Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755463AbdDEOsX (ORCPT ); Wed, 5 Apr 2017 10:48:23 -0400 Received: from mx07-00178001.pphosted.com ([62.209.51.94]:49397 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755065AbdDEOsU (ORCPT ); Wed, 5 Apr 2017 10:48:20 -0400 Subject: Re: [PATCH 1/4] dt-bindings: iio: stm32-dac: Add support for STM32 DAC To: Jonathan Cameron , , , , , References: <1490960707-22422-1-git-send-email-fabrice.gasnier@st.com> <1490960707-22422-2-git-send-email-fabrice.gasnier@st.com> CC: , , , , , , , , , , From: Fabrice Gasnier Message-ID: <2386fb3e-142b-48f2-9308-9ff085aa4c4f@st.com> Date: Wed, 5 Apr 2017 16:47:29 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.75.127.48] X-ClientProxiedBy: SFHDAG6NODE3.st.com (10.75.127.18) To SFHDAG5NODE3.st.com (10.75.127.15) X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2017-04-05_11:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3179 Lines: 89 On 04/02/2017 01:16 PM, Jonathan Cameron wrote: > On 31/03/17 12:45, Fabrice Gasnier wrote: >> Document STMicroelectronics STM32 DAC (digital-to-analog converter). >> >> Signed-off-by: Fabrice Gasnier >> --- >> .../devicetree/bindings/iio/dac/st,stm32-dac.txt | 56 ++++++++++++++++++++++ >> 1 file changed, 56 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt >> >> diff --git a/Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt b/Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt >> new file mode 100644 >> index 0000000..1981983 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/iio/dac/st,stm32-dac.txt >> @@ -0,0 +1,56 @@ >> +STMicroelectronics STM32 DAC >> + >> +The STM32 DAC is a 12-bit voltage output digital-to-analog converter. The DAC >> +can be configured in 8- or 12-bit mode. In 12-bit mode, the data could be >> +left- or right-aligned. > Whilst possibly true, do we care about the alignment? That'll all get wrapped > up in the driver. Hi Jonathan, I'll update this description in V2 > >> It has two output channels, each with its own converter. >> +It has built-in noise and triangle waveform generator and supports external >> +triggers for conversions. The DAC's output buffer allows a high drive output >> +current. > Ah.. This is going to be fun :) More unusual hardware to find in an SoC. Yes, let's discuss this on following patches. Thanks your review, Best Regards, Fabrice >> + >> +Contents of a stm32 dac root node: >> +----------------------------------- >> +Required properties: >> +- compatible: Must be "st,stm32h7-dac-core". >> +- reg: Offset and length of the device's register set. >> +- clocks: Must contain an entry for pclk (which feeds the peripheral bus >> + interface) >> +- clock-names: Must be "pclk". >> +- vref-supply: Phandle to the vref+ input analog reference supply. >> + >> +Optional properties: >> +- resets: Must contain the phandle to the reset controller. >> +- A pinctrl state named "default" for each DAC channel may be defined to set >> + DAC_OUTx pin in mode of operation for analog output on external pin. >> + >> +Contents of a stm32 dac child node: >> +----------------------------------- >> +DAC core node should contain at least one subnode, representing a >> +DAC instance/channel available on the machine. >> + >> +Required properties: >> +- compatible: Must be "st,stm32-dac". >> +- #io-channel-cells = <1>: See the IIO bindings section "IIO consumers" in >> + Documentation/devicetree/bindings/iio/iio-bindings.txt >> +- st,dac-channel: Must be either 1 or 2, to define channel in use (e.g. >> + single channels: 1 or 2) >> + >> +Example: >> + dac: dac@40007400 { >> + compatible = "st,stm32h7-dac-core"; >> + reg = <0x40007400 0x400>; >> + clocks = <&clk>; >> + clock-names = "pclk"; >> + vref-supply = <®_vref>; >> + >> + dac1: dac@1 { >> + compatible = "st,stm32-dac"; >> + #io-channels-cells = <1>; >> + st,dac-channel = <1>; >> + }; >> + >> + dac2: dac@2 { >> + compatible = "st,stm32-dac"; >> + #io-channels-cells = <1>; >> + st,dac-channel = <2>; >> + }; >> + }; >> >