Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934640Ab3FSMYH (ORCPT ); Wed, 19 Jun 2013 08:24:07 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:51146 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934108Ab3FSMYF (ORCPT ); Wed, 19 Jun 2013 08:24:05 -0400 Message-ID: <51C1A2AE.2020506@ti.com> Date: Wed, 19 Jun 2013 07:23:10 -0500 From: Benoit Cousson Organization: Texas Instruments User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: , Roger Quadros CC: , , , Subject: Re: [PATCH v2 1/4] ARM: dts: omap4-panda: Add USB Host support References: <1371571487-14389-1-git-send-email-rogerq@ti.com> <1371571487-14389-2-git-send-email-rogerq@ti.com> <51C106A1.9030001@ti.com> <51C15F7E.5020305@ti.com> <20130619074605.GW5523@atomide.com> <51C183AC.8040801@ti.com> <51C19011.5050107@ti.com> <51C19E6C.4040802@epfl.ch> In-Reply-To: <51C19E6C.4040802@epfl.ch> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3364 Lines: 95 On 06/19/2013 07:05 AM, Florian Vaussard wrote: > Hello, > > On 06/19/2013 01:03 PM, Roger Quadros wrote: >> On 06/19/2013 01:10 PM, Benoit Cousson wrote: >>> On 06/19/2013 02:46 AM, Tony Lindgren wrote: >>>> * Roger Quadros [130619 00:42]: >>>>> Hi Benoit, >>>>> >>>>> On 06/19/2013 04:17 AM, Benoit Cousson wrote: >>>>>> Hi Roger, >>>>>> >>>>>> On 06/18/2013 11:04 AM, Roger Quadros wrote: >>>>>>> Provide the RESET and Power regulators for the USB PHY, >>>>>>> the USB Host port mode and the PHY device. >>>>>>> >>>>>>> Also provide pin multiplexer information for the USB host >>>>>>> pins. >>>>>>> >>>>>>> Signed-off-by: Roger Quadros >>>>>>> --- >>>>>>> arch/arm/boot/dts/omap4-panda-common.dtsi | 62 >>>>>>> +++++++++++++++++++++++++++++ >>>>>>> 1 files changed, 62 insertions(+), 0 deletions(-) >>>>>>> >>>>>>> diff --git a/arch/arm/boot/dts/omap4-panda-common.dtsi >>>>>>> b/arch/arm/boot/dts/omap4-panda-common.dtsi >>>>>>> index 00cbaa5..7a21e8e 100644 >>>>>>> --- a/arch/arm/boot/dts/omap4-panda-common.dtsi >>>>>>> +++ b/arch/arm/boot/dts/omap4-panda-common.dtsi >>>>>>> @@ -59,6 +59,42 @@ >>>>>>> "AFML", "Line In", >>>>>>> "AFMR", "Line In"; >>>>>>> }; >>>>>>> + >>>>>>> + /* HS USB Port 1 RESET */ >>>>>>> + hsusb1_reset: hsusb1_reset_reg { >>>>>>> + compatible = "regulator-fixed"; >>>>>>> + regulator-name = "hsusb1_reset"; >>>>>>> + regulator-min-microvolt = <3300000>; >>>>>>> + regulator-max-microvolt = <3300000>; >>>>>>> + gpio = <&gpio2 30 0>; /* gpio_62 */ >>>>>>> + startup-delay-us = <70000>; >>>>>>> + enable-active-high; >>>>>>> + }; >>>>>> >>>>>> Is this really a regulator? Or just a GPIO line used to reset the >>>>>> USB PHY? >>>>> >>>>> It is in fact a GPIO line used as reset. >>>>>> >>>>>> If this is the case, I don't think it should be represented as a >>>>>> regulator. >>>>> >>>>> Why not? I think it fits very well in the regulator device model. >>> >>> I'm not sure fitting very well is the correct term. >>> It works, for sure, but it is no different than when we were trying >>> to abuse the regulator fmwk to enable the 32k clock in phoenix. >>> It is just a hack. >>> >> >> The only difference is there is a dedicated framework for clocks. >> Since there is nothing specific to >> handle reset lines it is left to the driver writer how he wants to >> manage it. >> > > There is a proposed binding for gpio-controlled reset lines, but it is > not yet merged [1]. > I guess it can fit most usage patterns, and it can be an interesting > move in the future. I'm glad to see that I was not the only one thinking that the regulator was not the right fmwk to do that :-) Thanks for the pointer Florian. I guess that series should be merged for 3.11? Based on the thread, it should to through arm-soc. Roger, It might be tricky to have dependency on that series, but if this is possible, you should try. Otherwise, just keep the existing one, adding that a new solution will be available soon as a disclaimer. Regards, Benoit -- 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/