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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 B3AC8C04EBF for ; Wed, 5 Dec 2018 10:12:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84845214E0 for ; Wed, 5 Dec 2018 10:12:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 84845214E0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=csie.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728202AbeLEKMP (ORCPT ); Wed, 5 Dec 2018 05:12:15 -0500 Received: from mirror2.csie.ntu.edu.tw ([140.112.30.76]:51430 "EHLO wens.csie.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728027AbeLEKL5 (ORCPT ); Wed, 5 Dec 2018 05:11:57 -0500 Received: by wens.csie.org (Postfix, from userid 1000) id 586DE5F863; Wed, 5 Dec 2018 18:11:53 +0800 (CST) From: Chen-Yu Tsai To: Maxime Ripard , Michael Turquette , Stephen Boyd Cc: Chen-Yu Tsai , linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-sunxi@googlegroups.com Subject: [PATCH 1/3] clk: sunxi-ng: a33: Use sigma-delta modulation for audio PLL Date: Wed, 5 Dec 2018 18:11:50 +0800 Message-Id: <20181205101152.22983-2-wens@csie.org> X-Mailer: git-send-email 2.20.0.rc1 In-Reply-To: <20181205101152.22983-1-wens@csie.org> References: <20181205101152.22983-1-wens@csie.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The audio blocks require specific clock rates. Until now we were using the closest clock rate possible with integer N-M factors. This resulted in audio playback being slightly slower than it should be. The vendor kernel gets around this (for newer SoCs) by using sigma-delta modulation to generate a fractional-N factor. As the PLL hardware is identical in most chips, we can back port the settings from the newer SoC, in this case the H3, onto the A33. Signed-off-by: Chen-Yu Tsai --- drivers/clk/sunxi-ng/ccu-sun8i-a33.c | 37 ++++++++++++++++++---------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c index 13eb5b23c5e7..f763648a5f20 100644 --- a/drivers/clk/sunxi-ng/ccu-sun8i-a33.c +++ b/drivers/clk/sunxi-ng/ccu-sun8i-a33.c @@ -51,18 +51,29 @@ static struct ccu_nkmp pll_cpux_clk = { * the base (2x, 4x and 8x), and one variable divider (the one true * pll audio). * - * We don't have any need for the variable divider for now, so we just - * hardcode it to match with the clock names + * With sigma-delta modulation for fractional-N on the audio PLL, + * we have to use specific dividers. This means the variable divider + * can no longer be used, as the audio codec requests the exact clock + * rates we support through this mechanism. So we now hard code the + * variable divider to 1. This means the clock rates will no longer + * match the clock names. */ #define SUN8I_A33_PLL_AUDIO_REG 0x008 -static SUNXI_CCU_NM_WITH_GATE_LOCK(pll_audio_base_clk, "pll-audio-base", - "osc24M", 0x008, - 8, 7, /* N */ - 0, 5, /* M */ - BIT(31), /* gate */ - BIT(28), /* lock */ - CLK_SET_RATE_UNGATE); +static struct ccu_sdm_setting pll_audio_sdm_table[] = { + { .rate = 22579200, .pattern = 0xc0010d84, .m = 8, .n = 7 }, + { .rate = 24576000, .pattern = 0xc000ac02, .m = 14, .n = 14 }, +}; + +static SUNXI_CCU_NM_WITH_SDM_GATE_LOCK(pll_audio_base_clk, "pll-audio-base", + "osc24M", 0x008, + 8, 7, /* N */ + 0, 5, /* M */ + pll_audio_sdm_table, BIT(24), + 0x284, BIT(31), + BIT(31), /* gate */ + BIT(28), /* lock */ + CLK_SET_RATE_UNGATE); static SUNXI_CCU_NM_WITH_FRAC_GATE_LOCK(pll_video_clk, "pll-video", "osc24M", 0x010, @@ -576,9 +587,9 @@ static struct ccu_common *sun8i_a33_ccu_clks[] = { &ats_clk.common, }; -/* We hardcode the divider to 4 for now */ +/* We hardcode the divider to 1 for now */ static CLK_FIXED_FACTOR(pll_audio_clk, "pll-audio", - "pll-audio-base", 4, 1, CLK_SET_RATE_PARENT); + "pll-audio-base", 1, 1, CLK_SET_RATE_PARENT); static CLK_FIXED_FACTOR(pll_audio_2x_clk, "pll-audio-2x", "pll-audio-base", 2, 1, CLK_SET_RATE_PARENT); static CLK_FIXED_FACTOR(pll_audio_4x_clk, "pll-audio-4x", @@ -781,10 +792,10 @@ static void __init sun8i_a33_ccu_setup(struct device_node *node) return; } - /* Force the PLL-Audio-1x divider to 4 */ + /* Force the PLL-Audio-1x divider to 1 */ val = readl(reg + SUN8I_A33_PLL_AUDIO_REG); val &= ~GENMASK(19, 16); - writel(val | (3 << 16), reg + SUN8I_A33_PLL_AUDIO_REG); + writel(val | (0 << 16), reg + SUN8I_A33_PLL_AUDIO_REG); /* Force PLL-MIPI to MIPI mode */ val = readl(reg + SUN8I_A33_PLL_MIPI_REG); -- 2.20.0.rc1