request_threaded_irq(9) [centos man page]

REQUEST_THREADED_IRQ(9) 				     Public Functions Provided					   REQUEST_THREADED_IRQ(9)

NAME

       request_threaded_irq - allocate an interrupt line

SYNOPSIS

       int request_threaded_irq(unsigned int irq, irq_handler_t handler, irq_handler_t thread_fn, unsigned long irqflags, const char * devname,
				void * dev_id);

ARGUMENTS

       irq
	   Interrupt line to allocate

       handler
	   Function to be called when the IRQ occurs. Primary handler for threaded interrupts If NULL and thread_fn != NULL the default primary
	   handler is installed

       thread_fn
	   Function called from the irq handler thread If NULL, no irq thread is created

       irqflags
	   Interrupt type flags

       devname
	   An ascii name for the claiming device

       dev_id
	   A cookie passed back to the handler function

DESCRIPTION

       This call allocates interrupt resources and enables the interrupt line and IRQ handling. From the point this call is made your handler
       function may be invoked. Since your handler function must clear any interrupt the board raises, you must take care both to initialise your
       hardware and to set up the interrupt handler in the right order.

       If you want to set up a threaded irq handler for your device then you need to supply handler and thread_fn.  handler is still called in
       hard interrupt context and has to check whether the interrupt originates from the device. If yes it needs to disable the interrupt on the
       device and return IRQ_WAKE_THREAD which will wake up the handler thread and run thread_fn. This split handler design is necessary to
       support shared interrupts.

       Dev_id must be globally unique. Normally the address of the device data structure is used as the cookie. Since the handler receives this
       value it makes sense to use it.

       If your interrupt is shared you must pass a non NULL dev_id as this is required when freeing the interrupt.

FLAGS

       IRQF_SHARED Interrupt is shared IRQF_TRIGGER_* Specify active edge(s) or level

AUTHORS

       Thomas Gleixner <tglx@linutronix.de>
	   Author.

       Ingo Molnar <mingo@elte.hu>
	   Author.

COPYRIGHT

Kernel Hackers Manual 3.10					     June 2014						   REQUEST_THREADED_IRQ(9)

STRUCT 
IRQ_DESC(9)						    Structures							STRUCT IRQ_DESC(9)

NAME

       struct_irq_desc - interrupt descriptor

SYNOPSIS

       struct irq_desc {
	 unsigned int irq;
	 struct timer_rand_state * timer_rand_state;
	 unsigned int * kstat_irqs;
       #ifdef CONFIG_INTR_REMAP
	 struct irq_2_iommu * irq_2_iommu;
       #endif
	 irq_flow_handler_t handle_irq;
	 struct irq_chip * chip;
	 struct msi_desc * msi_desc;
	 void * handler_data;
	 void * chip_data;
	 struct irqaction * action;
	 unsigned int status;
	 unsigned int depth;
	 unsigned int wake_depth;
	 unsigned int irq_count;
	 unsigned long last_unhandled;
	 unsigned int irqs_unhandled;
	 raw_spinlock_t lock;
       #ifdef CONFIG_SMP
	 cpumask_var_t affinity;
	 unsigned int node;
       #ifdef CONFIG_GENERIC_PENDING_IRQ
	 cpumask_var_t pending_mask;
       #endif
       #endif
	 atomic_t threads_active;
	 wait_queue_head_t wait_for_threads;
       #ifdef CONFIG_PROC_FS
	 struct proc_dir_entry * dir;
       #endif
	 const char * name;
       };

MEMBERS

       irq
	   interrupt number for this descriptor

       timer_rand_state
	   pointer to timer rand state struct

       kstat_irqs
	   irq stats per cpu

       irq_2_iommu
	   iommu with this irq

       handle_irq
	   highlevel irq-events handler [if NULL, __do_IRQ]

       chip
	   low level interrupt hardware access

       msi_desc
	   MSI descriptor

       handler_data
	   per-IRQ data for the irq_chip methods

       chip_data
	   platform-specific per-chip private data for the chip methods, to allow shared chip implementations

       action
	   the irq action chain

       status
	   status information

       depth
	   disable-depth, for nested irq_disable calls

       wake_depth
	   enable depth, for multiple set_irq_wake callers

       irq_count
	   stats field to detect stalled irqs

       last_unhandled
	   aging timer for unhandled count

       irqs_unhandled
	   stats field for spurious unhandled interrupts

       lock
	   locking for SMP

       affinity
	   IRQ affinity on SMP

       node
	   node index useful for balancing

       pending_mask
	   pending rebalanced interrupts

       threads_active
	   number of irqaction threads currently running

       wait_for_threads
	   wait queue for sync_irq to wait for threaded handlers

       dir
	   /proc/irq/ procfs entry

       name
	   flow handler name for /proc/interrupts output

AUTHORS

       Thomas Gleixner <tglx@linutronix.de>
	   Author.

       Ingo Molnar <mingo@elte.hu>
	   Author.

COPYRIGHT

Kernel Hackers Manual 2.6.					     July 2010							STRUCT IRQ_DESC(9)