From patchwork Tue Feb 15 08:44:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 12746706 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2E998C433FE for ; Tue, 15 Feb 2022 08:44:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234612AbiBOIou (ORCPT ); Tue, 15 Feb 2022 03:44:50 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:53472 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234596AbiBOIot (ORCPT ); Tue, 15 Feb 2022 03:44:49 -0500 Received: from phobos.denx.de (phobos.denx.de [IPv6:2a01:238:438b:c500:173d:9f52:ddab:ee01]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FD42111F88; Tue, 15 Feb 2022 00:44:40 -0800 (PST) Received: from tr.lan (ip-89-176-112-137.net.upcbroadband.cz [89.176.112.137]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: marex@denx.de) by phobos.denx.de (Postfix) with ESMTPSA id DCFF280F47; Tue, 15 Feb 2022 09:44:37 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=denx.de; s=phobos-20191101; t=1644914678; bh=pibTTjw3kBcqRPgO4XTGPBPhlKzmNPhhZZXTZVtS75g=; h=From:To:Cc:Subject:Date:From; b=XSbLL2KawJu9JITDnpyO4+geIdtMMzV8FpJTRmqwnSe95ME1s96PEaWIIvzcAsEYL L71a5DLGHSoHPDNXStR8NnZYZ1NKlWVeUiSR3QQXR+OzXS2c55CDmIk9HJ+Z09+4Gt l8hncF9qOUvqYNF/samQquxtmlgesa1ZShFyLUfHzhhiZ/5Fbjf4Awj3/onDXlnXUg CNP1AyzVxu41XpjKMn5Am6VXqXyK8JXiWfar8bPKxjeVj1g7c6v4taT2dJMcxmo/HP xZwIfcJa42LVnHuoN1jA2BWlB4aKJ+yoJI1PAAR1rH/qrog+JICI6VyyNMqPl81rc6 E0qj/fmVdYAMA== From: Marek Vasut To: linux-clk@vger.kernel.org Cc: Marek Vasut , Matti Vaittinen , Michael Turquette , Rob Herring , Stephen Boyd , devicetree@vger.kernel.org, linux-power@fi.rohmeurope.com Subject: [PATCH 1/3] dt-bindings: clk: Introduce 'critical-clocks' property Date: Tue, 15 Feb 2022 09:44:10 +0100 Message-Id: <20220215084412.8090-1-marex@denx.de> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Virus-Scanned: clamav-milter 0.103.5 at phobos.denx.de X-Virus-Status: Clean Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Some platforms require clock to be always running, e.g. because those clock supply devices which are not otherwise attached to the system. One example is a system where the SoC serves as a crystal oscillator replacement for a programmable logic device. The critical-clock property of a clock controller allows listing clock which must never be turned off. The implementation here is similar to "protected-clock". Signed-off-by: Marek Vasut Cc: Matti Vaittinen Cc: Michael Turquette Cc: Rob Herring Cc: Stephen Boyd Cc: devicetree@vger.kernel.org Cc: linux-power@fi.rohmeurope.com To: linux-clk@vger.kernel.org --- .../devicetree/bindings/clock/clock-bindings.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/devicetree/bindings/clock/clock-bindings.txt b/Documentation/devicetree/bindings/clock/clock-bindings.txt index f2ea53832ac63..d9a783c35c5a1 100644 --- a/Documentation/devicetree/bindings/clock/clock-bindings.txt +++ b/Documentation/devicetree/bindings/clock/clock-bindings.txt @@ -169,6 +169,22 @@ a shared clock is forbidden. Configuration of common clocks, which affect multiple consumer devices can be similarly specified in the clock provider node. +==Critical clocks== + +Some platforms require clock to be always running, e.g. because those clock +supply devices which are not otherwise attached to the system. One example +is a system where the SoC serves as a crystal oscillator replacement for a +programmable logic device. The critical-clock property of a clock controller +allows listing clock which must never be turned off. + + clock-controller@a000f000 { + compatible = "vendor,clk95; + reg = <0xa000f000 0x1000> + #clocks-cells = <1>; + ... + critical-clocks = , ; + }; + ==Protected clocks== Some platforms or firmwares may not fully expose all the clocks to the OS, such