From 7d8280624797bbe2f5170bd3c85c75a8c9c74242 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 3 Apr 2011 11:42:53 +0200 Subject: [PATCH] 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 Cc: linux-arm-kernel@lists.infradead.org Tested-by: H Hartley Sweeten Tested-by: Tony Lindgren Tested-by; Kevin Hilman --- include/linux/irq.h | 135 ++++++++++++++++++++ kernel/irq/Makefile | 1 + kernel/irq/generic-chip.c | 261 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 397 insertions(+) create mode 100644 kernel/irq/generic-chip.c diff --git a/include/linux/irq.h b/include/linux/irq.h index 39c23786c1db..2ba2f1216790 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -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 */ diff --git a/kernel/irq/Makefile b/kernel/irq/Makefile index 54329cd7b3ee..e7a13bd3316a 100644 --- a/kernel/irq/Makefile +++ b/kernel/irq/Makefile @@ -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 diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c new file mode 100644 index 000000000000..eb23e5924260 --- /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 +#include +#include +#include +#include + +#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; +} -- 2.20.1