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 33293C433F5 for ; Wed, 19 Jan 2022 17:33:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356446AbiASRdt (ORCPT ); Wed, 19 Jan 2022 12:33:49 -0500 Received: from eu-shark1.inbox.eu ([195.216.236.81]:48972 "EHLO eu-shark1.inbox.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356457AbiASRdt (ORCPT ); Wed, 19 Jan 2022 12:33:49 -0500 X-Greylist: delayed 531 seconds by postgrey-1.27 at vger.kernel.org; Wed, 19 Jan 2022 12:33:49 EST Received: from eu-shark1.inbox.eu (localhost [127.0.0.1]) by eu-shark1-out.inbox.eu (Postfix) with ESMTP id 406A66C0074E; Wed, 19 Jan 2022 19:24:56 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mail.ee; s=20150108; t=1642613096; bh=2ocrVwEK3JEDTeF+8QmkZiiLdEIYKrfKfVhvZh/P5Bc=; h=Date:From:To:Subject:Message-ID:Content-Type:X-ESPOL:from:date; b=iG9Mrn8jaNLyYkkloMjcgyRooNJHUfzwGUFruqm1KK9GrPLhq1DuM4mSAN5dDEm19 /A6ImwfYycZHU9+r7F6O+XYj47+/aBmZDylNE5F+dXj9qIyPB3TzNdtdwR59qrDyDC tg56gvrYKSpAI1xZj5DYPDppRJStIIZ0ZWwH8FYQ= Received: from localhost (localhost [127.0.0.1]) by eu-shark1-in.inbox.eu (Postfix) with ESMTP id 3298A6C0074B; Wed, 19 Jan 2022 19:24:56 +0200 (EET) Received: from eu-shark1.inbox.eu ([127.0.0.1]) by localhost (eu-shark1.inbox.eu [127.0.0.1]) (spamfilter, port 35) with ESMTP id G1qKrkS23hMb; Wed, 19 Jan 2022 19:24:55 +0200 (EET) Received: from mail.inbox.eu (eu-pop1 [127.0.0.1]) by eu-shark1-in.inbox.eu (Postfix) with ESMTP id 752616C0074A; Wed, 19 Jan 2022 19:24:55 +0200 (EET) Date: Wed, 19 Jan 2022 20:24:49 +0300 From: Boris Lysov To: linux-mediatek@lists.infradead.org, linux-clk@vger.kernel.org Subject: Looking for help with mt6577 clock driver Message-ID: <20220119202449.02a8b421@pc> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Virus-Scanned: OK X-ESPOL: 885ml41QGzuilFygRWXfBgUrzVlEXvGWher6j11F/g/3MCuNeEoFVBSznnAFPnHC3iM= Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org Hello! I'm developing a mainline kernel for mt6577 which is a dual-core Cortex-A9 SoC for smartphones/tablets. I'm stuck at the clock driver which looks hard to implement for such an old platform using mainline codebase from Mediatek. I do see common patterns li= ke using various subsystems for clock management (apmixed, pericfg, mmsys) but what I'm failing to understand is how are clocks related to each other (for example muxed ones) and what exactly drives each clock.=20 Analyzing Mediatek downstream kernel code [1][2] didn't help me much becaus= e it works in a "write some magic values to fire everything up because why not?"= [3] way. Right now my approaches are dumping and analyzing hardware registers w= hile the device runs downstream kernel [4], and just a plain guesswork which I think is rather unreliable.=20 =46rom =C2=A73.3 of [5] I understand that LKML is not a helpdesk but I still = would like to ask for any tips regarding writing a good clock driver, especially = how to determine how are clocks related to each other. Can someone from Mediatek explain the PLL/clock/mux subsystem on mt6577 please? Thanks. [1] ALPS.JB.MP.V1.19_MBK77_TB_JB source code package (kernel v3.4.x) [2] https://www.acer.com/ac/en/US/content/support-product/4817?b=3D1 in the "Documents (2)" section.=20 [3] mediatek/platform/mt6577/kernel/core/mt_clock_manager.c from [1] or [2] [4] https://github.com/arzam16/mt6577_kernel_Acer_B1_A71/commit/5a447eceda71723= 715af9cc215a67241efc83b3d [5] http://vger.kernel.org/lkml/ 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 50D1CC433EF for ; Wed, 19 Jan 2022 17:25:12 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:Message-ID:Subject:To:From :Date:Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References: List-Owner; bh=ydc3aig1DvoHDNYg0DrUMgQR4COiliF+naVuqRu5K0k=; b=x2N76p+GUFSa7w PM6O2kr4jxUlEYE8sbc/3W7tUZ7FDJ6U9xJ9MAKrQ+LuhUKLtf1xNVqGY+gDCCuJyiTSIyqn3j99C r53/URhYiMnhk4LSmySLCNH/Gyv+g4ik0eqjxeKtk/m/wO0+gfnwnWb4Lo2UClrM449vTO/iL8X/X F7X3aL7YrqDlxdsDPvASY6DO6DYBKJQn7L9AXnv8K/gyNx+dwC8v+ZEvqZ+OMgrSqC64rEGa/HhBr BsF0rNJkQ43vyhCyc/oeivJB4bEXNEFYqtGjRKZ9Jl0KHYKryrLcgTNP90fmk+Z/dZz2L515N9HQZ AQcpLEDnWNx4kQ2xhySg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAEhl-006Yef-Gj; Wed, 19 Jan 2022 17:25:05 +0000 Received: from eu-shark1.inbox.eu ([195.216.236.81]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nAEhi-006YdO-4q for linux-mediatek@lists.infradead.org; Wed, 19 Jan 2022 17:25:04 +0000 Received: from eu-shark1.inbox.eu (localhost [127.0.0.1]) by eu-shark1-out.inbox.eu (Postfix) with ESMTP id 406A66C0074E; Wed, 19 Jan 2022 19:24:56 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=mail.ee; s=20150108; t=1642613096; bh=2ocrVwEK3JEDTeF+8QmkZiiLdEIYKrfKfVhvZh/P5Bc=; h=Date:From:To:Subject:Message-ID:Content-Type:X-ESPOL:from:date; b=iG9Mrn8jaNLyYkkloMjcgyRooNJHUfzwGUFruqm1KK9GrPLhq1DuM4mSAN5dDEm19 /A6ImwfYycZHU9+r7F6O+XYj47+/aBmZDylNE5F+dXj9qIyPB3TzNdtdwR59qrDyDC tg56gvrYKSpAI1xZj5DYPDppRJStIIZ0ZWwH8FYQ= Received: from localhost (localhost [127.0.0.1]) by eu-shark1-in.inbox.eu (Postfix) with ESMTP id 3298A6C0074B; Wed, 19 Jan 2022 19:24:56 +0200 (EET) Received: from eu-shark1.inbox.eu ([127.0.0.1]) by localhost (eu-shark1.inbox.eu [127.0.0.1]) (spamfilter, port 35) with ESMTP id G1qKrkS23hMb; Wed, 19 Jan 2022 19:24:55 +0200 (EET) Received: from mail.inbox.eu (eu-pop1 [127.0.0.1]) by eu-shark1-in.inbox.eu (Postfix) with ESMTP id 752616C0074A; Wed, 19 Jan 2022 19:24:55 +0200 (EET) Date: Wed, 19 Jan 2022 20:24:49 +0300 From: Boris Lysov To: linux-mediatek@lists.infradead.org, linux-clk@vger.kernel.org Subject: Looking for help with mt6577 clock driver Message-ID: <20220119202449.02a8b421@pc> MIME-Version: 1.0 X-Virus-Scanned: OK X-ESPOL: 885ml41QGzuilFygRWXfBgUrzVlEXvGWher6j11F/g/3MCuNeEoFVBSznnAFPnHC3iM= X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220119_092502_563855_5849DBCA X-CRM114-Status: UNSURE ( 7.44 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org SGVsbG8hCgpJJ20gZGV2ZWxvcGluZyBhIG1haW5saW5lIGtlcm5lbCBmb3IgbXQ2NTc3IHdoaWNo IGlzIGEgZHVhbC1jb3JlIENvcnRleC1BOQpTb0MgZm9yIHNtYXJ0cGhvbmVzL3RhYmxldHMuCgpJ J20gc3R1Y2sgYXQgdGhlIGNsb2NrIGRyaXZlciB3aGljaCBsb29rcyBoYXJkIHRvIGltcGxlbWVu dCBmb3Igc3VjaCBhbiBvbGQKcGxhdGZvcm0gdXNpbmcgbWFpbmxpbmUgY29kZWJhc2UgZnJvbSBN ZWRpYXRlay4gSSBkbyBzZWUgY29tbW9uIHBhdHRlcm5zIGxpa2UKdXNpbmcgdmFyaW91cyBzdWJz eXN0ZW1zIGZvciBjbG9jayBtYW5hZ2VtZW50IChhcG1peGVkLCBwZXJpY2ZnLCBtbXN5cykgYnV0 CndoYXQgSSdtIGZhaWxpbmcgdG8gdW5kZXJzdGFuZCBpcyBob3cgYXJlIGNsb2NrcyByZWxhdGVk IHRvIGVhY2ggb3RoZXIgKGZvcgpleGFtcGxlIG11eGVkIG9uZXMpIGFuZCB3aGF0IGV4YWN0bHkg ZHJpdmVzIGVhY2ggY2xvY2suIAoKQW5hbHl6aW5nIE1lZGlhdGVrIGRvd25zdHJlYW0ga2VybmVs IGNvZGUgWzFdWzJdIGRpZG4ndCBoZWxwIG1lIG11Y2ggYmVjYXVzZSBpdAp3b3JrcyBpbiBhICJ3 cml0ZSBzb21lIG1hZ2ljIHZhbHVlcyB0byBmaXJlIGV2ZXJ5dGhpbmcgdXAgYmVjYXVzZSB3aHkg bm90PyIgWzNdCndheS4gUmlnaHQgbm93IG15IGFwcHJvYWNoZXMgYXJlIGR1bXBpbmcgYW5kIGFu YWx5emluZyBoYXJkd2FyZSByZWdpc3RlcnMgd2hpbGUKdGhlIGRldmljZSBydW5zIGRvd25zdHJl YW0ga2VybmVsIFs0XSwgYW5kIGp1c3QgYSBwbGFpbiBndWVzc3dvcmsgd2hpY2ggSQp0aGluayBp cyByYXRoZXIgdW5yZWxpYWJsZS4gCgpGcm9tIMKnMy4zIG9mIFs1XSBJIHVuZGVyc3RhbmQgdGhh dCBMS01MIGlzIG5vdCBhIGhlbHBkZXNrIGJ1dCBJIHN0aWxsIHdvdWxkCmxpa2UgdG8gYXNrIGZv ciBhbnkgdGlwcyByZWdhcmRpbmcgd3JpdGluZyBhIGdvb2QgY2xvY2sgZHJpdmVyLCBlc3BlY2lh bGx5IGhvdwp0byBkZXRlcm1pbmUgaG93IGFyZSBjbG9ja3MgcmVsYXRlZCB0byBlYWNoIG90aGVy LiBDYW4gc29tZW9uZSBmcm9tIE1lZGlhdGVrCmV4cGxhaW4gdGhlIFBMTC9jbG9jay9tdXggc3Vi c3lzdGVtIG9uIG10NjU3NyBwbGVhc2U/CgpUaGFua3MuCgpbMV0gQUxQUy5KQi5NUC5WMS4xOV9N Qks3N19UQl9KQiBzb3VyY2UgY29kZSBwYWNrYWdlIChrZXJuZWwgdjMuNC54KQpbMl0gaHR0cHM6 Ly93d3cuYWNlci5jb20vYWMvZW4vVVMvY29udGVudC9zdXBwb3J0LXByb2R1Y3QvNDgxNz9iPTEg aW4gdGhlCiJEb2N1bWVudHMgKDIpIiBzZWN0aW9uLiAKWzNdIG1lZGlhdGVrL3BsYXRmb3JtL210 NjU3Ny9rZXJuZWwvY29yZS9tdF9jbG9ja19tYW5hZ2VyLmMgZnJvbSBbMV0gb3IgWzJdCls0XQpo dHRwczovL2dpdGh1Yi5jb20vYXJ6YW0xNi9tdDY1Nzdfa2VybmVsX0FjZXJfQjFfQTcxL2NvbW1p dC81YTQ0N2VjZWRhNzE3MjM3MTVhZjljYzIxNWE2NzI0MWVmYzgzYjNkCls1XSBodHRwOi8vdmdl ci5rZXJuZWwub3JnL2xrbWwvCgpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fXwpMaW51eC1tZWRpYXRlayBtYWlsaW5nIGxpc3QKTGludXgtbWVkaWF0ZWtAbGlz dHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3Rp bmZvL2xpbnV4LW1lZGlhdGVrCg==