Re: [PATCH v2 9/9] media: i2c: tw9910: Remove soc_camera dependencies

Fabio Estevam
2018-01-03T18:14:39Z

On Wed, Jan 3, 2018 at 3:37 PM, jacopo mondi <jacopo@jmondi.org> wrote:

>> Initially the rest GPIO was doing:
>>
>> - gpio_set_value(GPIO_PTT3, 0);
>> - mdelay(10);
>> - gpio_set_value(GPIO_PTT3, 1);
>> - mdelay(10); /* wait to let chip come out of reset */
>
> And that's what my driver code does :)

No, on 5/9 you converted the original code to:

GPIO_LOOKUP("sh7722_pfc", GPIO_PTT3, "rstb", GPIO_ACTIVE_HIGH)

It should be GPIO_ACTIVE_LOW instead.

> My point is that if I read the manual and I see an active low gpio (0
> is reset state) then the driver code uses it as and active high one (1
> is the reset state), that would be weird to me.

Then on this patch you should do:

gpiod_set_value(priv->rstb_gpio, 1); ---> This tells the GPIO to go
to its active state (In this case active == logic level 0)
usleep_range(500, 1000);
gpiod_set_value(priv->rstb_gpio, 0); ---> This tells the GPIO to go to
its inactive state (In this case inactive == logic level 1)

You can also look at Documentation/gpio/consumer.txt where the usage
of the gpiod_xxx API is described.

It seems you are confusing it with the legacy gpio_set_value() API
(Documentation/gpio/gpio-legacy.txt)

Hope this helps.