Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757505AbdDRWrp (ORCPT ); Tue, 18 Apr 2017 18:47:45 -0400 Received: from bh-25.webhostbox.net ([208.91.199.152]:44631 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752695AbdDRWrn (ORCPT ); Tue, 18 Apr 2017 18:47:43 -0400 Date: Tue, 18 Apr 2017 15:47:39 -0700 From: Guenter Roeck To: Florian Fainelli Cc: Markus Mayer , Jean Delvare , Rob Herring , Mark Rutland , Markus Mayer , Broadcom Kernel List , Linux HWMON List , Device Tree List , ARM Kernel List , Linux Kernel Mailing List Subject: Re: [PATCH 2/2] hwmon: (brcmstb) Add driver for Broadcom STB DPFE Message-ID: <20170418224739.GA24376@roeck-us.net> References: <20170418201702.57019-1-code@mmayer.net> <20170418201702.57019-3-code@mmayer.net> <20170418205839.GA3554@roeck-us.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) X-Authenticated_sender: guenter@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: authenticated_id: guenter@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: guenter@roeck-us.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1998 Lines: 55 Hi Florian, On Tue, Apr 18, 2017 at 03:29:55PM -0700, Florian Fainelli wrote: > Hey Guenter, > > On 04/18/2017 01:58 PM, Guenter Roeck wrote: > > Hi Markus, > > > > On Tue, Apr 18, 2017 at 01:17:02PM -0700, Markus Mayer wrote: > >> From: Markus Mayer > >> > >> This driver allows access to DRAM properties, such as the refresh rate, > >> via the Broadcom STB DDR PHY Front End (DPFE). The refresh rate can be > >> used as indirect indicator of the DRAM temperature. > >> > >> The driver also allows setting of the sampling interval. > >> > >> Signed-off-by: Markus Mayer > >> --- > > [ ... ] > > > >> + > >> +static SENSOR_DEVICE_ATTR(dpfe_info, 0444, show_info, NULL, 1000); > >> +static SENSOR_DEVICE_ATTR(dpfe_refresh, 0644, show_refresh, store_refresh, > >> + 1000); > >> +static SENSOR_DEVICE_ATTR(dpfe_vendor, 0444, show_vendor, NULL, 1000); > >> +static struct attribute *dpfe_attrs[] = { > >> + &sensor_dev_attr_dpfe_info.dev_attr.attr, > >> + &sensor_dev_attr_dpfe_refresh.dev_attr.attr, > >> + &sensor_dev_attr_dpfe_vendor.dev_attr.attr, > >> + NULL > >> +}; > >> +ATTRIBUTE_GROUPS(dpfe); > >> + > > > > There is not a single standard hwmon attribute. I don't know how > > to classify this driver, and where it should reside, but it is not > > a hwmon driver. > > This is a driver that talks to an embedded CPU running firmware which is > capable of giving various informations about the DRAM chip being > populated, including a temperature trend (hotter or cooler). We thought > initially we would be able to expose the actual temperature, but this in > turn required a lot more knowledge about the DRAM chip that we wish we > knew about. That is sort of where and why this driver was proposed for > hwmon. > > Which subsystem do you think would be best for this driver drivers/misc/ > or drivers/soc/bcm/brcmstb/ maybe? Both should work. I would probably try misc first and let Greg tell me which way to go ;-). Thanks, Guenter