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[82.37.195.13]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-432bd5ee870sm51184009f8f.36.2026.01.14.07.53.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Jan 2026 07:53:36 -0800 (PST) Date: Wed, 14 Jan 2026 15:53:34 +0000 From: Daniel Thompson To: tessolveupstream@gmail.com Cc: lee@kernel.org, danielt@kernel.org, jingoohan1@gmail.com, deller@gmx.de, pavel@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1 1/2] dt-bindings: backlight: gpio-backlight: allow multiple GPIOs Message-ID: References: <20260105085120.230862-1-tessolveupstream@gmail.com> <20260105085120.230862-2-tessolveupstream@gmail.com> Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Jan 13, 2026 at 10:15:53AM +0530, tessolveupstream@gmail.com wrote: > > > On 05-01-2026 15:25, Daniel Thompson wrote: > > On Mon, Jan 05, 2026 at 02:21:19PM +0530, Sudarshan Shetty wrote: > >> Update the gpio-backlight binding to support configurations that require > >> more than one GPIO for enabling/disabling the backlight. > >> > >> Signed-off-by: Sudarshan Shetty > >> --- > >> .../bindings/leds/backlight/gpio-backlight.yaml | 12 +++++++++++- > >> 1 file changed, 11 insertions(+), 1 deletion(-) > >> > >> diff --git a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > >> index 584030b6b0b9..1483ce4a3480 100644 > >> --- a/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > >> +++ b/Documentation/devicetree/bindings/leds/backlight/gpio-backlight.yaml > >> @@ -17,7 +17,8 @@ properties: > >> > >> gpios: > >> description: The gpio that is used for enabling/disabling the backlight. > >> - maxItems: 1 > >> + minItems: 1 > >> + maxItems: 2 > > > > Why 2? > > > > In the current design, the LVDS panel has a single backlight that > is controlled by two GPIOs. Initially, It described as two separate > backlight devices using the same gpio-backlight driver, since the > existing driver supports only one GPIO per instance. > > So the maintainer suggested to extend the gpio-backlight driver > and bindings to support multiple GPIOs. > https://lore.kernel.org/all/q63bdon55app4gb2il5e7skyc6z2amcnaiqbqlhen7arkxphtb@3jejbelji2ti/ Right. So, once we support multiple GPIOs then why limit it to 2? Daniel.