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path: root/drivers/iio/industrialio-event.c
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Diffstat (limited to 'drivers/iio/industrialio-event.c')
-rw-r--r--drivers/iio/industrialio-event.c453
1 files changed, 453 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-event.c b/drivers/iio/industrialio-event.c
new file mode 100644
index 000000000000..b49059de5d02
--- /dev/null
+++ b/drivers/iio/industrialio-event.c
@@ -0,0 +1,453 @@
+/* Industrial I/O event handling
+ *
+ * Copyright (c) 2008 Jonathan Cameron
+ *
+ * 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.
+ *
+ * Based on elements of hwmon and input subsystems.
+ */
+
+#include <linux/anon_inodes.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/kfifo.h>
+#include <linux/module.h>
+#include <linux/poll.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/wait.h>
+#include <linux/iio/iio.h>
+#include "iio_core.h"
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+/**
+ * struct iio_event_interface - chrdev interface for an event line
+ * @wait: wait queue to allow blocking reads of events
+ * @det_events: list of detected events
+ * @dev_attr_list: list of event interface sysfs attribute
+ * @flags: file operations related flags including busy flag.
+ * @group: event interface sysfs attribute group
+ */
+struct iio_event_interface {
+ wait_queue_head_t wait;
+ DECLARE_KFIFO(det_events, struct iio_event_data, 16);
+
+ struct list_head dev_attr_list;
+ unsigned long flags;
+ struct attribute_group group;
+};
+
+int iio_push_event(struct iio_dev *indio_dev, u64 ev_code, s64 timestamp)
+{
+ struct iio_event_interface *ev_int = indio_dev->event_interface;
+ struct iio_event_data ev;
+ int copied;
+
+ /* Does anyone care? */
+ spin_lock(&ev_int->wait.lock);
+ if (test_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
+
+ ev.id = ev_code;
+ ev.timestamp = timestamp;
+
+ copied = kfifo_put(&ev_int->det_events, &ev);
+ if (copied != 0)
+ wake_up_locked_poll(&ev_int->wait, POLLIN);
+ }
+ spin_unlock(&ev_int->wait.lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(iio_push_event);
+
+/**
+ * iio_event_poll() - poll the event queue to find out if it has data
+ */
+static unsigned int iio_event_poll(struct file *filep,
+ struct poll_table_struct *wait)
+{
+ struct iio_event_interface *ev_int = filep->private_data;
+ unsigned int events = 0;
+
+ poll_wait(filep, &ev_int->wait, wait);
+
+ spin_lock(&ev_int->wait.lock);
+ if (!kfifo_is_empty(&ev_int->det_events))
+ events = POLLIN | POLLRDNORM;
+ spin_unlock(&ev_int->wait.lock);
+
+ return events;
+}
+
+static ssize_t iio_event_chrdev_read(struct file *filep,
+ char __user *buf,
+ size_t count,
+ loff_t *f_ps)
+{
+ struct iio_event_interface *ev_int = filep->private_data;
+ unsigned int copied;
+ int ret;
+
+ if (count < sizeof(struct iio_event_data))
+ return -EINVAL;
+
+ spin_lock(&ev_int->wait.lock);
+ if (kfifo_is_empty(&ev_int->det_events)) {
+ if (filep->f_flags & O_NONBLOCK) {
+ ret = -EAGAIN;
+ goto error_unlock;
+ }
+ /* Blocking on device; waiting for something to be there */
+ ret = wait_event_interruptible_locked(ev_int->wait,
+ !kfifo_is_empty(&ev_int->det_events));
+ if (ret)
+ goto error_unlock;
+ /* Single access device so no one else can get the data */
+ }
+
+ ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
+
+error_unlock:
+ spin_unlock(&ev_int->wait.lock);
+
+ return ret ? ret : copied;
+}
+
+static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
+{
+ struct iio_event_interface *ev_int = filep->private_data;
+
+ spin_lock(&ev_int->wait.lock);
+ __clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
+ /*
+ * In order to maintain a clean state for reopening,
+ * clear out any awaiting events. The mask will prevent
+ * any new __iio_push_event calls running.
+ */
+ kfifo_reset_out(&ev_int->det_events);
+ spin_unlock(&ev_int->wait.lock);
+
+ return 0;
+}
+
+static const struct file_operations iio_event_chrdev_fileops = {
+ .read = iio_event_chrdev_read,
+ .poll = iio_event_poll,
+ .release = iio_event_chrdev_release,
+ .owner = THIS_MODULE,
+ .llseek = noop_llseek,
+};
+
+int iio_event_getfd(struct iio_dev *indio_dev)
+{
+ struct iio_event_interface *ev_int = indio_dev->event_interface;
+ int fd;
+
+ if (ev_int == NULL)
+ return -ENODEV;
+
+ spin_lock(&ev_int->wait.lock);
+ if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
+ spin_unlock(&ev_int->wait.lock);
+ return -EBUSY;
+ }
+ spin_unlock(&ev_int->wait.lock);
+ fd = anon_inode_getfd("iio:event",
+ &iio_event_chrdev_fileops, ev_int, O_RDONLY);
+ if (fd < 0) {
+ spin_lock(&ev_int->wait.lock);
+ __clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
+ spin_unlock(&ev_int->wait.lock);
+ }
+ return fd;
+}
+
+static const char * const iio_ev_type_text[] = {
+ [IIO_EV_TYPE_THRESH] = "thresh",
+ [IIO_EV_TYPE_MAG] = "mag",
+ [IIO_EV_TYPE_ROC] = "roc",
+ [IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
+ [IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
+};
+
+static const char * const iio_ev_dir_text[] = {
+ [IIO_EV_DIR_EITHER] = "either",
+ [IIO_EV_DIR_RISING] = "rising",
+ [IIO_EV_DIR_FALLING] = "falling"
+};
+
+static ssize_t iio_ev_state_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ int ret;
+ bool val;
+
+ ret = strtobool(buf, &val);
+ if (ret < 0)
+ return ret;
+
+ ret = indio_dev->info->write_event_config(indio_dev,
+ this_attr->address,
+ val);
+ return (ret < 0) ? ret : len;
+}
+
+static ssize_t iio_ev_state_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ int val = indio_dev->info->read_event_config(indio_dev,
+ this_attr->address);
+
+ if (val < 0)
+ return val;
+ else
+ return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t iio_ev_value_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ int val, ret;
+
+ ret = indio_dev->info->read_event_value(indio_dev,
+ this_attr->address, &val);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t iio_ev_value_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ unsigned long val;
+ int ret;
+
+ if (!indio_dev->info->write_event_value)
+ return -EINVAL;
+
+ ret = strict_strtoul(buf, 10, &val);
+ if (ret)
+ return ret;
+
+ ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
+ val);
+ if (ret < 0)
+ return ret;
+
+ return len;
+}
+
+static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan)
+{
+ int ret = 0, i, attrcount = 0;
+ u64 mask = 0;
+ char *postfix;
+ if (!chan->event_mask)
+ return 0;
+
+ for_each_set_bit(i, &chan->event_mask, sizeof(chan->event_mask)*8) {
+ postfix = kasprintf(GFP_KERNEL, "%s_%s_en",
+ iio_ev_type_text[i/IIO_EV_DIR_MAX],
+ iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
+ if (postfix == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ if (chan->modified)
+ mask = IIO_MOD_EVENT_CODE(chan->type, 0, chan->channel,
+ i/IIO_EV_DIR_MAX,
+ i%IIO_EV_DIR_MAX);
+ else if (chan->differential)
+ mask = IIO_EVENT_CODE(chan->type,
+ 0, 0,
+ i%IIO_EV_DIR_MAX,
+ i/IIO_EV_DIR_MAX,
+ 0,
+ chan->channel,
+ chan->channel2);
+ else
+ mask = IIO_UNMOD_EVENT_CODE(chan->type,
+ chan->channel,
+ i/IIO_EV_DIR_MAX,
+ i%IIO_EV_DIR_MAX);
+
+ ret = __iio_add_chan_devattr(postfix,
+ chan,
+ &iio_ev_state_show,
+ iio_ev_state_store,
+ mask,
+ 0,
+ &indio_dev->dev,
+ &indio_dev->event_interface->
+ dev_attr_list);
+ kfree(postfix);
+ if (ret)
+ goto error_ret;
+ attrcount++;
+ postfix = kasprintf(GFP_KERNEL, "%s_%s_value",
+ iio_ev_type_text[i/IIO_EV_DIR_MAX],
+ iio_ev_dir_text[i%IIO_EV_DIR_MAX]);
+ if (postfix == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ ret = __iio_add_chan_devattr(postfix, chan,
+ iio_ev_value_show,
+ iio_ev_value_store,
+ mask,
+ 0,
+ &indio_dev->dev,
+ &indio_dev->event_interface->
+ dev_attr_list);
+ kfree(postfix);
+ if (ret)
+ goto error_ret;
+ attrcount++;
+ }
+ ret = attrcount;
+error_ret:
+ return ret;
+}
+
+static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
+{
+ struct iio_dev_attr *p, *n;
+ list_for_each_entry_safe(p, n,
+ &indio_dev->event_interface->
+ dev_attr_list, l) {
+ kfree(p->dev_attr.attr.name);
+ kfree(p);
+ }
+}
+
+static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
+{
+ int j, ret, attrcount = 0;
+
+ INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
+ /* Dynically created from the channels array */
+ for (j = 0; j < indio_dev->num_channels; j++) {
+ ret = iio_device_add_event_sysfs(indio_dev,
+ &indio_dev->channels[j]);
+ if (ret < 0)
+ goto error_clear_attrs;
+ attrcount += ret;
+ }
+ return attrcount;
+
+error_clear_attrs:
+ __iio_remove_event_config_attrs(indio_dev);
+
+ return ret;
+}
+
+static bool iio_check_for_dynamic_events(struct iio_dev *indio_dev)
+{
+ int j;
+
+ for (j = 0; j < indio_dev->num_channels; j++)
+ if (indio_dev->channels[j].event_mask != 0)
+ return true;
+ return false;
+}
+
+static void iio_setup_ev_int(struct iio_event_interface *ev_int)
+{
+ INIT_KFIFO(ev_int->det_events);
+ init_waitqueue_head(&ev_int->wait);
+}
+
+static const char *iio_event_group_name = "events";
+int iio_device_register_eventset(struct iio_dev *indio_dev)
+{
+ struct iio_dev_attr *p;
+ int ret = 0, attrcount_orig = 0, attrcount, attrn;
+ struct attribute **attr;
+
+ if (!(indio_dev->info->event_attrs ||
+ iio_check_for_dynamic_events(indio_dev)))
+ return 0;
+
+ indio_dev->event_interface =
+ kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
+ if (indio_dev->event_interface == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ iio_setup_ev_int(indio_dev->event_interface);
+ if (indio_dev->info->event_attrs != NULL) {
+ attr = indio_dev->info->event_attrs->attrs;
+ while (*attr++ != NULL)
+ attrcount_orig++;
+ }
+ attrcount = attrcount_orig;
+ if (indio_dev->channels) {
+ ret = __iio_add_event_config_attrs(indio_dev);
+ if (ret < 0)
+ goto error_free_setup_event_lines;
+ attrcount += ret;
+ }
+
+ indio_dev->event_interface->group.name = iio_event_group_name;
+ indio_dev->event_interface->group.attrs = kcalloc(attrcount + 1,
+ sizeof(indio_dev->event_interface->group.attrs[0]),
+ GFP_KERNEL);
+ if (indio_dev->event_interface->group.attrs == NULL) {
+ ret = -ENOMEM;
+ goto error_free_setup_event_lines;
+ }
+ if (indio_dev->info->event_attrs)
+ memcpy(indio_dev->event_interface->group.attrs,
+ indio_dev->info->event_attrs->attrs,
+ sizeof(indio_dev->event_interface->group.attrs[0])
+ *attrcount_orig);
+ attrn = attrcount_orig;
+ /* Add all elements from the list. */
+ list_for_each_entry(p,
+ &indio_dev->event_interface->dev_attr_list,
+ l)
+ indio_dev->event_interface->group.attrs[attrn++] =
+ &p->dev_attr.attr;
+ indio_dev->groups[indio_dev->groupcounter++] =
+ &indio_dev->event_interface->group;
+
+ return 0;
+
+error_free_setup_event_lines:
+ __iio_remove_event_config_attrs(indio_dev);
+ kfree(indio_dev->event_interface);
+error_ret:
+
+ return ret;
+}
+
+void iio_device_unregister_eventset(struct iio_dev *indio_dev)
+{
+ if (indio_dev->event_interface == NULL)
+ return;
+ __iio_remove_event_config_attrs(indio_dev);
+ kfree(indio_dev->event_interface->group.attrs);
+ kfree(indio_dev->event_interface);
+}