From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH 01/13] usb: phy: nop: Add device tree support and binding information Date: Mon, 11 Mar 2013 16:53:22 +0100 Message-ID: <513DFDF2.7060407@pengutronix.de> References: <1359993540-20780-1-git-send-email-rogerq@ti.com> <1359993540-20780-2-git-send-email-rogerq@ti.com> <5139C174.7030401@pengutronix.de> <513A079A.1020106@pengutronix.de> <513D9893.50703@ti.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="----enig2TCLIKDJTLQMOVVBRSSCO" Return-path: In-Reply-To: <513D9893.50703@ti.com> Sender: linux-omap-owner@vger.kernel.org To: Roger Quadros Cc: tony@atomide.com, b-cousson@ti.com, balbi@ti.com, stern@rowland.harvard.edu, linux@arm.linux.org.uk, linux-usb@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, rnayak@ti.com, paul@pwsan.com List-Id: devicetree@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) ------enig2TCLIKDJTLQMOVVBRSSCO Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 03/11/2013 09:40 AM, Roger Quadros wrote: > On 03/08/2013 05:45 PM, Marc Kleine-Budde wrote: >> On 03/08/2013 11:46 AM, Marc Kleine-Budde wrote: >>> On 02/04/2013 04:58 PM, Roger Quadros wrote: >>>> The PHY clock, clock rate, VCC regulator and RESET regulator >>>> can now be provided via device tree. >>>> >>>> Signed-off-by: Roger Quadros >>>> --- >>>> .../devicetree/bindings/usb/usb-nop-xceiv.txt | 34 +++++++++= +++++++++++ >>>> drivers/usb/otg/nop-usb-xceiv.c | 31 +++++++++= +++++++++ >>>> 2 files changed, 65 insertions(+), 0 deletions(-) >>>> create mode 100644 Documentation/devicetree/bindings/usb/usb-nop-xc= eiv.txt >>>> >>>> diff --git a/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt= b/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt >>>> new file mode 100644 >>>> index 0000000..d7e2726 >>>> --- /dev/null >>>> +++ b/Documentation/devicetree/bindings/usb/usb-nop-xceiv.txt >>>> @@ -0,0 +1,34 @@ >>>> +USB NOP PHY >>>> + >>>> +Required properties: >>>> +- compatible: should be usb-nop-xceiv >>>> + >>>> +Optional properties: >>>> +- clocks: phandle to the PHY clock. Use as per Documentation/device= tree >>>> + /bindings/clock/clock-bindings.txt >>>> + This property is required if clock-frequency is specified. >>>> + >>>> +- clock-names: Should be "main_clk" >>>> + >>>> +- clock-frequency: the clock frequency (in Hz) that the PHY clock m= ust >>>> + be configured to. >>>> + >>>> +- vcc-supply: phandle to the regulator that provides RESET to the P= HY. >>>> + >>>> +- reset-supply: phandle to the regulator that provides power to the= PHY. >>>> + >>>> +Example: >>>> + >>>> + hsusb1_phy { >>>> + compatible =3D "usb-nop-xceiv"; >>>> + clock-frequency =3D <19200000>; >>> >>> Why do you hardcode the clock frequency here? You should use >>> clk_get_rate() to get the frequency from the clock tree. >> >> What about declaring a "fixed-clock" node in the device tree? Then it >> should be possible to keep the driver free of any omap specific code. >> >=20 > The current implementation is not OMAP specific and is not limited to a= > fixed frequency clock. The PHY driver is using standard clock APIs to s= et > the clock rate 'only' if the 'clock-frequency' property is present in t= he > device tree node. >=20 > What is the benefit of declaring it as a "fixed-clock"? > FYI. The clock may not necessarily be a fixed frequency clock and someo= ne > needs to program the rate. Okay, now I got 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 | ------enig2TCLIKDJTLQMOVVBRSSCO Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlE9/fIACgkQjTAFq1RaXHN2ngCfWFzbH6bEHrsqTfMpyAZUsvgU KlYAn0UIBZeJyu8PDxFqrMhefCoUIWig =kvkj -----END PGP SIGNATURE----- ------enig2TCLIKDJTLQMOVVBRSSCO--