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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 AD4E1C531C9 for ; Fri, 24 Jul 2026 05:18:50 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [127.0.0.1]) by lists.ozlabs.org (Postfix) with ESMTP id 4h5x9P0yrfz2yYf; Fri, 24 Jul 2026 15:18:49 +1000 (AEST) Authentication-Results: lists.ozlabs.org; arc=none smtp.remote-ip=211.20.114.72 ARC-Seal: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1784784721; cv=none; b=EfBSW2j0SFmLYjZRCbkzPaGuyWv0n3UFWu8ziD+ahDFN5imI0u/nTZvKQ2XTCF5QG3/BETRM5Ro36VErqgiqOusXgND+/XCwYOguAfm5SanuYASIkvtyXTWY5GbP/t3XjMUnt80DPcCc6kJA6sDHC33gwB2qkUjT/D55WuK7h9PTO98iFlo4XZRubofWe4iFOjn8HAwivBtmmJf+YQlBJjOOsZq38QvyM8KlZqrtQ1ShIdUObIfRZg8UxTCoCyBiqQbtqljs4mGng06hahm6xElrX4PJsQ1BUGLoKt7M1sWxdGDNr4DnrNomuijOHMGwi9Dp5Mno90rnlsm2UggLBA== ARC-Message-Signature: i=1; a=rsa-sha256; d=lists.ozlabs.org; s=201707; t=1784784721; c=relaxed/relaxed; bh=4DvRcolxJFQZQro803cBP8dU4DY4mdGf3VxudjAxfQs=; h=From:Date:Subject:MIME-Version:Content-Type:Message-ID:References: In-Reply-To:To:CC; b=gHwfHN1OQypIc7M4mzQyYw7QvcK4+mJzcA+cpbWCRTINdCnDYmehKEhwKog5Em2ox04KnbLzjAFQ9NZDoYQ2Bef0tgOvfImTA9UXb4qDu7FU9isomrcOcKLd24bT5yMj21PdvTAOo9si+lRUXhwVI7UodJRCB5qe8u/EnmcFkvVjkYWt+JjmgIeUlawSvDVbARBpVYe378TZuHjOT2atAOz5UDC+QRrtO9EjbNUTO6inuRnuxUWZeLjosHeL+LI94j00p5HlIw3148wqUS3a7nH39fmUTjx0h+8WpluQqlVBTUSUfG3mIP2JVMzLVFVgnqPXlOOT3OQnyh0xqK9NFg== ARC-Authentication-Results: i=1; lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=aspeedtech.com; spf=pass (client-ip=211.20.114.72; helo=twmbx01.aspeedtech.com; envelope-from=yc_hsieh@aspeedtech.com; receiver=lists.ozlabs.org) smtp.mailfrom=aspeedtech.com Authentication-Results: lists.ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=aspeedtech.com Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=aspeedtech.com (client-ip=211.20.114.72; helo=twmbx01.aspeedtech.com; envelope-from=yc_hsieh@aspeedtech.com; receiver=lists.ozlabs.org) Received: from twmbx01.aspeedtech.com (mail.aspeedtech.com [211.20.114.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4h5KW4702Dz2xqJ for ; Thu, 23 Jul 2026 15:32:00 +1000 (AEST) Received: from TWMBX01.aspeed.com (192.168.0.62) by TWMBX01.aspeed.com (192.168.0.62) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1748.10; Thu, 23 Jul 2026 13:31:42 +0800 Received: from [127.0.1.1] (192.168.10.13) by TWMBX01.aspeed.com (192.168.0.62) with Microsoft SMTP Server id 15.2.1748.10 via Frontend Transport; Thu, 23 Jul 2026 13:31:42 +0800 From: Yu-Che Hsieh Date: Thu, 23 Jul 2026 13:31:37 +0800 Subject: [PATCH RFC 1/2] dt-bindings: mfd: aspeed-lpc: Document lpcN alias for multi-instance SoCs X-Mailing-List: linux-aspeed@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-ID: <20260723-upstream_kcs_multiple_lpc-v1-1-d918b5270b86@aspeedtech.com> References: <20260723-upstream_kcs_multiple_lpc-v1-0-d918b5270b86@aspeedtech.com> In-Reply-To: <20260723-upstream_kcs_multiple_lpc-v1-0-d918b5270b86@aspeedtech.com> To: Lee Jones , Rob Herring , "Krzysztof Kozlowski" , Conor Dooley , "Joel Stanley" , Andrew Jeffery , Chia-Wei Wang , Corey Minyard CC: Andrew Jeffery , , , , , , Yu-Che Hsieh X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1784784702; l=1505; i=yc_hsieh@aspeedtech.com; s=20260721; h=from:subject:message-id; bh=3fvCknCwajnOMYIUp1uHwU+nFkwRbCJkD6DOdmYgiUU=; b=54NDWFbpmjgTCayZVRksXExIbQ2rB7HOlCxNsWWxw8M7S7h+43hSKjtyzudtnvt8nN6bDg724 36wWYyTZKN7BWGSuOe/vc5BmPefUhb24zUV6FnBQslj5WmsmhjEU5rM X-Developer-Key: i=yc_hsieh@aspeedtech.com; a=ed25519; pk=7KnU2ozXGF2IATT+Hvu7RbRwPxBA3/b+zhfM+UsPJMs= Some SoCs (e.g. AST2700) expose more than one physical LPC controller instance. Downstream devices such as KCS channels need a stable, globally-unique index derived from which LPC controller instance they belong to, so document the "lpcN" alias convention on the LPC controller node that lets DT authors assign a fixed index per instance, mirroring the existing alias-based numbering convention used by mmc/i2c/spi/serial. Signed-off-by: Yu-Che Hsieh --- Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml b/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml index cbc3a2485a2f..81c12e0fb312 100644 --- a/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml +++ b/Documentation/devicetree/bindings/mfd/aspeed-lpc.yaml @@ -35,6 +35,13 @@ description: configuration, therefore the host portion of the controller is exposed as a syscon as a means to arbitrate access. + On SoCs that expose more than one LPC controller instance, it is possible to + assign a fixed index to a given instance (and thus to downstream devices + such as KCS channels that must be uniquely identified system-wide) by + defining an "lpcN" alias for it in the /aliases device tree node. If no such + alias is present, the SoC is treated as having a single LPC controller + instance. + properties: compatible: items: -- 2.34.1