Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752638AbdCESEY (ORCPT ); Sun, 5 Mar 2017 13:04:24 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:42315 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbdCESEW (ORCPT ); Sun, 5 Mar 2017 13:04:22 -0500 Subject: Re: [PATCH 2/2] hwmon: Aspeed AST2400/AST2500 ADC To: Rick Altherr References: <20170228201404.32125-1-raltherr@google.com> <20170228201404.32125-2-raltherr@google.com> Cc: Joel Stanley , Rob Herring , Mark Rutland , devicetree@vger.kernel.org, jdelvare@suse.com, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org From: Guenter Roeck Message-ID: <9a2c5522-9ff0-2ee2-af5b-0022b1fdff3a@roeck-us.net> Date: Sun, 5 Mar 2017 08:28:19 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@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: linux@roeck-us.net X-Authenticated-Sender: bh-25.webhostbox.net: linux@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: 1739 Lines: 44 On 03/01/2017 07:29 PM, Rick Altherr wrote: > Resending in plain text. > > On Tue, Feb 28, 2017 at 7:45 PM, Guenter Roeck wrote: >> On 02/28/2017 04:49 PM, Joel Stanley wrote: >>> >>> On Wed, Mar 1, 2017 at 6:44 AM, Rick Altherr wrote: >>>> >>>> Aspeed AST2400/AST2500 BMC SoCs include a 16 channel, 10-bit ADC. This >>>> driver implements reading the ADC values, enabling channels via device >>>> tree, and optionally providing channel labels via device tree. Low and >>>> high threshold interrupts are supported by the hardware but not >>>> implemented. >>>> >>>> Signed-off-by: Rick Altherr >>> >>> >>> Looks good. Some minor comments below. >>> >>> Is there a reason you wrote a hwmon driver instead of an iio driver? I >>> wasn't sure what the recommended subsystem is. >> >> >> Excellent point. Question is really if there is a plan to add support for >> thresholds. If not, an iio driver might be more appropriate. >> >> Guenter >> > > The hardware supports firing interrupts on high and low thresholds. > I'm not planning to use that feature yet so I didn't implement it. > Would you prefer that I leave it as is (maybe with a TODO), implement > the thresholding, or change to iio? > Let's try to determine the intended use of the ADC. I don't find the datasheet online; all I can find is brief summaries which don't me tell much, but suggest that it is a general purpose ADC and not specifically intended for hardware monitoring. What is the minimum sampling rate ? That should give us an idea. If it is in the uS range, iio would be more appropriate (and the iio-hwmon bridge could be used if a channel is in fact used for hardware monitoring). Thanks, Guenter