* Ben Dooks <[email protected]> [151012 10:38]: > The AM3715 OHCI controller will not function without the EHCI > unit's 120m fclk being enabled. If all the ports in the system > are set to OHCI then the 120m_fclk will not get enabled and no > devices are detected. > > Add a new (optional) property to signal the system must enable > the 120m_fck for OHCI so that if no EHCI ports are signalled > then the 120m_fclk should be enabled. > > We have found no information about why this is necessary, but > it is suspected the EHCI controller does not complete the initial > reset sequence and therefore does not hand control of the USB > port back. > > Signed-off-by: Ben Dooks <[email protected]> > --- > Documentation/devicetree/bindings/usb/omap-usb.txt | 3 +++ > drivers/mfd/omap-usb-host.c | 4 ++++ > 2 files changed, 7 insertions(+) > > diff --git a/Documentation/devicetree/bindings/usb/omap-usb.txt > b/Documentation/devicetree/bindings/usb/omap-usb.txt > index 38d9bb8..fb5fea5 100644 > --- a/Documentation/devicetree/bindings/usb/omap-usb.txt > +++ b/Documentation/devicetree/bindings/usb/omap-usb.txt > @@ -23,6 +23,9 @@ OMAP MUSB GLUE > Optional properties: > - ctrl-module : phandle of the control module this glue uses to write to > mailbox > + - ti,ohci-needs-120m-fck : bool, enable the 120m ehci clock even if just > + using ohci. Needed for AM3517 in OHCI only mode. > + > > SOC specific device node entry > usb_otg_hs: usb_otg_hs@4a0ab000 { > diff --git a/drivers/mfd/omap-usb-host.c b/drivers/mfd/omap-usb-host.c > index 1d924d1..13880cf 100644 > --- a/drivers/mfd/omap-usb-host.c > +++ b/drivers/mfd/omap-usb-host.c > @@ -680,6 +680,10 @@ static int usbhs_omap_probe(struct platform_device *pdev) > need_logic_fck |= true; > } > > + /* The AM3517 requries the 120m-fck active to allow the OHCI to > work */ > + if (of_property_read_bool(dev->of_node, > "ti,ohci-needs-120m-fck")) > + need_logic_fck |= true; > + > if (need_logic_fck) { > omap->ehci_logic_fck = devm_clk_get(dev, > "usbhost_120m_fck");
Hmm why not just use the standard device tree clocks property and then do clk_get_rate() on the clock? Regards, Tony -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
