Re: [PATCH 1/1] gpio: add Lynxpoint chipset gpio driver.

[Mathias Nyman]

On 12/11/2012 01:07 AM, Grant Likely wrote:
> On Fri,  7 Dec 2012 16:01:39 +0200, Mathias Nyman<mathias.nyman@xxxxxxxxxxxxxxx>  wrote:
> > Add gpio support for Intel Lynxpoint chipset.
> > Lynxpoint supports 94 gpio pins which can generate interrupts.
> > Driver will fail requests for pins that are marked as owned by ACPI, or
> > set in an alternate mode (non-gpio).
> >
> > Signed-off-by: Mathias Nyman<mathias.nyman@xxxxxxxxxxxxxxx>
> > ---
> > +static void lp_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
> > +{
> > +	struct lp_gpio *lg = container_of(chip, struct lp_gpio, chip);
> > +	unsigned long reg = gpio_reg(chip, gpio, LP_CONFIG1);
> > +	unsigned long flags;
> > +
> > +	spin_lock_irqsave(&lg->lock, flags);
> > +
> > +	if (value)
> > +		outl(inl(reg) | OUT_LVL_BIT, reg);
> > +	else
> > +		outl(inl(reg)&  ~OUT_LVL_BIT, reg);
> > +
> > +	spin_unlock_irqrestore(&lg->lock, flags);
> > +}
>
> A *lot* of drivers implement their own GPIO ops like this, and they all
> end up looking the same. Please take a look at
> drivers/gpio/gpio-generic.c and see if you can use the stock operations
> provided there.
>
> g.

Look quite similar but turns out the only potential generic ones which 
could be used are the bgpio_set() and bgpio_get() funtions. Using them 
would require custom pin2mask, write_reg, read_reg, etc functions.
bgpio_set_direction

I guess using gpio-generic code fits memory mapped devices better. 
Trying to use it for io port devices would require a lot of code mangling.

-Mathias
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