[PATCH v1 0/5] FUSB302 USB-C controller support

[Jonas Karlman]

Hi Sebastian,

On 2024-05-31 17:08, Sebastian Reichel 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).

Thanks for working on this!

Some initial quick feedback is that the tcpm uclass and driver should
probably take more advantage of the u-boot driver model.

Few quick thoughts:
- Split out uclass/driver api parts into tcpm-uclass.c
- Take advantage of uclass_driver ops such as post_probe and
  per_device_auto/per_device_plat_auto to e.g. handle tcpm_port_init and
  tcpm_port/tcpm_dev
- udevice should probably be passed to tcpm_ functions instead of a
  tcpm_port, dev_get_uclass_plat/priv could possible be used to get
  the tcpm_port data for the udevice

I have not yet had time to runtime test this but will do and get back
with a more in depth review later this week.

Regards,
Jonas

> 
> Greetings,
> 
> -- Sebastian
> 
> Sebastian Reichel (5):
>   usb: tcpm: add core framework
>   usb: tcpm: fusb302: add driver
>   board: rock5b-rk3588: add USB-C controller support
>   board: rock5b-rk3588: enable USB-C in operating system
>   MAINTAINERS: add TCPM section
> 
>  MAINTAINERS                               |    8 +
>  Makefile                                  |    1 +
>  arch/arm/dts/rk3588-rock-5b-u-boot.dtsi   |   28 +
>  board/radxa/rock5b-rk3588/Makefile        |    6 +
>  board/radxa/rock5b-rk3588/rock5b-rk3588.c |   33 +
>  cmd/Kconfig                               |    7 +
>  cmd/Makefile                              |    1 +
>  cmd/tcpm.c                                |  117 +
>  configs/rock5b-rk3588_defconfig           |    5 +
>  drivers/usb/Kconfig                       |    2 +
>  drivers/usb/tcpm/Kconfig                  |   16 +
>  drivers/usb/tcpm/Makefile                 |    4 +
>  drivers/usb/tcpm/fusb302.c                | 1427 ++++++++++++
>  drivers/usb/tcpm/fusb302_reg.h            |  177 ++
>  drivers/usb/tcpm/tcpm.c                   | 2406 +++++++++++++++++++++
>  include/dm/uclass-id.h                    |    1 +
>  include/usb/pd.h                          |  516 +++++
>  include/usb/tcpm.h                        |  116 +
>  18 files changed, 4871 insertions(+)
>  create mode 100644 board/radxa/rock5b-rk3588/Makefile
>  create mode 100644 board/radxa/rock5b-rk3588/rock5b-rk3588.c
>  create mode 100644 cmd/tcpm.c
>  create mode 100644 drivers/usb/tcpm/Kconfig
>  create mode 100644 drivers/usb/tcpm/Makefile
>  create mode 100644 drivers/usb/tcpm/fusb302.c
>  create mode 100644 drivers/usb/tcpm/fusb302_reg.h
>  create mode 100644 drivers/usb/tcpm/tcpm.c
>  create mode 100644 include/usb/pd.h
>  create mode 100644 include/usb/tcpm.h
>