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

[Marek Vasut]

On 10/4/24 2:03 PM, Abbarapu, Venkatesh wrote:
> Hi,
> 
>> -----Original Message-----
>> From: Marek Vasut <marex at denx.de>
>> Sent: Friday, October 4, 2024 4:52 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 10/4/24 5:02 AM, Abbarapu, Venkatesh wrote:
>>> 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.
>>
>> Please show me the i2c sequence that is missed in this patch hunk:
>>
>> +	if (hub->reset_gpio) {
>> +		ret = dm_gpio_set_value(hub->reset_gpio, 1);
>> +		if (ret)
>> +			return ret;
>> +
>> +		udelay(data->reset_us);
>> +
>> +		ret = dm_gpio_set_value(hub->reset_gpio, 0);
>> +		if (ret)
>> +			return ret;
>> +
>> +		udelay(data->power_on_delay_us);
>> +	}
>> +
>> +	return 0;
> 
> The i2c sequence change is part of   [PATCH v4 4/7] usb: onboard-hub: Add i2c initialization for usb5744 hub of the series
> 
> +	if (data->init) {
> +		ret = data->init(dev);
> +		if (ret) {
> +			dev_err(dev, "onboard i2c init failed: %d\n", ret);
> +			goto err;
> +		}
> +	}
> +
>   	return 0;
> +err:
> +	dm_gpio_set_value(hub->reset_gpio, 0);
> +	return ret;
>   }
This does not seem to be part of the if (hub->reset_gpio) { ... } code 
block ?