RE: [PATCH v2 1/2] gpio: mlxbf2: Introduce IRQ support

[Asmaa Mnebhi <asmaa@nvidia.com>]

> +static int
> +mlxbf2_gpio_irq_set_type(struct irq_data *irqd, unsigned int type) {
> +
> +	switch (type & IRQ_TYPE_SENSE_MASK) {
> +	case IRQ_TYPE_EDGE_BOTH:
> +		fall = true;
> +		rise = true;
> +		break;
> +	case IRQ_TYPE_EDGE_RISING:
> +		rise = true;
> +		break;
> +	case IRQ_TYPE_EDGE_FALLING:
> +		fall = true;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}

> What PHY are you using? I think every one i've looked at are 
> level triggered, not edge. Using an edge interrupt might work 99% 
> of the time, but when the timing is just wrong, you can loose an interrupt.
> Which might mean phylib thinks the link is down, when it fact it is up. 
> You will need to unplug and replug to recover from that.

It is the micrel PHY KSZ9031 so it is an active low level interrupt.
Here, IRQ_TYPE_EDGE* macros are mainly used to decide whether to write the
YU_GPIO_CAUSE_FALL_EN register vs the YU_GPIO_CAUSE_RISE_EN register.
These 2 registers are used in both LEVEL/EDGE interrupts.
So I will add back the IRQ_TYPE_LEVEL_LOW and IRQ_TYPE_LEVEL_HIGH as I
did before to configure YU_GPIO_CAUSE_FALL_EN and
YU_GPIO_CAUSE_HIGH_EN respectively. The PHY interrupt signal is physically
Connected to an open drain GPIO pin so software only needs to set
YU_GPIO_CAUSE_FALL_EN register in this case.

Thanks.
Asmaa