Subject: [PATCH v2 10/18] ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi

From: [email-masked] (Sudeep Holla)
Date: Mon, 18 Aug 2014 19:34:55 +0100

On 04/08/14 16:28, Hanjun Guo wrote:
> Introduce ACPI_IRQ_MODEL_GIC which is needed for ARM64 as GIC is
> used, and then register device's gsi with the core IRQ subsystem.
>
> acpi_register_gsi() is similar to DT based irq_of_parse_and_map(),
> since gsi is unique in the system, so use hwirq number directly
> for the mapping.
>
> Originally-by: Amit Daniel Kachhap <[email-masked]>
> Signed-off-by: Hanjun Guo <[email-masked]>
> ---
>   arch/arm64/kernel/acpi.c |   73 ++++++++++++++++++++++++++++++++++++++++++++++
>   drivers/acpi/bus.c       |    3 ++
>   include/linux/acpi.h     |    1 +
>   3 files changed, 77 insertions(+)
>
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index ac7ab34..621ced8 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -34,6 +34,12 @@ EXPORT_SYMBOL(acpi_pci_disabled);
>   static int enabled_cpus;	/* Processors (GICC) with enabled flag in MADT */
>
>   /*
> + * Since we're on ARM, the default interrupt routing model
> + * clearly has to be GIC.
> + */
> +enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_GIC;
> +
> +/*
>    * __acpi_map_table() will be called before page_init(), so early_ioremap()
>    * or early_memremap() should be called here to for ACPI table mapping.
>    */
> @@ -169,6 +175,73 @@ static int __init acpi_parse_madt_gic_cpu_interface_entries(void)
>   	return 0;
>   }
>
> +int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
> +{
> +	*irq = irq_find_mapping(NULL, gsi);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(acpi_gsi_to_irq);
> +
> +/*
> + * 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);
> +

Not sure if acpi_gsi_to_irq and acpi_{,un}register_gsi belong here.
These are GIC specific and should belong to GIC driver IMO.

Regards,
Sudeep