Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751842AbaKUSkb (ORCPT ); Fri, 21 Nov 2014 13:40:31 -0500 Received: from bhuna.collabora.co.uk ([93.93.135.160]:34730 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750755AbaKUSk3 (ORCPT ); Fri, 21 Nov 2014 13:40:29 -0500 Message-ID: <546F8711.70503@collabora.co.uk> Date: Fri, 21 Nov 2014 19:40:17 +0100 From: Javier Martinez Canillas User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.0 MIME-Version: 1.0 To: Bill Richardson CC: Lee Jones , Doug Anderson , Olof Johansson , Simon Glass , Gwendal Grignou , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 2/3] mfd: cros_ec: Create sysfs attributes for the ChromeOS EC. References: <1416238213-15263-1-git-send-email-javier.martinez@collabora.co.uk> <1416238213-15263-3-git-send-email-javier.martinez@collabora.co.uk> <20141118142645.GD24004@x1> <546DD783.2030902@collabora.co.uk> In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Bill, On 11/20/2014 07:16 PM, Bill Richardson wrote: >> >> I don't really know why there are two interfaces for this but I guess >> that different user-space utilities use one or another. Maybe the >> ChromiumOS folks can comment on this. > > The /dev/cros_ec interface responds to ioctls and is the primary means > by which userspace applications talk to the EC (replacing three really > awkward bus-specific libraries). It emits a simplified version string > when read so that humans can tell if the EC is alive and speaking the > same protocol that the userspace app expects. > > The /sys/class/chromeos/cros_ec/* tree was originally envisioned as a > way to provide additional human-readable interfaces to a subset of the > EC commands, but except for the lightbar it's not often used. The > version component here shows all the version-related info that the EC > can provide. > Got it, thanks a lot for the explanation. Best regards, Javier -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/