[PATCH v10 15/21] ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi

[lorenzo.pieralisi@arm.com (Lorenzo Pieralisi)]

On Thu, Mar 19, 2015 at 03:45:35AM +0000, Hanjun Guo wrote:

[...]

> >> +/*
> >> + * success: return IRQ number (>0)
> >> + * failure: return =< 0
> >> + */
> >> +int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
> >> +{
> >> +	unsigned int irq;
> >> +	unsigned int irq_type;
> >> +
> >> +	/*
> >> +	 * ACPI have no bindings to indicate SPI or PPI, so we
> >> +	 * use different mappings from DT in ACPI.
> >> +	 *
> >> +	 * For FDT
> >> +	 * PPI interrupt: in the range [0, 15];
> >> +	 * SPI interrupt: in the range [0, 987];
> >> +	 *
> >> +	 * For ACPI, GSI should be unique so using
> >> +	 * the hwirq directly for the mapping:
> >> +	 * PPI interrupt: in the range [16, 31];
> >> +	 * SPI interrupt: in the range [32, 1019];
> >> +	 */
> >> +
> >> +	if (trigger == ACPI_EDGE_SENSITIVE &&
> >> +				polarity == ACPI_ACTIVE_LOW)
> >> +		irq_type = IRQ_TYPE_EDGE_FALLING;
> >> +	else if (trigger == ACPI_EDGE_SENSITIVE &&
> >> +				polarity == ACPI_ACTIVE_HIGH)
> >> +		irq_type = IRQ_TYPE_EDGE_RISING;
> >> +	else if (trigger == ACPI_LEVEL_SENSITIVE &&
> >> +				polarity == ACPI_ACTIVE_LOW)
> >> +		irq_type = IRQ_TYPE_LEVEL_LOW;
> >> +	else if (trigger == ACPI_LEVEL_SENSITIVE &&
> >> +				polarity == ACPI_ACTIVE_HIGH)
> >> +		irq_type = IRQ_TYPE_LEVEL_HIGH;
> >> +	else
> >> +		irq_type = IRQ_TYPE_NONE;
> >> +
> >> +	/*
> >> +	 * Since only one GIC is supported in ACPI 5.0, we can
> >> +	 * create mapping refer to the default domain
> >> +	 */
> >> +	irq = irq_create_mapping(NULL, gsi);
> >> +	if (!irq)
> >> +		return irq;
> >> +
> >> +	/* Set irq type if specified and different than the current one */
> >> +	if (irq_type != IRQ_TYPE_NONE &&
> >> +		irq_type != irq_get_trigger_type(irq))
> >> +		irq_set_irq_type(irq, irq_type);
> >> +	return irq;
> >> +}
> >> +EXPORT_SYMBOL_GPL(acpi_register_gsi);
> > I see you've still got this buried in the arch code. Is there any plan to
> > move it out, as I moaned about this in the last version of the series and
> > nothing seems to have changed?
> 
> Ah, sorry. Last time when I was in Hongkong for LCA this Feb, I discussed with Lorenzo
> and he had a look into that too, he also met some obstacles to do that, so Lorenzo
> said that he will talk to you about this (Lorenzo, correct me if I'm wrong due to hearing
> problems of much noise in that room where we were talking).
> 
> Anyway, if we move those functions to core code, such as irqdomain code, which will be
> compiled for x86 too, we can only set those functions as _weak, or we guard with them
> as #ifdef CONFIG_ARM64 ... #endif, so for me, it's really not a big deal to move those code
> out of arch/arm64, but I'm still open for suggestions if you can do that in a proper way.

You heard me clear and sound in HK, Will has a point and I looked into
this. Code is generic but not enough to be useful on other arches at
the moment, I need more time to look into this and see if we can move
this code to acpi core in a way that makes sense, to have, as you say,
a "default" implementation.

Lorenzo