From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932440AbdJYJ3C (ORCPT ); Wed, 25 Oct 2017 05:29:02 -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 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 Content-Type: text/plain 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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>; + }; + }; -- 1.9.1