Re: [PATCH v7 2/4] MIPS: Octeon: Setup irq_domains for interrupts.

[David Daney]

On 03/26/2012 06:56 PM, Rob Herring wrote:
> On 03/26/2012 02:31 PM, David Daney wrote:
> > From: David Daney<david.daney@xxxxxxxxxx>
[...]
> > +static bool octeon_irq_ciu_is_edge(unsigned int line, unsigned int bit)
> > +{
> > +	bool edge = false;
> > +
> > +	if (line == 0)
> > +		switch (bit) {
> > +		case 48 ... 49: /* GMX DRP */
> > +		case 50: /* IPD_DRP */
> > +		case 52 ... 55: /* Timers */
> > +		case 58: /* MPI */
> > +			edge = true;
> > +			break;
> > +		default:
> > +			break;
> > +		}
> > +	else /* line == 1 */
> > +		switch (bit) {
> > +		case 47: /* PTP */
> > +			edge = true;
> > +			break;
> > +		default:
> > +			break;
> > +		}
> > +	return edge;
>
> Moving in the right direction, but I still don't get why this is not in
> the CIU binding as a 3rd cell?

There are a several reasons, in no particular order they are:

o There is no 3rd cell.  The bindings were discussed with Grant here:
  http://www.linux-mips.org/archives/linux-mips/2011-05/msg00355.html

o The edge/level thing cannot be changed, and the irq lines don't leave 
the SOC, so hard coding it is possible.

> > +}
> > +
> > +struct octeon_irq_gpio_domain_data {
> > +	unsigned int base_hwirq;
> > +};
> > +
> > +static int octeon_irq_gpio_xlat(struct irq_domain *d,
> > +				struct device_node *node,
> > +				const u32 *intspec,
> > +				unsigned int intsize,
> > +				unsigned long *out_hwirq,
> > +				unsigned int *out_type)
> > +{
> > +	unsigned int type;
> > +	unsigned int pin;
> > +	unsigned int trigger;
> > +	bool set_edge_handler = false;
> > +	struct octeon_irq_gpio_domain_data *gpiod;
> > +
> > +	if (d->of_node != node)
> > +		return -EINVAL;
> > +
> > +	if (intsize<  2)
> > +		return -EINVAL;
> > +
> > +	pin = intspec[0];
> > +	if (pin>= 16)
> > +		return -EINVAL;
> > +
> > +	trigger = intspec[1];
> > +
> > +	switch (trigger) {
> > +	case 1:
> > +		type = IRQ_TYPE_EDGE_RISING;
> > +		set_edge_handler = true;
>
> This is never used.

Right, it was leftover from the previous version.

> > +		break;
> > +	case 2:
> > +		type = IRQ_TYPE_EDGE_FALLING;
> > +		set_edge_handler = true;
> > +		break;
> > +	case 4:
> > +		type = IRQ_TYPE_LEVEL_HIGH;
> > +		break;
> > +	case 8:
> > +		type = IRQ_TYPE_LEVEL_LOW;
> > +		break;
> > +	default:
> > +		pr_err("Error: (%s) Invalid irq trigger specification: %x\n",
> > +		       node->name,
> > +		       trigger);
> > +		type = IRQ_TYPE_LEVEL_LOW;
> > +		break;
> > +	}
> > +	*out_type = type;
>
> Can't you get rid of the whole switch statement and just do:
>
> *out_type = intspec[1];

That wouldn't catch erroneous values like 6.

>
[...]
> > +static int octeon_irq_ciu_map(struct irq_domain *d,
> > +			      unsigned int virq, irq_hw_number_t hw)
> > +{
> > +	unsigned int line = hw>>  6;
> > +	unsigned int bit = hw&  63;
> > +
> > +	if (virq>= 256)
> > +		return -EINVAL;
>
> Drop this. You should not care what the virq numbers are.


I care that they don't overflow the width of octeon_irq_ciu_to_irq (a u8).

So really I want to say:

   if (virq >= (1 << sizeof (octeon_irq_ciu_to_irq[0][0]))) {
       WARN(...);
       return -EINVAL;
   }


I need a map external to any one irq_domain.  The irq handling code 
handles sources that come from two separate irq_domains, as well as irqs 
that are not part of any domain.


Thanks for looking at this again,  I will re-spin the patch,
David Daney
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