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>

2 files changed, 42 insertions, 0 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index ab8169faaa65..af7052c6a45c 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -678,6 +678,8 @@ struct irq_chip_type {
  * @wake_active:	Interrupt is marked as an wakeup from suspend source
  * @num_ct:		Number of available irq_chip_type instances (usually 1)
  * @private:		Private data for non generic chip callbacks
+ * @installed:		bitfield to denote installed interrupts
+ * @domain:		irq domain pointer
  * @list:		List head for keeping track of instances
  * @chip_types:		Array of interrupt irq_chip_types
  *
@@ -699,6 +701,8 @@ struct irq_chip_generic {
 	u32			wake_active;
 	unsigned int		num_ct;
 	void			*private;
+	unsigned long		installed;
+	struct irq_domain	*domain;
 	struct list_head	list;
 	struct irq_chip_type	chip_types[0];
 };
@@ -719,6 +723,24 @@ enum irq_gc_flags {
 	IRQ_GC_NO_MASK			= 1 << 3,
 };
 
+/*
+ * struct irq_domain_chip_generic - Generic irq chip data structure for irq domains
+ * @irqs_per_chip:	Number of interrupts per chip
+ * @num_chips:		Number of chips
+ * @irq_flags_to_set:	IRQ* flags to set on irq setup
+ * @irq_flags_to_clear:	IRQ* flags to clear on irq setup
+ * @gc_flags:		Generic chip specific setup flags
+ * @gc:			Array of pointers to generic interrupt chips
+ */
+struct irq_domain_chip_generic {
+	unsigned int		irqs_per_chip;
+	unsigned int		num_chips;
+	unsigned int		irq_flags_to_clear;
+	unsigned int		irq_flags_to_set;
+	enum irq_gc_flags	gc_flags;
+	struct irq_chip_generic	*gc[0];
+};
+
 /* Generic chip callback functions */
 void irq_gc_noop(struct irq_data *d);
 void irq_gc_mask_disable_reg(struct irq_data *d);
@@ -742,6 +764,14 @@ int irq_setup_alt_chip(struct irq_data *d, unsigned int type);
 void irq_remove_generic_chip(struct irq_chip_generic *gc, u32 msk,
 			     unsigned int clr, unsigned int set);
 
+struct irq_chip_generic *irq_get_domain_generic_chip(struct irq_domain *d, unsigned int hw_irq);
+int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
+				   int num_ct, const char *name,
+				   irq_flow_handler_t handler,
+				   unsigned int clr, unsigned int set,
+				   enum irq_gc_flags flags);
+
+
 static inline struct irq_chip_type *irq_data_get_chip_type(struct irq_data *d)
 {
 	return container_of(d->chip, struct irq_chip_type, chip);
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,