On Wed, Sep 16, 2015 at 12:23:26AM -0300, Fabio Estevam wrote: > On Tue, Sep 15, 2015 at 10:49 PM, Peter Chen <[email protected]> wrote: > > Some SoCs needs three clock to let controller work, but others only > > need one, add one property to differentiate this. > > > > Signed-off-by: Peter Chen <[email protected]> > > --- > > Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt | 3 +++ > > 1 file changed, 3 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > index f15a317..4900092 100644 > > --- a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > +++ b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt > > @@ -54,6 +54,9 @@ i.mx specific properties > > argument that indicate usb controller index > > - disable-over-current: disable over current detect > > - external-vbus-divider: enables off-chip resistor divider for Vbus > > +- need-three-clocks: the SoC before imx6 series (except for imx23/imx28) > > + needs three clcoks for controller, others only need one. Without this > > + property, the driver will consider this controller only need one clock. > > Looking at mx31, mx35, mx25 reference manuals we see that they don't > really need three usb clocks. > > Also, if we look at the old drivers/usb/host/ehci-mxc.c we only > require 'ipg' and 'ahb' clocks. >
but drivers/usb/gadget/udc/fsl_mxc_udc.c has three clocks > So it would be better to just require these two clocks and if they are > not found on dts, then we fall back to requesting clk_get(NULL), > without the need of an extra property. I considered before, but if it has clk_ipg, but without clk_ahb, do we consider it is an error or not ? Using extra property can make things cleaner. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
