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Received: from KL1PR03MB7149.apcprd03.prod.outlook.com (2603:1096:820:ca::7) by KUYPR03MB10359.apcprd03.prod.outlook.com (2603:1096:d10:9a::16) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.21.48.13; Wed, 20 May 2026 05:47:31 +0000 Received: from KL1PR03MB7149.apcprd03.prod.outlook.com ([fe80::2f06:12a:fff0:6506]) by KL1PR03MB7149.apcprd03.prod.outlook.com ([fe80::2f06:12a:fff0:6506%5]) with mapi id 15.21.0048.010; Wed, 20 May 2026 05:47:31 +0000 Message-ID: <8d89b669-e72e-4663-9596-999a12922d32@amlogic.com> Date: Wed, 20 May 2026 13:47:27 +0800 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 07/10] clk: amlogic: Support POWER_OF_TWO for PLL pre-divider To: Jerome Brunet , Jian Hu via B4 Relay Cc: Michael Turquette , Stephen Boyd , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Neil Armstrong , Xianwei Zhao , Kevin Hilman , Martin Blumenstingl , linux-kernel@vger.kernel.org, linux-clk@vger.kernel.org, devicetree@vger.kernel.org, linux-amlogic@lists.infradead.org, linux-arm-kernel@lists.infradead.org References: <20260511-b4-a9_clk-v1-0-41cb4071b7c9@amlogic.com> <20260511-b4-a9_clk-v1-7-41cb4071b7c9@amlogic.com> <1jy0hm6n7e.fsf@starbuckisacylon.baylibre.com> From: Jian Hu In-Reply-To: <1jy0hm6n7e.fsf@starbuckisacylon.baylibre.com> Content-Type: text/plain; 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If we use independent dividers, the n member would have to be removed from meson_clk_pll_data. However, n is referenced 35 times in clk-pll.c, which means we would need to modify all related logic across the file. This would be a relatively large change. Moreover, for all Amlogic chips, the n divider is an indispensable part of the DCO clock. The difference between SoC generations is as follows:     Previous SoCs PLL: n = 1, 2, 3, 4... (linear divider)     A9 SoC PLL:            n = 2^0, 2^1, 2^2, 2^3, 2^4... (power-of-two divider) Therefore, splitting out the n divider from the DCO clock might not be a good design choice. [...] Best regards, Jian