From patchwork Wed Apr 12 06:24:42 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ravikumar Kattekola X-Patchwork-Id: 9676617 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 000F560383 for ; Wed, 12 Apr 2017 06:22:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E59ED284D8 for ; Wed, 12 Apr 2017 06:22:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D9F6B2859E; Wed, 12 Apr 2017 06:22:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AC41D284D8 for ; Wed, 12 Apr 2017 06:22:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752192AbdDLGV5 (ORCPT ); Wed, 12 Apr 2017 02:21:57 -0400 Received: from fllnx210.ext.ti.com ([198.47.19.17]:29139 "EHLO fllnx210.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751205AbdDLGV4 (ORCPT ); Wed, 12 Apr 2017 02:21:56 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by fllnx210.ext.ti.com (8.15.1/8.15.1) with ESMTP id v3C6LNFP017458; Wed, 12 Apr 2017 01:21:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ti.com; s=ti-com-17Q1; t=1491978083; bh=S/nSig5XXAHbD1u5qh17AeYGNVzvigXIQ5aYbULmBM0=; h=From:To:CC:Subject:Date; b=ay4PWDhzEwsDoVmqsxzs/ITyqu5td6s77YJFyfkbO6ZqECu7OGdj+ZEUI9VmjKqCr frpJUKqCVge2e14ZFTBLXGdwiJ4CJ784Zk0asI4bPCBod6Jo2HR49VqSyA9IVFEJYL ZxsCfNpGbE1mrpJK1XoMXxyu+F5pdeRls5tsNlQ8= Received: from DFLE73.ent.ti.com (dfle73.ent.ti.com [128.247.5.110]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id v3C6LMuB028324; Wed, 12 Apr 2017 01:21:22 -0500 Received: from dflp33.itg.ti.com (10.64.6.16) by DFLE73.ent.ti.com (128.247.5.110) with Microsoft SMTP Server id 14.3.294.0; Wed, 12 Apr 2017 01:21:21 -0500 Received: from uda0131654.dhcp.ti.com (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp33.itg.ti.com (8.14.3/8.13.8) with ESMTP id v3C6LHxH010367; Wed, 12 Apr 2017 01:21:18 -0500 From: Ravikumar Kattekola To: , CC: , , , , , Subject: [PATCH 1/1] ARM: dts: dra7: Reduce cpu thermal shutdown temperature Date: Wed, 12 Apr 2017 11:54:42 +0530 Message-ID: <20170412062442.17736-1-rk@ti.com> X-Mailer: git-send-email 2.8.0.GIT MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- arch/arm/boot/dts/dra7.dtsi | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi index 57892f2..e714466 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"