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[75.72.117.212]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8c09689246asm2268104285a.20.2025.12.28.16.58.01 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 28 Dec 2025 16:58:02 -0800 (PST) Message-ID: <4a76e9bf-926e-4b77-a2f8-ee4a72b2f1dd@riscstar.com> Date: Sun, 28 Dec 2025 18:58:00 -0600 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 1/4] i2c: spacemit: configure ILCR for accurate SCL frequency To: Troy Mitchell , Lee Jones , Yixun Lan , Andi Shyti , Alexandre Belloni , Liam Girdwood , Mark Brown Cc: linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, spacemit@lists.linux.dev, linux-i2c@vger.kernel.org, linux-rtc@vger.kernel.org References: <20251118-p1-kconfig-fix-v3-0-8839c5ac5db3@linux.spacemit.com> <20251118-p1-kconfig-fix-v3-1-8839c5ac5db3@linux.spacemit.com> <81eca0ab-47a3-4b12-98ae-fbd46a15ff93@riscstar.com> <569E6DA87DE510D5+aU4-1Jl9XxjAWQq4@kernel.org> Content-Language: en-US From: Alex Elder In-Reply-To: <569E6DA87DE510D5+aU4-1Jl9XxjAWQq4@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/26/25 1:52 AM, Troy Mitchell wrote: >>>> +static int spacemit_i2c_clk_set_rate(struct clk_hw *hw, unsigned long rate, >>>> + unsigned long parent_rate) >>>> +{ >>>> + struct spacemit_i2c_dev *i2c = container_of(hw, struct spacemit_i2c_dev, scl_clk_hw); >>>> + u32 lv, lcr, mask, shift, max_lv; >>>> + >>>> + lv = DIV_ROUND_UP(parent_rate, rate); >>> >>> Would DIV_ROUND_CLOSEST() give a more accurate value? >> I'll test it. > Same result. So I'll keep it. Is that true for all clock rates? Anyway, it's not a huge deal, but especially when the number of rates isn't very high this can make a difference. -Alex > - Troy