--- zzzz-none-000/linux-3.10.107/drivers/iio/industrialio-event.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/iio/industrialio-event.c	2021-02-04 17:41:59.000000000 +0000
@@ -32,6 +32,7 @@
  * @dev_attr_list:	list of event interface sysfs attribute
  * @flags:		file operations related flags including busy flag.
  * @group:		event interface sysfs attribute group
+ * @read_lock:		lock to protect kfifo read operations
  */
 struct iio_event_interface {
 	wait_queue_head_t	wait;
@@ -40,27 +41,34 @@
 	struct list_head	dev_attr_list;
 	unsigned long		flags;
 	struct attribute_group	group;
+	struct mutex		read_lock;
 };
 
+/**
+ * iio_push_event() - try to add event to the list for userspace reading
+ * @indio_dev:		IIO device structure
+ * @ev_code:		What event
+ * @timestamp:		When the event occurred
+ *
+ * Note: The caller must make sure that this function is not running
+ * concurrently for the same indio_dev more than once.
+ **/
 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;
-	unsigned long flags;
 	int copied;
 
 	/* Does anyone care? */
-	spin_lock_irqsave(&ev_int->wait.lock, flags);
 	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);
+		copied = kfifo_put(&ev_int->det_events, ev);
 		if (copied != 0)
-			wake_up_locked_poll(&ev_int->wait, POLLIN);
+			wake_up_poll(&ev_int->wait, POLLIN);
 	}
-	spin_unlock_irqrestore(&ev_int->wait.lock, flags);
 
 	return 0;
 }
@@ -68,19 +76,26 @@
 
 /**
  * iio_event_poll() - poll the event queue to find out if it has data
+ * @filep:	File structure pointer to identify the device
+ * @wait:	Poll table pointer to add the wait queue on
+ *
+ * Return: (POLLIN | POLLRDNORM) if data is available for reading
+ *	   or a negative error code on failure
  */
 static unsigned int iio_event_poll(struct file *filep,
 			     struct poll_table_struct *wait)
 {
-	struct iio_event_interface *ev_int = filep->private_data;
+	struct iio_dev *indio_dev = filep->private_data;
+	struct iio_event_interface *ev_int = indio_dev->event_interface;
 	unsigned int events = 0;
 
+	if (!indio_dev->info)
+		return events;
+
 	poll_wait(filep, &ev_int->wait, wait);
 
-	spin_lock_irq(&ev_int->wait.lock);
 	if (!kfifo_is_empty(&ev_int->det_events))
 		events = POLLIN | POLLRDNORM;
-	spin_unlock_irq(&ev_int->wait.lock);
 
 	return events;
 }
@@ -90,48 +105,61 @@
 				     size_t count,
 				     loff_t *f_ps)
 {
-	struct iio_event_interface *ev_int = filep->private_data;
+	struct iio_dev *indio_dev = filep->private_data;
+	struct iio_event_interface *ev_int = indio_dev->event_interface;
 	unsigned int copied;
 	int ret;
 
+	if (!indio_dev->info)
+		return -ENODEV;
+
 	if (count < sizeof(struct iio_event_data))
 		return -EINVAL;
 
-	spin_lock_irq(&ev_int->wait.lock);
-	if (kfifo_is_empty(&ev_int->det_events)) {
-		if (filep->f_flags & O_NONBLOCK) {
-			ret = -EAGAIN;
-			goto error_unlock;
+	do {
+		if (kfifo_is_empty(&ev_int->det_events)) {
+			if (filep->f_flags & O_NONBLOCK)
+				return -EAGAIN;
+
+			ret = wait_event_interruptible(ev_int->wait,
+					!kfifo_is_empty(&ev_int->det_events) ||
+					indio_dev->info == NULL);
+			if (ret)
+				return ret;
+			if (indio_dev->info == NULL)
+				return -ENODEV;
 		}
-		/* Blocking on device; waiting for something to be there */
-		ret = wait_event_interruptible_locked_irq(ev_int->wait,
-					!kfifo_is_empty(&ev_int->det_events));
+
+		if (mutex_lock_interruptible(&ev_int->read_lock))
+			return -ERESTARTSYS;
+		ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
+		mutex_unlock(&ev_int->read_lock);
+
 		if (ret)
-			goto error_unlock;
-		/* Single access device so no one else can get the data */
-	}
+			return ret;
 
-	ret = kfifo_to_user(&ev_int->det_events, buf, count, &copied);
+		/*
+		 * If we couldn't read anything from the fifo (a different
+		 * thread might have been faster) we either return -EAGAIN if
+		 * the file descriptor is non-blocking, otherwise we go back to
+		 * sleep and wait for more data to arrive.
+		 */
+		if (copied == 0 && (filep->f_flags & O_NONBLOCK))
+			return -EAGAIN;
 
-error_unlock:
-	spin_unlock_irq(&ev_int->wait.lock);
+	} while (copied == 0);
 
-	return ret ? ret : copied;
+	return copied;
 }
 
 static int iio_event_chrdev_release(struct inode *inode, struct file *filep)
 {
-	struct iio_event_interface *ev_int = filep->private_data;
+	struct iio_dev *indio_dev = filep->private_data;
+	struct iio_event_interface *ev_int = indio_dev->event_interface;
 
-	spin_lock_irq(&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_irq(&ev_int->wait.lock);
+	clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
+
+	iio_device_put(indio_dev);
 
 	return 0;
 }
@@ -152,19 +180,20 @@
 	if (ev_int == NULL)
 		return -ENODEV;
 
-	spin_lock_irq(&ev_int->wait.lock);
-	if (__test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags)) {
-		spin_unlock_irq(&ev_int->wait.lock);
+	if (test_and_set_bit(IIO_BUSY_BIT_POS, &ev_int->flags))
 		return -EBUSY;
-	}
-	spin_unlock_irq(&ev_int->wait.lock);
-	fd = anon_inode_getfd("iio:event",
-				&iio_event_chrdev_fileops, ev_int, O_RDONLY);
+
+	iio_device_get(indio_dev);
+
+	fd = anon_inode_getfd("iio:event", &iio_event_chrdev_fileops,
+				indio_dev, O_RDONLY | O_CLOEXEC);
 	if (fd < 0) {
-		spin_lock_irq(&ev_int->wait.lock);
-		__clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
-		spin_unlock_irq(&ev_int->wait.lock);
+		clear_bit(IIO_BUSY_BIT_POS, &ev_int->flags);
+		iio_device_put(indio_dev);
+	} else {
+		kfifo_reset_out(&ev_int->det_events);
 	}
+
 	return fd;
 }
 
@@ -174,6 +203,7 @@
 	[IIO_EV_TYPE_ROC] = "roc",
 	[IIO_EV_TYPE_THRESH_ADAPTIVE] = "thresh_adaptive",
 	[IIO_EV_TYPE_MAG_ADAPTIVE] = "mag_adaptive",
+	[IIO_EV_TYPE_CHANGE] = "change",
 };
 
 static const char * const iio_ev_dir_text[] = {
@@ -182,6 +212,30 @@
 	[IIO_EV_DIR_FALLING] = "falling"
 };
 
+static const char * const iio_ev_info_text[] = {
+	[IIO_EV_INFO_ENABLE] = "en",
+	[IIO_EV_INFO_VALUE] = "value",
+	[IIO_EV_INFO_HYSTERESIS] = "hysteresis",
+	[IIO_EV_INFO_PERIOD] = "period",
+	[IIO_EV_INFO_HIGH_PASS_FILTER_3DB] = "high_pass_filter_3db",
+	[IIO_EV_INFO_LOW_PASS_FILTER_3DB] = "low_pass_filter_3db",
+};
+
+static enum iio_event_direction iio_ev_attr_dir(struct iio_dev_attr *attr)
+{
+	return attr->c->event_spec[attr->address & 0xffff].dir;
+}
+
+static enum iio_event_type iio_ev_attr_type(struct iio_dev_attr *attr)
+{
+	return attr->c->event_spec[attr->address & 0xffff].type;
+}
+
+static enum iio_event_info iio_ev_attr_info(struct iio_dev_attr *attr)
+{
+	return (attr->address >> 16) & 0xffff;
+}
+
 static ssize_t iio_ev_state_store(struct device *dev,
 				  struct device_attribute *attr,
 				  const char *buf,
@@ -197,8 +251,9 @@
 		return ret;
 
 	ret = indio_dev->info->write_event_config(indio_dev,
-						  this_attr->address,
-						  val);
+		this_attr->c, iio_ev_attr_type(this_attr),
+		iio_ev_attr_dir(this_attr), val);
+
 	return (ret < 0) ? ret : len;
 }
 
@@ -208,9 +263,11 @@
 {
 	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);
+	int val;
 
+	val = indio_dev->info->read_event_config(indio_dev,
+		this_attr->c, iio_ev_attr_type(this_attr),
+		iio_ev_attr_dir(this_attr));
 	if (val < 0)
 		return val;
 	else
@@ -223,14 +280,18 @@
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-	int val, ret;
+	int val, val2, val_arr[2];
+	int ret;
 
 	ret = indio_dev->info->read_event_value(indio_dev,
-						this_attr->address, &val);
+		this_attr->c, iio_ev_attr_type(this_attr),
+		iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
+		&val, &val2);
 	if (ret < 0)
 		return ret;
-
-	return sprintf(buf, "%d\n", val);
+	val_arr[0] = val;
+	val_arr[1] = val2;
+	return iio_format_value(buf, ret, 2, val_arr);
 }
 
 static ssize_t iio_ev_value_store(struct device *dev,
@@ -240,113 +301,125 @@
 {
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
-	int val;
+	int val, val2;
 	int ret;
 
 	if (!indio_dev->info->write_event_value)
 		return -EINVAL;
 
-	ret = kstrtoint(buf, 10, &val);
+	ret = iio_str_to_fixpoint(buf, 100000, &val, &val2);
 	if (ret)
 		return ret;
-
-	ret = indio_dev->info->write_event_value(indio_dev, this_attr->address,
-						 val);
+	ret = indio_dev->info->write_event_value(indio_dev,
+		this_attr->c, iio_ev_attr_type(this_attr),
+		iio_ev_attr_dir(this_attr), iio_ev_attr_info(this_attr),
+		val, val2);
 	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;
+static int iio_device_add_event(struct iio_dev *indio_dev,
+	const struct iio_chan_spec *chan, unsigned int spec_index,
+	enum iio_event_type type, enum iio_event_direction dir,
+	enum iio_shared_by shared_by, const unsigned long *mask)
+{
+	ssize_t (*show)(struct device *, struct device_attribute *, char *);
+	ssize_t (*store)(struct device *, struct device_attribute *,
+		const char *, size_t);
+	unsigned int attrcount = 0;
+	unsigned int i;
 	char *postfix;
-	if (!chan->event_mask)
-		return 0;
+	int ret;
 
-	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);
+	for_each_set_bit(i, mask, sizeof(*mask)*8) {
+		if (i >= ARRAY_SIZE(iio_ev_info_text))
+			return -EINVAL;
+		if (dir != IIO_EV_DIR_NONE)
+			postfix = kasprintf(GFP_KERNEL, "%s_%s_%s",
+					iio_ev_type_text[type],
+					iio_ev_dir_text[dir],
+					iio_ev_info_text[i]);
 		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;
+			postfix = kasprintf(GFP_KERNEL, "%s_%s",
+					iio_ev_type_text[type],
+					iio_ev_info_text[i]);
+		if (postfix == NULL)
+			return -ENOMEM;
+
+		if (i == IIO_EV_INFO_ENABLE) {
+			show = iio_ev_state_show;
+			store = iio_ev_state_store;
+		} else {
+			show = iio_ev_value_show;
+			store = iio_ev_value_store;
 		}
-		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);
+
+		ret = __iio_add_chan_devattr(postfix, chan, show, store,
+			 (i << 16) | spec_index, shared_by, &indio_dev->dev,
+			&indio_dev->event_interface->dev_attr_list);
 		kfree(postfix);
+
+		if ((ret == -EBUSY) && (shared_by != IIO_SEPARATE))
+			continue;
+
 		if (ret)
-			goto error_ret;
+			return ret;
+
 		attrcount++;
 	}
-	ret = attrcount;
-error_ret:
-	return ret;
+
+	return attrcount;
 }
 
-static inline void __iio_remove_event_config_attrs(struct iio_dev *indio_dev)
+static int iio_device_add_event_sysfs(struct iio_dev *indio_dev,
+	struct iio_chan_spec const *chan)
 {
-	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);
+	int ret = 0, i, attrcount = 0;
+	enum iio_event_direction dir;
+	enum iio_event_type type;
+
+	for (i = 0; i < chan->num_event_specs; i++) {
+		type = chan->event_spec[i].type;
+		dir = chan->event_spec[i].dir;
+
+		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
+			IIO_SEPARATE, &chan->event_spec[i].mask_separate);
+		if (ret < 0)
+			return ret;
+		attrcount += ret;
+
+		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
+			IIO_SHARED_BY_TYPE,
+			&chan->event_spec[i].mask_shared_by_type);
+		if (ret < 0)
+			return ret;
+		attrcount += ret;
+
+		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
+			IIO_SHARED_BY_DIR,
+			&chan->event_spec[i].mask_shared_by_dir);
+		if (ret < 0)
+			return ret;
+		attrcount += ret;
+
+		ret = iio_device_add_event(indio_dev, chan, i, type, dir,
+			IIO_SHARED_BY_ALL,
+			&chan->event_spec[i].mask_shared_by_all);
+		if (ret < 0)
+			return ret;
+		attrcount += ret;
 	}
+	ret = attrcount;
+	return ret;
 }
 
 static inline int __iio_add_event_config_attrs(struct iio_dev *indio_dev)
 {
 	int j, ret, attrcount = 0;
 
-	/* Dynically created from the channels array */
+	/* Dynamically 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]);
@@ -361,9 +434,10 @@
 {
 	int j;
 
-	for (j = 0; j < indio_dev->num_channels; j++)
-		if (indio_dev->channels[j].event_mask != 0)
+	for (j = 0; j < indio_dev->num_channels; j++) {
+		if (indio_dev->channels[j].num_event_specs != 0)
 			return true;
+	}
 	return false;
 }
 
@@ -371,6 +445,7 @@
 {
 	INIT_KFIFO(ev_int->det_events);
 	init_waitqueue_head(&ev_int->wait);
+	mutex_init(&ev_int->read_lock);
 }
 
 static const char *iio_event_group_name = "events";
@@ -386,10 +461,8 @@
 
 	indio_dev->event_interface =
 		kzalloc(sizeof(struct iio_event_interface), GFP_KERNEL);
-	if (indio_dev->event_interface == NULL) {
-		ret = -ENOMEM;
-		goto error_ret;
-	}
+	if (indio_dev->event_interface == NULL)
+		return -ENOMEM;
 
 	INIT_LIST_HEAD(&indio_dev->event_interface->dev_attr_list);
 
@@ -433,18 +506,31 @@
 	return 0;
 
 error_free_setup_event_lines:
-	__iio_remove_event_config_attrs(indio_dev);
+	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
 	kfree(indio_dev->event_interface);
-error_ret:
-
+	indio_dev->event_interface = NULL;
 	return ret;
 }
 
+/**
+ * iio_device_wakeup_eventset - Wakes up the event waitqueue
+ * @indio_dev: The IIO device
+ *
+ * Wakes up the event waitqueue used for poll() and blocking read().
+ * Should usually be called when the device is unregistered.
+ */
+void iio_device_wakeup_eventset(struct iio_dev *indio_dev)
+{
+	if (indio_dev->event_interface == NULL)
+		return;
+	wake_up(&indio_dev->event_interface->wait);
+}
+
 void iio_device_unregister_eventset(struct iio_dev *indio_dev)
 {
 	if (indio_dev->event_interface == NULL)
 		return;
-	__iio_remove_event_config_attrs(indio_dev);
+	iio_free_chan_devattr_list(&indio_dev->event_interface->dev_attr_list);
 	kfree(indio_dev->event_interface->group.attrs);
 	kfree(indio_dev->event_interface);
 }