1 files changed, 188 insertions, 13 deletions

diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index a95cc2da56be..e180728914c0 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -120,6 +120,9 @@ static ssize_t iio_buffer_read(struct file *filp, char __user *buf,
 	if (!rb || !rb->access->read)
 		return -EINVAL;
 
+	if (rb->direction != IIO_BUFFER_DIRECTION_IN)
+		return -EPERM;
+
 	datum_size = rb->bytes_per_datum;
 
 	/*
@@ -161,6 +164,65 @@ static ssize_t iio_buffer_read(struct file *filp, char __user *buf,
 	return ret;
 }
 
+static size_t iio_buffer_space_available(struct iio_buffer *buf)
+{
+	if (buf->access->space_available)
+		return buf->access->space_available(buf);
+
+	return SIZE_MAX;
+}
+
+static ssize_t iio_buffer_write(struct file *filp, const char __user *buf,
+				size_t n, loff_t *f_ps)
+{
+	struct iio_dev_buffer_pair *ib = filp->private_data;
+	struct iio_buffer *rb = ib->buffer;
+	struct iio_dev *indio_dev = ib->indio_dev;
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+	int ret = 0;
+	size_t written;
+
+	if (!indio_dev->info)
+		return -ENODEV;
+
+	if (!rb || !rb->access->write)
+		return -EINVAL;
+
+	if (rb->direction != IIO_BUFFER_DIRECTION_OUT)
+		return -EPERM;
+
+	written = 0;
+	add_wait_queue(&rb->pollq, &wait);
+	do {
+		if (indio_dev->info == NULL)
+			return -ENODEV;
+
+		if (!iio_buffer_space_available(rb)) {
+			if (signal_pending(current)) {
+				ret = -ERESTARTSYS;
+				break;
+			}
+
+			wait_woken(&wait, TASK_INTERRUPTIBLE,
+					MAX_SCHEDULE_TIMEOUT);
+			continue;
+		}
+
+		ret = rb->access->write(rb, n - written, buf + written);
+		if (ret == 0 && (filp->f_flags & O_NONBLOCK))
+			ret = -EAGAIN;
+
+		if (ret > 0) {
+			written += ret;
+			if (written != n && !(filp->f_flags & O_NONBLOCK))
+				continue;
+		}
+	} while (ret == 0);
+	remove_wait_queue(&rb->pollq, &wait);
+
+	return ret < 0 ? ret : n;
+}
+
 /**
  * iio_buffer_poll() - poll the buffer to find out if it has data
  * @filp:	File structure pointer for device access
@@ -181,8 +243,18 @@ static __poll_t iio_buffer_poll(struct file *filp,
 		return 0;
 
 	poll_wait(filp, &rb->pollq, wait);
-	if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
-		return EPOLLIN | EPOLLRDNORM;
+
+	switch (rb->direction) {
+	case IIO_BUFFER_DIRECTION_IN:
+		if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0))
+			return EPOLLIN | EPOLLRDNORM;
+		break;
+	case IIO_BUFFER_DIRECTION_OUT:
+		if (iio_buffer_space_available(rb))
+			return EPOLLOUT | EPOLLWRNORM;
+		break;
+	}
+
 	return 0;
 }
 
@@ -199,6 +271,19 @@ ssize_t iio_buffer_read_wrapper(struct file *filp, char __user *buf,
 	return iio_buffer_read(filp, buf, n, f_ps);
 }
 
+ssize_t iio_buffer_write_wrapper(struct file *filp, const char __user *buf,
+				 size_t n, loff_t *f_ps)
+{
+	struct iio_dev_buffer_pair *ib = filp->private_data;
+	struct iio_buffer *rb = ib->buffer;
+
+	/* check if buffer was opened through new API */
+	if (test_bit(IIO_BUSY_BIT_POS, &rb->flags))
+		return -EBUSY;
+
+	return iio_buffer_write(filp, buf, n, f_ps);
+}
+
 __poll_t iio_buffer_poll_wrapper(struct file *filp,
 				 struct poll_table_struct *wait)
 {
@@ -231,6 +316,15 @@ void iio_buffer_wakeup_poll(struct iio_dev *indio_dev)
 	}
 }
 
+int iio_pop_from_buffer(struct iio_buffer *buffer, void *data)
+{
+	if (!buffer || !buffer->access || !buffer->access->remove_from)
+		return -EINVAL;
+
+	return buffer->access->remove_from(buffer, data);
+}
+EXPORT_SYMBOL_GPL(iio_pop_from_buffer);
+
 void iio_buffer_init(struct iio_buffer *buffer)
 {
 	INIT_LIST_HEAD(&buffer->demux_list);
@@ -1156,6 +1250,10 @@ int iio_update_buffers(struct iio_dev *indio_dev,
 	if (insert_buffer == remove_buffer)
 		return 0;
 
+	if (insert_buffer &&
+	    (insert_buffer->direction == IIO_BUFFER_DIRECTION_OUT))
+		return -EINVAL;
+
 	mutex_lock(&iio_dev_opaque->info_exist_lock);
 	mutex_lock(&indio_dev->mlock);
 
@@ -1277,6 +1375,22 @@ static ssize_t iio_dma_show_data_available(struct device *dev,
 	return sysfs_emit(buf, "%zu\n", iio_buffer_data_available(buffer));
 }
 
+static ssize_t direction_show(struct device *dev,
+			      struct device_attribute *attr,
+			      char *buf)
+{
+	struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer;
+
+	switch (buffer->direction) {
+	case IIO_BUFFER_DIRECTION_IN:
+		return sprintf(buf, "in\n");
+	case IIO_BUFFER_DIRECTION_OUT:
+		return sprintf(buf, "out\n");
+	default:
+		return -EINVAL;
+	}
+}
+
 static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length,
 		   iio_buffer_write_length);
 static struct device_attribute dev_attr_length_ro = __ATTR(length,
@@ -1289,12 +1403,20 @@ static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark,
 	S_IRUGO, iio_buffer_show_watermark, NULL);
 static DEVICE_ATTR(data_available, S_IRUGO,
 		iio_dma_show_data_available, NULL);
+static DEVICE_ATTR_RO(direction);
 
+/*
+ * When adding new attributes here, put the at the end, at least until
+ * the code that handles the length/length_ro & watermark/watermark_ro
+ * assignments gets cleaned up. Otherwise these can create some weird
+ * duplicate attributes errors under some setups.
+ */
 static struct attribute *iio_buffer_attrs[] = {
 	&dev_attr_length.attr,
 	&dev_attr_enable.attr,
 	&dev_attr_watermark.attr,
 	&dev_attr_data_available.attr,
+	&dev_attr_direction.attr,
 };
 
 #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
@@ -1312,6 +1434,11 @@ static struct attribute *iio_buffer_wrap_attr(struct iio_buffer *buffer,
 	iio_attr->buffer = buffer;
 	memcpy(&iio_attr->dev_attr, dattr, sizeof(iio_attr->dev_attr));
 	iio_attr->dev_attr.attr.name = kstrdup_const(attr->name, GFP_KERNEL);
+	if (!iio_attr->dev_attr.attr.name) {
+		kfree(iio_attr);
+		return NULL;
+	}
+
 	sysfs_attr_init(&iio_attr->dev_attr.attr);
 
 	list_add(&iio_attr->l, &buffer->buffer_attr_list);
@@ -1362,10 +1489,10 @@ static int iio_buffer_register_legacy_sysfs_groups(struct iio_dev *indio_dev,
 
 	return 0;
 
-error_free_buffer_attrs:
-	kfree(iio_dev_opaque->legacy_buffer_group.attrs);
 error_free_scan_el_attrs:
 	kfree(iio_dev_opaque->legacy_scan_el_group.attrs);
+error_free_buffer_attrs:
+	kfree(iio_dev_opaque->legacy_buffer_group.attrs);
 
 	return ret;
 }
@@ -1397,6 +1524,7 @@ static const struct file_operations iio_buffer_chrdev_fileops = {
 	.owner = THIS_MODULE,
 	.llseek = noop_llseek,
 	.read = iio_buffer_read,
+	.write = iio_buffer_write,
 	.poll = iio_buffer_poll,
 	.release = iio_buffer_chrdev_release,
 };
@@ -1531,6 +1659,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
 		       sizeof(struct attribute *) * buffer_attrcount);
 
 	buffer_attrcount += ARRAY_SIZE(iio_buffer_attrs);
+	buffer->buffer_group.attrs = attr;
 
 	for (i = 0; i < buffer_attrcount; i++) {
 		struct attribute *wrapped;
@@ -1538,7 +1667,7 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
 		wrapped = iio_buffer_wrap_attr(buffer, attr[i]);
 		if (!wrapped) {
 			ret = -ENOMEM;
-			goto error_free_scan_mask;
+			goto error_free_buffer_attrs;
 		}
 		attr[i] = wrapped;
 	}
@@ -1553,8 +1682,6 @@ static int __iio_buffer_alloc_sysfs_and_mask(struct iio_buffer *buffer,
 		goto error_free_buffer_attrs;
 	}
 
-	buffer->buffer_group.attrs = attr;
-
 	ret = iio_device_register_sysfs_group(indio_dev, &buffer->buffer_group);
 	if (ret)
 		goto error_free_buffer_attr_group_name;
@@ -1583,8 +1710,12 @@ error_cleanup_dynamic:
 	return ret;
 }
 
-static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer)
+static void __iio_buffer_free_sysfs_and_mask(struct iio_buffer *buffer,
+					     struct iio_dev *indio_dev,
+					     int index)
 {
+	if (index == 0)
+		iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
 	bitmap_free(buffer->scan_mask);
 	kfree(buffer->buffer_group.name);
 	kfree(buffer->buffer_group.attrs);
@@ -1616,7 +1747,7 @@ int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
 		buffer = iio_dev_opaque->attached_buffers[i];
 		ret = __iio_buffer_alloc_sysfs_and_mask(buffer, indio_dev, i);
 		if (ret) {
-			unwind_idx = i;
+			unwind_idx = i - 1;
 			goto error_unwind_sysfs_and_mask;
 		}
 	}
@@ -1638,7 +1769,7 @@ int iio_buffers_alloc_sysfs_and_mask(struct iio_dev *indio_dev)
 error_unwind_sysfs_and_mask:
 	for (; unwind_idx >= 0; unwind_idx--) {
 		buffer = iio_dev_opaque->attached_buffers[unwind_idx];
-		__iio_buffer_free_sysfs_and_mask(buffer);
+		__iio_buffer_free_sysfs_and_mask(buffer, indio_dev, unwind_idx);
 	}
 	return ret;
 }
@@ -1655,11 +1786,9 @@ void iio_buffers_free_sysfs_and_mask(struct iio_dev *indio_dev)
 	iio_device_ioctl_handler_unregister(iio_dev_opaque->buffer_ioctl_handler);
 	kfree(iio_dev_opaque->buffer_ioctl_handler);
 
-	iio_buffer_unregister_legacy_sysfs_groups(indio_dev);
-
 	for (i = iio_dev_opaque->attached_buffers_cnt - 1; i >= 0; i--) {
 		buffer = iio_dev_opaque->attached_buffers[i];
-		__iio_buffer_free_sysfs_and_mask(buffer);
+		__iio_buffer_free_sysfs_and_mask(buffer, indio_dev, i);
 	}
 }
 
@@ -1732,6 +1861,52 @@ int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data)
 EXPORT_SYMBOL_GPL(iio_push_to_buffers);
 
 /**
+ * iio_push_to_buffers_with_ts_unaligned() - push to registered buffer,
+ *    no alignment or space requirements.
+ * @indio_dev:		iio_dev structure for device.
+ * @data:		channel data excluding the timestamp.
+ * @data_sz:		size of data.
+ * @timestamp:		timestamp for the sample data.
+ *
+ * This special variant of iio_push_to_buffers_with_timestamp() does
+ * not require space for the timestamp, or 8 byte alignment of data.
+ * It does however require an allocation on first call and additional
+ * copies on all calls, so should be avoided if possible.
+ */
+int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev,
+					  const void *data,
+					  size_t data_sz,
+					  int64_t timestamp)
+{
+	struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev);
+
+	/*
+	 * Conservative estimate - we can always safely copy the minimum
+	 * of either the data provided or the length of the destination buffer.
+	 * This relaxed limit allows the calling drivers to be lax about
+	 * tracking the size of the data they are pushing, at the cost of
+	 * unnecessary copying of padding.
+	 */
+	data_sz = min_t(size_t, indio_dev->scan_bytes, data_sz);
+	if (iio_dev_opaque->bounce_buffer_size !=  indio_dev->scan_bytes) {
+		void *bb;
+
+		bb = devm_krealloc(&indio_dev->dev,
+				   iio_dev_opaque->bounce_buffer,
+				   indio_dev->scan_bytes, GFP_KERNEL);
+		if (!bb)
+			return -ENOMEM;
+		iio_dev_opaque->bounce_buffer = bb;
+		iio_dev_opaque->bounce_buffer_size = indio_dev->scan_bytes;
+	}
+	memcpy(iio_dev_opaque->bounce_buffer, data, data_sz);
+	return iio_push_to_buffers_with_timestamp(indio_dev,
+						  iio_dev_opaque->bounce_buffer,
+						  timestamp);
+}
+EXPORT_SYMBOL_GPL(iio_push_to_buffers_with_ts_unaligned);
+
+/**
  * iio_buffer_release() - Free a buffer's resources
  * @ref: Pointer to the kref embedded in the iio_buffer struct
  *