adds a new <linux/temperature.h> that provides the equivalent inline
functions for any drivers or subsystems. It is intended to replace the
helpers in <linux/thermal.h>.
Cc: Sujith Thomas <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Andy Shevchenko <[email protected]>
Cc: Zhang Rui <[email protected]>
Cc: Daniel Lezcano <[email protected]>
Cc: Amit Kucheria <[email protected]>
Cc: Jean Delvare <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Keith Busch <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Sagi Grimberg <[email protected]>
Signed-off-by: Akinobu Mita <[email protected]>
---
* v2
- add deci_kelvin_to_millicelsius_with_offset() in linux/temperature.h
- stop including linux/temperature.h from linux/thermal.h
include/linux/temperature.h | 51 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 51 insertions(+)
create mode 100644 include/linux/temperature.h
diff --git a/include/linux/temperature.h b/include/linux/temperature.h
new file mode 100644
index 0000000..679e70a
--- /dev/null
+++ b/include/linux/temperature.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_TEMPERATURE_H
+#define _LINUX_TEMPERATURE_H
+
+#include <linux/kernel.h>
+
+#define ABSOLUTE_ZERO_MILLICELSIUS -273150
+
+static inline long kelvin_to_millicelsius(long t)
+{
+ return t * 1000 + ABSOLUTE_ZERO_MILLICELSIUS;
+}
+
+static inline long millicelsius_to_kelvin(long t)
+{
+ return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 1000);
+}
+
+static inline long deci_kelvin_to_celsius(long t)
+{
+ return DIV_ROUND_CLOSEST(t * 100 + ABSOLUTE_ZERO_MILLICELSIUS, 1000);
+}
+
+static inline long celsius_to_deci_kelvin(long t)
+{
+ return t * 10 - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 100);
+}
+
+/**
+ * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
+ * @t: temperature value in decidegrees Kelvin
+ * @offset: difference between Kelvin and Celsius in millidegrees
+ *
+ * Return: temperature value in millidegrees Celsius
+ */
+static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
+{
+ return t * 100 - offset;
+}
+
+static inline long deci_kelvin_to_millicelsius(long t)
+{
+ return t * 100 + ABSOLUTE_ZERO_MILLICELSIUS;
+}
+
+static inline long millicelsius_to_deci_kelvin(long t)
+{
+ return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 100);
+}
+
+#endif /* _LINUX_TEMPERATURE_H */
--
2.7.4
On 28/11/2019 15:54, Akinobu Mita wrote:
> There are several helper macros to convert kelvin to/from Celsius in
> <linux/thermal.h> for thermal drivers. These are useful for any other
> drivers or subsystems, but it's odd to include <linux/thermal.h> just for
> the helpers.
>
> This adds a new <linux/temperature.h> that provides the equivalent inline
> functions for any drivers or subsystems. It is intended to replace the
> helpers in <linux/thermal.h>.
>
> Cc: Sujith Thomas <[email protected]>
> Cc: Darren Hart <[email protected]>
> Cc: Andy Shevchenko <[email protected]>
> Cc: Zhang Rui <[email protected]>
> Cc: Daniel Lezcano <[email protected]>
> Cc: Amit Kucheria <[email protected]>
> Cc: Jean Delvare <[email protected]>
> Cc: Guenter Roeck <[email protected]>
> Cc: Keith Busch <[email protected]>
> Cc: Jens Axboe <[email protected]>
> Cc: Christoph Hellwig <[email protected]>
> Cc: Sagi Grimberg <[email protected]>
> Signed-off-by: Akinobu Mita <[email protected]>
> ---
> * v2
> - add deci_kelvin_to_millicelsius_with_offset() in linux/temperature.h
> - stop including linux/temperature.h from linux/thermal.h
>
> include/linux/temperature.h | 51 +++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
> create mode 100644 include/linux/temperature.h
>
> diff --git a/include/linux/temperature.h b/include/linux/temperature.h
> new file mode 100644
> index 0000000..679e70a
> --- /dev/null
> +++ b/include/linux/temperature.h
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _LINUX_TEMPERATURE_H
> +#define _LINUX_TEMPERATURE_H
It sounds strange to create a temperature file just for a few conversion
functions. Why not create an units.h file, so some more conversions
could be added later (not necessarily related to temperature) ?
> +#include <linux/kernel.h>
> +
> +#define ABSOLUTE_ZERO_MILLICELSIUS -273150
> +
> +static inline long kelvin_to_millicelsius(long t)
Why 'long' ?
> +{
> + return t * 1000 + ABSOLUTE_ZERO_MILLICELSIUS;
> +}
> +
> +static inline long millicelsius_to_kelvin(long t)
> +{
> + return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 1000);
Please don't duplicate these operations, just do the conversion to the
right unit and then call a single function.
Replace the constant by macros like what we find in time64.h.
eg.
#define MILLICELSIUS_PER_CELCIUS 1000
So you can really do the cleanup in all the drivers, like removing:
drivers/iio/adc/qcom-vadc-common.h:#define KELVINMIL_CELSIUSMIL
273150
drivers/iio/pressure/st_pressure_core.c:#define MCELSIUS_PER_CELSIUS
1000
drivers/hwmon/xgene-hwmon.c:#define CELSIUS_TO_mCELSIUS(x)
((x) * 1000)
drivers/net/wireless/intel/iwlegacy/common.h:#define
KELVIN_TO_CELSIUS(x) ((x)-273)
drivers/net/wireless/intel/iwlegacy/common.h:#define
CELSIUS_TO_KELVIN(x) ((x)+273)
drivers/net/wireless/intel/iwlwifi/dvm/dev.h:#define
KELVIN_TO_CELSIUS(x) ((x)-273)
drivers/net/wireless/intel/iwlwifi/dvm/dev.h:#define
CELSIUS_TO_KELVIN(x) ((x)+273)
drivers/power/supply/sbs-battery.c:#define TEMP_KELVIN_TO_CELSIUS
2731
drivers/thermal/armada_thermal.c:#define TO_MCELSIUS(c)
((c) * 1000)
drivers/thermal/rcar_gen3_thermal.c:#define MCELSIUS(temp) ((temp)
* 1000)
drivers/thermal/rcar_thermal.c:#define MCELSIUS(temp)
((temp) * 1000)
drivers/thermal/samsung/exynos_tmu.c:#define MCELSIUS 1000
drivers/thermal/samsung/exynos_tmu.c: temp /= MCELSIUS;
drivers/thermal/samsung/exynos_tmu.c: hyst /= MCELSIUS;
drivers/thermal/samsung/exynos_tmu.c: ref = trips[0].temperature /
MCELSIUS;
drivers/thermal/samsung/exynos_tmu.c: *temp =
code_to_temp(data, value) * MCELSIUS;
drivers/thermal/samsung/exynos_tmu.c: temp /= MCELSIUS;
> +}
> +
> +static inline long deci_kelvin_to_celsius(long t)
> +{
> + return DIV_ROUND_CLOSEST(t * 100 + ABSOLUTE_ZERO_MILLICELSIUS, 1000);
> +}
> +
> +static inline long celsius_to_deci_kelvin(long t)
> +{
> + return t * 10 - DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 100);
> +}
> +
> +/**
> + * deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
> + * @t: temperature value in decidegrees Kelvin
> + * @offset: difference between Kelvin and Celsius in millidegrees
> + *
> + * Return: temperature value in millidegrees Celsius
> + */
> +static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
> +{
> + return t * 100 - offset;
> +}
> +
> +static inline long deci_kelvin_to_millicelsius(long t)
> +{
> + return t * 100 + ABSOLUTE_ZERO_MILLICELSIUS;
> +}
> +
> +static inline long millicelsius_to_deci_kelvin(long t)
> +{
> + return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 100);
> +}
> +
> +#endif /* _LINUX_TEMPERATURE_H */
>
--
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2019年12月7日(土) 1:49 Daniel Lezcano <[email protected]>:
>
> On 28/11/2019 15:54, Akinobu Mita wrote:
> > There are several helper macros to convert kelvin to/from Celsius in
> > <linux/thermal.h> for thermal drivers. These are useful for any other
> > drivers or subsystems, but it's odd to include <linux/thermal.h> just for
> > the helpers.
> >
> > This adds a new <linux/temperature.h> that provides the equivalent inline
> > functions for any drivers or subsystems. It is intended to replace the
> > helpers in <linux/thermal.h>.
> >
> > Cc: Sujith Thomas <[email protected]>
> > Cc: Darren Hart <[email protected]>
> > Cc: Andy Shevchenko <[email protected]>
> > Cc: Zhang Rui <[email protected]>
> > Cc: Daniel Lezcano <[email protected]>
> > Cc: Amit Kucheria <[email protected]>
> > Cc: Jean Delvare <[email protected]>
> > Cc: Guenter Roeck <[email protected]>
> > Cc: Keith Busch <[email protected]>
> > Cc: Jens Axboe <[email protected]>
> > Cc: Christoph Hellwig <[email protected]>
> > Cc: Sagi Grimberg <[email protected]>
> > Signed-off-by: Akinobu Mita <[email protected]>
> > ---
> > * v2
> > - add deci_kelvin_to_millicelsius_with_offset() in linux/temperature.h
> > - stop including linux/temperature.h from linux/thermal.h
> >
> > include/linux/temperature.h | 51 +++++++++++++++++++++++++++++++++++++++++++++
> > 1 file changed, 51 insertions(+)
> > create mode 100644 include/linux/temperature.h
> >
> > diff --git a/include/linux/temperature.h b/include/linux/temperature.h
> > new file mode 100644
> > index 0000000..679e70a
> > --- /dev/null
> > +++ b/include/linux/temperature.h
> > @@ -0,0 +1,51 @@
> > +/* SPDX-License-Identifier: GPL-2.0 */
> > +#ifndef _LINUX_TEMPERATURE_H
> > +#define _LINUX_TEMPERATURE_H
>
> It sounds strange to create a temperature file just for a few conversion
> functions. Why not create an units.h file, so some more conversions
> could be added later (not necessarily related to temperature) ?
Fine with me.
> > +#include <linux/kernel.h>
> > +
> > +#define ABSOLUTE_ZERO_MILLICELSIUS -273150
> > +
> > +static inline long kelvin_to_millicelsius(long t)
>
> Why 'long' ?
There's no specific reason, but the existing DECI_KELVIN_TO_CELSIUS() in
linux/thermal.h converts to 'long'.
Do you prefer changing 'long' to 'int'?
> > +{
> > + return t * 1000 + ABSOLUTE_ZERO_MILLICELSIUS;
> > +}
> > +
> > +static inline long millicelsius_to_kelvin(long t)
> > +{
> > + return DIV_ROUND_CLOSEST(t - ABSOLUTE_ZERO_MILLICELSIUS, 1000);
>
> Please don't duplicate these operations, just do the conversion to the
> right unit and then call a single function.
>
> Replace the constant by macros like what we find in time64.h.
>
> eg.
> #define MILLICELSIUS_PER_CELCIUS 1000
How about this?
#define ABSOLUTE_ZERO_MILLICELSIUS -273150
static inline long milli_kelvin_to_millicelsius(long t)
{
return t + ABSOLUTE_ZERO_MILLICELSIUS;
}
static inline long millicelsius_to_milli_kelvin(long t)
{
return t - ABSOLUTE_ZERO_MILLICELSIUS;
}
#define MILLIDEGREE_PER_DEGREE 1000
#define MILLIDEGREE_PER_DECIDEGREE 100
static inline long kelvin_to_millicelsius(long t)
{
return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DEGREE);
}
static inline long millicelsius_to_kelvin(long t)
{
t = millicelsius_to_milli_kelvin(t);
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
}
static inline long deci_kelvin_to_celsius(long t)
{
t = milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DEGREE);
}
static inline long celsius_to_deci_kelvin(long t)
{
t = millicelsius_to_milli_kelvin(t * MILLIDEGREE_PER_DEGREE);
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
}
/**
* deci_kelvin_to_millicelsius_with_offset - convert Kelvin to Celsius
* @t: temperature value in decidegrees Kelvin
* @offset: difference between Kelvin and Celsius in millidegrees
*
* Return: temperature value in millidegrees Celsius
*/
static inline long deci_kelvin_to_millicelsius_with_offset(long t, long offset)
{
return t * MILLIDEGREE_PER_DECIDEGREE - offset;
}
static inline long deci_kelvin_to_millicelsius(long t)
{
return milli_kelvin_to_millicelsius(t * MILLIDEGREE_PER_DECIDEGREE);
}
static inline long millicelsius_to_deci_kelvin(long t)
{
t = millicelsius_to_milli_kelvin(t);
return DIV_ROUND_CLOSEST(t, MILLIDEGREE_PER_DECIDEGREE);
}
> So you can really do the cleanup in all the drivers, like removing:
OK. I'll try as much as possible.