[U-Boot] [PATCH 3/3] imx: mx6sllevk: add usb support

[Peng Fan]

> -----Original Message-----
> From: Marek Vasut [mailto:marex at denx.de]
> Sent: Wednesday, December 21, 2016 10:10 PM
> To: Peng Fan <peng.fan at nxp.com>; sbabic at denx.de
> Cc: u-boot at lists.denx.de; van.freenix at gmail.com
> Subject: Re: [PATCH 3/3] imx: mx6sllevk: add usb support
> 
> On 12/21/2016 09:14 AM, Peng Fan wrote:
> > Add usb support for mx6sllevk board.
> >
> > Signed-off-by: Peng Fan <peng.fan at nxp.com>
> > Cc: Stefano Babic <sbabic at denx.de>
> > ---
[......]

> > +
> > +#define USB_OTHERREGS_OFFSET   0x800
> > +#define UCTRL_PWR_POL          (1 << 9)
> > +
> > +int board_ehci_hcd_init(int port)
> > +{
> > +	u32 *usbnc_usb_ctrl;
> > +
> > +	if (port > 1)
> > +		return -EINVAL;
> > +
> > +	usbnc_usb_ctrl = (u32 *)(USB_BASE_ADDR + USB_OTHERREGS_OFFSET
> +
> > +				 port * 4);
> > +
> > +	/* Set Power polarity */
> > +	setbits_le32(usbnc_usb_ctrl, UCTRL_PWR_POL);
> > +	return 0;
> > +}
> 
> Is this function similar to what usb_oc_config() does ?

No, this bit is not for overcurrent. According to RM, this is OTG Power Polarity
This bit should be set according to power switch's enable polarity.
1 Power switch has an active-high enable input
0 Power switch has an active-low enable input

This is board specific.

Regards,
Peng.

> 
> --
> Best regards,
> Marek Vasut