Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752082AbcDRMaw (ORCPT ); Mon, 18 Apr 2016 08:30:52 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:53163 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751879AbcDRMau (ORCPT ); Mon, 18 Apr 2016 08:30:50 -0400 Subject: Re: [PATCH v2 1/5] phy: Add a driver for simple phy To: Arnd Bergmann References: <1447708924-15076-1-git-send-email-albeu@free.fr> <1447708924-15076-2-git-send-email-albeu@free.fr> <570F303A.6030605@ti.com> <4848615.OezLJod6Cv@wuerfel> CC: Alban Bedel , , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Ralf Baechle , , From: Kishon Vijay Abraham I Message-ID: <5714D35B.8000208@ti.com> Date: Mon, 18 Apr 2016 18:00:19 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <4848615.OezLJod6Cv@wuerfel> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1759 Lines: 43 Hi Arnd, On Sunday 17 April 2016 01:20 AM, Arnd Bergmann wrote: > On Thursday 14 April 2016 11:22:58 Kishon Vijay Abraham I wrote: >> >> IMO simple-phy driver should be an independent driver and shouldn't export >> symbols. The dt binding for the simple phy device should be something like >> below where all the properties of the simple phy device should be in the >> binding documentation. >> usbphy { >> compatible = "simple-phy"; >> phy-supply = <&supply>; >> clocks = <&clock>; >> reset = <&reset>; >> }; >> >> Anything that needs more than this shouldn't be a simple phy. > > I think there are two aspects here: > > a) I agree that a driver that matches "simple-phy" should only call > the generic functions and not use any other properties. > > b) Independent of that, I think that it makes a lot of sense to export > those functions from the generic PHY subsystems so they can be > called from drivers that are a little less generic, or that already > have an established binding but need no other code. These export functions can be abused and called directly from the controller driver bypassing the phy core. Actually lot of generic PHY programming are done in the phy-core itself. (For example, the generic PHY regulator binding "phy-supply" can be used for the phy core to enable the regulator during power on and disable during power off, phy core also invokes pm_runtime API's during power_on and power_off which can be used to enable/disable clocks). So drivers which are less generic can just populate their specific handling part in their phy ops and leave the rest to be done in phy core. "simple-phy" should be used to avoid adding new PHY drivers that does simple PHY ops. Thanks Kishon