[U-Boot] [PATCH 7/7] gpio: tegra: remove flags parsing in xlate routine

Eric Nelson eric at nelint.com
Sun Apr 10 17:55:06 CEST 2016


On 04/10/2016 07:45 AM, Eric Nelson wrote:
> On 04/09/2016 11:34 AM, Simon Glass wrote:
>> On 5 April 2016 at 16:09, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>> On 04/01/2016 09:47 AM, Eric Nelson wrote:
>>>>
>>>> With the addition of GPIO_ACTIVE_LOW parsing in gpio-uclass, it is
>>>> no longer necessary for the tegra-specific xlate function to do this.
>>>
>>>> diff --git a/drivers/gpio/tegra_gpio.c b/drivers/gpio/tegra_gpio.c
>>>
>>>> @@ -246,7 +246,6 @@ static int tegra_gpio_xlate(struct udevice *dev,
>>>> struct gpio_desc *desc,
>>>>         if (ret)
>>>>                 return ret;
>>>>         desc->offset = gpio % TEGRA_GPIOS_PER_PORT;
>>>> -       desc->flags = args->args[1] & GPIO_ACTIVE_LOW ? GPIOD_ACTIVE_LOW :
>>>> 0;
>>>
>>>
>>> I expect that after that, you can also remove the following at the top of
>>> the file:
>>>
>>> #include <dt-bindings/gpio/gpio.h>
>>>
>>> I expect that's true of other GPIO drivers too.
>>
>> But I don't think we want this patch for Tegra since we need to keep
>> the xlate() method, and with your suggested approach earlier, we won't
>> call the default xlate() method in the uclass for Tegra.
>>
> 
> Based on your comments and Stephens, I can re-work this to have a
> __maybe_unused xlate function for the common case of handling
> offset+active low, but I think the handling of offset inside of
> gpio_find_and_xlate() should be removed at the same time.
> 
> It seems weird to have processing for one argument in the common code
> when it may not be used (as is the case with tegra).
> 

While reviewing this, I think I found that the sunxi gpio driver
is broken.

The device trees have #gpio-cells=<3>, and gpio declaration like this:
	<&pio 1 8 GPIO_ACTIVE_HIGH>

but there's no custom xlate routine, the offset is currently going to
have what I presume is the bank number.

Hans, can you confirm this?

Please advise,


Eric


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