Hello.
(2014/10/07 18:46), Sergei Shtylyov wrote:
> On 10/7/2014 7:25 AM, Yoshihiro Shimoda wrote:
>
>>>>> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
>>>>> ---
>>>>> arch/arm/boot/dts/r8a7790-lager.dts | 5 +++++
>>>>> 1 file changed, 5 insertions(+)
>
>>>>> diff --git a/arch/arm/boot/dts/r8a7790-lager.dts b/arch/arm/boot/dts/r8a7790-lager.dts
>>>>> index 1698591..4badd0a 100644
>>>>> --- a/arch/arm/boot/dts/r8a7790-lager.dts
>>>>> +++ b/arch/arm/boot/dts/r8a7790-lager.dts
>>>>> @@ -445,3 +445,8 @@
>>>>> };
>>>>> };
>>>>> };
>>>>> +
>>>>> +&hsusb {
>>>>> + status = "okay";
>>>>> + renesas,enable-gpio = <&gpio5 18 GPIO_ACTIVE_LOW>;
>
>>>> It's certainly active-high.
>
>>> Since the current code has the following, we have to set the active_low...
>>> However, the code is unreadable, I think. So, I will modify the code.
>>>
>>> /* check GPIO determining if USB function should be enabled */
>>> if (priv->dparam.enable_gpio) {
>>> gpio_request_one(priv->dparam.enable_gpio, GPIOF_IN, NULL);
>>> ret = !gpio_get_value(priv->dparam.enable_gpio);
>>> gpio_free(priv->dparam.enable_gpio);
>>> if (ret) {
>>> dev_warn(&pdev->dev,
>>> "USB function not selected (GPIO %d)\n",
>>> priv->dparam.enable_gpio);
>>> ret = -ENOTSUPP;
>>> goto probe_end_mod_exit;
>>> }
>>> }
>
>> I am confusing about the gpio_get_value()...
>> In case of ARM, gpio_get_value() will call gpiod_get_raw_value() finally.
>
>> gpio_get_value() in arch/arm/include/asm/gpio.h
>> --> __gpio_get_value() in include/asm-generic/gpio.h
>> --> gpiod_get_raw_value() in drivers/gpio/gpiolib.c
>
>> The gpiod_get_raw_value() doesn't care of the GPIO_ACTIVE_{HIGH,LOW}.
>> So, should I add gpiod_is_active_low() or someting in the renesas_usbhs driver?
>
> Why do you still think it's active-low?!
>
>> Or, Do I misunderstand something?
>
> Look at the above code again.
Thank you for the comment.
Finally, I understood this. I will not modify the driver and
I just change the "GPIO_ACTIVE_LOW" in the dts file to "GPIO_ACTIVE_HIGH"
because of your previous comment below:
>> 'ret' is non-zero here if gpio_get_value() returned 0, so 0 means "host"
>> and 1 means "gadget", i.e. GPIO is active-high.
Best regards,
Yoshihiro Shimoda
>> Best regards,
>> Yoshihiro Shimoda
>
> WBR, Sergei
>
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