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-rw-r--r--drivers/acpi/gsi.c105
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);