From mboxrd@z Thu Jan 1 00:00:00 1970 From: mkl@pengutronix.de (Marc Kleine-Budde) Date: Mon, 11 Mar 2013 16:53:22 +0100 Subject: [PATCH 01/13] usb: phy: nop: Add device tree support and binding information In-Reply-To: <513D9893.50703@ti.com> 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> Message-ID: <513DFDF2.7060407@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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-xceiv.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/devicetree >>>> + /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 must >>>> + be configured to. >>>> + >>>> +- vcc-supply: phandle to the regulator that provides RESET to the PHY. >>>> + >>>> +- reset-supply: phandle to the regulator that provides power to the PHY. >>>> + >>>> +Example: >>>> + >>>> + hsusb1_phy { >>>> + compatible = "usb-nop-xceiv"; >>>> + clock-frequency = <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. >> > > 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 set > the clock rate 'only' if the 'clock-frequency' property is present in the > device tree node. > > What is the benefit of declaring it as a "fixed-clock"? > FYI. The clock may not necessarily be a fixed frequency clock and someone > needs to program the rate. Okay, now I got it. Marc -- 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 | -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 263 bytes Desc: OpenPGP digital signature URL: