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 538FEC02181 for ; Tue, 21 Jan 2025 00:06:43 +0000 (UTC) Received: from h2850616.stratoserver.net (localhost [IPv6:::1]) by phobos.denx.de (Postfix) with ESMTP id 7F57B8032B; Tue, 21 Jan 2025 01:06:41 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=u-boot-bounces@lists.denx.de Received: by phobos.denx.de (Postfix, from userid 109) id 1C7D0800C2; Tue, 21 Jan 2025 01:06:40 +0100 (CET) Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by phobos.denx.de (Postfix) with ESMTP id A1964800C2 for ; Tue, 21 Jan 2025 01:06:37 +0100 (CET) Authentication-Results: phobos.denx.de; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: phobos.denx.de; spf=pass smtp.mailfrom=andre.przywara@arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 36449106F; Mon, 20 Jan 2025 16:07:05 -0800 (PST) Received: from minigeek.lan (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6AA2B3F5A1; Mon, 20 Jan 2025 16:06:35 -0800 (PST) Date: Tue, 21 Jan 2025 00:05:08 +0000 From: Andre Przywara To: Simon Glass Cc: Jernej =?UTF-8?B?xaBrcmFiZWM=?= , u-boot@lists.denx.de, Lukasz Majewski , Sean Anderson , Jaehoon Chung , Tom Rini , Cody Eksal , linux-sunxi@lists.linux.dev, Parthiban Subject: Re: [PATCH 2/8] sunxi: pmic_bus: support alternative I2C address Message-ID: <20250121000508.22db819a@minigeek.lan> In-Reply-To: References: <20250117014537.22513-1-andre.przywara@arm.com> <2352334.ElGaqSPkdT@jernej-laptop> <20250119222530.1fd97018@minigeek.lan> <4622391.LvFx2qVVIh@jernej-laptop> Organization: Arm Ltd. X-Mailer: Claws Mail 4.2.0 (GTK 3.24.31; x86_64-slackware-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable 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 Mon, 20 Jan 2025 12:21:28 -0700 Simon Glass wrote: Hi Simon, > On Mon, 20 Jan 2025 at 09:42, Jernej =C5=A0krabec wrote: > > > > Dne nedelja, 19. januar 2025 ob 23:25:30 Srednjeevropski standardni =C4= =8Das je Andre Przywara napisal(a): =20 > > > On Sat, 18 Jan 2025 08:21:31 +0100 > > > Jernej =C5=A0krabec wrote: > > > > > > Hi Jernej, > > > > > > many thanks for the review and your opinion. > > > =20 > > > > Dne petek, 17. januar 2025 ob 02:45:31 Srednjeevropski standardni = =C4=8Das je Andre Przywara napisal(a): =20 > > > > > Some of the X-Power AXP PMICs can be ordered with an alternative = I2C > > > > > address, for instance an AXP717 could be shipped with address 0x3= 4 or > > > > > with address 0x35. > > > > > The datasheets for the AXP717 and AXP803 list two possible addres= ses, > > > > > and they are always consecutive. For DM (DT) based drivers this i= s no > > > > > problem, but the Allwinner SPL code relies on a hardcoded address. > > > > > > > > > > Add a Kconfig variable that will add "1" to the existing address = if it > > > > > is set. > > > > > This enables to use the AXP717 as used on boards with the new All= winner > > > > > A523 chip. > > > > > > > > > > Signed-off-by: Andre Przywara =20 > > > > > > > > This works until some board vendor start mixing one or another addr= ess > > > > PMIC. Note that BSP boot0 does address autodetection, so it's not e= ntirely > > > > out of the question. Anyway, let's hope we don't see anything like = that. =20 > > > > > > I looked at the datasheets for all supported PMICs, and they either > > > state one or two supported addresses, in the latter case both > > > consecutive. Autodetection sounds nice, but also unnecessary: we sure= ly > > > know what address it is for a certain board? And with those A523 boar= ds > > > having two PMICs, autodetection might become sketchy, as we don't know > > > for sure which PMIC we got? =20 > > > > Speaking for T527 BSP boot0 - they check version register to make sure = that > > correct PMIC is installed. > > =20 > > > > > > But that got me thinking: what about putting the I2C address in Kconf= ig > > > directly, with defaults depending on the PMIC type? > > > > > > config AXP_I2C_ADDR > > > hex "AXP PMIC I2C address" > > > depends on ARCH_SUNXI && !SUNXI_NO_PMIC > > > default 0x36 if AXP305_POWER > > > .... > > > > > > That's should work seamlessly for all supported PMICs, and we just ne= ed > > > one line for the Avaota, same as with this patch here. > > > > > > What do you think? =20 > > > > Yeah, looks more universal and avoids code changes in pmic_bus.c when > > adding support for new AXP PMIC, which is very nice indeed. =20 >=20 > Shouldn't this be in the devicetree? It is, and the DM based I2C driver used in U-Boot proper does this properly, and works fine. But this here is for the SPL, where we don't have DT support. We need just minimal support to adjust the regulator for the DRAMs. So far there is one fixed address used by each PMIC, so this is simply hardcoded, based on which PMIC is selected. The patch I am now proposing (snippet above) just moves that hardcoding into Kconfig. Cheers, Andre > [..] > Regards, > Simon >=20