[U-Boot] [PATCH RFC] OMAP5: uEVM: Enable USB EHCI functionality (preliminary, not tested)

Lubomir Popov
2013-05-18T19:24:11Z

> On 05/18/2013 09:13 PM, Lubomir Popov wrote:
>
>> Hi Gilles,
>>
>>> On 05/16/2013 10:39 AM, Lubomir Popov wrote:
>>>
>>>> Hi Gilles,
>>>>
>>>> On 16/05/13 01:31, Gilles Chanteperdrix wrote:
>>>>> On 05/15/2013 05:55 PM, Lubomir Popov wrote:
>>>>>
>>>>>> Prerequisites: appropriate patches to the USB EHCI and Eth
>>>>>> drivers, and to the OMAP5 clock register definitions.
>>>>>
>>>>>
>>>>> Hi Lubomir,
>>>>>
>>>>> I have been trying to get the USB working on omap5 uEVM yesterday. In
>>>>> addition to your code, I added the changes necessary to pinmux the 79
>>>>> and 80 GPIOS correctly, but it does not seem to work. I suspect there
>>>>> is
>>>>> something else missing than simply USB specific bits, because when
>>>>> the
>>>>> ethernet phy is supposedly out of reset, the ethernet leds keep
>>>>> turned
>>>>> off. I was thinking about checking the PMIC registers.
>>>> PMIC wouldn't be related.
>>>
>>>
>>> Hi,
>>>
>>> My idea was that if the ethernet chip does not power up, maybe it is
>>> because some LDO or SMPS needs to be powered on. The board
>>> documentation
>>> says for some LDOs that they are enabled on boot and does not say for
>>> others, so that may be because they need to be enabled.
>> Both USB devices are powered by VCC_3V3_MAIN, provided by an external
>> SMPS
>> chip (U3). With the default configuration of the uEVM, this SMPS turns
>> on
>> whenever DC wall power is present; the other option - control by the
>> PMIC
>> SYSEN1 output, has no relation to software as well (SYSEN1 is driven by
>> the PMIC power-on/off sequencer, which is burnt into the PMIC EPROM.
>> Upon
>> power-on it goes high at the very beginning of the sequence). So,
>> unfortunately, this could not be the cause.
>> Regarding the Ethernet LEDs, as far as I remember, they didn't light up
>> at
>> all, although Ethernet worked. The smsc95xx driver in u-boot supports
>> the
>> LAN9730 in compatibility mode and probably does not setup LED operation
>> properly.
>
>
> Reading the schematics, it seems to me that the ethernet reset arrives
> on a component using 1.8V which if I am not mistaken comes from the PMIC
> SMPS7.
>
Well, this (1.8 V) is the main I/O supply of the OMAP and most peripherals;
if it were not OK, the board wouldn't work at all.
> --
> Gilles.
>
BR
Lubo