Return-path: Received: from avon.wwwdotorg.org ([70.85.31.133]:42508 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756313Ab2FNPy0 (ORCPT ); Thu, 14 Jun 2012 11:54:26 -0400 Message-ID: <4FDA092E.10301@wwwdotorg.org> (sfid-20120614_175431_421246_7683308E) Date: Thu, 14 Jun 2012 09:54:22 -0600 From: Stephen Warren MIME-Version: 1.0 To: Mark Brown CC: Thierry Reding , Wei Ni , Mursalin Akon , "'linux-mmc@vger.kernel.org'" , "devicetree-discuss@lists.ozlabs.org" , "'linux-wireless@vger.kernel.org'" , "linux-tegra@vger.kernel.org" , Rakesh Kumar , "linux-arm-kernel@lists.infradead.org" Subject: Re: Where to power on the wifi device before loading the driver. References: <6B4D417B830BC44B8026029FD256F7F1C377BFFE88@HKMAIL01.nvidia.com> <4FD90352.9090606@wwwdotorg.org> <20120614063120.GA20167@avionic-0098.mockup.avionic-design.de> <20120614121234.GC3913@opensource.wolfsonmicro.com> In-Reply-To: <20120614121234.GC3913@opensource.wolfsonmicro.com> Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 06/14/2012 06:12 AM, Mark Brown wrote: > On Thu, Jun 14, 2012 at 08:31:20AM +0200, Thierry Reding wrote: >> On Wed, Jun 13, 2012 at 03:17:06PM -0600, Stephen Warren wrote: > >>> The core of the issue is that: > >>> * Tegra30 support is via device tree. * We have an SDIO bus, >>> and the WiFi device attached to that bus is enumerable. * Since >>> the WiFi device is enumerable, no node exists in the DT to >>> represent it. * However, the driver for the WiFi device needs >>> certain information, such as the reset GPIO ID and perhaps >>> power GPIO. > >> PCI devices are also enumerable and yet they can be matched up >> with nodes in the device tree. Perhaps something similar could be >> added for the SDIO bus? > > This seems to make the most sense - pushing this through the > regulator API is just a bodge. Yes, that seems reasonable. Presumably the power GPIO should be a fixed regulator though, since it is a power control not just a plain old GPIO? That said, the current driver apparently deals with this as a GPIO already. The reset GPIO can separately/directly controlled by the WiFi driver though.