usb: host: ohci-at91: fix request of irq for optional gpio

[Nicolas Ferre <nicolas.ferre@microchip.com>]

On 15/10/2018 at 10:34, Tudor Ambarus - M18064 wrote:
> atmel,oc-gpio is optional. Request it's irq only when atmel,oc is set
> in device tree.
> 
> devm_gpiod_get_index_optional returns NULL if -ENOENT. Check its
> return value for NULL before error, because it is more probably that
> atmel,oc is not set.
> 
> This fixes the following errors on boards where atmel,oc is not set in
> device tree:
> [    0.960000] at91_ohci 500000.ohci: failed to request gpio "overcurrent" IRQ
> [    0.960000] at91_ohci 500000.ohci: failed to request gpio "overcurrent" IRQ
> [    0.970000] at91_ohci 500000.ohci: failed to request gpio "overcurrent" IRQ
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>

Yes, indeed:
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>

Thanks, best regards,
   Nicolas

> ---
> Based on https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git,
> usb-next branch.
> 
>   drivers/usb/host/ohci-at91.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/host/ohci-at91.c b/drivers/usb/host/ohci-at91.c
> index e98673954020..ec6739ef3129 100644
> --- a/drivers/usb/host/ohci-at91.c
> +++ b/drivers/usb/host/ohci-at91.c
> @@ -551,6 +551,8 @@ static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
>   		pdata->overcurrent_pin[i] =
>   			devm_gpiod_get_index_optional(&pdev->dev, "atmel,oc",
>   						      i, GPIOD_IN);
> +		if (!pdata->overcurrent_pin[i])
> +			continue;
>   		if (IS_ERR(pdata->overcurrent_pin[i])) {
>   			err = PTR_ERR(pdata->overcurrent_pin[i]);
>   			dev_err(&pdev->dev, "unable to claim gpio \"overcurrent\": %d\n", err);
>