first commit

3 files changed, 316 insertions, 0 deletions

diff --git a/drivers/iio/trigger/Kconfig b/drivers/iio/trigger/Kconfig
new file mode 100755
index 000000000..db7bb879c
--- /dev/null
+++ b/drivers/iio/trigger/Kconfig
@@ -0,0 +1,18 @@
+#
+# Industrial I/O standalone triggers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Triggers - standalone"
+
+config IIO_HRTIMER_TRIGGER
+	tristate "HRTIMER trigger"
+	select IRQ_WORK
+	help
+	  Provides support for using HRTIMER entries as IIO triggers.
+	  If unsure, say N (but it's safe to say "Y").
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called iio-trig-hrtimer.
+
+endmenu
diff --git a/drivers/iio/trigger/Makefile b/drivers/iio/trigger/Makefile
new file mode 100755
index 000000000..d04c5f706
--- /dev/null
+++ b/drivers/iio/trigger/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for triggers not associated with iio-devices
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_IIO_HRTIMER_TRIGGER) += iio-trig-hrtimer.o
diff --git a/drivers/iio/trigger/iio-trig-hrtimer.c b/drivers/iio/trigger/iio-trig-hrtimer.c
new file mode 100755
index 000000000..a657cbb0d
--- /dev/null
+++ b/drivers/iio/trigger/iio-trig-hrtimer.c
@@ -0,0 +1,292 @@
+/*
+ * Industrial I/O - hrtimer trigger support
+ *
+ * Copyright 2014 STMicroelectronics Inc.
+ * Denis Ciocca <denis.ciocca@st.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/hrtimer.h>
+#include <linux/ktime.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+
+struct iio_hrtimer_trigger_data {
+	struct iio_trigger *trig;
+	struct hrtimer timer;
+	struct list_head l;
+	ktime_t period;
+	u16  freq;
+	int id;
+};
+
+static LIST_HEAD(iio_hrtimer_trigger_list);
+static DEFINE_MUTEX(iio_hrtimer_trigger_list_mut);
+
+static int iio_hrtimer_trigger_probe(int id);
+static int iio_hrtimer_trigger_remove(int id);
+
+static ssize_t iio_sysfs_hrtimer_trig_add(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	int ret;
+	unsigned int input;
+
+	ret = kstrtouint(buf, 10, &input);
+	if (ret)
+		return ret;
+
+	ret = iio_hrtimer_trigger_probe(input);
+	if (ret)
+		return ret;
+
+	return len;
+}
+static DEVICE_ATTR(add_trigger, S_IWUSR, NULL, &iio_sysfs_hrtimer_trig_add);
+
+static ssize_t iio_sysfs_hrtimer_trig_remove(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	int ret;
+	unsigned int input;
+
+	ret = kstrtouint(buf, 10, &input);
+	if (ret)
+		return ret;
+
+	ret = iio_hrtimer_trigger_remove(input);
+	if (ret)
+		return ret;
+
+	return len;
+}
+static DEVICE_ATTR(remove_trigger, S_IWUSR,
+					NULL, &iio_sysfs_hrtimer_trig_remove);
+
+static struct attribute *iio_hrtimer_trig_attrs[] = {
+	&dev_attr_add_trigger.attr,
+	&dev_attr_remove_trigger.attr,
+	NULL,
+};
+
+static const struct attribute_group iio_hrtimer_trig_group = {
+	.attrs = iio_hrtimer_trig_attrs,
+};
+
+static const struct attribute_group *iio_hrtimer_trig_groups[] = {
+	&iio_hrtimer_trig_group,
+	NULL,
+};
+
+static struct device iio_hrtimer_trig_dev = {
+	.bus = &iio_bus_type,
+	.groups = iio_hrtimer_trig_groups,
+};
+
+static int iio_hrtimer_trig_set_state(struct iio_trigger *trig, bool state)
+{
+	struct iio_hrtimer_trigger_data *trig_data =
+						iio_trigger_get_drvdata(trig);
+
+	if (trig_data->freq == 0)
+		return -EINVAL;
+
+	if (state)
+		hrtimer_start(&trig_data->timer,
+					trig_data->period, HRTIMER_MODE_REL);
+	else
+		hrtimer_cancel(&trig_data->timer);
+
+	return 0;
+}
+
+static ssize_t iio_hrtimer_trigger_set_freq_value(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	int ret;
+	u16 frequency;
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct iio_hrtimer_trigger_data *trig_data =
+						iio_trigger_get_drvdata(trig);
+
+	ret = kstrtou16(buf, 10, &frequency);
+	if (ret < 0)
+		return ret;
+
+	trig_data->freq = frequency;
+
+	if (frequency)
+		trig_data->period =
+				ktime_set(0, NSEC_PER_SEC / trig_data->freq);
+
+	return len;
+}
+
+static ssize_t iio_hrtimer_trigger_get_freq_value(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct iio_hrtimer_trigger_data *trig_data =
+						iio_trigger_get_drvdata(trig);
+
+	return sprintf(buf, "%hu\n", trig_data->freq);
+}
+
+static DEVICE_ATTR(frequency, S_IWUSR | S_IRUGO,
+					iio_hrtimer_trigger_get_freq_value,
+					iio_hrtimer_trigger_set_freq_value);
+
+static ssize_t iio_hrtimer_trigger_get_id(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct iio_trigger *trig = to_iio_trigger(dev);
+	struct iio_hrtimer_trigger_data *trig_data =
+						iio_trigger_get_drvdata(trig);
+
+	return sprintf(buf, "%d\n", trig_data->id);
+}
+
+static DEVICE_ATTR(id, S_IRUGO, iio_hrtimer_trigger_get_id, NULL);
+
+static struct attribute *iio_hrtimer_trigger_attrs[] = {
+	&dev_attr_frequency.attr,
+	&dev_attr_id.attr,
+	NULL,
+};
+
+static const struct attribute_group iio_hrtimer_trigger_attr_group = {
+	.attrs = iio_hrtimer_trigger_attrs,
+};
+
+static const struct attribute_group *iio_hrtimer_trigger_attr_groups[] = {
+	&iio_hrtimer_trigger_attr_group,
+	NULL,
+};
+
+static const struct iio_trigger_ops iio_hrtimer_trigger_ops = {
+	.owner = THIS_MODULE,
+	.set_trigger_state = &iio_hrtimer_trig_set_state,
+};
+
+enum hrtimer_restart iio_hrtimer_trigger_func(struct hrtimer *timer)
+{
+	struct iio_hrtimer_trigger_data *trig_data;
+
+	trig_data = container_of(timer, struct iio_hrtimer_trigger_data, timer);
+
+	hrtimer_forward_now(timer, trig_data->period);
+	iio_trigger_poll(trig_data->trig, iio_get_time_ns());
+
+	return HRTIMER_RESTART;
+}
+
+static int iio_hrtimer_trigger_probe(int id)
+{
+	int err;
+	bool foundit = false;
+	struct iio_hrtimer_trigger_data *trig_data;
+
+	mutex_lock(&iio_hrtimer_trigger_list_mut);
+	list_for_each_entry(trig_data, &iio_hrtimer_trigger_list, l) {
+		if (id == trig_data->id) {
+			foundit = true;
+			break;
+		}
+	}
+	if (foundit) {
+		err = -EINVAL;
+		goto iio_hrtimer_mutex_unlock;
+	}
+
+	trig_data = kmalloc(sizeof(*trig_data), GFP_KERNEL);
+	if (trig_data == NULL) {
+		err = -ENOMEM;
+		goto iio_hrtimer_mutex_unlock;
+	}
+
+	trig_data->id = id;
+	trig_data->trig = iio_trigger_alloc("hrtimer_trig%d", id);
+	if (!trig_data->trig) {
+		err = -ENOMEM;
+		goto iio_hrtimer_free_trig_data;
+	}
+
+	trig_data->trig->dev.groups = iio_hrtimer_trigger_attr_groups;
+	trig_data->trig->ops = &iio_hrtimer_trigger_ops;
+	trig_data->trig->dev.parent = &iio_hrtimer_trig_dev;
+	iio_trigger_set_drvdata(trig_data->trig, trig_data);
+
+	trig_data->freq = 0;
+	hrtimer_init(&trig_data->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	trig_data->timer.function = &iio_hrtimer_trigger_func;
+
+	err = iio_trigger_register(trig_data->trig);
+	if (err)
+		goto iio_hrtimer_free_trig_data;
+
+	list_add(&trig_data->l, &iio_hrtimer_trigger_list);
+	__module_get(THIS_MODULE);
+	mutex_unlock(&iio_hrtimer_trigger_list_mut);
+
+	return 0;
+
+iio_hrtimer_free_trig_data:
+	kfree(trig_data);
+iio_hrtimer_mutex_unlock:
+	mutex_unlock(&iio_hrtimer_trigger_list_mut);
+	return err;
+}
+
+static int iio_hrtimer_trigger_remove(int id)
+{
+	bool foundit = false;
+	struct iio_hrtimer_trigger_data *trig_data;
+
+	mutex_lock(&iio_hrtimer_trigger_list_mut);
+	list_for_each_entry(trig_data, &iio_hrtimer_trigger_list, l) {
+		if (id == trig_data->id) {
+			foundit = true;
+			break;
+		}
+	}
+	if (!foundit) {
+		mutex_unlock(&iio_hrtimer_trigger_list_mut);
+		return -EINVAL;
+	}
+
+	iio_trigger_unregister(trig_data->trig);
+	iio_trigger_free(trig_data->trig);
+
+	list_del(&trig_data->l);
+	kfree(trig_data);
+	module_put(THIS_MODULE);
+	mutex_unlock(&iio_hrtimer_trigger_list_mut);
+
+	return 0;
+}
+
+static int __init iio_hrtimer_trig_init(void)
+{
+	device_initialize(&iio_hrtimer_trig_dev);
+	dev_set_name(&iio_hrtimer_trig_dev, "iio_hrtimer_trigger");
+	return device_add(&iio_hrtimer_trig_dev);
+}
+module_init(iio_hrtimer_trig_init);
+
+static void __exit iio_hrtimer_trig_exit(void)
+{
+	device_unregister(&iio_hrtimer_trig_dev);
+}
+module_exit(iio_hrtimer_trig_exit);
+
+MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
+MODULE_DESCRIPTION("Hrtimer trigger for the iio subsystem");
+MODULE_LICENSE("GPL v2");