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authorThomas Gleixner <tglx@linutronix.de>2009-08-13 12:17:22 +0200
committerThomas Gleixner <tglx@linutronix.de>2009-08-17 10:54:05 +0200
commitb25c340c195447afb1860da580fe2a85a6b652c5 (patch)
tree99578092c1e6100f50786e44a1a4fe9cfdb11662 /include/linux/interrupt.h
parentb2add73dbf93fd50f00564d7abc3e2b9aa9dd20c (diff)
downloadblackbird-op-linux-b25c340c195447afb1860da580fe2a85a6b652c5.tar.gz
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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/interrupt.h')
-rw-r--r--include/linux/interrupt.h4
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h
index 35e7df1e9f30..1ac57e522a1f 100644
--- a/include/linux/interrupt.h
+++ b/include/linux/interrupt.h
@@ -50,6 +50,9 @@
* IRQF_IRQPOLL - Interrupt is used for polling (only the interrupt that is
* registered first in an shared interrupt is considered for
* performance reasons)
+ * IRQF_ONESHOT - Interrupt is not reenabled after the hardirq handler finished.
+ * Used by threaded interrupts which need to keep the
+ * irq line disabled until the threaded handler has been run.
*/
#define IRQF_DISABLED 0x00000020
#define IRQF_SAMPLE_RANDOM 0x00000040
@@ -59,6 +62,7 @@
#define IRQF_PERCPU 0x00000400
#define IRQF_NOBALANCING 0x00000800
#define IRQF_IRQPOLL 0x00001000
+#define IRQF_ONESHOT 0x00002000
/*
* Bits used by threaded handlers:
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