linux-kernel - Re: [PATCH] clk: Add clk_determine

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Message-ID: <aFHr9sVnU3Nx6yh0@shell.armlinux.org.uk>
Date: Tue, 17 Jun 2025 23:28:06 +0100
From: "Russell King (Oracle)" <linux@...linux.org.uk>
To: Jayesh Choudhary <j-choudhary@...com>
Cc: mturquette@...libre.com, sboyd@...nel.org, linux-clk@...r.kernel.org,
	devarsht@...com, linux-kernel@...r.kernel.org,
	tomi.valkeinen@...asonboard.com
Subject: Re: [PATCH] clk: Add clk_determine_rate function call

On Mon, Jun 16, 2025 at 04:05:27PM +0530, Jayesh Choudhary wrote:
> Add a function to determine if a particular rate can be set for a clock
> with its argument being the clock and the desired rate so that it could
> be exposed to other peripherals.
> For example, the display controllers typically has to perform multiple
> checks for supported display resolutions including those related to
> clock rates. The controller has to check this way before it actually
> enables the clock and has to do it multiple times (typically for each
> mode), and therefore using the clk_set_rate when its not needed, does
> not make sense.

So what's up with using clk_round_rate(), which returns the clock rate
that one would actually get if one calls clk_set_rate() with the the
value passed into clk_round_rate() ?

Why is clk_round_rate() not sufficient?

-- 
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