From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:47630 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495Ab3ILKl3 (ORCPT ); Thu, 12 Sep 2013 06:41:29 -0400 Date: Thu, 12 Sep 2013 12:41:26 +0200 From: Sascha Hauer To: Sean Cross Cc: devicetree@vger.kernel.org, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Shawn Guo Subject: Re: [PATCH v3 3/3] PCI: imx6: Add support for i.MX6 PCIe controller Message-ID: <20130912104126.GS30088@pengutronix.de> References: <1378958611-4274-1-git-send-email-xobs@kosagi.com> <1378958611-4274-4-git-send-email-xobs@kosagi.com> <20130912062859.GM30088@pengutronix.de> <6FF3113C3FCC43A4A0D711C8656A4C03@kosagi.com> <20130912070131.GO30088@pengutronix.de> <65E0D2C79B2B43D28CC77454F44ECCFA@kosagi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <65E0D2C79B2B43D28CC77454F44ECCFA@kosagi.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Thu, Sep 12, 2013 at 03:11:45PM +0800, Sean Cross wrote: > > Even if it should be configurable I'm still unsure whether this should > > be done at pci driver level. > > I'm a bit wary of including clock setup like this in the SoC code, as > different boards might be different. If a board designer wants to run > LVDS2 to the PCIe slot, that's entirely acceptable. It might not > actually ever get done, but it seems like the sort of board-specific > thing that device tree was designed to handle. The devicetree was designed to handle hardware descriptions, not configuration options. Chosing the clock parent is probably in the grey area between hardware description and configuration, so I assume when we find a good reason to add this option to the devicetree then it's acceptable to add it there. But we shouldn't add this option for something that, as you say, 'might not actually ever get done'. Just hardcode the clock selection in SoC code for now. If someone ever finds the good reason to make this configurable then he will speak up and we can discuss this again. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |