[PATCH v3 0/7] FUSB302 USB-C controller support

[Marek Vasut]

On 8/18/24 11:43 PM, Jonas Karlman wrote:

Hi,

>>> On ROCK 5B power is usually supplied via it's USB-C port. This port has the
>>> data lines connected to RK3588, VBUS connected to the input regulator and
>>> CC pins connected to FUSB302. FUSB302 is a USB-C controller, which can be
>>> accessed via I2C from RK3588. The USB-C controller is needed to figure out
>>> the USB-C cable orientation, but also to do USB PD communication. Thus it
>>> would be great to enable support for it in the operating system.
>>>
>>> But the USB-PD specification requires, that a device reacts to USB-PD messages
>>> send by the power-supply within around 5 seconds. If that does not happen the
>>> power-supply assumes, that the device does not support USB-PD. If a device
>>> later starts sending USB-PD messages it is considered an error, which is solved
>>> by doing a hard reset. A USB-PD hard reset means, that all supply voltages are
>>> removed for a short period of time. For boards, which are solely powered
>>> through their USB-C port, like the Radxa Rock 5B, this results in an machine
>>> reset. This is currently worked around by not describing the FUSB302 in the
>>> kernel DT, so nothing will ever speak USB-PD on the Rock 5B. This means
>>>
>>> 1. the USB-C port cannot be used at all
>>> 2. the board will be running via fallback supply, which provides limited
>>>      power capabilities
>>>
>>> In order to avoid the hard reset, this adds FUSB302 support to U-Boot, so
>>> that we react to the power-supply's queries in time. The code, which is
>>> originally from the Linux kernel, consists of two parts:
>>>
>>> 1. the tcpm state machine, which implements the Type C port manager state
>>>      machine as described in the USB PD specification
>>> 2. the fusb302 driver, which knows about specific registers
>>>
>>> Especially the first part has been heavily modified compared to the
>>> kernel, which makes use of multiple delayed works and threads. For this
>>> I used a priorly ported version from Rockchip, removed their hacks and
>>> any states not necessary in U-Boot (e.g. audio accessory support).
>>>
>>> Sorry for the delay in getting PATCHv3 ready.
>>
>> I am the one who should be sorry here, really, sorry for the abysmal
>> delay in my replies.
>>
>> So ... this series looks good to me. Thank you for working on this !
>>
>> Jonas, are your concerns resolved ?
> 
> No, for ROCK 5B the full overwrite of the Rockchip common misc_init_r()
> in mach-rockchip/board.c should be fixed, rockchip_early_misc_init_r()
> could probably be used instead (or possible a PREBOOT cmd), see [1].

Can you use DM_FLAG_PROBE_AFTER_BIND instead of misc_init_r for this ?

drivers/led/led-uclass.c: dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);

This will probe the driver after it got bound, and you won't have to 
hack around board files or arch files for this.