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,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 EAEE5C433FF for ; Mon, 5 Aug 2019 13:20:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B34452075B for ; Mon, 5 Aug 2019 13:20:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565011231; bh=Suut7lwdLdJ61gbHawlyeba1bXqBVef4rcqN5FBxiIw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=L3+Ha9lUmWnpQYMGEcCLiwvpoZfLuZj0qm1+jgszvgyZHUOp7Q3IrpDAC3bOaEKIP SqH1g+TcBes30KZe3Gpy4aAUwPDFg36m1zY9spMPw8lzcj4MOppTV8PX5xj15HKbF0 axlAoFmXaDDziHE7E0Q+JXNfh0J5gQvhFv7JlquA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730256AbfHENUa (ORCPT ); Mon, 5 Aug 2019 09:20:30 -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: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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