* Ben Dooks <[email protected]> [151012 11:22]: > On 12/10/15 18:45, Tony Lindgren wrote: > > * 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? > > I don't see that helps enabling the clock. The code decideds if > no EHCI ports in use that it doesn't need to enable the EHCI fclk.
Right, you need to do clk_prepare_enable() in it first? :) 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
