[PATCH] ARM: S5P64X0: External Interrupt Support

[Russell King - ARM Linux]

On Fri, Jul 15, 2011 at 05:23:33PM +0530, padma venkat wrote:
> Hi Russell,
> 
> On Fri, Jul 15, 2011 at 2:30 PM, Russell King - ARM Linux
> <linux at arm.linux.org.uk> wrote:
> > On Fri, Jul 15, 2011 at 12:11:34PM +0530, Padmavathi Venna wrote:
> >> +#define eint_offset(irq)     ((irq) - IRQ_EINT(0))
> >> +#define eint_irq_to_bit(irq) ((u32)(1 << eint_offset(irq)))
> >> +
> >> +static inline void s5p64x0_irq_eint_mask(struct irq_data *data)
> >> +{
> >> +     u32 mask;
> >> +
> >> +     mask = __raw_readl(S5P64X0_EINT0MASK);
> >> +     mask |= (u32)data->chip_data;
> >> +     __raw_writel(mask, S5P64X0_EINT0MASK);
> >> +}
> >> +
> >> +static void s5p64x0_irq_eint_unmask(struct irq_data *data)
> >> +{
> >> +     u32 mask;
> >> +
> >> +     mask = __raw_readl(S5P64X0_EINT0MASK);
> >> +     mask &= ~((u32)data->chip_data);
> >> +     __raw_writel(mask, S5P64X0_EINT0MASK);
> >> +}
> >> +
> >> +static inline void s5p64x0_irq_eint_ack(struct irq_data *data)
> >> +{
> >> +     __raw_writel((u32)data->chip_data, S5P64X0_EINT0PEND);
> >> +}
> >> +
> >> +static void s5p64x0_irq_eint_maskack(struct irq_data *data)
> >> +{
> >> +     /* compiler should in-line these */
> >> +     s5p64x0_irq_eint_mask(data);
> >> +     s5p64x0_irq_eint_ack(data);
> >> +}
> >
> > Won't genirqchip support deal with all of the above for you?
> As per my understanding, to deal with low level interrupt hardware access
> we need to use the accessor functions. Please suggest me if there is
> any better way of doing this.

I'm not saying don't have these.  I'm saying use the _generic_ irqchip
support which has the code implemented to set and clear bits in registers.
Something like this:

	struct irq_chip_generic *gc;

	gc = irq_alloc_generic_chip(name, 1, first_irq, base_of_controller,
			handler);

	gc->chip_types->chip.irq_ack = irq_gc_ack;
	gc->chip_types->chip.irq_mask = irq_gc_mask_set_bit;
	gc->chip_types->chip.irq_unmask = irq_gc_mask_clr_bit;

	/* replace the two below with the _real_ offset, rather than these calculations */
	gc->chip_types->reg.ack = S5P64X0_EINT0PEND - base_of_controller;
	gc->chip_types->reg.mask = S5P64X0_EINT0MASK - base_of_controller;

	irq_setup_generic_chip(gc, mask_of_irqs_to_setup,
		IRQ_GC_INIT_MASK_CACHE, flags_to_clear, flags_to_set);