From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtpout-04.galae.net (smtpout-04.galae.net [185.171.202.116]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C9F31327208; Tue, 23 Dec 2025 10:02:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.171.202.116 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766484167; cv=none; b=SOrpKafSpbRdwijaNtGxbS0If2ZPnMwe8axXxPH2nFWc1JpXDaJL25X5ZJTF7C0khxvnJQsvLG81Bd1hzbHc3k5+VPAdzu4YNVb6sV0n0JZY4s3tp8SQZbqcOxwnvT0yAwJTSz6rNnxq1H06XXIvZUpCwcDfzHHcXmIh+KxgWyw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766484167; c=relaxed/simple; bh=UrVZCW5lbAV7kJ6TBwnmGdMgCEBIQ8VniS4vRI8N5LU=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Vnyu+Lt1cFiMAEUNXKc2zJjW4D2V2M0uTzKz87FvNMHN5eszT+LHdpWkyKbk8qygtZkhS1Uvnecl3lM+05mLlAYOgzbJL7dgknnG0k0fzsG3vwNzaRGAc+KbVvl51i/mka1AjRXYGnRflkhRCNpzw8S58idqTSCRe0O3HHNzAYE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=Th8UG8F/; arc=none smtp.client-ip=185.171.202.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="Th8UG8F/" Received: from smtpout-01.galae.net (smtpout-01.galae.net [212.83.139.233]) by smtpout-04.galae.net (Postfix) with ESMTPS id 0D2F0C1AE1A; Tue, 23 Dec 2025 10:02:18 +0000 (UTC) Received: from mail.galae.net (mail.galae.net [212.83.136.155]) by smtpout-01.galae.net (Postfix) with ESMTPS id 2077660716; Tue, 23 Dec 2025 10:02:43 +0000 (UTC) Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 214C210AB09BE; Tue, 23 Dec 2025 11:02:40 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=dkim; t=1766484161; h=from:subject:date:message-id:to:cc:mime-version:content-type: content-transfer-encoding:in-reply-to:references; bh=LAlm/ECW4o7ColMRo13P/K3LTb6LJ/lSZfggJLOeA6M=; b=Th8UG8F/pMFgTagv9kvVVPuonkRvM/KXJKO11w5tzUJibutxihotzMrodgWznttT2Esoob tyqzMPOfRYzQF4x1jAO2AhDrcepwIsa+lybbTGASn/JCCDoLN/MXmEK3leUmOasA5lTEcY Q5dHjIwkFrzvWXdv9zJZ1QT6JG9HI/I8fx/6Q4m7z8sy9RMKx5mGTXsVvbtVZzujLbvB65 PkAdqB/f6MT/xa67gsOaB0aJQhV9kfNEku4sG8R6bT1paPKJAl0WUfmWJuvrM0odlHtgXL NdySDrIV7GOPeHa5HJXm0+F0nS3Wnx8gsT8GjDcuZRHWBXGEoP1TOSQnIOGS5w== From: =?utf-8?q?Beno=C3=AEt_Monin?= Date: Tue, 23 Dec 2025 11:02:23 +0100 Subject: [PATCH v2 08/13] clk: eyeq: Adjust PLL accuracy computation Precedence: bulk X-Mailing-List: linux-mips@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Message-Id: <20251223-eyeq6lplus-v2-8-cd1fd21d182c@bootlin.com> References: <20251223-eyeq6lplus-v2-0-cd1fd21d182c@bootlin.com> In-Reply-To: <20251223-eyeq6lplus-v2-0-cd1fd21d182c@bootlin.com> To: Vladimir Kondratiev , Gregory CLEMENT , =?utf-8?q?Th=C3=A9o_Lebrun?= , Thomas Bogendoerfer , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Michael Turquette , Stephen Boyd , Philipp Zabel , Linus Walleij Cc: Thomas Petazzoni , Tawfik Bayouk , linux-mips@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, linux-gpio@vger.kernel.org, =?utf-8?q?Beno=C3=AEt_Monin?= X-Mailer: b4 0.14.3 X-Last-TLS-Session-Version: TLSv1.3 The spread spectrum of the PLL found in eyeQ OLB is in 1/1024 parts of the frequency, not in 1/1000, so adjust the computation of the accuracy. Also correct the downspreading to match. Signed-off-by: Benoît Monin --- drivers/clk/clk-eyeq.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/clk/clk-eyeq.c b/drivers/clk/clk-eyeq.c index 182b408b6aa4..8fb32f365f3d 100644 --- a/drivers/clk/clk-eyeq.c +++ b/drivers/clk/clk-eyeq.c @@ -163,7 +163,7 @@ static void eqc_pll_downshift_factors(unsigned long *mult, unsigned long *div) static int eqc_pll_parse_registers(u32 r0, u32 r1, unsigned long *mult, unsigned long *div, unsigned long *acc) { - u32 spread; + unsigned long spread; if (r0 & PCSR0_BYPASS) { *mult = 1; @@ -195,23 +195,23 @@ static int eqc_pll_parse_registers(u32 r0, u32 r1, unsigned long *mult, /* * Spread spectrum. * - * Spread is 1/1000 parts of frequency, accuracy is half of - * that. To get accuracy, convert to ppb (parts per billion). + * Spread is in 1/1024 parts of frequency. Clock accuracy + * is half the spread value expressed in parts per billion. * - * acc = spread * 1e6 / 2 - * with acc in parts per billion and, - * spread in parts per thousand. + * accuracy = (spread * 1e9) / (1024 * 2) + * + * Care is taken to avoid overflowing or losing precision. */ spread = FIELD_GET(PCSR1_SPREAD, r1); - *acc = spread * 500000; + *acc = DIV_ROUND_CLOSEST(spread * 1000000000, 1024 * 2); if (r1 & PCSR1_DOWN_SPREAD) { /* * Downspreading: the central frequency is half a * spread lower. */ - *mult *= 2000 - spread; - *div *= 2000; + *mult *= 2048 - spread; + *div *= 2048; /* * Previous operation might overflow 32 bits. If it -- 2.52.0