[PATCH] IRQ type flags

Some ARM platforms have the ability to program the interrupt controller to
detect various interrupt edges and/or levels.  For some platforms, this is
critical to setup correctly, particularly those which the setting is dependent
on the device.

Currently, ARM drivers do (eg) the following:

	err = request_irq(irq, ...);

	set_irq_type(irq, IRQT_RISING);

However, if the interrupt has previously been programmed to be level sensitive
(for whatever reason) then this will cause an interrupt storm.

Hence, if we combine set_irq_type() with request_irq(), we can then safely set
the type prior to unmasking the interrupt.  The unfortunate problem is that in
order to support this, these flags need to be visible outside of the ARM
architecture - drivers such as smc91x need these flags and they're
cross-architecture.

Finally, the SA_TRIGGER_* flag passed to request_irq() should reflect the
property that the device would like.  The IRQ controller code should do its
best to select the most appropriate supported mode.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c
index 869c466e625852689c6f1e792d4ee1e0262884f6..b5645c4462cffa95f5887d2cf8b8c9cfcbd2e4a1 100644 (file)
--- a/arch/arm/kernel/irq.c
+++ b/arch/arm/kernel/irq.c
@@ -684,8 +684,12 @@ int setup_irq(unsigned int irq, struct irqaction *new)
        spin_lock_irqsave(&irq_controller_lock, flags);
        p = &desc->action;
        if ((old = *p) != NULL) {
-               /* Can't share interrupts unless both agree to */
-               if (!(old->flags & new->flags & SA_SHIRQ)) {
+               /*
+                * Can't share interrupts unless both agree to and are
+                * the same type.
+                */
+               if (!(old->flags & new->flags & SA_SHIRQ) ||
+                   (~old->flags & new->flags) & SA_TRIGGER_MASK) {
                        spin_unlock_irqrestore(&irq_controller_lock, flags);
                        return -EBUSY;
                }
@@ -705,6 +709,12 @@ int setup_irq(unsigned int irq, struct irqaction *new)
                desc->running = 0;
                desc->pending = 0;
                desc->disable_depth = 1;
+
+               if (new->flags & SA_TRIGGER_MASK) {
+                       unsigned int type = new->flags & SA_TRIGGER_MASK;
+                       desc->chip->set_type(irq, type);
+               }
+
                if (!desc->noautoenable) {
                        desc->disable_depth = 0;
                        desc->chip->unmask(irq);

diff --git a/arch/arm/mach-omap1/serial.c b/arch/arm/mach-omap1/serial.c
index fcfb81d13cfe69490810d225e6ac40386bb16366..7a68f098a0254365da8f1da60edd94f081f9df65 100644 (file)
--- a/arch/arm/mach-omap1/serial.c
+++ b/arch/arm/mach-omap1/serial.c
@@ -252,9 +252,8 @@ static void __init omap_serial_set_port_wakeup(int gpio_nr)
                return;
        }
        omap_set_gpio_direction(gpio_nr, 1);
-       set_irq_type(OMAP_GPIO_IRQ(gpio_nr), IRQT_RISING);
        ret = request_irq(OMAP_GPIO_IRQ(gpio_nr), &omap_serial_wake_interrupt,
-                         0, "serial wakeup", NULL);
+                         SA_TRIGGER_RISING, "serial wakeup", NULL);
        if (ret) {
                omap_free_gpio(gpio_nr);
                printk(KERN_ERR "No interrupt for UART wake GPIO: %i\n",

diff --git a/arch/arm/mach-pxa/corgi.c b/arch/arm/mach-pxa/corgi.c
index 100fb31b5156df4a9cb3e6b0372ef2736d23d7e0..5a7b873f29b3cd853a9975626182dcb38d5463c0 100644 (file)
--- a/arch/arm/mach-pxa/corgi.c
+++ b/arch/arm/mach-pxa/corgi.c
@@ -213,15 +213,14 @@ static int corgi_mci_init(struct device *dev, irqreturn_t (*corgi_detect_int)(in
 
        corgi_mci_platform_data.detect_delay = msecs_to_jiffies(250);
 
-       err = request_irq(CORGI_IRQ_GPIO_nSD_DETECT, corgi_detect_int, SA_INTERRUPT,
-                            "MMC card detect", data);
+       err = request_irq(CORGI_IRQ_GPIO_nSD_DETECT, corgi_detect_int,
+                         SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                         "MMC card detect", data);
        if (err) {
                printk(KERN_ERR "corgi_mci_init: MMC/SD: can't request MMC card detect IRQ\n");
                return -1;
        }
 
-       set_irq_type(CORGI_IRQ_GPIO_nSD_DETECT, IRQT_BOTHEDGE);
-
        return 0;
 }
 

diff --git a/arch/arm/mach-pxa/poodle.c b/arch/arm/mach-pxa/poodle.c
index eef3de26ad3704dba4604255abcf13bb3942b16a..663c9500598553604f0f04c3f3b9355b29c2e640 100644 (file)
--- a/arch/arm/mach-pxa/poodle.c
+++ b/arch/arm/mach-pxa/poodle.c
@@ -146,15 +146,14 @@ static int poodle_mci_init(struct device *dev, irqreturn_t (*poodle_detect_int)(
 
        poodle_mci_platform_data.detect_delay = msecs_to_jiffies(250);
 
-       err = request_irq(POODLE_IRQ_GPIO_nSD_DETECT, poodle_detect_int, SA_INTERRUPT,
-                            "MMC card detect", data);
+       err = request_irq(POODLE_IRQ_GPIO_nSD_DETECT, poodle_detect_int,
+                         SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                         "MMC card detect", data);
        if (err) {
                printk(KERN_ERR "poodle_mci_init: MMC/SD: can't request MMC card detect IRQ\n");
                return -1;
        }
 
-       set_irq_type(POODLE_IRQ_GPIO_nSD_DETECT, IRQT_BOTHEDGE);
-
        return 0;
 }
 

diff --git a/arch/arm/mach-pxa/spitz.c b/arch/arm/mach-pxa/spitz.c
index f2007db0cda5aebe5ad398a3909f8ddecd1f688f..a9eacc06555f2e775da7f0a859ad671293324a2a 100644 (file)
--- a/arch/arm/mach-pxa/spitz.c
+++ b/arch/arm/mach-pxa/spitz.c
@@ -296,15 +296,14 @@ static int spitz_mci_init(struct device *dev, irqreturn_t (*spitz_detect_int)(in
 
        spitz_mci_platform_data.detect_delay = msecs_to_jiffies(250);
 
-       err = request_irq(SPITZ_IRQ_GPIO_nSD_DETECT, spitz_detect_int, SA_INTERRUPT,
-                            "MMC card detect", data);
+       err = request_irq(SPITZ_IRQ_GPIO_nSD_DETECT, spitz_detect_int,
+                         SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                         "MMC card detect", data);
        if (err) {
                printk(KERN_ERR "spitz_mci_init: MMC/SD: can't request MMC card detect IRQ\n");
                return -1;
        }
 
-       set_irq_type(SPITZ_IRQ_GPIO_nSD_DETECT, IRQT_BOTHEDGE);
-
        return 0;
 }
 

diff --git a/arch/arm/mach-s3c2410/usb-simtec.c b/arch/arm/mach-s3c2410/usb-simtec.c
index 5098b50158a332ce81b8bdd36945c5916d9f8cb3..495f8c6ffcb6e6d39c51bbb67d95e63688c86c5c 100644 (file)
--- a/arch/arm/mach-s3c2410/usb-simtec.c
+++ b/arch/arm/mach-s3c2410/usb-simtec.c
@@ -84,13 +84,13 @@ static void usb_simtec_enableoc(struct s3c2410_hcd_info *info, int on)
        int ret;
 
        if (on) {
-               ret = request_irq(IRQ_USBOC, usb_simtec_ocirq, SA_INTERRUPT,
+               ret = request_irq(IRQ_USBOC, usb_simtec_ocirq,
+                                 SA_INTERRUPT | SA_TRIGGER_RISING |
+                                  SA_TRIGGER_FALLING,
                                  "USB Over-current", info);
                if (ret != 0) {
                        printk(KERN_ERR "failed to request usb oc irq\n");
                }
-
-               set_irq_type(IRQ_USBOC, IRQT_BOTHEDGE);
        } else {
                free_irq(IRQ_USBOC, info);
        }

diff --git a/drivers/i2c/chips/tps65010.c b/drivers/i2c/chips/tps65010.c
index e70b3db69eddd66bf82565bbb32c2141ec1ee13e..1af3dfbb808686146b324c3ce60fcee67d0e7100 100644 (file)
--- a/drivers/i2c/chips/tps65010.c
+++ b/drivers/i2c/chips/tps65010.c
@@ -494,6 +494,7 @@ tps65010_probe(struct i2c_adapter *bus, int address, int kind)
 {
        struct tps65010         *tps;
        int                     status;
+       unsigned long           irqflags;
 
        if (the_tps) {
                dev_dbg(&bus->dev, "only one %s for now\n", DRIVER_NAME);
@@ -520,13 +521,14 @@ tps65010_probe(struct i2c_adapter *bus, int address, int kind)
        }
 
 #ifdef CONFIG_ARM
+       irqflags = SA_SAMPLE_RANDOM | SA_TRIGGER_LOW;
        if (machine_is_omap_h2()) {
                tps->model = TPS65010;
                omap_cfg_reg(W4_GPIO58);
                tps->irq = OMAP_GPIO_IRQ(58);
                omap_request_gpio(58);
                omap_set_gpio_direction(58, 1);
-               set_irq_type(tps->irq, IRQT_FALLING);
+               irqflags |= SA_TRIGGER_FALLING;
        }
        if (machine_is_omap_osk()) {
                tps->model = TPS65010;
@@ -534,7 +536,7 @@ tps65010_probe(struct i2c_adapter *bus, int address, int kind)
                tps->irq = OMAP_GPIO_IRQ(OMAP_MPUIO(1));
                omap_request_gpio(OMAP_MPUIO(1));
                omap_set_gpio_direction(OMAP_MPUIO(1), 1);
-               set_irq_type(tps->irq, IRQT_FALLING);
+               irqflags |= SA_TRIGGER_FALLING;
        }
        if (machine_is_omap_h3()) {
                tps->model = TPS65013;
@@ -542,13 +544,12 @@ tps65010_probe(struct i2c_adapter *bus, int address, int kind)
                // FIXME set up this board's IRQ ...
        }
 #else
-#define set_irq_type(num,trigger)      do{}while(0)
+       irqflags = SA_SAMPLE_RANDOM;
 #endif
 
        if (tps->irq > 0) {
-               set_irq_type(tps->irq, IRQT_LOW);
                status = request_irq(tps->irq, tps65010_irq,
-                       SA_SAMPLE_RANDOM, DRIVER_NAME, tps);
+                       irqflags, DRIVER_NAME, tps);
                if (status < 0) {
                        dev_dbg(&tps->client.dev, "can't get IRQ %d, err %d\n",
                                        tps->irq, status);

diff --git a/drivers/input/keyboard/corgikbd.c b/drivers/input/keyboard/corgikbd.c
index 64672d491222a99e62f48849f9b7c3139e72a06e..e301ee4ca264e6a5b1315a81a88fdda6880da112 100644 (file)
--- a/drivers/input/keyboard/corgikbd.c
+++ b/drivers/input/keyboard/corgikbd.c
@@ -19,7 +19,6 @@
 #include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <asm/irq.h>
 
 #include <asm/arch/corgi.h>
 #include <asm/arch/hardware.h>
@@ -343,10 +342,9 @@ static int __init corgikbd_probe(struct platform_device *pdev)
        for (i = 0; i < CORGI_KEY_SENSE_NUM; i++) {
                pxa_gpio_mode(CORGI_GPIO_KEY_SENSE(i) | GPIO_IN);
                if (request_irq(CORGI_IRQ_GPIO_KEY_SENSE(i), corgikbd_interrupt,
-                                               SA_INTERRUPT, "corgikbd", corgikbd))
+                               SA_INTERRUPT | SA_TRIGGER_RISING,
+                               "corgikbd", corgikbd))
                        printk(KERN_WARNING "corgikbd: Can't get IRQ: %d!\n", i);
-               else
-                       set_irq_type(CORGI_IRQ_GPIO_KEY_SENSE(i),IRQT_RISING);
        }
 
        /* Set Strobe lines as outputs - set high */

diff --git a/drivers/input/keyboard/spitzkbd.c b/drivers/input/keyboard/spitzkbd.c
index 6a15fe3bc527071e683fa12c0eb4944a4a6e5251..83999d5831225e20ffa0bc000c326673596089f2 100644 (file)
--- a/drivers/input/keyboard/spitzkbd.c
+++ b/drivers/input/keyboard/spitzkbd.c
@@ -19,7 +19,6 @@
 #include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <asm/irq.h>
 
 #include <asm/arch/spitz.h>
 #include <asm/arch/hardware.h>
@@ -407,10 +406,9 @@ static int __init spitzkbd_probe(struct platform_device *dev)
        for (i = 0; i < SPITZ_KEY_SENSE_NUM; i++) {
                pxa_gpio_mode(spitz_senses[i] | GPIO_IN);
                if (request_irq(IRQ_GPIO(spitz_senses[i]), spitzkbd_interrupt,
-                                               SA_INTERRUPT, "Spitzkbd Sense", spitzkbd))
+                               SA_INTERRUPT|SA_TRIGGER_RISING,
+                               "Spitzkbd Sense", spitzkbd))
                        printk(KERN_WARNING "spitzkbd: Can't get Sense IRQ: %d!\n", i);
-               else
-                       set_irq_type(IRQ_GPIO(spitz_senses[i]),IRQT_RISING);
        }
 
        /* Set Strobe lines as outputs - set high */
@@ -422,15 +420,18 @@ static int __init spitzkbd_probe(struct platform_device *dev)
        pxa_gpio_mode(SPITZ_GPIO_SWA | GPIO_IN);
        pxa_gpio_mode(SPITZ_GPIO_SWB | GPIO_IN);
 
-       request_irq(SPITZ_IRQ_GPIO_SYNC, spitzkbd_interrupt, SA_INTERRUPT, "Spitzkbd Sync", spitzkbd);
-       request_irq(SPITZ_IRQ_GPIO_ON_KEY, spitzkbd_interrupt, SA_INTERRUPT, "Spitzkbd PwrOn", spitzkbd);
-       request_irq(SPITZ_IRQ_GPIO_SWA, spitzkbd_hinge_isr, SA_INTERRUPT, "Spitzkbd SWA", spitzkbd);
-       request_irq(SPITZ_IRQ_GPIO_SWB, spitzkbd_hinge_isr, SA_INTERRUPT, "Spitzkbd SWB", spitzkbd);
-
-       set_irq_type(SPITZ_IRQ_GPIO_SYNC, IRQT_BOTHEDGE);
-       set_irq_type(SPITZ_IRQ_GPIO_ON_KEY, IRQT_BOTHEDGE);
-       set_irq_type(SPITZ_IRQ_GPIO_SWA, IRQT_BOTHEDGE);
-       set_irq_type(SPITZ_IRQ_GPIO_SWB, IRQT_BOTHEDGE);
+       request_irq(SPITZ_IRQ_GPIO_SYNC, spitzkbd_interrupt,
+                   SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                   "Spitzkbd Sync", spitzkbd);
+       request_irq(SPITZ_IRQ_GPIO_ON_KEY, spitzkbd_interrupt,
+                   SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                   "Spitzkbd PwrOn", spitzkbd);
+       request_irq(SPITZ_IRQ_GPIO_SWA, spitzkbd_hinge_isr,
+                   SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                   "Spitzkbd SWA", spitzkbd);
+       request_irq(SPITZ_IRQ_GPIO_SWB, spitzkbd_hinge_isr,
+                   SA_INTERRUPT | SA_TRIGGER_RISING | SA_TRIGGER_FALLING,
+                   "Spitzkbd SWB", spitzkbd);
 
        printk(KERN_INFO "input: Spitz Keyboard Registered\n");
 

diff --git a/drivers/mfd/ucb1x00-core.c b/drivers/mfd/ucb1x00-core.c
index e335d54c4659ce2161bdb88e8a80a13e46915614..b42e0fbab59b6f880897e1d2303e48342341b8f7 100644 (file)
--- a/drivers/mfd/ucb1x00-core.c
+++ b/drivers/mfd/ucb1x00-core.c
@@ -27,7 +27,6 @@
 
 #include <asm/dma.h>
 #include <asm/hardware.h>
-#include <asm/irq.h>
 
 #include "ucb1x00.h"
 
@@ -507,14 +506,14 @@ static int ucb1x00_probe(struct mcp *mcp)
                goto err_free;
        }
 
-       ret = request_irq(ucb->irq, ucb1x00_irq, 0, "UCB1x00", ucb);
+       ret = request_irq(ucb->irq, ucb1x00_irq, SA_TRIGGER_RISING,
+                         "UCB1x00", ucb);
        if (ret) {
                printk(KERN_ERR "ucb1x00: unable to grab irq%d: %d\n",
                        ucb->irq, ret);
                goto err_free;
        }
 
-       set_irq_type(ucb->irq, IRQT_RISING);
        mcp_set_drvdata(mcp, ucb);
 
        ret = class_device_register(&ucb->cdev);

diff --git a/drivers/net/smc91x.c b/drivers/net/smc91x.c
index 28bf2e69eb5e1a1c9f181d2810447f8dd30ac10a..7ec08127c9d6c4f8594d805392155e3bddccd875 100644 (file)
--- a/drivers/net/smc91x.c
+++ b/drivers/net/smc91x.c
@@ -88,7 +88,6 @@ static const char version[] =
 #include <linux/skbuff.h>
 
 #include <asm/io.h>
-#include <asm/irq.h>
 
 #include "smc91x.h"
 
@@ -2007,12 +2006,10 @@ static int __init smc_probe(struct net_device *dev, void __iomem *ioaddr)
        }
 
        /* Grab the IRQ */
-       retval = request_irq(dev->irq, &smc_interrupt, 0, dev->name, dev);
+       retval = request_irq(dev->irq, &smc_interrupt, SMC_IRQ_FLAGS, dev->name, dev);
        if (retval)
                goto err_out;
 
-       set_irq_type(dev->irq, SMC_IRQ_TRIGGER_TYPE);
-
 #ifdef SMC_USE_PXA_DMA
        {
                int dma = pxa_request_dma(dev->name, DMA_PRIO_LOW,

diff --git a/drivers/net/smc91x.h b/drivers/net/smc91x.h
index 5c2824be4ee6399a73a49cad2fc986e8e704bba1..e0efd1964e72fc78f384da66e7260158375035fd 100644 (file)
--- a/drivers/net/smc91x.h
+++ b/drivers/net/smc91x.h
@@ -90,7 +90,7 @@
                        __l--;                                          \
                }                                                       \
        } while (0)
-#define set_irq_type(irq, type)
+#define SMC_IRQ_FLAGS          (0)
 
 #elif defined(CONFIG_SA1100_PLEB)
 /* We can only do 16-bit reads and writes in the static memory space. */
@@ -109,7 +109,7 @@
 #define SMC_outw(v, a, r)      writew(v, (a) + (r))
 #define SMC_outsw(a, r, p, l)  writesw((a) + (r), p, l)
 
-#define set_irq_type(irq, type) do {} while (0)
+#define SMC_IRQ_FLAGS          (0)
 
 #elif defined(CONFIG_SA1100_ASSABET)
 
@@ -185,11 +185,11 @@ SMC_outw(u16 val, void __iomem *ioaddr, int reg)
 #include <asm/mach-types.h>
 #include <asm/arch/cpu.h>
 
-#define        SMC_IRQ_TRIGGER_TYPE (( \
+#define        SMC_IRQ_FLAGS (( \
                   machine_is_omap_h2() \
                || machine_is_omap_h3() \
                || (machine_is_omap_innovator() && !cpu_is_omap1510()) \
-       ) ? IRQT_FALLING : IRQT_RISING)
+       ) ? SA_TRIGGER_FALLING : SA_TRIGGER_RISING)
 
 
 #elif  defined(CONFIG_SH_SH4202_MICRODEV)
@@ -209,7 +209,7 @@ SMC_outw(u16 val, void __iomem *ioaddr, int reg)
 #define SMC_insw(a, r, p, l)   insw((a) + (r) - 0xa0000000, p, l)
 #define SMC_outsw(a, r, p, l)  outsw((a) + (r) - 0xa0000000, p, l)
 
-#define set_irq_type(irq, type)        do {} while(0)
+#define SMC_IRQ_FLAGS          (0)
 
 #elif  defined(CONFIG_ISA)
 
@@ -237,7 +237,7 @@ SMC_outw(u16 val, void __iomem *ioaddr, int reg)
 #define SMC_insw(a, r, p, l)   insw(((u32)a) + (r), p, l)
 #define SMC_outsw(a, r, p, l)  outsw(((u32)a) + (r), p, l)
 
-#define set_irq_type(irq, type)        do {} while(0)
+#define SMC_IRQ_FLAGS          (0)
 
 #define RPC_LSA_DEFAULT                RPC_LED_TX_RX
 #define RPC_LSB_DEFAULT                RPC_LED_100_10
@@ -319,7 +319,7 @@ static inline void SMC_outsw (unsigned long a, int r, unsigned char* p, int l)
                        au_writew(*_p++ , _a); \
        } while(0)
 
-#define set_irq_type(irq, type) do {} while (0)
+#define SMC_IRQ_FLAGS          (0)
 
 #else
 
@@ -342,8 +342,8 @@ static inline void SMC_outsw (unsigned long a, int r, unsigned char* p, int l)
 
 #endif
 
-#ifndef        SMC_IRQ_TRIGGER_TYPE
-#define        SMC_IRQ_TRIGGER_TYPE    IRQT_RISING
+#ifndef        SMC_IRQ_FLAGS
+#define        SMC_IRQ_FLAGS           SA_TRIGGER_RISING
 #endif
 
 #ifdef SMC_USE_PXA_DMA

diff --git a/include/asm-arm/irq.h b/include/asm-arm/irq.h
index 59975ee43cf139138503288801c7d8758dada859..7772432d3fd7750506943eaf88ea7eda9e720a7d 100644 (file)
--- a/include/asm-arm/irq.h
+++ b/include/asm-arm/irq.h
@@ -25,10 +25,14 @@ extern void disable_irq_nosync(unsigned int);
 extern void disable_irq(unsigned int);
 extern void enable_irq(unsigned int);
 
-#define __IRQT_FALEDGE (1 << 0)
-#define __IRQT_RISEDGE (1 << 1)
-#define __IRQT_LOWLVL  (1 << 2)
-#define __IRQT_HIGHLVL (1 << 3)
+/*
+ * These correspond with the SA_TRIGGER_* defines, and therefore the
+ * IRQRESOURCE_IRQ_* defines.
+ */
+#define __IRQT_RISEDGE (1 << 0)
+#define __IRQT_FALEDGE (1 << 1)
+#define __IRQT_HIGHLVL (1 << 2)
+#define __IRQT_LOWLVL  (1 << 3)
 
 #define IRQT_NOEDGE    (0)
 #define IRQT_RISING    (__IRQT_RISEDGE)

diff --git a/include/linux/signal.h b/include/linux/signal.h
index 5dd5f02c5c5fd6b1c3f192f13b6b28373763061f..ea9eff16c4b74f41de0e4e3027409948f9a0bcec 100644 (file)
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -18,6 +18,19 @@
 #define SA_PROBE               SA_ONESHOT
 #define SA_SAMPLE_RANDOM       SA_RESTART
 #define SA_SHIRQ               0x04000000
+/*
+ * As above, these correspond to the IORESOURCE_IRQ_* defines in
+ * linux/ioport.h to select the interrupt line behaviour.  When
+ * requesting an interrupt without specifying a SA_TRIGGER, the
+ * setting should be assumed to be "as already configured", which
+ * may be as per machine or firmware initialisation.
+ */
+#define SA_TRIGGER_LOW         0x00000008
+#define SA_TRIGGER_HIGH                0x00000004
+#define SA_TRIGGER_FALLING     0x00000002
+#define SA_TRIGGER_RISING      0x00000001
+#define SA_TRIGGER_MASK        (SA_TRIGGER_HIGH|SA_TRIGGER_LOW|\
+                                SA_TRIGGER_RISING|SA_TRIGGER_FALLING)
 
 /*
  * Real Time signals may be queued.