From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from relay9-d.mail.gandi.net (relay9-d.mail.gandi.net [217.70.183.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 01AE729409; Wed, 20 Mar 2024 07:46:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710920792; cv=none; b=lOgovI0QOkeBQFVsEsh0PCHJvqDqymxQFFkAKwP0yAPcUIJmKgCCfIV0NsDkXWxThguRY6/1y3WH+AEU5XEkG7z2CGhCucWdr3WR2hXpt1GAtASLhBwGxOsh8w+MZsLcetFVJNuimE8JDuOFpKYpAE3JnRlOli/ucHq5tZAgFy4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710920792; c=relaxed/simple; bh=Ib1YGi6+k7//xZhCELUHLMN5Yymzlzl+jC3TmZzQS9Y=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dBAeM9DHk0pFsUlk/BKeeuWN/0XG41FWt/577JcpQudrvurAyNAJC7SDtUs7TXpsfIduRR50pdtP56CkM9FdPJ0r+wJC5LRWdCMsscNk04IWl+LXvP2NpO74ztSxFsWju+CrMMKf6hye50hezajPjboSm/VAtokm/evYqYuvpww= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=CntIZw8p; arc=none smtp.client-ip=217.70.183.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="CntIZw8p" Received: by mail.gandi.net (Postfix) with ESMTPSA id 92281FF807; Wed, 20 Mar 2024 07:46:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1710920781; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5e54mRdfjOEsN/nbRi2WZI4kTVdEISox3uake09K72s=; b=CntIZw8pN/VwkZVAO2SKwwcoAtquLsqesAgaQpn/KPk1iEZfAC8HeTtQHdijlfn6YGgsSx RQos6KXPFCJ4c+Xi5wqSS70s9jR4Zxwn5dareb5xQLoAPE3QoIrSICgKBVpvUdicaLz7tL wIKiOyqdbu88jmtnChKDI3UnAImFTS9B0/OAy9UvC3GUyqh3zn31c+5JvDi0HKX2kPTeQS 7kalN+DfuBkBhSOnaZj3grj22/4vg70ATfphQ174JcteuOWhGa1BD317xg1aOTsUa0uI9O +ak0xuplA037PBZYHBDJJhmMdYh6XEXakJ5DiuGKbgj0s4IakIvCwG1PAHS++g== Message-ID: <773cd098-0678-4edc-aea3-0418bedebc13@bootlin.com> Date: Wed, 20 Mar 2024 08:46:20 +0100 Precedence: bulk X-Mailing-List: linux-sound@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 12/13] ASoC: dt-bindings: davinic-mcbsp: Add the 'ti,drive-dx' property Content-Language: en-US To: =?UTF-8?Q?P=C3=A9ter_Ujfalusi?= , Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jaroslav Kysela , Takashi Iwai Cc: linux-sound@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, Thomas Petazzoni , herve.codina@bootlin.com, christophercordahi@nanometrics.ca References: <20240315112745.63230-1-bastien.curutchet@bootlin.com> <20240315112745.63230-13-bastien.curutchet@bootlin.com> <6e120eee-5cec-460c-87d2-40ef776efc3d@gmail.com> From: Bastien Curutchet In-Reply-To: <6e120eee-5cec-460c-87d2-40ef776efc3d@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-GND-Sasl: bastien.curutchet@bootlin.com Hi Péter, On 3/19/24 19:02, Péter Ujfalusi wrote: > > > On 15/03/2024 13:27, Bastien Curutchet wrote: >> McBSP is able to handle capture and playback stream. >> The McBSP's DX pins that outputs serial data during playback streams can >> be used to output a chosen pattern during capture streams. For instance, >> this can be useful to drive an active-low signal during capture streams >> (by choosing <0> as pattern) > > or configure the MCBSPx.DX pin as GPO and use it as a GPIO? In my use case, DX pin is connected to the ADC chip select pin so I want the DX pin to toggle the closest possible to capture's start. That's why I introduced this feature over configuring the pin as GPO. > > Quite novel use of the hardware, no doubt about it. If you don't have > DMA servicing the TX, it will just re-transmit the word from from the > DXR register when the transmitter is pulled out of reset. > > Interesting, but I'm not sure if this belongs to DT. > >> Add a 'ti,drive-dx' property that can be used to repeatedly output a >> chosen pattern on DX pin while capture stream is ON. >> >> Signed-off-by: Bastien Curutchet >> --- >> Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml >> index d8d4e7ea6e02..f4d1fc6bcd61 100644 >> --- a/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml >> +++ b/Documentation/devicetree/bindings/sound/davinci-mcbsp.yaml >> @@ -80,6 +80,13 @@ properties: >> Enable synchronisation error detections when an unexpected frame pulse is >> received. If not present, unexpected frame pulses are ignored. >> >> + ti,drive-dx: >> + $ref: /schemas/types.yaml#/definitions/uint32 >> + description: >> + If the property is present, McBSP will repeatedly output the selected >> + value on DX pin during capture streams. For instance, if set to 0, this >> + can be used to drive an active-low signal. >> + >> required: >> - "#sound-dai-cells" >> - compatible > Best regards, Bastien