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>
This commit is contained in:
Thomas Gleixner 2011-04-03 11:42:53 +02:00
parent 7f1b1244e1
commit 7d82806247
3 changed files with 397 additions and 0 deletions

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@ -568,6 +568,141 @@ static inline int irq_reserve_irq(unsigned int irq)
return irq_reserve_irqs(irq, 1);
}
#ifndef irq_reg_writel
# define irq_reg_writel(val, addr) writel(val, addr)
#endif
#ifndef irq_reg_readl
# define irq_reg_readl(addr) readl(addr)
#endif
/**
* struct irq_chip_regs - register offsets for struct irq_gci
* @enable: Enable register offset to reg_base
* @disable: Disable register offset to reg_base
* @mask: Mask register offset to reg_base
* @ack: Ack register offset to reg_base
* @eoi: Eoi register offset to reg_base
* @type: Type configuration register offset to reg_base
* @polarity: Polarity configuration register offset to reg_base
*/
struct irq_chip_regs {
unsigned long enable;
unsigned long disable;
unsigned long mask;
unsigned long ack;
unsigned long eoi;
unsigned long type;
unsigned long polarity;
};
/**
* struct irq_chip_type - Generic interrupt chip instance for a flow type
* @chip: The real interrupt chip which provides the callbacks
* @regs: Register offsets for this chip
* @handler: Flow handler associated with this chip
* @type: Chip can handle these flow types
*
* A irq_generic_chip can have several instances of irq_chip_type when
* it requires different functions and register offsets for different
* flow types.
*/
struct irq_chip_type {
struct irq_chip chip;
struct irq_chip_regs regs;
irq_flow_handler_t handler;
u32 type;
};
/**
* struct irq_chip_generic - Generic irq chip data structure
* @lock: Lock to protect register and cache data access
* @reg_base: Register base address (virtual)
* @irq_base: Interrupt base nr for this chip
* @irq_cnt: Number of interrupts handled by this chip
* @mask_cache: Cached mask register
* @type_cache: Cached type register
* @polarity_cache: Cached polarity register
* @wake_enabled: Interrupt can wakeup from suspend
* @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
* @chip_types: Array of interrupt irq_chip_types
*
* Note, that irq_chip_generic can have multiple irq_chip_type
* implementations which can be associated to a particular irq line of
* an irq_chip_generic instance. That allows to share and protect
* state in an irq_chip_generic instance when we need to implement
* different flow mechanisms (level/edge) for it.
*/
struct irq_chip_generic {
raw_spinlock_t lock;
void __iomem *reg_base;
unsigned int irq_base;
unsigned int irq_cnt;
u32 mask_cache;
u32 type_cache;
u32 polarity_cache;
u32 wake_enabled;
u32 wake_active;
unsigned int num_ct;
void *private;
struct irq_chip_type chip_types[0];
};
/**
* enum irq_gc_flags - Initialization flags for generic irq chips
* @IRQ_GC_INIT_MASK_CACHE: Initialize the mask_cache by reading mask reg
* @IRQ_GC_INIT_NESTED_LOCK: Set the lock class of the irqs to nested for
* irq chips which need to call irq_set_wake() on
* the parent irq. Usually GPIO implementations
*/
enum irq_gc_flags {
IRQ_GC_INIT_MASK_CACHE = 1 << 0,
IRQ_GC_INIT_NESTED_LOCK = 1 << 1,
};
/* Generic chip callback functions */
void irq_gc_noop(struct irq_data *d);
void irq_gc_mask_disable_reg(struct irq_data *d);
void irq_gc_mask_set_bit(struct irq_data *d);
void irq_gc_mask_clr_bit(struct irq_data *d);
void irq_gc_unmask_enable_reg(struct irq_data *d);
void irq_gc_ack(struct irq_data *d);
void irq_gc_mask_disable_reg_and_ack(struct irq_data *d);
void irq_gc_eoi(struct irq_data *d);
int irq_gc_set_wake(struct irq_data *d, unsigned int on);
/* Setup functions for irq_chip_generic */
struct irq_chip_generic *
irq_alloc_generic_chip(const char *name, int nr_ct, unsigned int irq_base,
void __iomem *reg_base, irq_flow_handler_t handler);
void irq_setup_generic_chip(struct irq_chip_generic *gc, u32 msk,
enum irq_gc_flags flags, unsigned int clr,
unsigned int set);
int irq_setup_alt_chip(struct irq_data *d, unsigned int type);
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);
}
#define IRQ_MSK(n) (u32)((n) < 32 ? ((1 << (n)) - 1) : UINT_MAX)
#ifdef CONFIG_SMP
static inline void irq_gc_lock(struct irq_chip_generic *gc)
{
raw_spin_lock(&gc->lock);
}
static inline void irq_gc_unlock(struct irq_chip_generic *gc)
{
raw_spin_unlock(&gc->lock);
}
#else
static inline void irq_gc_lock(struct irq_chip_generic *gc) { }
static inline void irq_gc_unlock(struct irq_chip_generic *gc) { }
#endif
#endif /* CONFIG_GENERIC_HARDIRQS */
#endif /* !CONFIG_S390 */

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@ -1,5 +1,6 @@
obj-y := irqdesc.o handle.o manage.o spurious.o resend.o chip.o dummychip.o devres.o
obj-y += generic-chip.o
obj-$(CONFIG_GENERIC_IRQ_PROBE) += autoprobe.o
obj-$(CONFIG_PROC_FS) += proc.o
obj-$(CONFIG_GENERIC_PENDING_IRQ) += migration.o

261
kernel/irq/generic-chip.c Normal file
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@ -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;
}