From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754746Ab2ISOud (ORCPT ); Wed, 19 Sep 2012 10:50:33 -0400 Received: from metis.ext.pengutronix.de ([92.198.50.35]:49601 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752415Ab2ISOub (ORCPT ); Wed, 19 Sep 2012 10:50:31 -0400 Message-ID: <5059DBA4.5010906@pengutronix.de> Date: Wed, 19 Sep 2012 16:50:12 +0200 From: Marc Kleine-Budde Organization: Pengutronix e.K. User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120907 Thunderbird/15.0.1 MIME-Version: 1.0 To: balbi@ti.com CC: Kishon Vijay Abraham I , grant.likely@secretlab.ca, rob.herring@calxeda.com, rob@landley.net, linux@arm.linux.org.uk, linux-usb@vger.kernel.org, linux-omap@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 4/4] usb: phy: omap-usb2: enable 960Mhz clock for omap5 References: <1348054229-27362-1-git-send-email-kishon@ti.com> <1348054229-27362-5-git-send-email-kishon@ti.com> <20120919115647.GI3772@arwen.pp.htv.fi> <5059DA6D.4070205@pengutronix.de> <20120919144247.GB7004@arwen.pp.htv.fi> In-Reply-To: <20120919144247.GB7004@arwen.pp.htv.fi> X-Enigmail-Version: 1.4.4 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigB3CF75A3AD14BF42133A3BDE" X-SA-Exim-Connect-IP: 2001:6f8:1178:4:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigB3CF75A3AD14BF42133A3BDE Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 09/19/2012 04:42 PM, Felipe Balbi wrote: > On Wed, Sep 19, 2012 at 04:45:01PM +0200, Marc Kleine-Budde wrote: >> On 09/19/2012 01:56 PM, Felipe Balbi wrote: >>> On Wed, Sep 19, 2012 at 05:00:29PM +0530, Kishon Vijay Abraham I wrot= e: >>>> "usb_otg_ss_refclk960m" is needed by usb2 phy present in omap5. For >>>> omap4, the clk_get of this clock will fail since it does not have th= is >>>> clock. >>>> >>>> Signed-off-by: Kishon Vijay Abraham I >>>> --- >>>> Documentation/devicetree/bindings/usb/usb-phy.txt | 3 +++ >>>> drivers/usb/phy/omap-usb2.c | 28 ++++++++++= ++++++++++- >>>> 2 files changed, 30 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/Documentation/devicetree/bindings/usb/usb-phy.txt b/Doc= umentation/devicetree/bindings/usb/usb-phy.txt >>>> index 7c5fd89..d5626de 100644 >>>> --- a/Documentation/devicetree/bindings/usb/usb-phy.txt >>>> +++ b/Documentation/devicetree/bindings/usb/usb-phy.txt >>>> @@ -24,6 +24,9 @@ Required properties: >>>> add the address of control module phy power register until a driver= for >>>> control module is added >>>> =20 >>>> +Optional properties: >>>> + - has960mhzclk: should be added if the phy needs 960mhz clock >>>> + >>>> This is usually a subnode of ocp2scp to which it is connected. >>>> =20 >>>> usb3phy@4a084400 { >>>> diff --git a/drivers/usb/phy/omap-usb2.c b/drivers/usb/phy/omap-usb2= =2Ec >>>> index d36c282..d6612ba 100644 >>>> --- a/drivers/usb/phy/omap-usb2.c >>>> +++ b/drivers/usb/phy/omap-usb2.c >>>> @@ -146,6 +146,7 @@ static int __devinit omap_usb2_probe(struct plat= form_device *pdev) >>>> struct omap_usb *phy; >>>> struct usb_otg *otg; >>>> struct resource *res; >>>> + struct device_node *np =3D pdev->dev.of_node; >>>> =20 >>>> phy =3D devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL); >>>> if (!phy) { >>>> @@ -190,6 +191,15 @@ static int __devinit omap_usb2_probe(struct pla= tform_device *pdev) >>>> } >>>> clk_prepare(phy->wkupclk); >>>> =20 >>>> + if (of_property_read_bool(np, "has960mhzclk")) { >>>> + phy->optclk =3D devm_clk_get(phy->dev, "usb_otg_ss_refclk960m"); >>>> + if (IS_ERR(phy->optclk)) { >>>> + dev_err(&pdev->dev, "unable to get refclk960m\n"); >>>> + return PTR_ERR(phy->optclk); >>>> + } >>>> + clk_prepare(phy->optclk); >>>> + } >>> >>> instead, can't you just always try to get the clock but ignore the er= ror >>> if it fails ? >> >> On imx we add no-op dummy clocks, so that the drivers will always find= >> all needed clocks. If a clk_get fails it's an error. >=20 > It's an error from a clk API point of view, it doesn't mean device can'= t > work without that optional clock. Drivers are free to treat errors > however they like, even by ignoring it and defaulting to some other > behavior. Sure. > Adding dummy clocks just bloats the kernel with useless data IMHO. Just wanted to point out there's more than one way to do it. Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --------------enigB3CF75A3AD14BF42133A3BDE Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://www.enigmail.net/ iEYEARECAAYFAlBZ26QACgkQjTAFq1RaXHNidACgiQOB957xoy/7jcqi73SjGClP 9MEAmQE9zu7t4GFsHTiTINrqyDesLx0G =EMT4 -----END PGP SIGNATURE----- --------------enigB3CF75A3AD14BF42133A3BDE--