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From: Yixun Lan <dlan@gentoo.org>
To: Andi Shyti <andi.shyti@kernel.org>
Cc: Troy Mitchell <troy.mitchell@linux.spacemit.com>,
	linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-riscv@lists.infradead.org, spacemit@lists.linux.dev
Subject: Re: [PATCH v4] i2c: spacemit: configure ILCR for accurate SCL frequency
Date: Mon, 20 Oct 2025 07:24:55 +0800	[thread overview]
Message-ID: <20251019232455-GYB1506524@gentoo.org> (raw)
In-Reply-To: <b6lafouoz6f6al5ki4oh7jj6gfpejwyh62sdrh7lia37sadd4u@rle3aw6grsiw>

Hi Andi,

On 00:32 Mon 20 Oct     , Andi Shyti wrote:
> Hi,
> 
> On Fri, Oct 17, 2025 at 03:27:39PM +0800, Troy Mitchell wrote:
> > The SpacemiT I2C controller's SCL (Serial Clock Line) frequency for
> > master mode operations is determined by the ILCR (I2C Load Count Register).
> > Previously, the driver relied on the hardware's reset default
> > values for this register.
> > 
> > The hardware's default ILCR values (SLV=0x156, FLV=0x5d) yield SCL
> > frequencies lower than intended. For example, with the default
> > 31.5 MHz input clock, these default settings result in an SCL
> > frequency of approximately 93 kHz (standard mode) when targeting 100 kHz,
> > and approximately 338 kHz (fast mode) when targeting 400 kHz.
> > These frequencies are below the 100 kHz/400 kHz nominal speeds.
> > 
> > This patch integrates the SCL frequency management into
> > the Common Clock Framework (CCF). Specifically, the ILCR register,
> > which acts as a frequency divider for the SCL clock, is now registered
> > as a managed clock (scl_clk) within the CCF.
> > 
> > This patch also cleans up unnecessary whitespace
> > in the included header files.
> > 
> > Signed-off-by: Troy Mitchell <troy.mitchell@linux.spacemit.com>
> 
> looks OK to me. Yixun, any comment here? Do you mind giving it an
> ack?
> 
Please go ahead, I gave a Reviewed-by, thanks

-- 
Yixun Lan (dlan)

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  reply	other threads:[~2025-10-19 23:25 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-10-17  7:27 [PATCH v4] i2c: spacemit: configure ILCR for accurate SCL frequency Troy Mitchell
2025-10-19 22:32 ` Andi Shyti
2025-10-19 23:24   ` Yixun Lan [this message]
2025-10-19 23:22 ` Yixun Lan
2025-10-20  9:28 ` Andi Shyti
2025-10-21 16:03   ` Andi Shyti
2025-10-22  1:48     ` Troy Mitchell
2025-10-23 10:34       ` Andi Shyti
2025-10-24 10:48         ` Troy Mitchell

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