From bca5238816939436d72ae6bab124c4b0641a3a99 Mon Sep 17 00:00:00 2001 From: Ravikumar Kattekola Date: Wed, 17 May 2017 06:51:38 -0700 Subject: ARM: dts: dra7: Reduce cpu thermal shutdown temperature MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On dra7, as per TRM, the HW shutdown (TSHUT) temperature is hardcoded to 123C and cannot be modified by SW. This means when the temperature reaches 123C HW asserts TSHUT output which signals a warm reset. This reset is held until the temperature goes below the TSHUT low (105C). While in SW, the thermal driver continuously monitors current temperature and takes decisions based on whether it reached an alert or a critical point. The intention of setting a SW critical point is to prevent force reset by HW and instead do an orderly_poweroff(). But if the SW critical temperature is greater than or equal to that of HW then it defeats the purpose. To address this and let SW take action before HW does keep the SW critical temperature less than HW TSHUT value. The value for SW critical temperature was chosen as 120C just to ensure we give SW sometime before HW catches up. Document reference SPRUI30C – DRA75x, DRA74x Technical Reference Manual - November 2016 SPRUHZ6H - AM572x Technical Reference Manual - November 2016 Tested on: DRA75x PG 2.0 Rev H EVM Signed-off-by: Ravikumar Kattekola Signed-off-by: Tony Lindgren --- arch/arm/boot/dts/dra7.dtsi | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch') diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi index 57892f264cea..e7144662af45 100644 --- a/arch/arm/boot/dts/dra7.dtsi +++ b/arch/arm/boot/dts/dra7.dtsi @@ -2017,4 +2017,8 @@ coefficients = <0 2000>; }; +&cpu_crit { + temperature = <120000>; /* milli Celsius */ +}; + /include/ "dra7xx-clocks.dtsi" -- cgit v1.2.3