Re: [PATCH 2/2] gpio: davinci: Remove gpio2regs function to accommodate multi instances

From: Linus Walleij
Date: Wed Jan 11 2017 - 06:04:58 EST


On Wed, Jan 4, 2017 at 9:26 AM, Keerthy <j-keerthy@xxxxxx> wrote:

> gpio2regs is written making an assumption that driver supports only
> one instance of gpio controller. Removing this and adding a generic
> array so as to support multiple instances of gpio controllers.
>
> Signed-off-by: Keerthy <j-keerthy@xxxxxx>

> - regs = gpio2regs(base);
> + regs = gpio_base + offset_array[i];

I understand this.

> - struct davinci_gpio_regs __iomem *g = gpio2regs(hw);
> + struct davinci_gpio_controller *chips =
> + (struct davinci_gpio_controller *)d->host_data;
> + struct davinci_gpio_regs __iomem *g = chips[hw / 32].regs;

And this, if each instans has 32 GPIOs.

> - g = gpio2regs(0);
> + g = chips[0].regs;

Also makes sense.

> - g = gpio2regs(gpio);
> + g = chips[bank / 2].regs;

But what is this? I don't understand that /2 at all. Please insert a
comment explaining it so I can figure it out. Are there two banks
per instance?

Yours,
Linus Walleij