Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / acpi / gsi.c

diff --git a/kernel/drivers/acpi/gsi.c b/kernel/drivers/acpi/gsi.c
new file mode 100644 (file)
index 0000000..38208f2
--- /dev/null
+++ b/kernel/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);