[PATCH 5/7] usb: onboard-hub: Bail out if peer hub is already probed

[Marek Vasut]

On 6/5/24 12:02 PM, Venkatesh Yadav Abbarapu wrote:
> Many physical hub chips include multiple logical hubs to handle both
> USB and 

Remove the 'and' here.

> 2 and 3

USB 2.0 and USB 3.0 .

>. Both logical hubs will then match the onboard hub
> driver, which means it will end up with two driver instances trying to
> control the reset GPIO that is only present once on the physical chip.
> 
> The reference for this change is taken from
> https://lore.barebox.org/barebox/20240327165554.894805-1-l.stach@pengutronix.de/
> 
> Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu at amd.com>
> ---
>   common/usb_onboard_hub.c | 16 +++++++++++++++-
>   1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/common/usb_onboard_hub.c b/common/usb_onboard_hub.c
> index 09ce452af1b..519bad337e1 100644
> --- a/common/usb_onboard_hub.c
> +++ b/common/usb_onboard_hub.c
> @@ -11,6 +11,7 @@
>   #include <common.h>
>   #include <dm.h>
>   #include <dm/device_compat.h>
> +#include <dm/uclass-internal.h>
>   #include <i2c.h>
>   #include <linux/delay.h>
>   #include <power/regulator.h>
> @@ -21,7 +22,7 @@
>   #define USB5744_CONFIG_REG_ACCESS_LSB 0x99
>   
>   struct onboard_hub {
> -	struct udevice *vdd;
> +	struct udevice *vdd, *dev;

One field per line please.

>   	struct gpio_desc *reset_gpio;
>   };
>   
> @@ -106,8 +107,18 @@ static int usb_onboard_hub_probe(struct udevice *dev)
>   	struct onboard_hub_data *data =
>   		(struct onboard_hub_data *)dev_get_driver_data(dev);
>   	struct onboard_hub *hub = dev_get_priv(dev);
> +	struct ofnode_phandle_args phandle;
> +	struct udevice *hub_dev;
>   	int ret;
>   
> +	if (!dev_read_phandle_with_args(dev, "peer-hub", NULL, 0, 0, &phandle)) {
> +		if (ofnode_valid(phandle.node)) {
> +			ret = uclass_find_device_by_ofnode(UCLASS_USB_HUB, phandle.node, &hub_dev);
> +			if (hub_dev && hub_dev->priv_)
> +				return 0;
> +		}
> +	}
> +

Implement .bind function of this driver, bind the correct "half" of the 
hub that you want the driver to bind to, and return -ENODEV for the 
other "half". See rpc_spi_bind() in drivers/spi/renesas_rpc_spi.c for 
example of this.