--- /dev/null
+/*
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/irq_work.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger.h>
+
+struct iio_sysfs_trig {
+ struct iio_trigger *trig;
+ struct irq_work work;
+ int id;
+ struct list_head l;
+};
+
+static LIST_HEAD(iio_sysfs_trig_list);
+static DEFINE_MUTEX(iio_syfs_trig_list_mut);
+
+static int iio_sysfs_trigger_probe(int id);
+static ssize_t iio_sysfs_trig_add(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret;
+ unsigned long input;
+
+ ret = strict_strtoul(buf, 10, &input);
+ if (ret)
+ return ret;
+ ret = iio_sysfs_trigger_probe(input);
+ if (ret)
+ return ret;
+ return len;
+}
+static DEVICE_ATTR(add_trigger, S_IWUSR, NULL, &iio_sysfs_trig_add);
+
+static int iio_sysfs_trigger_remove(int id);
+static ssize_t iio_sysfs_trig_remove(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ int ret;
+ unsigned long input;
+
+ ret = strict_strtoul(buf, 10, &input);
+ if (ret)
+ return ret;
+ ret = iio_sysfs_trigger_remove(input);
+ if (ret)
+ return ret;
+ return len;
+}
+
+static DEVICE_ATTR(remove_trigger, S_IWUSR, NULL, &iio_sysfs_trig_remove);
+
+static struct attribute *iio_sysfs_trig_attrs[] = {
+ &dev_attr_add_trigger.attr,
+ &dev_attr_remove_trigger.attr,
+ NULL,
+};
+
+static const struct attribute_group iio_sysfs_trig_group = {
+ .attrs = iio_sysfs_trig_attrs,
+};
+
+static const struct attribute_group *iio_sysfs_trig_groups[] = {
+ &iio_sysfs_trig_group,
+ NULL
+};
+
+
+/* Nothing to actually do upon release */
+static void iio_trigger_sysfs_release(struct device *dev)
+{
+}
+
+static struct device iio_sysfs_trig_dev = {
+ .bus = &iio_bus_type,
+ .groups = iio_sysfs_trig_groups,
+ .release = &iio_trigger_sysfs_release,
+};
+
+static void iio_sysfs_trigger_work(struct irq_work *work)
+{
+ struct iio_sysfs_trig *trig = container_of(work, struct iio_sysfs_trig,
+ work);
+
+ iio_trigger_poll(trig->trig, 0);
+}
+
+static ssize_t iio_sysfs_trigger_poll(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct iio_trigger *trig = to_iio_trigger(dev);
+ struct iio_sysfs_trig *sysfs_trig = iio_trigger_get_drvdata(trig);
+
+ irq_work_queue(&sysfs_trig->work);
+
+ return count;
+}
+
+static DEVICE_ATTR(trigger_now, S_IWUSR, NULL, iio_sysfs_trigger_poll);
+
+static struct attribute *iio_sysfs_trigger_attrs[] = {
+ &dev_attr_trigger_now.attr,
+ NULL,
+};
+
+static const struct attribute_group iio_sysfs_trigger_attr_group = {
+ .attrs = iio_sysfs_trigger_attrs,
+};
+
+static const struct attribute_group *iio_sysfs_trigger_attr_groups[] = {
+ &iio_sysfs_trigger_attr_group,
+ NULL
+};
+
+static const struct iio_trigger_ops iio_sysfs_trigger_ops = {
+ .owner = THIS_MODULE,
+};
+
+static int iio_sysfs_trigger_probe(int id)
+{
+ struct iio_sysfs_trig *t;
+ int ret;
+ bool foundit = false;
+ mutex_lock(&iio_syfs_trig_list_mut);
+ list_for_each_entry(t, &iio_sysfs_trig_list, l)
+ if (id == t->id) {
+ foundit = true;
+ break;
+ }
+ if (foundit) {
+ ret = -EINVAL;
+ goto out1;
+ }
+ t = kmalloc(sizeof(*t), GFP_KERNEL);
+ if (t == NULL) {
+ ret = -ENOMEM;
+ goto out1;
+ }
+ t->id = id;
+ t->trig = iio_trigger_alloc("sysfstrig%d", id);
+ if (!t->trig) {
+ ret = -ENOMEM;
+ goto free_t;
+ }
+
+ t->trig->dev.groups = iio_sysfs_trigger_attr_groups;
+ t->trig->ops = &iio_sysfs_trigger_ops;
+ t->trig->dev.parent = &iio_sysfs_trig_dev;
+ iio_trigger_set_drvdata(t->trig, t);
+
+ init_irq_work(&t->work, iio_sysfs_trigger_work);
+
+ ret = iio_trigger_register(t->trig);
+ if (ret)
+ goto out2;
+ list_add(&t->l, &iio_sysfs_trig_list);
+ __module_get(THIS_MODULE);
+ mutex_unlock(&iio_syfs_trig_list_mut);
+ return 0;
+
+out2:
+ iio_trigger_put(t->trig);
+free_t:
+ kfree(t);
+out1:
+ mutex_unlock(&iio_syfs_trig_list_mut);
+ return ret;
+}
+
+static int iio_sysfs_trigger_remove(int id)
+{
+ bool foundit = false;
+ struct iio_sysfs_trig *t;
+ mutex_lock(&iio_syfs_trig_list_mut);
+ list_for_each_entry(t, &iio_sysfs_trig_list, l)
+ if (id == t->id) {
+ foundit = true;
+ break;
+ }
+ if (!foundit) {
+ mutex_unlock(&iio_syfs_trig_list_mut);
+ return -EINVAL;
+ }
+
+ iio_trigger_unregister(t->trig);
+ iio_trigger_free(t->trig);
+
+ list_del(&t->l);
+ kfree(t);
+ module_put(THIS_MODULE);
+ mutex_unlock(&iio_syfs_trig_list_mut);
+ return 0;
+}
+
+
+static int __init iio_sysfs_trig_init(void)
+{
+ device_initialize(&iio_sysfs_trig_dev);
+ dev_set_name(&iio_sysfs_trig_dev, "iio_sysfs_trigger");
+ return device_add(&iio_sysfs_trig_dev);
+}
+module_init(iio_sysfs_trig_init);
+
+static void __exit iio_sysfs_trig_exit(void)
+{
+ device_unregister(&iio_sysfs_trig_dev);
+}
+module_exit(iio_sysfs_trig_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Sysfs based trigger for the iio subsystem");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:iio-trig-sysfs");
projects / firefly-linux-kernel-4.4.55.git / blobdiff