Add ifdef to make kernel compile without CONFIG_BCM2708_DT=y

[mikroskeem]

GCC throws implicit declaration of function 'pinctrl_request_gpio' and implicit declaration of function 'pinctrl_free_gpio' when CONFIG_BCM2708_DT is not defined

This change removes this issue

EDIT: Changed "not defined" to actual error, write it at late night, sorry

[notro]

Try adding this instead:

#include <linux/pinctrl/consumer.h>

Ref: http://lxr.free-electrons.com/source/include/linux/pinctrl/consumer.h#L62

[popcornmix]

Is it the same for 3.18 kernel?
We're likely to be moving to 3.18 kernel for next stable kernel bump.

[mikroskeem]

I haven't looked at it yet, but I try

[mikroskeem]

@notro it won't solve the problem, adding it will remove the error, but GPIO doesn't work at all then

[notro]

How do you determine that the gpios don't work? What error is returned?

I don't understand why this fails.

gpio_request call chain:
gpio_request->gpiod_request->__gpiod_request:

static int __gpiod_request(struct gpio_desc *desc, const char *label)
[...]
        if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
                desc_set_label(desc, label ? : "?");
                status = 0;
        } else {
                status = -EBUSY;
                goto done;
        }

        if (chip->request) {
                /* chip->request may sleep */
                spin_unlock_irqrestore(&gpio_lock, flags);
                status = chip->request(chip, gpio_chip_hwgpio(desc));
                spin_lock_irqsave(&gpio_lock, flags);

                if (status < 0) {
                        desc_set_label(desc, NULL);
                        clear_bit(FLAG_REQUESTED, &desc->flags);
                        goto done;
                }
        }

And we have:

#else /* !CONFIG_PINCTRL */

static inline int pinctrl_request_gpio(unsigned gpio)
{
        return 0;
}

We have two versions here, which should amount to the same:

• ucb->gc.request is NULL (not set, removed by ifdefs)
  __gpiod_request(): status==0, chip->request is NULL and status remains unchanged
• ucb->gc.request = bcm2708_gpio_request and bcm2708_gpio_request calls pinctrl_request_gpio()
  __gpiod_request(): chip->request returns 0, and thus status==0

How can this break anything? Am I missing something here?

[mikroskeem]

@notro I can see with my eyes that GPIO doesn't work. ACT LED doesn't work and echo 22 > /sys/class/gpio/export threw echo: No such device or address

[mikroskeem]

@popcornmix Yes, it exists in 3.18 too

[mikroskeem]

I started over with new config and adding include line worked. GPIO works.

[notro]

bcm2708_gpio_request and bcm2708_gpio_free are now removed from 3.18: 18b06d2

[popcornmix]

@mikroskeem okay to close?

[mikroskeem]

@popcornmix yep