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=-15.5 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_2 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 2EB5FC432BE for ; Mon, 30 Aug 2021 15:19:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0C3F060F45 for ; Mon, 30 Aug 2021 15:19:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237286AbhH3PUF (ORCPT ); Mon, 30 Aug 2021 11:20:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:35218 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237473AbhH3PTt (ORCPT ); Mon, 30 Aug 2021 11:19:49 -0400 Received: from jic23-huawei (cpc108967-cmbg20-2-0-cust86.5-4.cable.virginm.net [81.101.6.87]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B0E0660F45; Mon, 30 Aug 2021 15:18:52 +0000 (UTC) Date: Mon, 30 Aug 2021 16:22:03 +0100 From: Jonathan Cameron To: Mihail Chindris Cc: , , , , , , Subject: Re: [PATCH v4 4/6] Documentation:ABI:testing:add doc for AD3552R ABI Message-ID: <20210830162203.6f40790c@jic23-huawei> In-Reply-To: <20210820165927.4524-5-mihail.chindris@analog.com> References: <20210820165927.4524-1-mihail.chindris@analog.com> <20210820165927.4524-5-mihail.chindris@analog.com> X-Mailer: Claws Mail 4.0.0 (GTK+ 3.24.30; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org On Fri, 20 Aug 2021 16:59:25 +0000 Mihail Chindris wrote: > Add documentation for option for enabling precision mode > of ad3552r > > Signed-off-by: Mihail Chindris > --- > Documentation/ABI/testing/sysfs-bus-iio-dac-ad3552r | 10 ++++++++++ > 1 file changed, 10 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-dac-ad3552r > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac-ad3552r b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad3552r > new file mode 100644 > index 000000000000..37573245f3d5 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac-ad3552r > @@ -0,0 +1,10 @@ > +What: /sys/bus/iio/devices/iio:deviceX/precision_mode_en > +KernelVersion: 5.13 > +Contact: linux-iio@vger.kernel.org > +Description: > + Select between fast mode and precison mode. > + 0: Fast mode - For 12 bits precision, the most significant > + bits are used and 16 bits are sent to the > + device per channel, lats bits being 0. least significant bits being 0 perhaps and definitely not lats bits :) > + 1: Precision mode - For 16 bits precision, 24 bits are sent to > + the device per channel, last bits being 0. I don't think the ABI cares about how many bits are sent, but rather it cares about the precision. I'm not keen on this ABI if we can possibly avoid it. It is highly device specific and therefore unlikely to ever get used by any standard userspace code. Given I'm fairly sure no linux host is ever going to get anywhere near the maximum rates this device supports, perhaps we should just always use precision mode and not worry about this detail? Jonathan