diff options
Diffstat (limited to 'drivers/acpi/gsi.c')
| -rw-r--r-- | drivers/acpi/gsi.c | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/drivers/acpi/gsi.c b/drivers/acpi/gsi.c new file mode 100644 index 000000000000..38208f2d0e69 --- /dev/null +++ b/drivers/acpi/gsi.c @@ -0,0 +1,105 @@ +/* + * ACPI GSI IRQ layer + * + * Copyright (C) 2015 ARM Ltd. + * Author: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include <linux/acpi.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> + +enum acpi_irq_model_id acpi_irq_model; + +static unsigned int acpi_gsi_get_irq_type(int trigger, int polarity) +{ + switch (polarity) { + case ACPI_ACTIVE_LOW: + return trigger == ACPI_EDGE_SENSITIVE ? + IRQ_TYPE_EDGE_FALLING : + IRQ_TYPE_LEVEL_LOW; + case ACPI_ACTIVE_HIGH: + return trigger == ACPI_EDGE_SENSITIVE ? + IRQ_TYPE_EDGE_RISING : + IRQ_TYPE_LEVEL_HIGH; + case ACPI_ACTIVE_BOTH: + if (trigger == ACPI_EDGE_SENSITIVE) + return IRQ_TYPE_EDGE_BOTH; + default: + return IRQ_TYPE_NONE; + } +} + +/** + * acpi_gsi_to_irq() - Retrieve the linux irq number for a given GSI + * @gsi: GSI IRQ number to map + * @irq: pointer where linux IRQ number is stored + * + * irq location updated with irq value [>0 on success, 0 on failure] + * + * Returns: linux IRQ number on success (>0) + * -EINVAL on failure + */ +int acpi_gsi_to_irq(u32 gsi, unsigned int *irq) +{ + /* + * Only default domain is supported at present, always find + * the mapping corresponding to default domain by passing NULL + * as irq_domain parameter + */ + *irq = irq_find_mapping(NULL, gsi); + /* + * *irq == 0 means no mapping, that should + * be reported as a failure + */ + return (*irq > 0) ? *irq : -EINVAL; +} +EXPORT_SYMBOL_GPL(acpi_gsi_to_irq); + +/** + * acpi_register_gsi() - Map a GSI to a linux IRQ number + * @dev: device for which IRQ has to be mapped + * @gsi: GSI IRQ number + * @trigger: trigger type of the GSI number to be mapped + * @polarity: polarity of the GSI to be mapped + * + * Returns: a valid linux IRQ number on success + * -EINVAL on failure + */ +int acpi_register_gsi(struct device *dev, u32 gsi, int trigger, + int polarity) +{ + unsigned int irq; + unsigned int irq_type = acpi_gsi_get_irq_type(trigger, polarity); + + /* + * There is no way at present to look-up the IRQ domain on ACPI, + * hence always create mapping referring to the default domain + * by passing NULL as irq_domain parameter + */ + irq = irq_create_mapping(NULL, gsi); + if (!irq) + return -EINVAL; + + /* 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); + +/** + * acpi_unregister_gsi() - Free a GSI<->linux IRQ number mapping + * @gsi: GSI IRQ number + */ +void acpi_unregister_gsi(u32 gsi) +{ + int irq = irq_find_mapping(NULL, gsi); + + irq_dispose_mapping(irq); +} +EXPORT_SYMBOL_GPL(acpi_unregister_gsi); |