genirq: Implement a generic interrupt chip
Implement a generic interrupt chip, which is configurable and is able
to handle the most common irq chip implementations.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by; Kevin Hilman <khilman@ti.com>
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
new file mode 100644
index 0000000..eb23e59
--- /dev/null
+++ b/kernel/irq/generic-chip.c
@@ -0,0 +1,261 @@
+/*
+ * Library implementing the most common irq chip callback functions
+ *
+ * Copyright (C) 2011, Thomas Gleixner
+ */
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/kernel_stat.h>
+
+#include "internals.h"
+
+static inline struct irq_chip_regs *cur_regs(struct irq_data *d)
+{
+ return &container_of(d->chip, struct irq_chip_type, chip)->regs;
+}
+
+/**
+ * irq_gc_noop - NOOP function
+ * @d: irq_data
+ */
+void irq_gc_noop(struct irq_data *d)
+{
+}
+
+/**
+ * irq_gc_mask_disable_reg - Mask chip via disable register
+ * @d: irq_data
+ *
+ * Chip has separate enable/disable registers instead of a single mask
+ * register.
+ */
+void irq_gc_mask_disable_reg(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ irq_reg_writel(mask, gc->reg_base + cur_regs(d)->disable);
+ gc->mask_cache &= ~mask;
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_mask_set_mask_bit - Mask chip via setting bit in mask register
+ * @d: irq_data
+ *
+ * Chip has a single mask register. Values of this register are cached
+ * and protected by gc->lock
+ */
+void irq_gc_mask_set_bit(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ gc->mask_cache |= mask;
+ irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask);
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_mask_set_mask_bit - Mask chip via clearing bit in mask register
+ * @d: irq_data
+ *
+ * Chip has a single mask register. Values of this register are cached
+ * and protected by gc->lock
+ */
+void irq_gc_mask_clr_bit(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ gc->mask_cache &= ~mask;
+ irq_reg_writel(gc->mask_cache, gc->reg_base + cur_regs(d)->mask);
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_unmask_enable_reg - Unmask chip via enable register
+ * @d: irq_data
+ *
+ * Chip has separate enable/disable registers instead of a single mask
+ * register.
+ */
+void irq_gc_unmask_enable_reg(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ irq_reg_writel(mask, gc->reg_base + cur_regs(d)->enable);
+ gc->mask_cache |= mask;
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_ack - Ack pending interrupt
+ * @d: irq_data
+ */
+void irq_gc_ack(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_mask_disable_reg_and_ack- Mask and ack pending interrupt
+ * @d: irq_data
+ */
+void irq_gc_mask_disable_reg_and_ack(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ irq_reg_writel(mask, gc->reg_base + cur_regs(d)->mask);
+ irq_reg_writel(mask, gc->reg_base + cur_regs(d)->ack);
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_eoi - EOI interrupt
+ * @d: irq_data
+ */
+void irq_gc_eoi(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ irq_gc_lock(gc);
+ irq_reg_writel(mask, gc->reg_base + cur_regs(d)->eoi);
+ irq_gc_unlock(gc);
+}
+
+/**
+ * irq_gc_set_wake - Set/clr wake bit for an interrupt
+ * @d: irq_data
+ *
+ * For chips where the wake from suspend functionality is not
+ * configured in a separate register and the wakeup active state is
+ * just stored in a bitmask.
+ */
+int irq_gc_set_wake(struct irq_data *d, unsigned int on)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ u32 mask = 1 << (d->irq - gc->irq_base);
+
+ if (!(mask & gc->wake_enabled))
+ return -EINVAL;
+
+ irq_gc_lock(gc);
+ if (on)
+ gc->wake_active |= mask;
+ else
+ gc->wake_active &= ~mask;
+ irq_gc_unlock(gc);
+ return 0;
+}
+
+/**
+ * irq_alloc_generic_chip - Allocate a generic chip and initialize it
+ * @name: Name of the irq chip
+ * @num_ct: Number of irq_chip_type instances associated with this
+ * @irq_base: Interrupt base nr for this chip
+ * @reg_base: Register base address (virtual)
+ * @handler: Default flow handler associated with this chip
+ *
+ * Returns an initialized irq_chip_generic structure. The chip defaults
+ * to the primary (index 0) irq_chip_type and @handler
+ */
+struct irq_chip_generic *
+irq_alloc_generic_chip(const char *name, int num_ct, unsigned int irq_base,
+ void __iomem *reg_base, irq_flow_handler_t handler)
+{
+ struct irq_chip_generic *gc;
+ unsigned long sz = sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
+
+ gc = kzalloc(sz, GFP_KERNEL);
+ if (gc) {
+ raw_spin_lock_init(&gc->lock);
+ gc->num_ct = num_ct;
+ gc->irq_base = irq_base;
+ gc->reg_base = reg_base;
+ gc->chip_types->chip.name = name;
+ gc->chip_types->handler = handler;
+ }
+ return gc;
+}
+
+/*
+ * Separate lockdep class for interrupt chip which can nest irq_desc
+ * lock.
+ */
+static struct lock_class_key irq_nested_lock_class;
+
+/**
+ * irq_setup_generic_chip - Setup a range of interrupts with a generic chip
+ * @gc: Generic irq chip holding all data
+ * @msk: Bitmask holding the irqs to initialize relative to gc->irq_base
+ * @flags: Flags for initialization
+ * @clr: IRQ_* bits to clear
+ * @set: IRQ_* bits to set
+ *
+ * Set up max. 32 interrupts starting from gc->irq_base. Note, this
+ * initializes all interrupts to the primary irq_chip_type and its
+ * associated handler.
+ */
+void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
+ enum irq_gc_flags flags, unsigned int clr,
+ unsigned int set)
+{
+ struct irq_chip_type *ct = gc->chip_types;
+ unsigned int i;
+
+ /* Init mask cache ? */
+ if (flags & IRQ_GC_INIT_MASK_CACHE)
+ gc->mask_cache = irq_reg_readl(gc->reg_base + ct->regs.mask);
+
+ for (i = gc->irq_base; msk; msk >>= 1, i++) {
+ if (!msk & 0x01)
+ continue;
+
+ if (flags & IRQ_GC_INIT_NESTED_LOCK)
+ irq_set_lockdep_class(i, &irq_nested_lock_class);
+
+ irq_set_chip_and_handler(i, &ct->chip, ct->handler);
+ irq_set_chip_data(i, gc);
+ irq_modify_status(i, clr, set);
+ }
+ gc->irq_cnt = i - gc->irq_base;
+}
+
+/**
+ * irq_setup_alt_chip - Switch to alternative chip
+ * @d: irq_data for this interrupt
+ * @type Flow type to be initialized
+ *
+ * Only to be called from chip->irq_set_type() callbacks.
+ */
+int irq_setup_alt_chip(struct irq_data *d, unsigned int type)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct irq_chip_type *ct = gc->chip_types;
+ unsigned int i;
+
+ for (i = 0; i < gc->num_ct; i++, ct++) {
+ if (ct->type & type) {
+ d->chip = &ct->chip;
+ irq_data_to_desc(d)->handle_irq = ct->handler;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}