[PATCH 1/2] gpio: xgene: add support to configure GPIO line as input, output or external IRQ pin

[Linus Walleij]

On Fri, Sep 11, 2015 at 2:22 AM, Y Vo <yvo at apm.com> wrote:

> Add support to configure GPIO line as input, output or external IRQ pin.
>
> Signed-off-by: Y Vo <yvo at apm.com>

Mostly OK but...

>  #define XGENE_MAX_GPIO_DS              22
>  #define XGENE_MAX_GPIO_DS_IRQ          6
> +#define XGENE_GPIO8_HWIRQ              0x48
> +#define XGENE_GPIO8_IDX                        8
(...)
> +static int xgene_irq_to_line(u32 irq)
> +{
> +       u32 offset = irq_get_irq_data(irq)->hwirq - XGENE_GPIO8_HWIRQ;
> +
> +       return (offset < XGENE_MAX_GPIO_DS_IRQ) ?
> +                       (offset + XGENE_GPIO8_IDX) : -EINVAL;
> +}

What is this hardcoded IRQ 0x48 business?

This patch needs kerneldoc for this xgene_irq_to_line() to explain
what exactly is going on, or noone will understand it enough to
debug or refactor the code.

I hope this 0x48 is not some way of compensating for Linux internal
IRQ offsets, that is what irqdomain is for.

Yours,
Linus Walleij