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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CA22CC38150 for ; Wed, 10 Jul 2024 07:45:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:Cc:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=szAAY2PpJEXuI3RSE+e8zii5jQYDDmWaMqyBuKq4Zb4=; b=AEGfvqlwfns72Nw3kGWPMii6XH QyecrGY68BhpOLZBewX2ayvwcbl/X4GKU7MZMc9/mcJGgoEQ8yHVVX/mV9jg1ZEgct21Er5fao2ju fsjqhluvyb2M/uXsKX4zBOzSzBbYT9GSnIWbXs0JS6Kh/ba+mM1xWZKVmzz01iapomryVCRFKeaVJ MXBmuNbn9/Pem9VazRfcnGfVvta/QmOczK8MJv5YK/PL1kjWMFl1y9xA5+mRITHwE4qro6diTwGVT +howmCXPvHaIi+Q2PtYdeJ1tIrx2Zf3NIICetPcjIF3ErxHb7I4/rMFereAMHqXnXg04ZbWDyLeE9 AB2nH8SQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sRS1I-00000009mCV-0jHH; Wed, 10 Jul 2024 07:45:44 +0000 Received: from gloria.sntech.de ([185.11.138.130]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sRS11-00000009m7w-0sZ6; Wed, 10 Jul 2024 07:45:28 +0000 Received: from i5e860d18.versanet.de ([94.134.13.24] helo=diego.localnet) by gloria.sntech.de with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sRS0s-0005KV-SD; Wed, 10 Jul 2024 09:45:18 +0200 From: Heiko =?ISO-8859-1?Q?St=FCbner?= To: mturquette@baylibre.com, sboyd@kernel.org, Alexander Stein Cc: robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, quentin.schulz@cherry.de, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org Subject: Re: [PATCH 1/6] dt-bindings: clocks: add binding for generic clock-generators Date: Wed, 10 Jul 2024 09:45:17 +0200 Message-ID: <21244242.0c2gjJ1VT2@diego> In-Reply-To: <12478313.O9o76ZdvQC@steina-w> References: <20240709123121.1452394-1-heiko@sntech.de> <20240709123121.1452394-2-heiko@sntech.de> <12478313.O9o76ZdvQC@steina-w> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240710_004527_286809_5D589D0E X-CRM114-Status: GOOD ( 33.31 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi, Am Mittwoch, 10. Juli 2024, 09:02:34 CEST schrieb Alexander Stein: > Am Dienstag, 9. Juli 2024, 14:31:16 CEST schrieb Heiko Stuebner: > > In contrast to fixed clocks that are described as ungateable, boards > > sometimes use additional clock generators for things like PCIe reference > > clocks, that need actual supplies to get enabled and enable-gpios to be > > toggled for them to work. > > Fixed clocks are intended to be ungateable? Where does this come from? "DOC: basic fixed-rate clock that cannot gate" https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/clk/clk-fixed-rate.c#n18 > > This adds a binding for such clock generators that are not configurable > > themself, but need to handle supplies for them to work. > > > > While in a lot of cases the type of the IC used is described in board > > schematics, in some cases just a generic type description like > > "100MHz, 3.3V" might also be used. The binding therefore allows both > > cases. Specifying the type is of course preferred. > > > > The clock-frequency is set in devicetree, because while some clock > > generators have pins to decide between multipls output rates, those > > are generally set statically on the board-layout-level. > > > > Signed-off-by: Heiko Stuebner > > --- > > .../bindings/clock/clock-generator.yaml | 62 +++++++++++++++++++ > > 1 file changed, 62 insertions(+) > > create mode 100644 Documentation/devicetree/bindings/clock/clock-generator.yaml > > > > diff --git a/Documentation/devicetree/bindings/clock/clock-generator.yaml b/Documentation/devicetree/bindings/clock/clock-generator.yaml > > new file mode 100644 > > index 0000000000000..f44e61e414e89 > > --- /dev/null > > +++ b/Documentation/devicetree/bindings/clock/clock-generator.yaml > > @@ -0,0 +1,62 @@ > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > +%YAML 1.2 > > +--- > > +$id: http://devicetree.org/schemas/clock/clock-generator.yaml# > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > + > > +title: Simple clock generators > > + > > +maintainers: > > + - Heiko Stuebner > > + > > +properties: > > + $nodename: > > + anyOf: > > + - description: > > + Preferred name is 'clock-' with being the output > > + frequency as defined in the 'clock-frequency' property. > > + pattern: "^clock-([0-9]+|[a-z0-9-]+)$" > > + - description: Any name allowed > > + deprecated: true > > + > > + compatible: > > + oneOf: > > + - const: clock-generator > > + - items: > > + - enum: > > + - diodes,pi6c557-03b > > + - diodes,pi6c557-05b > > + - const: clock-generator > > + > > + "#clock-cells": > > + const: 0 > > + > > + clock-frequency: true > > + > > + clock-output-names: > > + maxItems: 1 > > + > > + enable-gpios: > > + description: > > + Contains a single GPIO specifier for the GPIO that enables and disables > > + the clock generator. > > + maxItems: 1 > > + > > + vdd-supply: > > + description: handle of the regulator that provides the supply voltage > > So essentially only enable-gpios and vdd-supply is added in comparison to > fixed-clock. Does it make sense to add that to the fixed-clocks instead? > Similar to fixed-regulator. I wasn't that sure which way to go in the first place. The deciding point was reading that line about the fixed clock not being gateable, so I opted to not touch the fixed-clock. But you're definitly right, this _could_ live inside the fixed-clock as well, if we decide to get rid of the not-gateable thing above. Heiko