linux-kernel - Re: [PATCH V4 6/6] cpufreq: ti-cpufreq: Update efuse/rev offsets in AM62 family

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Message-ID: <20241001075230.j6rpis57la2zn4iu@lcpd911>
Date: Tue, 1 Oct 2024 13:22:30 +0530
From: Dhruva Gole <d-gole@...com>
To: Viresh Kumar <viresh.kumar@...aro.org>
CC: Nishanth Menon <nm@...com>, Vignesh Raghavendra <vigneshr@...com>,
        Tero
 Kristo <kristo@...nel.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>, <linux-pm@...r.kernel.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>, Rob
 Herring <robh@...nel.org>,
        Krzysztof Kozlowski <krzk+dt@...nel.org>
Subject: Re: [PATCH V4 6/6] cpufreq: ti-cpufreq: Update efuse/rev offsets in
 AM62 family

On Oct 01, 2024 at 11:59:19 +0530, Viresh Kumar wrote:
> On 19-09-24, 13:58, Dhruva Gole wrote:
> > With the Silicon revision being taken directly from socinfo, there's no
> > longer any need for reading any SOC register for revision from this driver.
> > Hence, we do not require any rev_offset for AM62 family of devices.
> > The efuse offset should be 0x0 for AM625 as well, as the syscon
> > register being used from DT refers to the efuse_offset directly.
> > 
> > Signed-off-by: Dhruva Gole <d-gole@...com>
> > ---
> > 
> > Viresh, Nishanth, Vignesh,
> > 
> > This driver fix is better to go with PATCH 5/6.
> > 
> > Subject: [PATCH V4 5/6] arm64: dts: ti: k3-am62: use opp_efuse_table for
> >  opp-table syscon
> > 
> > That patch fixes the efuse offset in the AM625 DT.
> > Without it, the driver will read from an incorrect efuse offset, and end
> > up breaking things in -next till all the DT changes make it in.
> > Hence, it would be preferrable if this entire series goes via a single
> > maintainer's tree.
> > Viresh, perhaps if you can ack this single patch, then Vignesh/Nishanth
> > could take it up if there are no objections?
> > 
> > I am sorry that this break compatibility with older AM625 devicetree.
> > However, the old devicetree was marking the entire wkup_conf as "syscon",
> > "simple-mfd" which was wrong and needed to be fixed.
> > 
> > This series finally tries to bring order to DT and the driver.
> > 
> > However, if there is still any way to maintain the backward
> > compatibility, then I am open to suggestions. Please try
> > and understand here that the ask for backward compatibility here
> > is to ask the driver to support a case where the register offset itself
> > was to be picked from a different node. I am not sure there's any
> > clean way to do this.
> > 
> > ---
> >  drivers/cpufreq/ti-cpufreq.c | 5 +----
> >  1 file changed, 1 insertion(+), 4 deletions(-)
> > 
> > diff --git a/drivers/cpufreq/ti-cpufreq.c b/drivers/cpufreq/ti-cpufreq.c
> > index ba621ce1cdda..870ab0b376c1 100644
> > --- a/drivers/cpufreq/ti-cpufreq.c
> > +++ b/drivers/cpufreq/ti-cpufreq.c
> > @@ -313,10 +313,9 @@ static const struct soc_device_attribute k3_cpufreq_soc[] = {
> >  
> >  static struct ti_cpufreq_soc_data am625_soc_data = {
> >  	.efuse_xlate = am625_efuse_xlate,
> > -	.efuse_offset = 0x0018,
> > +	.efuse_offset = 0x0,
> >  	.efuse_mask = 0x07c0,
> >  	.efuse_shift = 0x6,
> > -	.rev_offset = 0x0014,
> >  	.multi_regulator = false,
> >  };
> >  
> > @@ -325,7 +324,6 @@ static struct ti_cpufreq_soc_data am62a7_soc_data = {
> >  	.efuse_offset = 0x0,
> >  	.efuse_mask = 0x07c0,
> >  	.efuse_shift = 0x6,
> > -	.rev_offset = 0x0014,
> >  	.multi_regulator = false,
> >  };
> >  
> > @@ -334,7 +332,6 @@ static struct ti_cpufreq_soc_data am62p5_soc_data = {
> >  	.efuse_offset = 0x0,
> >  	.efuse_mask = 0x07c0,
> >  	.efuse_shift = 0x6,
> > -	.rev_offset = 0x0014,
> >  	.multi_regulator = false,
> >  };
> 
> Acked-by: Viresh Kumar <viresh.kumar@...aro.org>

Really sorry for any confusion here, but this series has been overall
split up and posted afresh here:
https://lore.kernel.org/all/20240930-b4-ti-cpufreq-am62-quirk-v1-0-b5e04f0f899b@ti.com/

This was done to avoid breaking any backward compatibility issues with
older DTs in a clean way.

-- 
Best regards,
Dhruva Gole
Texas Instruments Incorporated