Re: [PATCH 3/3 v4] thermal: db8500: Rewrite to be a pure OF sensor

[Daniel Lezcano <daniel.lezcano@linaro.org>]

On 28/08/2019 15:03, Linus Walleij wrote:
> This patch rewrites the DB8500 thermal sensor to be a
> pure OF sensor, so that it can be used with thermal zones
> defined in the device tree.
> 
> This driver was initially merged before we had generic
> thermal zone device tree bindings, and now it gets
> modernized to the way we do things these days.
> 
> The old driver depended on a set of trigger points
> provided in the device tree or platform data to
> interpolate the current temperature between trigger
> points depending on whether the trend was rising or
> falling. This was bad because the trigger points should
> be used for defining temperature zone policies and
> bind to cooling devices.
> 
> As the PRCMU (power reset control management unit) can
> only issue IRQs when we pass temperature trigger points
> upward or downward We instead define a number of
> temperature points inside the driver ranging from
> 15 to 100 degrees celsius. The effect is that when
> we register the device we quickly trigger 15, 20 ... up
> to the room temperature in succession and then we
> get continous event IRQs also under normal operating
> conditions, and the temperature of the system is now
> reported more accurately (+/- 2.5 degrees celsius)
> while in the past the first trigger point was at 70
> degrees and the average temperature was simply reported
> as 35 degrees celsius (between 70 degrees and 0) until
> we passed 70 degrees which didn't accurately represent
> the temperature of the system.
> 
> As a result of dropping all the trigger points from the
> driver and reusing the core DT thermal zone management
> code we reduce the code footprint quite a bit.
> 
> Cc: Vincent Guittot <vincent.guittot@linaro.org>
> Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>

> ChangeLog v3->v4:
> - Drop the pointless work and update the thermal zone
>   directly from the threaded interrupt handler, we are in
>   process context already.
> ChangeLog v2->v3:
> - Drop pointless mode in the state container
> - Drop pointless mutex
> ChangeLog v1->v2:
> - New patch as suggested by Daniel.
> ---

[ ... ]


-- 
 <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog