[U-Boot] [PATCH v5 10/18] tegra: usb: fdt: Add additional device tree definitions for USB ports

[Simon Glass]

Hi Stephen,

On Thu, Feb 2, 2012 at 2:07 PM, Stephen Warren <swarren at nvidia.com> wrote:
> On 01/24/2012 04:21 PM, Simon Glass wrote:
>> This adds clock references to the USB part of the device tree for U-Boot.
>>
>> The USB timing information may vary between boards sometimes, but for
>> now we hard-code it in C. This is because all current T2x boards use
>> the same values, we will deal with T3x later and we first need to agree
>> on the format for this timing information in the fdt and may in fact
>> decide that it has no place there.
>
> The patch below does more than what's covered by this description...
>
>> Signed-off-by: Simon Glass <sjg at chromium.org>
>> ---
>> Changes in v5:
>> - Add dr_mode property to control host/device/otg mode
>> - Add nvidia,has-legacy-mode property per review comments
>> - Change device tree comment style from // to /* */
>>
>>  arch/arm/dts/tegra20.dtsi |    7 +++++++
>>  1 files changed, 7 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/arm/dts/tegra20.dtsi b/arch/arm/dts/tegra20.dtsi
>> index ec75747..b2e3a40 100644
>> --- a/arch/arm/dts/tegra20.dtsi
>> +++ b/arch/arm/dts/tegra20.dtsi
>> @@ -176,6 +176,9 @@
>>               reg = <0xc5000000 0x4000>;
>>               interrupts = < 52 >;
>>               phy_type = "utmi";
>> +             clocks = <&periph_clk 22>;      /* PERIPH_ID_USBD */
>> +             dr_mode = "otg";
>
> The dr_mode value is board-specific, so should be in tegra-seaboard.dts
> not tegra20.dtsi.

Done

>
> For example, on true Seaboard, perhaps USB3 could operate in "otg" mode
> since it's an external port, whereas on Springbank, USB3 is hard-wired
> to a keyboard controller, so should be marked "host" mode only.

OK. I was seeing it as an SOC capability rather than a board feature.

>
> Related, I assume that any port marked as "otg" needs to have a VBUS
> GPIO defined so that it can be turned off in device mode, or is VBUS
> controlled by some other mechanism in some cases? Given that, I /think/
> you can't actually mark USB3 as "otg" or "device" on Seaboard since
> there's no VBUS GPIO.

Done. In principle VBUS can be controlled by a bit in the peripheral
controller driving out a VBUS enable line, but that's not how it works
in this case.

>
> --
> nvpublic

Regards,
Simon