From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7D9831FBE8F for ; Thu, 20 Feb 2025 14:11:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740060689; cv=none; b=cQbeZUb/QjpPblbWfk2UM5foe4DhM5traajvmohK8FD5GGXTuo3WCDpRpYMGzktZFu5QHklL8MpRuDf4AjtGHKS19wGACu0f15L5n2gxjzVySKj1k1yqP666tz9U7nRRn6c2YJwToRV9Ggx7lyiFNs6di5BBvOd8+MelNFu4vdc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740060689; c=relaxed/simple; bh=LI0Je3OsQZgBdDqnX2MsMKsQ8lnkBp+kiW/gf9oGHNY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=kDCvrhoevJ1i4tCEuR1fMQ7rRwcpST2s7SV1yDUXC/5dC/znCBYIL3GTA/cFEmstqtv+zIktQJgmxzaK5aTAXUdbqEQmXn+SGCcj/PVZbCwiPXlSOp9U2oDrY6IuudgMH56IBjmADmC/m0Eehw1xFXtd82AIw/I8KBqwC+fdJ8Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=ratatoskr.pengutronix.de) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tl7Gt-0001Vy-Sa; Thu, 20 Feb 2025 15:11:23 +0100 From: Steffen Trumtrar To: Pavel Machek Cc: Lee Jones , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Steffen Trumtrar , linux-leds@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] LED: Add basic LP5860 LED matrix driver In-Reply-To: <20250220-v6-14-topic-ti-lp5860-v1-0-42874bdc7513@pengutronix.de> (Steffen Trumtrar's message of "Thu, 20 Feb 2025 13:57:55 +0100") References: <20250220-v6-14-topic-ti-lp5860-v1-0-42874bdc7513@pengutronix.de> User-Agent: mu4e 1.12.8; emacs 30.0.93 Date: Thu, 20 Feb 2025 15:11:22 +0100 Message-ID: <87zfigaeph.fsf@pengutronix.de> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; format=flowed X-SA-Exim-Connect-IP: 2a0a:edc0:0:900:1d::77 X-SA-Exim-Mail-From: s.trumtrar@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: devicetree@vger.kernel.org Hi, On 2025-02-20 at 13:57 +01, Steffen Trumtrar 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 -- Pengutronix e.K. | Dipl.-Inform. Steffen Trumtrar | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686| Fax: +49-5121-206917-5555 |