From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3BBC8C43381 for ; Mon, 25 Feb 2019 10:31:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAC982084D for ; Mon, 25 Feb 2019 10:31:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="aQmpiv9O" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726648AbfBYKbM (ORCPT ); Mon, 25 Feb 2019 05:31:12 -0500 Received: from mail-it1-f174.google.com ([209.85.166.174]:54695 "EHLO mail-it1-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726574AbfBYKbM (ORCPT ); Mon, 25 Feb 2019 05:31:12 -0500 Received: by mail-it1-f174.google.com with SMTP id w18so10726863itj.4 for ; Mon, 25 Feb 2019 02:31:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=yM4mpyzH7u5xt2ZlOjQ2CBSK7+5zjB/Bq2SaWyVHjvg=; b=aQmpiv9OdfnSYsU0x8V1hGChQV1pIw5d8p/e/R370lsTABPnRWU4/b7iIyBpvvEipX bCTEb2zm1BIeEJq2juG9I37GuobWyCpyuKBYmWBc3zkGlROMQpaxVc/19268eMnSIN2M 2mkkzKWqjyuFcQJjnXKcONxOhyurmUq2MRIVzRCndC7YwMMFK+jmn+fShHaEZnvFUPva AEsB8EfeGYKDLcvFDiSBb3g/F/E1l+mPpJHlqQ+pHJ676x/L/Gu9D+XEmcICL297TO9O k53pxcZwIZO9TdVXlnrEi3ncyeDN4AzCgxArNZDyO9/VuvEjtD0kYQdG9MDlpQQE0oQt fU5g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=yM4mpyzH7u5xt2ZlOjQ2CBSK7+5zjB/Bq2SaWyVHjvg=; b=ooEMQlylMHfFet24nfR6N6XkZUNeMoXpBt9mslG34mlrJHrCmwJgEBru4vYSEoGFee HN/4TqBT00adK+xITmR9D9LOZOt+mQOASbI6pl9+3HWg4eAqKNQ6AIEemxG73n4igTfP 457f3LCRclErvZgrX5xA2QECE0ok0nDFbHGStiGq1hXam9NmdJ4rlNbIXHtNYkAejeoH 2pdV4kEv60yvjIShPKuRTe0vSzzq/JZS9hTH/kvqQloIozmxldUGm3vqfFEqpTv5xnjA SbsHudDClwgAelQze3N2io4Ffbd+MVP6lMCBEGnM3L9Iv47ZZWp0hVAhLBVibnsg4kwt x8SQ== X-Gm-Message-State: AHQUAuZPPRRdw8uHmEAOrfZjFzVQYiwt/5KX31GpQp9NZAiJ7Q8ktmqy sxfQ8usKnQ5m7K3p3CfwZo6r0efrNr0WkIJK7XEToRnn X-Google-Smtp-Source: AHgI3IaaAkD/gQ+bMWatYYeHl3Qz6h29050ZJ48HJT4EfFbdoXeUlFRXZqB09wc4paBSDjk3pekToql5+9nBe7SPzMk= X-Received: by 2002:a24:298b:: with SMTP id p133mr10390448itp.43.1551090670941; Mon, 25 Feb 2019 02:31:10 -0800 (PST) MIME-Version: 1.0 References: <20190221175511.GA22715@roeck-us.net> <20190221184805.GC22715@roeck-us.net> <20190221194929.GA676@roeck-us.net> In-Reply-To: <20190221194929.GA676@roeck-us.net> From: Vinay Simha B N Date: Mon, 25 Feb 2019 16:00:59 +0530 Message-ID: Subject: Re: tmp102 hwmon accessing temp1_input, max, max_hyst To: Guenter Roeck Cc: jdelvare@suse.com, linux-hwmon@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org attached the tmp102 to thermal zone, i am able to read the thermal_zone_get_temp, tz_dev->ops->get_trip_temp, get_trip_hyst. the trip point of temperature and hystersis values does not get updated in hwmon/hwmon1/temp1_max_hyst and hwmon/hwmon1/temp1_max. Do we need to manually set these values, though we are attaching the tmp102 to thermal_zone? otherwise will not get the interrupt. please suggest. &thermal_zones { hdmi-thermal { polling-delay-passive = <250>; polling-delay = <1000>; thermal-sensors = <&temp_sensor_u49 0>; trips { hdmi_alert: trip0 { temperature = <75000>; hysteresis = <2000>; type = "passive"; }; hdmi_crit: trip1 { temperature = <95000>; hysteresis = <2000>; type = "critical"; }; }; }; }; On Fri, Feb 22, 2019 at 1:19 AM Guenter Roeck wrote: > > On Fri, Feb 22, 2019 at 12:32:08AM +0530, Vinay Simha B N wrote: > > On Fri, Feb 22, 2019 at 12:18 AM Guenter Roeck wrote: > > > > > > On Thu, Feb 21, 2019 at 11:46:32PM +0530, Vinay Simha B N wrote: > > > > guenter, > > > > > > > > i want to use these three tmp102 temp1_input, max and max_hys in > > > > dsi2hdmi(adv7533) driver to enable or disabled based on temperature > > > > range. > > > > > > > > https://github.com/vinaysimha/kernel-msm/commit/8ee2b9104fa56765320d4846086d91b8271f5609 > > > > > > > > dsi2hdmi operating temperature range is -10 to 85 deg C, we will > > > > enable dsi2hdmi only when temperate in operating range otherwise will > > > > disable the chip. > > > > > > > Do you envision a system utilizing this chip that would have an operating range > > > outsize -10 .. +85 degrees C ? That seems to be quite unlikely. > > this system sits in a place below this temperature range, cpu can > > handle upto -30, but the adv7535(dsi2hdmi) operating range -10 to +85, > > so we want the system to be on and disable and enable display based on > > temp range. > > > > > > Your solution will only work for a system with exactly one tempperature sensor; > > > otherwise there is no guarantee that the sensor will be instantiated as hwmon1 > > we do have two temperature sensor, currently i had used hwmon1 for testing, > > i have to read hwmon1 otherwise interrupt will not get cleared. > > thought to have polling method also, since in this code reading from > > userspace is not feasible, is it possible to optimize, any suggestion? > > either i need to have global variable declared in adv7511_drv.c and > > export it to tmp102.c driver . please suggest > > You might want to consider attaching the tmp102 to a thermal zone, and then > use thermal_zone_get_temp() to read the temperature. > > > > > > > Either case, a decison like this would not only apply to a single chip, > > > but to other chips in the system. It might be in the scope of power > > > or thermal management, though it seems to me that it might make more > > > sense to control it from user space. > > > > > > Overall, with the above in mind, I don't think a hwmon specific solution > > > would make sense. If a solution is really warranted in the first place > > > (I really wonder about that operating range), it should be implemented > > > as generic solution which applies to the rest of the system as well. > > > > > > There are some pieces which should be implemented in the hwmon driver - > > > for example, it looks like your code implements interrupt handling for > > > the tmp102. That should be handled in the tmp102 driver, which would > > > then read the alert bit and report the status as temp1_alarm. > > initially i had implemented irq in tmp102.c , but how to inform this > > information to dsi2hdmi(adv7511_drv.c) > > any references how temp1_alarm is used. > > This would require some work, since the infrastructure does not currently > support handling thermal alarms. In a nutshell, > > - the tmp102 driver would implement an interrupt handler > - the interrupt handler would notify the hwmon core that an > interrupt was observed. This notification callback would have > to be implemented. It would notify userspace using sysfs_notify() > and possibly with a udev event, and it would notify the thermal > core by calling thermal_zone_device_update(). I don't know how > the thermal core would then notify the dsi2hdmi driver. > > Guenter > > > > > > > Thanks, > > > Guenter > > > > > > > > > > > On Thu, Feb 21, 2019 at 11:25 PM Guenter Roeck wrote: > > > > > > > > > > On Thu, Feb 21, 2019 at 08:21:09PM +0530, Vinay Simha B N wrote: > > > > > > hi, > > > > > > > > > > > > could you please suggest, how to export_symbol the tmp102 temp1_input, max > > > > > > and max_hyst values to another kernel driver? > > > > > > > > > > > > We can acess the values > > > > > > from filp_open("/sys/class/hwmon/hwmon1/temp1_input", O_RDONLY, 0); in > > > > > > kernel space, but is there better apporach to access the values in the > > > > > > kernel space. > > > > > > > > > > > There is no in-kernel API to do that, and I do not immediately see > > > > > the purpose. Either case, accessing the sysfs attribute directly is > > > > > as wrong as it can get, if for nothing else since there is no guarantee > > > > > that this will always be the hwmon1 device. > > > > > > > > > > Can you explain what you are trying to do ? > > > > > > > > > > Thanks, > > > > > Guenter > > > > > > > > > > > > > > > > -- > > > > regards, > > > > vinaysimha > > > > > > > > -- > > regards, > > vinaysimha -- regards, vinaysimha