diff --git a/triggers/Makefile b/triggers/Makefile
index 2729569764dec6586225805d543a62824a20e1a1..ecd25a0f47c97654348ec77eb653c3479461f225 100644
--- a/triggers/Makefile
+++ b/triggers/Makefile
@@ -3,6 +3,7 @@ LINUX ?= /lib/modules/$(shell uname -r)/build
EXTRA_CFLAGS += -I$(obj)/../include/
obj-m = zio-trig-timer.o
+obj-m += zio-trig-irq.o
all:
$(MAKE) -C $(LINUX) M=$(shell /bin/pwd) modules
diff --git a/triggers/zio-trig-irq.c b/triggers/zio-trig-irq.c
new file mode 100644
index 0000000000000000000000000000000000000000..ba6bcbe649abca1bd19c785697438d37bbd07482
--- /dev/null
+++ b/triggers/zio-trig-irq.c
@@ -0,0 +1,204 @@
+/* Alessandro Rubini for CERN, 2011, GNU GPLv2 or later */
+
+/*
+ * This is a trigger based on an external IRQ. You can specify the IRQ
+ * number or the GPIO number -- then the associated IRQ is used
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+
+#include <linux/zio.h>
+#include <linux/zio-sysfs.h>
+#include <linux/zio-buffer.h>
+#include <linux/zio-trigger.h>
+
+static int zti_irq = -1;
+static int zti_gpio = -1;
+module_param_named(irq, zti_irq, int, 0444);
+module_param_named(gpio, zti_gpio, int, 0444);
+
+enum zti_attrs {
+ ZTI_ATTR_NSAMPLES = 0,
+ ZTI_ATTR_IRQ,
+ ZTI_ATTR_GPIO,
+};
+
+static DEFINE_ZATTR_STD(TRIG, zti_std_attr) = {
+ ZATTR_REG(trig, ZATTR_TRIG_NSAMPLES, S_IRUGO | S_IWUGO,
+ ZTI_ATTR_NSAMPLES, 16),
+};
+
+static struct zio_attribute zti_ext_attr[] = {
+ ZATTR_EXT_REG("irq", S_IRUGO, ZTI_ATTR_IRQ, -1),
+ ZATTR_EXT_REG("gpio", S_IRUGO, ZTI_ATTR_GPIO, -1),
+};
+int zti_conf_set (struct kobject *kobj, struct zio_attribute *zattr,
+ uint32_t usr_val)
+{
+ struct zio_ti *ti = to_zio_ti(kobj);
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ zattr->value = usr_val;
+ switch (zattr->priv.addr) {
+ case ZTI_ATTR_NSAMPLES:
+ ti->current_ctrl->nsamples = usr_val;
+ break;
+ /* other attributes are read-only */
+ default:
+ pr_err("%s: unknown \"addr\" for configuration\n", __func__);
+ return -EINVAL;
+ }
+ return 0;
+}
+
+struct zio_sys_operations zti_s_ops = {
+ .conf_set = zti_conf_set,
+};
+
+irqreturn_t zti_handler(int irq, void *dev_id)
+{
+ struct zio_ti *ti = dev_id;
+
+ /* When a trigger fires, we must prepare our control and timestamp */
+ getnstimeofday(&ti->tstamp);
+ zio_fire_trigger(ti);
+ return IRQ_HANDLED;
+}
+
+/*
+ * The trigger operations are the core of a trigger type
+ */
+static int zti_push_block(struct zio_ti *ti, struct zio_channel *chan,
+ struct zio_block *block)
+{
+ /* software triggers must store pending stuff in chan->t_priv */
+ pr_debug("%s:%d\n", __func__, __LINE__);
+
+ if (chan->t_priv)
+ return -EBUSY;
+ chan->t_priv = block;
+ return 0;
+}
+
+static int zti_config(struct zio_ti *ti, struct zio_control *ctrl)
+{
+ /* FIXME: config is not supported yet */
+
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ return 0;
+}
+
+static struct zio_ti *zti_create(struct zio_trigger_type *trig,
+ struct zio_cset *cset,
+ struct zio_control *ctrl, fmode_t flags)
+{
+ struct zio_ti *ti;
+
+ int ret;
+ pr_debug("%s:%d\n", __func__, __LINE__);
+
+ ti = kzalloc(sizeof(*ti), GFP_KERNEL);
+ if (!ti)
+ return ERR_PTR(-ENOMEM);
+
+ /* The current control is already filled: just set nsamples */
+ ctrl->nsamples = zti_std_attr[ZATTR_TRIG_NSAMPLES].value;
+ ti->current_ctrl = ctrl;
+
+ ret = request_irq(zti_irq, zti_handler, IRQF_SHARED
+ | IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
+ KBUILD_MODNAME, ti);
+ if (ret < 0) {
+ kfree(ti);
+ return ERR_PTR(ret);
+ }
+ return ti;
+}
+
+static void zti_destroy(struct zio_ti *ti)
+{
+ pr_debug("%s:%d\n", __func__, __LINE__);
+ free_irq(zti_irq, &ti);
+ kfree(ti);
+}
+
+static const struct zio_trigger_operations zti_trigger_ops = {
+ .push_block = zti_push_block,
+ .pull_block = NULL,
+ .data_done = zio_generic_data_done,
+ .config = zti_config,
+ .create = zti_create,
+ .destroy = zti_destroy,
+};
+
+static struct zio_trigger_type zti_trigger = {
+ .owner = THIS_MODULE,
+ .zattr_set = {
+ .std_zattr = zti_std_attr,
+ .ext_zattr = zti_ext_attr,
+ .n_ext_attr = ARRAY_SIZE(zti_ext_attr),
+ },
+ .s_op = &zti_s_ops,
+ .t_op = &zti_trigger_ops,
+ .f_op = NULL, /* we use buffer fops */
+};
+
+/*
+ * A validation function, called at insmod and at parameter change
+ */
+static int zti_validate(int irq, int gpio)
+{
+ int ret = 0;
+
+ if (irq != -1 && gpio != -1) {
+ pr_err("%s: only set irq or gpio, not both\n", KBUILD_MODNAME);
+ return -EINVAL;
+ }
+ if (irq == -1 && gpio == -1) {
+ pr_err("%s: please set irq or gpio\n", KBUILD_MODNAME);
+ return -EINVAL;
+ }
+ if (gpio != -1) {
+ irq = gpio_to_irq(gpio);
+ if (irq >= 0) {
+ ret = gpio_request(gpio, KBUILD_MODNAME);
+ } else {
+ ret = irq;
+ }
+ }
+ if (ret < 0) {
+ pr_err("%s: invalid irq/gpio (%i/%i)\n", KBUILD_MODNAME,
+ gpio, irq);
+ return ret;
+ }
+ zti_irq = irq; /* used at trigger_create time */
+ return 0;
+}
+
+/*
+ * init and exit
+ */
+static int __init zti_init(void)
+{
+ int ret = zti_validate(zti_irq, zti_gpio);
+ if (ret)
+ return ret;
+ return zio_register_trig(&zti_trigger, "irq");
+}
+
+static void __exit zti_exit(void)
+{
+ zio_unregister_trig(&zti_trigger);
+ if (zti_gpio)
+ gpio_free(zti_gpio);
+}
+
+module_init(zti_init);
+module_exit(zti_exit);
+MODULE_AUTHOR("Alessandro Rubini");
+MODULE_LICENSE("GPL");