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authorThomas Gleixner <tglx@linutronix.de>2009-08-13 14:17:22 +0400
committerThomas Gleixner <tglx@linutronix.de>2009-08-17 12:54:05 +0400
commitb25c340c195447afb1860da580fe2a85a6b652c5 (patch)
tree99578092c1e6100f50786e44a1a4fe9cfdb11662 /include/linux/irq.h
parentb2add73dbf93fd50f00564d7abc3e2b9aa9dd20c (diff)
downloadlinux-b25c340c195447afb1860da580fe2a85a6b652c5.tar.xz
genirq: Add oneshot support
For threaded interrupt handlers we expect the hard interrupt handler part to mask the interrupt on the originating device. The interrupt line itself is reenabled after the hard interrupt handler has executed. This requires access to the originating device from hard interrupt context which is not always possible. There are devices which can only be accessed via a bus (i2c, spi, ...). The bus access requires thread context. For such devices we need to keep the interrupt line masked until the threaded handler has executed. Add a new flag IRQF_ONESHOT which allows drivers to request that the interrupt is not unmasked after the hard interrupt context handler has been executed and the thread has been woken. The interrupt line is unmasked after the thread handler function has been executed. Note that for now IRQF_ONESHOT cannot be used with IRQF_SHARED to avoid complex accounting mechanisms. For oneshot interrupts the primary handler simply returns IRQ_WAKE_THREAD and does nothing else. A generic implementation irq_default_primary_handler() is provided to avoid useless copies all over the place. It is automatically installed when request_threaded_irq() is called with handler=NULL and thread_fn!=NULL. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Trilok Soni <soni.trilok@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Brian Swetland <swetland@google.com> Cc: Joonyoung Shim <jy0922.shim@samsung.com> Cc: m.szyprowski@samsung.com Cc: t.fujak@samsung.com Cc: kyungmin.park@samsung.com, Cc: David Brownell <david-b@pacbell.net> Cc: Daniel Ribeiro <drwyrm@gmail.com> Cc: arve@android.com Cc: Barry Song <21cnbao@gmail.com>
Diffstat (limited to 'include/linux/irq.h')
-rw-r--r--include/linux/irq.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/irq.h b/include/linux/irq.h
index cb2e77a3f7f7..5e7c6ee8c35c 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -69,6 +69,7 @@ typedef void (*irq_flow_handler_t)(unsigned int irq,
#define IRQ_MOVE_PCNTXT 0x01000000 /* IRQ migration from process context */
#define IRQ_AFFINITY_SET 0x02000000 /* IRQ affinity was set from userspace*/
#define IRQ_SUSPENDED 0x04000000 /* IRQ has gone through suspend sequence */
+#define IRQ_ONESHOT 0x08000000 /* IRQ is not unmasked after hardirq */
#ifdef CONFIG_IRQ_PER_CPU
# define CHECK_IRQ_PER_CPU(var) ((var) & IRQ_PER_CPU)