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

[Peng Fan]

Hi Marek,

> -----Original Message-----
> From: Marek Vasut [mailto:marex at denx.de]
> Sent: Thursday, December 22, 2016 12:40 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 12/22/2016 02:13 AM, Peng Fan wrote:
> >
> >
> >> -----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.
> 
> Great, except it should also be part of the driver , the same way as polarity is
> configured, yes ?

I just found that there is code for mx7, http://lists.denx.de/pipermail/u-boot/2016-July/260321.html

Then do you agree I add such piece code in usb_power_config for mx6?
"
#ifdef CONFIG_MXC_USB_OTG_HACTIVE
        setbits_le32(ctrl, UCTRL_PWR_POL); 
#else 
        clrbits_le32(ctrl, UCTRL_PWR_POL);        
#endif
"

Thanks,
Peng
> 
> 
> --
> Best regards,
> Marek Vasut