linux-kernel - [PATCH v3 2/3] dt-bindings: leds: Document pull-up supply for interrupt and I2C

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230815-aw2013-vio-v3-2-2505296b0856@gerhold.net>
Date:   Tue, 15 Aug 2023 19:21:05 +0200
From:   Stephan Gerhold <stephan@...hold.net>
To:     Pavel Machek <pavel@....cz>, Lee Jones <lee@...nel.org>
Cc:     Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Conor Dooley <conor+dt@...nel.org>,
        Nikita Travkin <nikita@...n.ru>, linux-leds@...r.kernel.org,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
        "Lin, Meng-Bo" <linmengbo0689@...tonmail.com>,
        Stephan Gerhold <stephan@...hold.net>
Subject: [PATCH v3 2/3] dt-bindings: leds: Document pull-up supply for
 interrupt and I2C

Since the interrupt and I2C lines of AW2013 operate in open drain low
active mode a pull-up supply is needed for correct operation.
Unfortunately there is no ideal place to describe it in the DT: The
pull-up needed for the I2C lines could be described on the I2C bus.
However, the pull-up needed for the interrupt line belongs neither
directly to the interrupt controller nor to AW2013. Since the AW2013
driver will be typically in control of the power management and
interrupt masking it makes more sense to describe it inside the AW2013
device tree node.

Add it to the AW2013 DT schema together with a comment that makes it
clear what exactly it represents.

Signed-off-by: Stephan Gerhold <stephan@...hold.net>
---
Related previous discussion:
https://lore.kernel.org/linux-leds/20230321220825.GA1685482-robh@kernel.org/
---
 Documentation/devicetree/bindings/leds/leds-aw2013.yaml | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/leds/leds-aw2013.yaml b/Documentation/devicetree/bindings/leds/leds-aw2013.yaml
index a0a0dabcfbf3..26238446f2bd 100644
--- a/Documentation/devicetree/bindings/leds/leds-aw2013.yaml
+++ b/Documentation/devicetree/bindings/leds/leds-aw2013.yaml
@@ -28,6 +28,12 @@ properties:
   vcc-supply:
     description: Regulator providing power to the "VCC" pin.
 
+  vio-supply:
+    description: Regulator providing power for pull-up of the I/O lines.
+      "VIO1" in the typical application circuit example of the datasheet.
+      Note that this regulator does not directly connect to AW2013, but is
+      needed for the correct operation of the interrupt and I2C lines.
+
   "#address-cells":
     const: 1
 

-- 
2.41.0