Re: [PATCH v13 4/5] ARM: dts: add main Thermal info to rk3288

From: Caesar Wang
Date: Thu Oct 23 2014 - 22:06:36 EST



å 2014/10/24 9:37, Dmitry Torokhov åé:
On October 23, 2014 6:08:52 PM PDT, Caesar Wang <caesar.wang@xxxxxxxxxxxxxx> wrote:
Dmitry,

å 2014/10/24 8:46, Dmitry Torokhov åé:
Hi Caesar,

On Thu, Oct 23, 2014 at 05:40:06PM +0800, Caesar Wang wrote:
This patch is depend on rk3288-thermal.dtsi,or
it will compile error.

If the temperature over a period of time High,over 120C
the resulting TSHUT gave CRU module,let it reset
the entire chip,or via GPIO give PMIC.

Signed-off-by: Caesar Wang <caesar.wang@xxxxxxxxxxxxxx>
---
arch/arm/boot/dts/rk3288.dtsi | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/arch/arm/boot/dts/rk3288.dtsi
b/arch/arm/boot/dts/rk3288.dtsi
index cb18bb4..85fc17a 100644
--- a/arch/arm/boot/dts/rk3288.dtsi
+++ b/arch/arm/boot/dts/rk3288.dtsi
@@ -15,6 +15,7 @@
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/pinctrl/rockchip.h>
#include <dt-bindings/clock/rk3288-cru.h>
+#include <dt-bindings/thermal/thermal.h>
#include "skeleton.dtsi"
/ {
@@ -66,6 +67,7 @@
216000 900000
126000 900000
>;
+ #cooling-cells = <2>; /* min followed by max */
clock-latency = <40000>;
clocks = <&cru ARMCLK>;
};
@@ -346,6 +348,19 @@
status = "disabled";
};
+ tsadc: tsadc@ff280000 {
+ compatible = "rockchip,rk3288-tsadc";
+ reg = <0xff280000 0x100>;
+ interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&cru SCLK_TSADC>, <&cru PCLK_TSADC>;
+ clock-names = "tsadc", "apb_pclk";
+ pinctrl-names = "default";
+ pinctrl-0 = <&otp_out>;
+ #thermal-sensor-cells = <1>;
+ hw-shut-temp = <120000>;
I do not think this is a good value. You have (in the other DTS file)
passive trip point at 80 and critical (which should result in orderly
shutdown) at 125. But here you define hardware-controlled shutdown at
120C, which is backwards. You should have:

passive <= critical <= hardware
Hmmm....
but, the system will shutdown when temperature over critial value,
there is no chance of triggering the TSHUT.

If the temperature over a period of time High,as we know,
the resulting TSHUT gave CRU module,let it hot-reset the entire chip,
or via GPIO give PMIC cold-reset the entire chip.
Having tshut trigger is not the goal, tshut is the measure of last resort. If we can handle thermal conditions without triggering tshut, we achieved our goal.

Tshut triggering is " oh, crap, nothing we tried works" scenario.

I don't think so.

In general,We should have:
passive <= hardware(reset entire chip) <= critical(shutdown)

The temperature be rising qulckly if have some other conditions,
the "critical" will play a role.

Agreed?



Thanks.


--
Best regards,
Caesar


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