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 Received: from phobos.denx.de (phobos.denx.de [85.214.62.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 018BBC0015E for ; Wed, 26 Jul 2023 20:26:54 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 0C26F861CC; Wed, 26 Jul 2023 22:26:53 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Authentication-Results: phobos.denx.de; dkim=pass (1024-bit key; unprotected) header.d=ti.com header.i=@ti.com header.b="KeJ7j/Ls"; dkim-atps=neutral Received: by phobos.denx.de (Postfix, from userid 109) id 0F0D4861E6; Wed, 26 Jul 2023 22:26:51 +0200 (CEST) Received: from fllv0015.ext.ti.com (fllv0015.ext.ti.com [198.47.19.141]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by phobos.denx.de (Postfix) with ESMTPS id C5E5385F50 for ; Wed, 26 Jul 2023 22:26:46 +0200 (CEST) Authentication-Results: phobos.denx.de; dmarc=pass (p=quarantine dis=none) header.from=ti.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=nm@ti.com Received: from fllv0034.itg.ti.com ([10.64.40.246]) by fllv0015.ext.ti.com (8.15.2/8.15.2) with ESMTP id 36QBAJCs065614; Wed, 26 Jul 2023 06:10:19 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1690369819; bh=L3Q1LpHUpKXRQtSJHa9HUc0ECEraI4PVkHtbCMdRn5o=; h=Date:From:To:CC:Subject:References:In-Reply-To; b=KeJ7j/LshhkTx0HK013ThCOBWg12aWCGLkr8vMVbtZ9qTuEmXZNjVFdYFB1HBqd1P eDTbgjT2qN5EHXDQOnuuGUaLaT2uOXGyPypm1UeKWb5P7bj1QQrx7JPCry2lXYEfDr +P/7SiByE6R9Z5UI3NQJqXc8rWMUOe1WNmrDfGbU= Received: from DFLE113.ent.ti.com (dfle113.ent.ti.com [10.64.6.34]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 36QBAJcE064164 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 26 Jul 2023 06:10:19 -0500 Received: from DFLE114.ent.ti.com (10.64.6.35) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23; Wed, 26 Jul 2023 06:10:19 -0500 Received: from fllv0040.itg.ti.com (10.64.41.20) by DFLE114.ent.ti.com (10.64.6.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2507.23 via Frontend Transport; Wed, 26 Jul 2023 06:10:19 -0500 Received: from localhost (ileaxei01-snat2.itg.ti.com [10.180.69.6]) by fllv0040.itg.ti.com (8.15.2/8.15.2) with ESMTP id 36QBAJCP113834; Wed, 26 Jul 2023 06:10:19 -0500 Date: Wed, 26 Jul 2023 06:10:19 -0500 From: Nishanth Menon To: Francesco Dolcini CC: Tom Rini , Neha Malcom Francis , Bryan Brattlof , Praneeth Bajjuri , Andrew Davis , Robert Nelson , Vignesh R , Subject: Re: [PATCH 3/6] board: ti: am62x: Add basic initialization for usb voltage, 32k crystal, debounce Message-ID: <20230726111019.gotprceqsrmpwgyg@stopwatch> References: <20230725185253.2123433-1-nm@ti.com> <20230725185253.2123433-4-nm@ti.com> <20230725212504.GH3630934@bill-the-cat> <20230725213755.kc6qcvmkmt2yzzqz@perfected> <20230725214210.GL3630934@bill-the-cat> <20230725220328.fruxsldln7o5geil@tassel> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 X-BeenThere: u-boot@lists.denx.de X-Mailman-Version: 2.1.39 Precedence: list List-Id: U-Boot discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: u-boot-bounces@lists.denx.de Sender: "U-Boot" X-Virus-Scanned: clamav-milter 0.103.8 at phobos.denx.de X-Virus-Status: Clean On 00:35-20230726, Francesco Dolcini wrote: [...] > > > > > > At least the ones we have currently (I am not sure about toradex, > > > phytech etc), seem to operate the vdd_core at 0.85V .. (which is what > > > USB is dependent upon). > > > > For Toradex, we do have the equivalent code in our board file, see > > https://git.toradex.com/cgit/u-boot-toradex.git/tree/board/toradex/verdin-am62/verdin-am62.c?h=toradex_ti-u-boot-2023.04#n92 > > > > The 32kHz configuration is just different for us, we do not re-use the > > same you have here. True, you are hitting the bypass control and not powering on the oscillator control since the 32k is incoming from RTC, in my case, since I have an actual 32k crystal, I am clearing the powerdown. > > > > The debounce conf registers I have no idea what they are about, > > something we should have also on our board? Any additional details? > > So, I got curious and checked on the datasheet/TRM on this debounce. If > I understood correctly this is to have debounce on GPIO and/or EQEP. Typically, yes - input signals more useful for eQEP or GPIO. but the implementation is at pin level which, technically could be used for other purposes (but I have'nt seen any). > > However to my understanding this would need to have the corresponding > DEBOUNCE_SEL register written on the pad configuration, and by default it's 0. > > What's the use case for this debounce configuration you have here? TRM was a bit of a crap (internal ticket was filed to improve), but long story short: * bootloader configures delays per index * in the pinmux configuration, we pick which index to use for the pin On Beagleplay, for example, the HDMI hot plug detect GPIO benefited from this[1]. Corresponding pinctrl.h macros were posted in [2]. Why do it in the bootloader? since gpio inputs could also used in u-boot (e.g. MMC/CD) All said, Tom's question is very valid - we'd rather not modify evm.c for these specific configurations (popcorn as they might be), and we need to figure out a better option to introduce this kind of variation cleanly. For now, I will try dropping this patch. [1] https://git.beagleboard.org/beagleboard/linux/-/blob/v6.1.33-ti-rt-arm64-r6/arch/arm64/boot/dts/ti/k3-am625-beagleplay.dts#L311 [2] https://lore.kernel.org/all/20230619131620.3286650-1-nm@ti.com/ -- Regards, Nishanth Menon Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D