[PATCH 1/2] ARM: dts: imx51-babbage: Add USB Host1 support

[Peter Chen]

> 
> Peter,
> 
> Yes for the i.MX51 EVK the USB host 1 has an external PHY (USB3317 HS
> ULPI USB transceiver) which has an integrated 3.3V regulator.  It is used
> in host only mode.  In the older versions (pre device tree) of the code,
> the isp1504 driver was used for the USB3317.  For the device tree in the
> usbphy1 node it is defined as usb-nop-xceiv, but in the usbh1 node
> phy_type is ulpi.  The reason the usb-nop-xceiv was used is because we
> could not find any other specific "compatible" value in the PHY drivers
> for the USB3317 external PHY (HS ULPI USB transceiver) for the USB host 1
> port, thus using the generic driver.  Could not find an isp1504 or
> USB3317 driver.  Again it is a host only port and thus the generic phy
> driver is working at least on the i.MX51 EVK.  The hub attached to the
> host port comes up and have successfully attached several types of USB
> devices to the two ports on the attached hub.
> 
> The phy_type of ulpi is needed by the ChipIdea drivers for PHY
> initialization.  So it is using ulpi PHY init.
> 
> I looked for all references to ulpi_viewport_access_ops and did find that
> imx_otg_ulpi_create() references it, but this function is not called from
> any i.MX51 code (does not use ulpi viewport).  For the i.MX51 the
> external PHY/transceiver is not used for OTG, it is only used as a host
> port.
> 

The ulpi phy driver still has not device tree version, so you can't
find related driver.

So, the default ulpi configuration at imx5-bbg board (3317 ulpi phy on it)
works fine according to you and Fabio's test.
The current situation is: nop phy driver can be used due to default configuration
can be used. But in fact, your phy at host 1 is ulpi, but ulpi driver is lack of
device tree support.

Let Shawn decide whether it can be accept or not.

Peter

> Dave
> 
> -----Original Message-----
> From: Peter Chen [mailto:Peter.Chen at freescale.com]
> Sent: Wednesday, March 26, 2014 1:36 AM
> To: Fabio Estevam
> Cc: Shawn Guo; linux-arm-kernel at lists.infradead.org;
> Fabio.Estevam at freescale.com; Ebright, Dave
> Subject: RE: [PATCH 1/2] ARM: dts: imx51-babbage: Add USB Host1 support
> 
> 
> 
> >
> > On Tue, Mar 25, 2014 at 11:00 PM, Peter Chen
> > <Peter.Chen at freescale.com>
> > wrote:
> >
> > >> +
> > >> +             usbphy1: usbphy at 1 {
> > >> +                     compatible = "usb-nop-xceiv";
> > >> +                     reg = <1>;
> > >> +                     clocks = <&clks IMX5_CLK_USB_PHY_GATE>;
> > >> +                     clock-names = "main_clk";
> > >> +             };
> > >>       };
> > >>
> > >
> > > You are using usb nop phy driver (phy-generic.c) for ulpi phy, Are
> > > you sure your phy doesn't need any configurations from viewport?
> >
> > I am not sure I understood your comment.
> >
> > This node is the same like we do on mx53 and other i.mx SoCs.
> >
> 
> For imx53, it can work since both usbotg and host 1 use utmi internal phy.
> But for SoCs before than imx53 (including imx51), the host1 uses external
> phy. At non-dt version, they should use ulpi phy driver.
> 
> Peter
> 
> > Both USB host and OTG are functional.
> >
> > Could you please explain your concern?
> >
> > Regards,
> >
> > Fabio Estevam
> >