Re: [patch 2.6.24-rc2 1/3] generic gpio -- gpio_chip support

From: Thomas Gleixner
Date: Thu Nov 15 2007 - 02:36:22 EST


On Wed, 14 Nov 2007, David Brownell wrote:

> On Wednesday 14 November 2007, Thomas Gleixner wrote:
> > struct gpio_desc {
> > struct gpio_chip *chip;
> > int pinoffset;
> > };
>
> Eric Miao has a different notion of "gpio_desc" more analagous to
> the "irq_desc", so I'll not use that name for such a structure.
>
> Let me call yours a "struct gpio_pin" instead -- purely for some
> discussion here.
>
>
> There's been some desire for a "gpio_pin" struct for entirely
> different reasons ... as the identifiers passed into a slightly
> different type of GPIO programming interface. So for example
>
> static inline void gpiopin_set_value(struct gpio_pin *p, int v)
> {
> p->chip->set(p->chip, p->pinoffset, v);
> }
>
> One reason to be interested in gpio_chip is that it it would
> easily support interoperation between traditional GPIO ID schemes
> (numbered to match the SOC at the heart of a given board) and
> more dynamic ones that might be needed to use curiousities like
> a set of USB-to-GPIO adapters.

So can we please do this right from the beginning instead of adding a
new library first which suffers from bad design compromises.

tglx
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/