[RFC v1 7/7] usb: onboard-hub: Add conditional compilation for I2C initialization

[Anand Moon]

Hi Quentin,

On Mon, 12 May 2025 at 12:36, Quentin Schulz <quentin.schulz at cherry.de> wrote:
>
> Hi Anand,
>
> On 5/9/25 7:45 PM, Anand Moon wrote:
> > Hi Quentin,
> >
> > On Fri, 9 May 2025 at 17:21, Quentin Schulz <quentin.schulz at cherry.de> wrote:
> >>
> >> Hi Neil, Anand,
> >>
> >> On 5/9/25 9:57 AM, Neil Armstrong wrote:
> >>> On 09/05/2025 09:02, Anand Moon wrote:
> >>>> Add conditional compilation for the usb5744_i2c_init() function based
> >>>> on the CONFIG_DM_I2C configuration, to avoid compilation failure.
> >>>>
> >>>>     CC      net/net-common.o
> >>>>     AR      net/built-in.o
> >>>>     LDS     u-boot.lds
> >>>>     LD      u-boot
> >>>> aarch64-linux-gnu-ld.bfd: common/usb_onboard_hub.o: in function
> >>>> `usb5744_i2c_init':
> >>>> /home/amoon/mainline/u-boot/amlogic/u-boot-maineline/common/
> >>>> usb_onboard_hub.c:74:(.text.usb5744_i2c_init+0xfc): undefined
> >>>> reference to `i2c_get_chip'
> >>>> aarch64-linux-gnu-ld.bfd: /home/amoon/mainline/u-boot/amlogic/u-boot-
> >>>> maineline/common/usb_onboard_hub.c:89:(.text.usb5744_i2c_init+0x1a0):
> >>>> undefined reference to `dm_i2c_write'
> >>>> aarch64-linux-gnu-ld.bfd: /home/amoon/mainline/u-boot/amlogic/u-boot-
> >>>> maineline/common/usb_onboard_hub.c:96:(.text.usb5744_i2c_init+0x1c8):
> >>>> undefined reference to `dm_i2c_write'
> >>>> aarch64-linux-gnu-ld.bfd: /home/amoon/mainline/u-boot/amlogic/u-boot-
> >>>> maineline/common/usb_onboard_hub.c:104:(.text.usb5744_i2c_init+0x1f0):
> >>>> undefined reference to `dm_i2c_write'
> >>>> Segmentation fault (core dumped)
> >>>> make: *** [Makefile:1824: u-boot] Error 139
> >>>> make: *** Deleting file 'u-boot'
> >>>>
> >>>> Signed-off-by: Anand Moon <linux.amoon at gmail.com>
> >>>> ---
> >>>>    common/usb_onboard_hub.c | 4 ++++
> >>>>    1 file changed, 4 insertions(+)
> >>>>
> >>>> diff --git a/common/usb_onboard_hub.c b/common/usb_onboard_hub.c
> >>>> index 1242513c631..92e3f3a92c9 100644
> >>>> --- a/common/usb_onboard_hub.c
> >>>> +++ b/common/usb_onboard_hub.c
> >>>> @@ -30,6 +30,7 @@ struct onboard_hub_data {
> >>>>        int (*init)(struct udevice *dev);
> >>>>    };
> >>>> +#if CONFIG_IS_ENABLED(DM_I2C)
> >>>>    static int usb5744_i2c_init(struct udevice *dev)
> >>>>    {
> >>>>        /*
> >>>> @@ -109,6 +110,7 @@ static int usb5744_i2c_init(struct udevice *dev)
> >>>>        return 0;
> >>>>    }
> >>>> +#endif
> >>>>    int usb_onboard_hub_reset(struct udevice *dev)
> >>>>    {
> >>>> @@ -222,7 +224,9 @@ static const struct onboard_hub_data usb2514_data = {
> >>>>    };
> >>>>    static const struct onboard_hub_data usb5744_data = {
> >>>> +#if CONFIG_IS_ENABLED(DM_I2C)
> >>>>        .init = usb5744_i2c_init,
> >>>> +#endif
> >>>>        .power_on_delay_us = 1000,
> >>>>        .reset_us = 5,
> >>>>    };
> >>>
> >>> I think you should completely disable usb5744_data in this case
> >>>
> >>
> >> I would recommend to go the same route as the Linux kernel which has a
> >> special Kconfig option for it, c.f. USB_ONBOARD_DEV_USB5744 which adds
> >> the necessary dependencies.
> >>
> > On Linux kernel, it needs to parse the device node with i2c-bus.
> >
>
> Seems like it does in U-Boot too? c.f. usb5744_i2c_init() with
> dev_read_phandle_with_args with i2c-bus?
>
ok.
> >> We probably should be careful and figure out which boards are actually
> >> using the usb5744 and add this symbol to their defconfig so they don't
> >> regress.
> >>
> >  From my initial analysis configs/xilinx_zynqmp_kria_defconfig
> > which use CONFIG_USB_ONBOARD_HUB
> > I believe using DM_I2C to guard the code is the best approach.
> > it should be around .init() callback to guard this to work.
> >
>
> I disagree. The driver clearly supports the USB5744 and the driver is
> compiled regardless of DM_I2C support which is required (as far as I
> understood, maybe that's incorrect?) for being able to use USB5744? I
> don't like hidden dependencies.
>
Okay, I will add a new configuration option to guard the code as done
in the Linux kernel.
> Also, I believe Neil's point is we shouldn't try to probe the USB5744 if
> there is no DM_I2C support, simply excluding .init() callback will
> probably just render this "support" of USB5744 non-functional?
>
Let me debug this more, I will update the next version.
I need to check if this binds correctly to the USB hub reset.
> Cheers,
> Quentin
Thanks
-Anand