linux-kernel - Re: [PATCH 0/2] LED: Add basic LP5860 LED matrix driver

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Message-ID: <87zfigaeph.fsf@pengutronix.de>
Date: Thu, 20 Feb 2025 15:11:22 +0100
From: Steffen Trumtrar <s.trumtrar@...gutronix.de>
To: Pavel Machek <pavel@....cz>
Cc: Lee Jones <lee@...nel.org>,  Rob Herring <robh@...nel.org>,  Krzysztof
 Kozlowski <krzk+dt@...nel.org>,  Conor Dooley <conor+dt@...nel.org>,
  Steffen Trumtrar <kernel@...gutronix.de>,  linux-leds@...r.kernel.org,
  devicetree@...r.kernel.org,  linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/2] LED: Add basic LP5860 LED matrix driver


Hi,

On 2025-02-20 at 13:57 +01, Steffen Trumtrar <s.trumtrar@...gutronix.de> wrote:

> The lp5860 is a LED matrix driver with 18 constant current sinks and 11
> scan switches which allows controlling up to 198 LED dots.
>
> This series adds just the basic support for the device on the SPI bus.
> It is also possible to use it on I2C. The interface can be
> switched/selected via an interface select pin.
>
> Next step for this driver will be adding open and short detection of the
> LEDs.

for this next step I wonder what would be the best way to propagate the failure states of the LED to the userspace? As far as I can tell, there are already TI LED drivers (lp55xx) that check open and short failures. These drivers only emit failures via sysfs_emit.
I need to be able to tell from userspace if an LED that is supposed to show some state info isn't broken in hardware.

Any ideas welcome,

Thanks,
Steffen

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