[PATCH v3 1/7] usb: onboard-hub: Add reset-gpio support

[Abbarapu, Venkatesh]

Hi Marek,

> -----Original Message-----
> From: Marek Vasut <marex at denx.de>
> Sent: Thursday, October 3, 2024 10:35 PM
> To: Abbarapu, Venkatesh <venkatesh.abbarapu at amd.com>; u-boot at lists.denx.de
> Cc: Simek, Michal <michal.simek at amd.com>; fabrice.gasnier at foss.st.com; git
> (AMD-Xilinx) <git at amd.com>
> Subject: Re: [PATCH v3 1/7] usb: onboard-hub: Add reset-gpio support
> 
> On 10/3/24 4:54 PM, Abbarapu, Venkatesh wrote:
> > Hi Marek,
> >
> >> -----Original Message-----
> >> From: Marek Vasut <marex at denx.de>
> >> Sent: Thursday, October 3, 2024 5:38 PM
> >> To: Abbarapu, Venkatesh <venkatesh.abbarapu at amd.com>;
> >> u-boot at lists.denx.de
> >> Cc: Simek, Michal <michal.simek at amd.com>;
> >> fabrice.gasnier at foss.st.com; git
> >> (AMD-Xilinx) <git at amd.com>
> >> Subject: Re: [PATCH v3 1/7] usb: onboard-hub: Add reset-gpio support
> >>
> >> On 10/3/24 6:40 AM, Abbarapu, Venkatesh wrote:
> >>> Hi Marek,
> >>
> >> Hi,
> >>
> >>>>> @@ -30,7 +40,24 @@ static int usb_onboard_hub_probe(struct udevice
> *dev)
> >>>>>     	if (ret)
> >>>>>     		dev_err(dev, "can't enable vdd-supply: %d\n", ret);
> >>>>>
> >>>>> -	return ret;
> >>>>> +	hub->reset_gpio = devm_gpiod_get_optional(dev, "reset",
> >>>>> +						  GPIOD_IS_OUT |
> >>>> GPIOD_ACTIVE_LOW);
> >>>>> +	/* property is optional, don't return error! */
> >>>>> +	if (hub->reset_gpio) {
> >>>>
> >>>> if (!hub->reset_gpio)
> >>>>      return 0;
> >>> <Venkatesh> As reset_gpio is optional property,  by returning 0 the
> >>> i2c sequence
> >> wont be executed.
> >> The code in if (hub->reset_gpio) { ... } only toggles the GPIO reset ?
> > <Venkatesh> Yes...if(hub->reset_gpio) only toggles the GPIO reset.
> So you can return 0 if reset_gpio is NULL and exit early . What's the problem ?
<Venkatesh> if reset_gpio is NULL by returning 0 we miss the below code which does i2c initialization sequence.
Need to toggle the gpio and then does the i2c sequence if the reset_gpio is present, else we do the i2c initialization sequence.

Thanks
Venkatesh