genirq: Generic chip: Add linear irq domain support

Provide infrastructure for irq chip implementations which work on
linear irq domains.

- Interface to allocate multiple generic chips which are associated to
  the irq domain.

- Interface to get the generic chip pointer for a particular hardware
  interrupt in the domain.

- irq domain mapping function to install the chip for a particular
  interrupt.

Note: This lacks a removal function for now.

[ Sebastian Hesselbarth: Mask cache and pointer math fixups ]

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jean-Francois Moine <moinejf@free.fr>
Cc: devicetree-discuss@lists.ozlabs.org
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Cc: Gregory Clement <gregory.clement@free-electrons.com>
Cc: Gerlando Falauto <gerlando.falauto@keymile.com>
Cc: Rob Landley <rob@landley.net>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Link: http://lkml.kernel.org/r/20130506142539.450634298@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 0d5b17bf5e51..ba2c708adcff 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -66,6 +66,10 @@ struct irq_domain_ops {
                      unsigned long *out_hwirq, unsigned int *out_type);
 };
 
+extern struct irq_domain_ops irq_generic_chip_ops;
+
+struct irq_domain_chip_generic;
+
 /**
  * struct irq_domain - Hardware interrupt number translation object
  * @link: Element in global irq_domain list.
@@ -109,8 +113,16 @@ struct irq_domain {
 
         /* Optional device node pointer */
         struct device_node *of_node;
+        /* Optional pointer to generic interrupt chips */
+        struct irq_domain_chip_generic *gc;
 };
 
+#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
+                                 * ie. legacy 8259, gets irqs 1..15 */
+#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
+#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
+#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
+
 #ifdef CONFIG_IRQ_DOMAIN
 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
                                          unsigned int size,