linux-kernel - Re: [PATCH v2] cpufreq: airoha: Add EN7581 Cpufreq SMC driver

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Message-ID: <20241119072054.64hi347qmv7ng3un@vireshk-i7>
Date: Tue, 19 Nov 2024 12:50:54 +0530
From: Viresh Kumar <viresh.kumar@...aro.org>
To: Christian Marangi <ansuelsmth@...il.com>
Cc: "Rafael J. Wysocki" <rafael@...nel.org>, linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org, Lorenzo Bianconi <lorenzo@...nel.org>,
	upstream@...oha.com
Subject: Re: [PATCH v2] cpufreq: airoha: Add EN7581 Cpufreq SMC driver

On 17-10-24, 21:07, Christian Marangi wrote:
> Add simple Cpufreq driver for Airoha EN7581 SoC that control CPU
> frequency scaling with SMC APIs.
> 
> All CPU share the same frequency and can't be controlled independently.
> Current shared CPU frequency is returned by the related SMC command.
> 
> Add SoC compatible to cpufreq-dt-plat block list as a dedicated cpufreq
> driver is needed with OPP v2 nodes declared in DTS.
> 
> Signed-off-by: Christian Marangi <ansuelsmth@...il.com>
> ---
> Changes v2:
> - Fix kernel bot error with missing slab.h and bitfield.h header
> - Limit COMPILE_TEST to ARM64 due to smcc 1.2

Hi,

Sorry for delay at my side to review this driver.

Now that I looked at it, I don't see a lot of special stuff happening in the
driver. There are many other platforms with similar situation. What we have done
for all them, which rely on OPPs coming from DT, is to add a clk for the CPUs
and do all this magically smcc stuff from clk_get_rate() and clk_set_rate().
Once that is done, you should be able to reuse the cpufreq-dt driver as is.

So a CPU clk is the only missing thing in your case I guess.

-- 
viresh