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

[Marek Vasut]

On 12/22/2016 07:38 AM, Peng Fan wrote:
> 
> 
>> -----Original Message-----
>> From: Marek Vasut [mailto:marex at denx.de]
>> Sent: Thursday, December 22, 2016 2:12 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 07:03 AM, Peng Fan wrote:
>>>
>>> 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
>>> "
>>
>> Didn't you add DT support in a patch sent like ... yesterday ? :) Just use DT
>> property instead of ifdef.
> 
> There is no property for otg power polatiry in upstream Linux. I would not like to introduce one
> in U-Boot. We can drop the ifdef when there is an property in upstream. What do you think?

So uh, how can the USB work in mainline Linux on that board ?

-- 
Best regards,
Marek Vasut