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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B64FC43334 for ; Thu, 7 Jul 2022 15:25:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235576AbiGGPZq (ORCPT ); Thu, 7 Jul 2022 11:25:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235122AbiGGPZp (ORCPT ); Thu, 7 Jul 2022 11:25:45 -0400 Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCF2B2CC95; Thu, 7 Jul 2022 08:25:43 -0700 (PDT) Received: by mail-lf1-x12f.google.com with SMTP id d12so8397327lfq.12; Thu, 07 Jul 2022 08:25:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=4z3J663gkFkbp472Bx8Crc/uidLLLx8KpS8uotKO5LA=; b=iLcRUJzeI4c2gYOsmAYZ5/Dhcz85wIaP3s5pEOdCBIIVKzFTP/ogqV+Mnh5tiM0JpQ qwMvF5G7Fd39dTWmpr91gPPAsMRyJWMec//lNDQ/gvJE3sk0WVZxUBRm1GxNngw4jDcF gDXE9smqoqNZSJoPNUxCnkV0PeasTtsm7PVEWpsug/21zRWSIsomNYLKat6NjDJBkoWl krEYoeRZrSS4BcgEHGLqnHzwl4m9B0LTsJC4oY7T8RVWoCrbVM0yh1hiFzfxfT79U6Wr 0hsgZC4cttaqDDamuPpVI3yWXTtlG91/YrIzBcX1H4PUC7X3/dvcBp7mp60eWfvldEY8 K6hQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=4z3J663gkFkbp472Bx8Crc/uidLLLx8KpS8uotKO5LA=; b=2s3Q9vakp8oD3MSSf29oDkpKZQ/vvTJUIzwvUiCfbuDLAoPsZMaQQQzvtpUAvnXl0F Wc4+c7RpRWgDcd8FgVbSUDEsWZ4sotApXoIfbTaEjEAdW2MlC7IOTRfdTNmX4KOhMah2 67KiGu6Sm+QOLo2HZEetJROf7L1H4ApXd8GNfa3gb4Dds7yFxwW8AC7yyhrUZu9rEoTK B1amnhoJa11ZatoHTED2ThkIGtSGoUMoy/11lm7mWKDzEDzIOZ3PXa8F+kHKmiEK0Y4q TEJRS6ESBo7fqsE0yCS9UNk1ERzXPnPhd8bO5cESpju0nDhR0wtMcEmCDS7/1zYOzuee 87eQ== X-Gm-Message-State: AJIora87z5g5dGCUq5/vb12NN9LFYGkxFRZttPe6LBqgBE9rQRWSmlYQ HcVwQ9PaQxbTgEI0rJn7xG4= X-Google-Smtp-Source: AGRyM1sB79BSnFqpgp1BveiIrl7G8QFiRp/78fOZt4UfoGYkhtPFEwIc/2uZIadvSM/Uv0DLI1omrg== X-Received: by 2002:a05:6512:3b83:b0:47f:7419:5e58 with SMTP id g3-20020a0565123b8300b0047f74195e58mr29966749lfv.302.1657207541912; Thu, 07 Jul 2022 08:25:41 -0700 (PDT) Received: from mobilestation ([95.79.140.178]) by smtp.gmail.com with ESMTPSA id o1-20020a05651205c100b0048459950d65sm1352593lfo.306.2022.07.07.08.25.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 Jul 2022 08:25:41 -0700 (PDT) Date: Thu, 7 Jul 2022 18:25:39 +0300 From: Serge Semin To: Rob Herring Cc: Serge Semin , Damien Le Moal , Hans de Goede , Jens Axboe , Hannes Reinecke , Krzysztof Kozlowski , Alexey Malahov , Pavel Parkhomenko , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v4 17/23] dt-bindings: ata: ahci: Add DWC AHCI SATA controller DT schema Message-ID: <20220707152539.tktdo4qnvwormkqk@mobilestation> References: <20220610081801.11854-1-Sergey.Semin@baikalelectronics.ru> <20220610081801.11854-18-Sergey.Semin@baikalelectronics.ru> <20220614222754.GA2830345-robh@kernel.org> <20220617193744.av27axznbogademt@mobilestation> <20220706223642.GC572635-robh@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220706223642.GC572635-robh@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On Wed, Jul 06, 2022 at 04:36:42PM -0600, Rob Herring wrote: > On Fri, Jun 17, 2022 at 10:37:44PM +0300, Serge Semin wrote: > > On Tue, Jun 14, 2022 at 04:27:54PM -0600, Rob Herring wrote: > > > On Fri, Jun 10, 2022 at 11:17:55AM +0300, Serge Semin wrote: > > > > Synopsys AHCI SATA controller is mainly compatible with the generic AHCI > > > > SATA controller except a few peculiarities and the platform environment > > > > requirements. In particular it can have one or two reference clocks to > > > > feed up its AXI/AHB interface and SATA PHYs domain and at least one reset > > > > control for the application clock domain. In addition to that the DMA > > > > interface of each port can be tuned up to work with the predefined maximum > > > > data chunk size. Note unlike generic AHCI controller DWC AHCI can't have > > > > more than 8 ports. All of that is reflected in the new DWC AHCI SATA > > > > device DT binding. > > > > > > > > Note the DWC AHCI SATA controller DT-schema has been created in a way so > > > > to be reused for the vendor-specific DT-schemas (see for example the > > > > "snps,dwc-ahci" compatible string binding). One of which we are about to > > > > introduce. > > > > > > > > Signed-off-by: Serge Semin > > > > > > > > --- > > > > > > > > Changelog v2: > > > > - Replace min/max constraints of the snps,{tx,rx}-ts-max property with > > > > enum [ 1, 2, 4, ..., 1024 ]. (@Rob) > > > > > > > > Changelog v4: > > > > - Decrease the "additionalProperties" property identation otherwise it's > > > > percieved as the node property instead of the key one. (@Rob) > > > > - Use the ahci-port properties definition from the AHCI common schema > > > > in order to extend it with DWC AHCI SATA port properties. (@Rob) > > > > - Remove the Hannes' rb tag since the patch content has changed. > > > > --- > > > > .../bindings/ata/ahci-platform.yaml | 8 -- > > > > .../bindings/ata/snps,dwc-ahci.yaml | 129 ++++++++++++++++++ > > > > 2 files changed, 129 insertions(+), 8 deletions(-) > > > > create mode 100644 Documentation/devicetree/bindings/ata/snps,dwc-ahci.yaml > > > > > > > > diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.yaml b/Documentation/devicetree/bindings/ata/ahci-platform.yaml > > > > index e19cf9828e68..7dc2a2e8f598 100644 > > > > --- a/Documentation/devicetree/bindings/ata/ahci-platform.yaml > > > > +++ b/Documentation/devicetree/bindings/ata/ahci-platform.yaml > > > > @@ -30,8 +30,6 @@ select: > > > > - marvell,armada-3700-ahci > > > > - marvell,armada-8k-ahci > > > > - marvell,berlin2q-ahci > > > > - - snps,dwc-ahci > > > > - - snps,spear-ahci > > > > required: > > > > - compatible > > > > > > > > @@ -48,17 +46,11 @@ properties: > > > > - marvell,berlin2-ahci > > > > - marvell,berlin2q-ahci > > > > - const: generic-ahci > > > > - - items: > > > > - - enum: > > > > - - rockchip,rk3568-dwc-ahci > > > > - - const: snps,dwc-ahci > > > > - enum: > > > > - cavium,octeon-7130-ahci > > > > - hisilicon,hisi-ahci > > > > - ibm,476gtr-ahci > > > > - marvell,armada-3700-ahci > > > > - - snps,dwc-ahci > > > > - - snps,spear-ahci > > > > > > > > reg: > > > > minItems: 1 > > > > diff --git a/Documentation/devicetree/bindings/ata/snps,dwc-ahci.yaml b/Documentation/devicetree/bindings/ata/snps,dwc-ahci.yaml > > > > new file mode 100644 > > > > index 000000000000..af78f6c9b857 > > > > --- /dev/null > > > > +++ b/Documentation/devicetree/bindings/ata/snps,dwc-ahci.yaml > > > > @@ -0,0 +1,129 @@ > > > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) > > > > +%YAML 1.2 > > > > +--- > > > > +$id: http://devicetree.org/schemas/ata/snps,dwc-ahci.yaml# > > > > +$schema: http://devicetree.org/meta-schemas/core.yaml# > > > > + > > > > +title: Synopsys DWC AHCI SATA controller > > > > + > > > > +maintainers: > > > > + - Serge Semin > > > > + > > > > +description: > > > > + This document defines device tree bindings for the Synopsys DWC > > > > + implementation of the AHCI SATA controller. > > > > + > > > > +allOf: > > > > + - $ref: ahci-common.yaml# > > > > + > > > > +properties: > > > > + compatible: > > > > + oneOf: > > > > + - description: Synopsys AHCI SATA-compatible devices > > > > + contains: > > > > + const: snps,dwc-ahci > > > > + - description: SPEAr1340 AHCI SATA device > > > > + const: snps,spear-ahci > > > > + - description: Rockhip RK3568 ahci controller > > > > + const: rockchip,rk3568-dwc-ahci > > > > > > > > This is never true because there is a fallback. We should keep what we > > > had before. > > > > Could you be more specific what you meant? I don't see > > "snps,spear-ahci" and "rockchip,rk3568-dwc-ahci" used with the fallback > > string so modification is correct in that case. > > Spear does not, just rockchip: > > arch/arm64/boot/dts/rockchip/rk3568.dtsi: compatible = "rockchip,rk3568-dwc-ahci", "snps,dwc-ahci"; > arch/arm64/boot/dts/rockchip/rk356x.dtsi: compatible = "rockchip,rk3568-dwc-ahci", "snps,dwc-ahci"; > arch/arm64/boot/dts/rockchip/rk356x.dtsi: compatible = "rockchip,rk3568-dwc-ahci", "snps,dwc-ahci"; > > So the 3rd entry is never true. Then I'll have to split the schema up into two bindings: 1. snps,dwc-ahci-common.yaml: generic DW SATA AHCI properties and no "compatible" property constraint since you said fallback was useless. 2. snps,dwc-ahci.yaml: generic DW SATA AHCI DT-schema with competibles: ("snps,dwc-ahci"), ("snps,spear-ahci"), ("rockchip,rk3568-dwc-ahci","snps,dwc-ahci"). Are you ok with this? BTW if we had the fallback required the splitting up couldn't have been needed. > > > My idea was to have the compatible strings with the required generic > > fallback "snps,dwc-ahci" for all new devices thus identifying the > > controller IP-core origin. But later you said "The generic IP block > > fallbacks have proven to be useless." I do agree that functionally it > > isn't that often used, but in some cases it can be handy for instance > > to implement quirks in the generic code or use the fallback as an > > additional info regarding the IP-core origin/version. So if I were you > > I wouldn't be that strict about dropping the generic IP-core fallback > > identifier. It's much easier to have it specified from the very > > beginning than adding it after it has been declared as not required. > > I wish they were useful, but experience has shown they are not. So what to do with the generic fallback compatibles then? Please answer to the next questions so I would correct all my currently stashed patches in accordance with it. 1) Do you want all the new DT-binding schemas refusing to have the fallback compatibles except for the nodes which bindings have already been defined that way? 2) What if a device IP-core has some versioning, but it's either not auto-detectable at runtime or can be auto-detected but starting from some IP-core version? Do we need it being specified in addition to the vendor-specific compatible string? 3) The same as 2), but shall it have a generic version-less fallback compatible string too? 4) The same as 2), but what if it concerns a device which driver relies on the versioning? 5) The same as 2), but what if it concerns the device which currently doesn't have a driver relying on the IP-core version? 6) What if we don't have the generic fallback compatible string required, but at some point a kernel would need it to implement a version/IP-core-specific quirk? If we had the generic fallback specified in dts the older systems would have been supported out-of-box, otherwise the firmware update would also needed. IMO having the IP-core version + generic compatibles give many benefits and it's much easier to have them required from the very beginning instead of adding afterwards when then a need arises. -Sergey > > > > > + reg: > > > > + maxItems: 1 > > > > + > > > > + interrupts: > > > > + maxItems: 1 > > > > + > > > > + clocks: > > > > + description: > > > > + Basic DWC AHCI SATA clock sources like application AXI/AHB BIU clock > > > > + and embedded PHYs reference clock together with vendor-specific set > > > > + of clocks. > > > > + minItems: 1 > > > > + maxItems: 4 > > > > + > > > > + clock-names: > > > > + contains: > > > > + anyOf: > > > > + - description: Application AXI/AHB BIU clock source > > > > + enum: > > > > + - aclk > > > > + - sata > > > > + - description: SATA Ports reference clock > > > > + enum: > > > > + - ref > > > > + - sata_ref > > > > + > > > > + resets: > > > > + description: > > > > + At least basic core and application clock domains reset is normally > > > > + supported by the DWC AHCI SATA controller. Some platform specific > > > > + clocks can be also specified though. > > > > > > > > s/clocks/resets/ ? > > > > Right, but only in the reference to "platform specific clocks" -> "... resets". > > > > > > > > This allows any number of resets which isn't great. I think this schema > > > should just be the 'simple' cases where there's only 1 reset and 1 > > > clock (or how many the DWC block actually has if you have that info). > > > More complicated cases get there own schema. > > > > DWC SATA reference manual claims there can be resets implemented to > > each clock domain. > > 1) PM-clk <- PM-rst - PM keep-alive clock/reset. > > 2) aclk/hclk <- aresetn/hresetn - AXI/AHB clock domain/reset. > > 3) rbc*_clk <- rbc*_rst - PHY Receive Clock domain/reset. (Up to > > number of ports <= 8.) > > 4) asic*_clk <- asic*_rst - PHY Transmit Clock domain/reset. (Up to > > number of ports <= 8.) > > 5) rxoob*_clk <- rxoob*_rst - RxOOB Detection Clock domain/reset. (Up > > to number of ports <= 8.) > > > > So to speak the IP-core can be equipped with up to 26 clocks and > > resets. Should we be more strict we would have needed to define the > > properties with all the names above and permit up to 26 clocks/resets > > items. (Do you want it to be done?). In our case for instance there > > is "aclk" and a single common "ref" clock for all 3, 4 and 5 domain > > (clock 1 is missing). > > I imagine most implementations just tie most clocks together. > > I guess there's not going to be much new SATA h/w, so perhaps fine > as-is. Do you mean to keep the "resets" property with no num-of-items constraints then? -Sergey > > Rob