Hello Lukasz,

On Wed, Nov 12, 2014 at 10:42:41AM +0100, Lukasz Majewski wrote:

Hi Eduardo,

quoted

Hello Lukasz,

On Fri, Nov 07, 2014 at 11:05:51AM +0100, Lukasz Majewski wrote:

quoted

Hi Eduardo,

quoted

On Thu, Oct 09, 2014 at 06:38:39PM +0200, Lukasz Majewski wrote:

quoted

This patch extends the of-thermal.c to provide information about
number of available non critical (i.e. non HW) trip points in
the system.

Signed-off-by: Lukasz Majewski <redacted>
---
 drivers/thermal/of-thermal.c   | 12 ++++++++++++
 drivers/thermal/thermal_core.h |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/thermal/of-thermal.c

b/drivers/thermal/of-thermal.c index 23c8d6c..cd74e64 100644

--- a/drivers/thermal/of-thermal.c
+++ b/drivers/thermal/of-thermal.c

@@ -128,6 +128,18 @@ int of_thermal_is_trip_en(struct

thermal_zone_device *tz, int trip) return 1;
 }
 
+int of_thermal_get_non_crit_ntrips(struct thermal_zone_device
*tz) +{
+	struct __thermal_zone *data = tz->devdata;
+	int i;
+
+	for (i = 0; i < data->ntrips; i++)
+		if (data->trips[i].type !=
THERMAL_TRIP_CRITICAL)
+			continue;
+
+	return --i;
+}
+

I am not against this addition. But looks like we start to spread
some specific APIs that may not be used to other drivers.

Why do you think that this is a specific API? In the thermal OF we
can define trip point as "active", "passive", "hot" and "critical".

With the first three we can handle them and properly react. For the
last one SoC's PMU will power down the board.

Do you know if any board (e.g. from TI) is NOT supposed to shut down
when "critical" temperature is passed?

So, my point is not really about the usage of trip points. It is just
that the of-thermal  API will grow with in a wide way with specific
functions to check some property on the trip point array. And not all
drivers may be using these function, e.g. the above proposal.

quoted

The real problem here is the accessibility to __thermal_trip and
__thermal_bind arrays.

Use case:
In the Exynos driver we do need to initialize TMU registers with
threshold temperatures.
The temperature is read via tz->ops->get_trip_temp() [1] (from
of-thermal.c).
Unfortunately, the current API is not exporting the number of
non-critical trip points to know how many times call [1].
Of course we could by hand instantiate [1] n times, but this looks
for me a bit clumsy.

I understand your use case. My point was simply that this use case may
be specific to your driver (or few drivers).

quoted

Additionally, we now have implicit assumption about the order of
defined temperatures for trip points, but I think this is not a big
issue.

quoted

Maybe having a
single API to provide a read-only copy the list / array of trips
might be a better approach. I will think of a better way.

Definitely. Exporting available trip points is crucial.

Yeah, I think it is the best thing to do. Share a read-only array /
copy of the needed data, and then drivers would check what ever
property they need from the array. Just make sure you document that
this is a read-only array (i.e. any possible change they do, won't
affect the original array).

So I assume that you don't mind that I will prepare such of-thermal.c
modification?

No, please, feel free to send the proposal along with your patchset. To
me, it makes sense you do it, because you will also present a real use
case of this required change.

quoted

quoted

quoted

I also request you to document it accordingly.

Ok, I will do that.

Cool!

quoted

quoted

quoted

 static int of_thermal_get_trend(struct thermal_zone_device *tz,
int trip, enum thermal_trend *trend)
 {

diff --git a/drivers/thermal/thermal_core.h

b/drivers/thermal/thermal_core.h index ed8ff05..334a7be 100644

--- a/drivers/thermal/thermal_core.h
+++ b/drivers/thermal/thermal_core.h

@@ -83,6 +83,7 @@ int of_parse_thermal_zones(void);
 void of_thermal_destroy_zones(void);
 int of_thermal_get_ntrips(struct thermal_zone_device *);
 int of_thermal_is_trip_en(struct thermal_zone_device *, int);
+int of_thermal_get_non_crit_ntrips(struct thermal_zone_device

*); #else
 static inline int of_parse_thermal_zones(void) { return 0; }
 static inline void of_thermal_destroy_zones(void) { }

@@ -94,6 +95,10 @@ int of_thermal_is_trip_en(struct

thermal_zone_device *, int) {
 	return 0;
 }
+int of_thermal_get_non_crit_ntrips(struct thermal_zone_device
*)

here, it is supposed to be static inline.

quoted

+{
+	return 0;
+}
 #endif
 
 #endif /* __THERMAL_CORE_H__ */
-- 
2.0.0.rc2

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group

-- 
Best regards,

Lukasz Majewski

Samsung R&D Institute Poland (SRPOL) | Linux Platform Group

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