Re: [PATCH v3] arm64: dts: ti: k3-am65: Add support for UHS-I modes in MMCSD1 subsystem

From: Nishanth Menon <nm@ti.com>
To: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Aswath Govindraju <a-govindraju@ti.com>,
	Vignesh Raghavendra <vigneshr@ti.com>,
	Lokesh Vutla <lokeshvutla@ti.com>,
	Kishon Vijay Abraham I <kishon@ti.com>,
	Tero Kristo <kristo@kernel.org>, Rob Herring <robh+dt@kernel.org>,
	<linux-arm-kernel@lists.infradead.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v3] arm64: dts: ti: k3-am65: Add support for UHS-I modes in MMCSD1 subsystem
Date: Fri, 28 May 2021 16:29:48 -0500	[thread overview]
Message-ID: <20210528212948.tmrsean2jj2v6bum@snuggle> (raw)
In-Reply-To: <7157b8ca-74e4-b7dd-c069-533db6a1cf0c@siemens.com>

On 20:34-20210528, Jan Kiszka wrote:
> On 11.05.21 18:48, Aswath Govindraju wrote:
> > UHS-I speed modes are supported in AM65 S.R. 2.0 SoC[1].
> > 
> > Add support by removing the no-1-8-v tag and including the voltage
> > regulator device tree nodes for power cycling.
> > 
> > However, the 4 bit interface of AM65 SR 1.0 cannot be supported at 3.3 V or
> > 1.8 V because of erratas i2025 and i2026 [2]. As the SD card is the primary
> > boot mode for development usecases, continue to enable SD card and disable
> > UHS-I modes in it to minimize any ageing issues happening because of
> > erratas.
> > 
> > k3-am6528-iot2050-basic and k3-am6548-iot2050-advanced boards use S.R. 1.0
> > version of AM65 SoC. Therefore, add no-1-8-v in sdhci1 device tree node of
> > the common iot2050 device tree file.
> > 
> > [1] - https://www.ti.com/lit/ug/spruid7e/spruid7e.pdf, section 12.3.6.1.1
> > [2] - https://www.ti.com/lit/er/sprz452e/sprz452e.pdf
> > 
> > Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
> > ---
> > 
> > changes since v2:
> > - moved the no-1-8-v tag to common iot2050 dtsi file.
> > 
> > changes since v1:
> > - added no-1-8-v tag in sdhci1 dt nodes of k3-am6528-iot2050-basic and
> >   k3-am6548-iot2050-advanced boards as they use S.R.1.0 version AM65 SoC.
> > 
> >  .../boot/dts/ti/k3-am65-iot2050-common.dtsi   |  1 +
> >  arch/arm64/boot/dts/ti/k3-am65-main.dtsi      |  1 -
> >  .../arm64/boot/dts/ti/k3-am654-base-board.dts | 33 +++++++++++++++++++
> >  3 files changed, 34 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
> > index de763ca9251c..46cc348cd4be 100644
> > --- a/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
> > +++ b/arch/arm64/boot/dts/ti/k3-am65-iot2050-common.dtsi
> > @@ -555,6 +555,7 @@
> >  	pinctrl-0 = <&main_mmc1_pins_default>;
> >  	ti,driver-strength-ohm = <50>;
> >  	disable-wp;
> > +	no-1-8-v;
> >  };
> >  
> 
> Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
> 

Thanks Jan.

Aswath:

It does'nt apply cleanly on my tree as I am picking up patches.. There are
new cleanups and nodes I have picked up, so could be conflicting with
those.

Please rebase and post based on:
https://git.kernel.org/pub/scm/linux/kernel/git/nmenon/linux.git/log/?h=ti-k3-dts-next

I'd suggest you do that on monday OR base on monday's linux-next tag for
the next post.

We need to make sure it does'nt conflict with Suman's repost[1] - So,
lets sync with suman offline to make sure we queue this up in the right
order.

[1] https://lore.kernel.org/linux-arm-kernel/e0da118a-077b-2e04-1e75-1550bcfa3540@ti.com/

-- 
Regards,
Nishanth Menon
Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D