From patchwork Wed Oct 25 09:27:43 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabrice Gasnier X-Patchwork-Id: 10026185 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 0860360375 for ; Wed, 25 Oct 2017 09:29:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id DFE1628B38 for ; Wed, 25 Oct 2017 09:29:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D45A828B44; Wed, 25 Oct 2017 09:29:00 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable 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 8499928B3C for ; Wed, 25 Oct 2017 09:29:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932378AbdJYJ26 (ORCPT ); Wed, 25 Oct 2017 05:28:58 -0400 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:15815 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932315AbdJYJ25 (ORCPT ); Wed, 25 Oct 2017 05:28:57 -0400 Received: from pps.filterd (m0046660.ppops.net [127.0.0.1]) by mx08-.pphosted.com (8.16.0.21/8.16.0.21) with SMTP id v9P9ORfZ011811; Wed, 25 Oct 2017 11:28:05 +0200 Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx08-00178001.pphosted.com with ESMTP id 2dtg42jmxp-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT); Wed, 25 Oct 2017 11:28:05 +0200 Received: from zeta.dmz-eu.st.com (zeta.dmz-eu.st.com [164.129.230.9]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 94A9734; Wed, 25 Oct 2017 09:28:04 +0000 (GMT) Received: from Webmail-eu.st.com (sfhdag5node3.st.com [10.75.127.15]) by zeta.dmz-eu.st.com (STMicroelectronics) with ESMTP id 6ABC215B9; Wed, 25 Oct 2017 09:28:04 +0000 (GMT) Received: from localhost (10.75.127.48) by SFHDAG5NODE3.st.com (10.75.127.15) with Microsoft SMTP Server (TLS) id 15.0.1347.2; Wed, 25 Oct 2017 11:28:03 +0200 From: Fabrice Gasnier To: , CC: , , , , , , , , , , , , , Subject: [PATCH v2 1/3] dt-bindings: iio: adc: stm32: add support for diff channels Date: Wed, 25 Oct 2017 11:27:43 +0200 Message-ID: <1508923665-2274-2-git-send-email-fabrice.gasnier@st.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1508923665-2274-1-git-send-email-fabrice.gasnier@st.com> References: <1508923665-2274-1-git-send-email-fabrice.gasnier@st.com> MIME-Version: 1.0 X-Originating-IP: [10.75.127.48] X-ClientProxiedBy: SFHDAG2NODE1.st.com (10.75.127.4) To SFHDAG5NODE3.st.com (10.75.127.15) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-10-25_05:, , signatures=0 Sender: linux-iio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP STM32H7 ADC channels may be configured either as single-ended or differential. Add 'st,adc-diff-channels' property to support differential channels. Differential channels are defined as a pair of positive and negative inputs: vinp & vinn. Signed-off-by: Fabrice Gasnier Acked-by: Rob Herring --- Changes in v2: - Add differential channels example - Add a note on mixed single-ended / differential channels --- .../devicetree/bindings/iio/adc/st,stm32-adc.txt | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt index 48bfcaa3..e8bb824 100644 --- a/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt +++ b/Documentation/devicetree/bindings/iio/adc/st,stm32-adc.txt @@ -62,6 +62,15 @@ Required properties: - st,adc-channels: List of single-ended channels muxed for this ADC. It can have up to 16 channels on stm32f4 or 20 channels on stm32h7, numbered from 0 to 15 or 19 (resp. for in0..in15 or in0..in19). +- st,adc-diff-channels: List of differential channels muxed for this ADC. + Depending on part used, some channels can be configured as differential + instead of single-ended (e.g. stm32h7). List here positive and negative + inputs pairs as , ,... vinp and vinn are numbered + from 0 to 19 on stm32h7) + Note: At least one of "st,adc-channels" or "st,adc-diff-channels" is required. + Both properties can be used together. Some channels can be used as + single-ended and some other ones as differential (mixed). But channels + can't be configured both as single-ended and differential (invalid). - #io-channel-cells = <1>: See the IIO bindings section "IIO consumers" in Documentation/devicetree/bindings/iio/iio-bindings.txt @@ -111,3 +120,18 @@ Example: ... other adc child nodes follow... }; + +Example to setup: +- channel 1 as single-ended +- channels 2 & 3 as differential (with resp. 6 & 7 negative inputs) + + adc: adc@40022000 { + compatible = "st,stm32h7-adc-core"; + ... + adc1: adc@0 { + compatible = "st,stm32h7-adc"; + ... + st,adc-channels = <1>; + st,adc-diff-channels = <2 6>, <3 7>; + }; + };