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 05660C433F5 for ; Mon, 17 Jan 2022 07:04:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:CC:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Hy6HG6aQeSreuLLeYFtc74Dqoip6LfYUgBED6PbnuZM=; b=JZom5OUyMHM1Io jXTUke0CetMdB+iBKkNNYR69fix0hzWKBR3+sD+joLzEbW4Ktn1LuzEAT8USGr03+cNXP3+89Umev M7vvmrfjNXjWtqHA8MappXlq4oUhS1ZTISnRKBi2XvBbd37W59txP2cvcLbpQf5ic8yg6kWrN6Jny 18G39sCiIZan2FmrSJYsuGVjEuy3uiPTlQpGw7mM2aQSBjBBrJipxA2a7gqB6KoB29JQDuA6WEIME g85yFIja4W/JEn1TeuC13uGnKvfYZDbBZgoScwUJ0oAnhJ0BbV6FEy82w8ek1jMIUpplluAjPO9wP aay8RLBgBWXeFl0wKdmg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9M3d-00Djrn-GK; Mon, 17 Jan 2022 07:04:01 +0000 Received: from mail-sz.amlogic.com ([211.162.65.117]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n9M3R-00DjqW-KR; Mon, 17 Jan 2022 07:03:50 +0000 Received: from [10.28.39.106] (10.28.39.106) by mail-sz.amlogic.com (10.28.11.5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Mon, 17 Jan 2022 15:03:47 +0800 Message-ID: <8783eb66-16ee-3b8b-5d55-73b49deab3a2@amlogic.com> Date: Mon, 17 Jan 2022 15:03:47 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 6.1; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v9 3/4] clk: meson: add DT documentation for emmc clock controller Content-Language: en-US To: Martin Blumenstingl CC: Stephen Boyd , Jerome Brunet , Kevin Hilman , Michael Turquette , Neil Armstrong , Rob Herring , , Jianxin Pan , Victor Wan , XianWei Zhao , Kelvin Zhang , BiChao Zheng , YongHui Yu , , , References: <20220113115745.45826-1-liang.yang@amlogic.com> <20220113115745.45826-4-liang.yang@amlogic.com> <20220113212957.768FFC36AE3@smtp.kernel.org> <5d99ac02-a246-5bcc-2ecb-371b0d193537@amlogic.com> From: Liang Yang In-Reply-To: X-Originating-IP: [10.28.39.106] X-ClientProxiedBy: mail-sz.amlogic.com (10.28.11.5) To mail-sz.amlogic.com (10.28.11.5) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220116_230349_729910_0C179BF2 X-CRM114-Status: GOOD ( 15.44 ) X-BeenThere: linux-amlogic@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-amlogic" Errors-To: linux-amlogic-bounces+linux-amlogic=archiver.kernel.org@lists.infradead.org Hi Martin, On 2022/1/15 8:09, Martin Blumenstingl wrote: > [ EXTERNAL EMAIL ] > > Hi Liang, > > On Fri, Jan 14, 2022 at 4:06 AM Liang Yang wrote: > [...] >>>> +properties: >>>> + compatible: >>>> + enum: >>>> + - "amlogic,axg-mmc-clkc", "syscon" >>> >>> Why is it a syscon? >> >> The register documented by reg is shared with SD/eMMC controller port C, >> and it need to be ops on NFC driver. > Can you please share an example how the .dts would look like in the > end for two example cases: > 1) using the sd_emmc_c MMC interface > 2) not using the MMC interface of sd_emmc_c but only using it's clocks > for the NFC I think both EMMC(although it is not implemented by 'axg-mmc-clkc' yet) and NAND clock have the same way in dts: ...... clocks = <&clkc CLKID_SD_EMMC_C>, <&sd_emmc_c_clkc CLKID_MMC_DIV>, <&sd_emmc_c_clkc CLKID_MMC_PHASE_RX>, <&sd_emmc_c_clkc CLKID_MMC_PHASE_TX>; clock-names = "core", "device", "rx", "tx"; amlogic,mmc-syscon = <&sd_emmc_c_clkc>; ...... > > Initially I wanted to suggest the usage of a sub-node with compatible > = "mmc-slot" (see > Documentation/devicetree/bindings/mmc/amlogic,meson-mx-sdio.txt for an > example) to decide whether the MMC controller is registered or whether > just the clock controller is registered. > However, the mmc-slot compatible string is not documented in > Documentation/devicetree/bindings/mmc/mmc-controller.yaml currently. > Maybe the MMC maintainers have any suggestions if other IPs have > similar requirements (for IPs with shared parts). > > > Best regards, > Martin > > . _______________________________________________ linux-amlogic mailing list linux-amlogic@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-amlogic