Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934652Ab3FSMFH (ORCPT ); Wed, 19 Jun 2013 08:05:07 -0400 Received: from smtp0.epfl.ch ([128.178.224.218]:59765 "HELO smtp0.epfl.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S934297Ab3FSMFF (ORCPT ); Wed, 19 Jun 2013 08:05:05 -0400 Message-ID: <51C19E6C.4040802@epfl.ch> Date: Wed, 19 Jun 2013 14:05:00 +0200 From: Florian Vaussard Reply-To: florian.vaussard@epfl.ch User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130514 Thunderbird/17.0.6 MIME-Version: 1.0 To: Roger Quadros CC: Benoit Cousson , devicetree-discuss@lists.ozlabs.org, linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org 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> In-Reply-To: <51C19011.5050107@ti.com> 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: 2818 Lines: 75 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. Regards, Florian [1] http://thread.gmane.org/gmane.linux.drivers.devicetree/36830 -- 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/