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 X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 02946C433FF for ; Mon, 5 Aug 2019 13:30:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE9E12087B for ; Mon, 5 Aug 2019 13:30:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011844; bh=Suut7lwdLdJ61gbHawlyeba1bXqBVef4rcqN5FBxiIw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=jzrANC4a+HMLwnLtOqupbi5cclUV9LfwfHwvdfjwcpRJgoAfEPiN1usB9C9Lv3DQN 1HQHN6zgmEgxKHE4oZa0Tty1UISqKC38ZEdoQNSqhVOgypUpfag+Hkw7lkXUAROWuu 0IhqorEfbs/7dNQOsY3DgMpNY9PifSQgBd/PAlT8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729060AbfHENU2 (ORCPT ); Mon, 5 Aug 2019 09:20:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:56486 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728800AbfHENU0 (ORCPT ); Mon, 5 Aug 2019 09:20:26 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BA34D20657; Mon, 5 Aug 2019 13:20:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011225; bh=Suut7lwdLdJ61gbHawlyeba1bXqBVef4rcqN5FBxiIw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=K3uG/d4eJ2VLGYr2kL9tSmV8xxuy/YBf4T7Mhuj2umxq3CT84kDkcR6hQOsQGfWaB 8XwCi2WPlv5uMIzJC2baR+N2rqXpSO9JX9lUtn6MlnmiQPgpIZCEM/t/5gTMgJ+p70 69eiNVRuTosKcJN2aFURDqEH9Cuf8iOywWctN6w0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Martin Blumenstingl , Jerome Brunet , Sasha Levin Subject: [PATCH 5.2 004/131] clk: meson: mpll: properly handle spread spectrum Date: Mon, 5 Aug 2019 15:01:31 +0200 Message-Id: <20190805124951.724105609@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190805124951.453337465@linuxfoundation.org> References: <20190805124951.453337465@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit f9b3eeebef6aabaa37a351715374de53b6da860c ] The bit 'SSEN' available on some MPLL DSS outputs is not related to the fractional part of the divider but to the function called 'Spread Spectrum'. This function might be used to solve EM issues by adding a jitter on clock signal. This widens the signal spectrum and weakens the peaks in it. While spread spectrum might be useful for some application, it is problematic for others, such as audio. This patch introduce a new flag to the MPLL driver to enable (or not) the spread spectrum function. Fixes: 1f737ffa13ef ("clk: meson: mpll: fix mpll0 fractional part ignored") Tested-by: Martin Blumenstingl Signed-off-by: Jerome Brunet Signed-off-by: Sasha Levin --- drivers/clk/meson/clk-mpll.c | 9 ++++++--- drivers/clk/meson/clk-mpll.h | 1 + 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/clk/meson/clk-mpll.c b/drivers/clk/meson/clk-mpll.c index f76850d99e591..d3f42e0864313 100644 --- a/drivers/clk/meson/clk-mpll.c +++ b/drivers/clk/meson/clk-mpll.c @@ -119,9 +119,12 @@ static int mpll_set_rate(struct clk_hw *hw, meson_parm_write(clk->map, &mpll->sdm, sdm); meson_parm_write(clk->map, &mpll->sdm_en, 1); - /* Set additional fractional part enable if required */ - if (MESON_PARM_APPLICABLE(&mpll->ssen)) - meson_parm_write(clk->map, &mpll->ssen, 1); + /* Set spread spectrum if possible */ + if (MESON_PARM_APPLICABLE(&mpll->ssen)) { + unsigned int ss = + mpll->flags & CLK_MESON_MPLL_SPREAD_SPECTRUM ? 1 : 0; + meson_parm_write(clk->map, &mpll->ssen, ss); + } /* Set the integer divider part */ meson_parm_write(clk->map, &mpll->n2, n2); diff --git a/drivers/clk/meson/clk-mpll.h b/drivers/clk/meson/clk-mpll.h index cf79340006dd7..0f948430fed48 100644 --- a/drivers/clk/meson/clk-mpll.h +++ b/drivers/clk/meson/clk-mpll.h @@ -23,6 +23,7 @@ struct meson_clk_mpll_data { }; #define CLK_MESON_MPLL_ROUND_CLOSEST BIT(0) +#define CLK_MESON_MPLL_SPREAD_SPECTRUM BIT(1) extern const struct clk_ops meson_clk_mpll_ro_ops; extern const struct clk_ops meson_clk_mpll_ops; -- 2.20.1