Re: [PATCH v5 2/8] dt-bindings: firmware: thead,th1520: Add resets for GPU clkgen

From: Drew Fustini <drew@pdp7.com>
To: Michal Wilczynski <m.wilczynski@samsung.com>,
	Rob Herring <robh@kernel.org>,
	Krzysztof Kozlowski <krzk+dt@kernel.org>,
	Conor Dooley <conor+dt@kernel.org>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Ulf Hansson <ulf.hansson@linaro.org>
Cc: Guo Ren <guoren@kernel.org>, Fu Wei <wefu@redhat.com>,
	Bartosz Golaszewski <brgl@bgdev.pl>,
	Frank Binns <frank.binns@imgtec.com>,
	Matt Coster <matt.coster@imgtec.com>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <mripard@kernel.org>,
	Thomas Zimmermann <tzimmermann@suse.de>,
	David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Alexandre Ghiti <alex@ghiti.fr>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v5 2/8] dt-bindings: firmware: thead,th1520: Add resets for GPU clkgen
Date: Wed, 18 Jun 2025 18:50:48 -0700	[thread overview]
Message-ID: <aFNs+PLgw1jqqiUm@x1> (raw)
In-Reply-To: <20250618-apr_14_for_sending-v5-2-27ed33ea5c6f@samsung.com>

On Wed, Jun 18, 2025 at 12:22:08PM +0200, Michal Wilczynski wrote:
> Extend the TH1520 AON to describe the GPU clkgen reset line, required
> for proper GPU clock and reset sequencing.
> 
> The T-HEAD TH1520 GPU requires coordinated management of two clocks
> (core and sys) and two resets (GPU core reset and GPU clkgen reset).
> Only the clkgen reset is exposed at the AON level, to support SoC
> specific initialization handled through a dedicated auxiliary power
> sequencing driver. The GPU core reset remains described in the GPU
> device node, as from the GPU driver's perspective, there is only a
> single reset line [1].
> 
> This follows upstream maintainers' recommendations [2] to abstract SoC
> specific details into the PM domain layer rather than exposing them to
> drivers directly.
> 
> Link: https://lore.kernel.org/all/816db99d-7088-4c1a-af03-b9a825ac09dc@imgtec.com/ - [1]
> Link: https://lore.kernel.org/all/38d9650fc11a674c8b689d6bab937acf@kernel.org/ - [2]
> 
> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Michal Wilczynski <m.wilczynski@samsung.com>
> ---
>  Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml b/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml
> index bbc183200400de7aadbb21fea21911f6f4227b09..3365124c7fd4736922717bd31caa13272f4a4ea6 100644
> --- a/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml
> +++ b/Documentation/devicetree/bindings/firmware/thead,th1520-aon.yaml
> @@ -32,6 +32,13 @@ properties:
>      items:
>        - const: aon
>  
> +  resets:
> +    maxItems: 1
> +
> +  reset-names:
> +    items:
> +      - const: gpu-clkgen
> +
>    "#power-domain-cells":
>      const: 1
>  
> 
> -- 
> 2.34.1
> 

Reviewed-by: Drew Fustini <drew@pdp7.com>

I'm wondering what tree this should go through. Ulf took the original
patch that created the binding.

Thanks,
Drew