1 files changed, 186 insertions, 57 deletions

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index 5f85ba38e6f6..e9d9a7d39fe1 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -64,15 +64,63 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue,
 	struct dmaengine_buffer *dmaengine_buffer =
 		iio_buffer_to_dmaengine_buffer(&queue->buffer);
 	struct dma_async_tx_descriptor *desc;
+	enum dma_transfer_direction dma_dir;
+	struct scatterlist *sgl;
+	struct dma_vec *vecs;
+	size_t max_size;
 	dma_cookie_t cookie;
+	size_t len_total;
+	unsigned int i;
+	int nents;
 
-	block->bytes_used = min(block->size, dmaengine_buffer->max_size);
-	block->bytes_used = round_down(block->bytes_used,
-			dmaengine_buffer->align);
+	max_size = min(block->size, dmaengine_buffer->max_size);
+	max_size = round_down(max_size, dmaengine_buffer->align);
 
-	desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
-		block->phys_addr, block->bytes_used, DMA_DEV_TO_MEM,
-		DMA_PREP_INTERRUPT);
+	if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN)
+		dma_dir = DMA_DEV_TO_MEM;
+	else
+		dma_dir = DMA_MEM_TO_DEV;
+
+	if (block->sg_table) {
+		sgl = block->sg_table->sgl;
+		nents = sg_nents_for_len(sgl, block->bytes_used);
+		if (nents < 0)
+			return nents;
+
+		vecs = kmalloc_array(nents, sizeof(*vecs), GFP_ATOMIC);
+		if (!vecs)
+			return -ENOMEM;
+
+		len_total = block->bytes_used;
+
+		for (i = 0; i < nents; i++) {
+			vecs[i].addr = sg_dma_address(sgl);
+			vecs[i].len = min(sg_dma_len(sgl), len_total);
+			len_total -= vecs[i].len;
+
+			sgl = sg_next(sgl);
+		}
+
+		desc = dmaengine_prep_peripheral_dma_vec(dmaengine_buffer->chan,
+							 vecs, nents, dma_dir,
+							 DMA_PREP_INTERRUPT);
+		kfree(vecs);
+	} else {
+		max_size = min(block->size, dmaengine_buffer->max_size);
+		max_size = round_down(max_size, dmaengine_buffer->align);
+
+		if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN)
+			block->bytes_used = max_size;
+
+		if (!block->bytes_used || block->bytes_used > max_size)
+			return -EINVAL;
+
+		desc = dmaengine_prep_slave_single(dmaengine_buffer->chan,
+						   block->phys_addr,
+						   block->bytes_used,
+						   dma_dir,
+						   DMA_PREP_INTERRUPT);
+	}
 	if (!desc)
 		return -ENOMEM;
 
@@ -112,14 +160,23 @@ static void iio_dmaengine_buffer_release(struct iio_buffer *buf)
 
 static const struct iio_buffer_access_funcs iio_dmaengine_buffer_ops = {
 	.read = iio_dma_buffer_read,
+	.write = iio_dma_buffer_write,
 	.set_bytes_per_datum = iio_dma_buffer_set_bytes_per_datum,
 	.set_length = iio_dma_buffer_set_length,
 	.request_update = iio_dma_buffer_request_update,
 	.enable = iio_dma_buffer_enable,
 	.disable = iio_dma_buffer_disable,
-	.data_available = iio_dma_buffer_data_available,
+	.data_available = iio_dma_buffer_usage,
+	.space_available = iio_dma_buffer_usage,
 	.release = iio_dmaengine_buffer_release,
 
+	.enqueue_dmabuf = iio_dma_buffer_enqueue_dmabuf,
+	.attach_dmabuf = iio_dma_buffer_attach_dmabuf,
+	.detach_dmabuf = iio_dma_buffer_detach_dmabuf,
+
+	.lock_queue = iio_dma_buffer_lock_queue,
+	.unlock_queue = iio_dma_buffer_unlock_queue,
+
 	.modes = INDIO_BUFFER_HARDWARE,
 	.flags = INDIO_BUFFER_FLAG_FIXED_WATERMARK,
 };
@@ -149,39 +206,29 @@ static const struct iio_dev_attr *iio_dmaengine_buffer_attrs[] = {
 
 /**
  * iio_dmaengine_buffer_alloc() - Allocate new buffer which uses DMAengine
- * @dev: Parent device for the buffer
- * @channel: DMA channel name, typically "rx".
+ * @chan: DMA channel.
  *
  * This allocates a new IIO buffer which internally uses the DMAengine framework
- * to perform its transfers. The parent device will be used to request the DMA
- * channel.
+ * to perform its transfers.
  *
  * Once done using the buffer iio_dmaengine_buffer_free() should be used to
  * release it.
  */
-static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
-	const char *channel)
+static struct iio_buffer *iio_dmaengine_buffer_alloc(struct dma_chan *chan)
 {
 	struct dmaengine_buffer *dmaengine_buffer;
 	unsigned int width, src_width, dest_width;
 	struct dma_slave_caps caps;
-	struct dma_chan *chan;
 	int ret;
 
+	ret = dma_get_slave_caps(chan, &caps);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
 	dmaengine_buffer = kzalloc(sizeof(*dmaengine_buffer), GFP_KERNEL);
 	if (!dmaengine_buffer)
 		return ERR_PTR(-ENOMEM);
 
-	chan = dma_request_chan(dev, channel);
-	if (IS_ERR(chan)) {
-		ret = PTR_ERR(chan);
-		goto err_free;
-	}
-
-	ret = dma_get_slave_caps(chan, &caps);
-	if (ret < 0)
-		goto err_free;
-
 	/* Needs to be aligned to the maximum of the minimums */
 	if (caps.src_addr_widths)
 		src_width = __ffs(caps.src_addr_widths);
@@ -205,10 +252,6 @@ static struct iio_buffer *iio_dmaengine_buffer_alloc(struct device *dev,
 	dmaengine_buffer->queue.buffer.access = &iio_dmaengine_buffer_ops;
 
 	return &dmaengine_buffer->queue.buffer;
-
-err_free:
-	kfree(dmaengine_buffer);
-	return ERR_PTR(ret);
 }
 
 /**
@@ -223,73 +266,159 @@ static void iio_dmaengine_buffer_free(struct iio_buffer *buffer)
 		iio_buffer_to_dmaengine_buffer(buffer);
 
 	iio_dma_buffer_exit(&dmaengine_buffer->queue);
-	dma_release_channel(dmaengine_buffer->chan);
-
 	iio_buffer_put(buffer);
 }
 
-static void __devm_iio_dmaengine_buffer_free(void *buffer)
+/**
+ * iio_dmaengine_buffer_teardown() - Releases DMA channel and frees buffer
+ * @buffer: Buffer to free
+ *
+ * Releases the DMA channel and frees the buffer previously setup with
+ * iio_dmaengine_buffer_setup_ext().
+ */
+void iio_dmaengine_buffer_teardown(struct iio_buffer *buffer)
 {
+	struct dmaengine_buffer *dmaengine_buffer =
+		iio_buffer_to_dmaengine_buffer(buffer);
+	struct dma_chan *chan = dmaengine_buffer->chan;
+
 	iio_dmaengine_buffer_free(buffer);
+	dma_release_channel(chan);
+}
+EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_teardown, "IIO_DMAENGINE_BUFFER");
+
+static struct iio_buffer
+*__iio_dmaengine_buffer_setup_ext(struct iio_dev *indio_dev,
+				  struct dma_chan *chan,
+				  enum iio_buffer_direction dir)
+{
+	struct iio_buffer *buffer;
+	int ret;
+
+	buffer = iio_dmaengine_buffer_alloc(chan);
+	if (IS_ERR(buffer))
+		return ERR_CAST(buffer);
+
+	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
+
+	buffer->direction = dir;
+
+	ret = iio_device_attach_buffer(indio_dev, buffer);
+	if (ret) {
+		iio_dmaengine_buffer_free(buffer);
+		return ERR_PTR(ret);
+	}
+
+	return buffer;
 }
 
 /**
- * devm_iio_dmaengine_buffer_alloc() - Resource-managed iio_dmaengine_buffer_alloc()
- * @dev: Parent device for the buffer
+ * iio_dmaengine_buffer_setup_ext() - Setup a DMA buffer for an IIO device
+ * @dev: DMA channel consumer device
+ * @indio_dev: IIO device to which to attach this buffer.
  * @channel: DMA channel name, typically "rx".
+ * @dir: Direction of buffer (in or out)
  *
- * This allocates a new IIO buffer which internally uses the DMAengine framework
- * to perform its transfers. The parent device will be used to request the DMA
- * channel.
+ * This allocates a new IIO buffer with devm_iio_dmaengine_buffer_alloc()
+ * and attaches it to an IIO device with iio_device_attach_buffer().
+ * It also appends the INDIO_BUFFER_HARDWARE mode to the supported modes of the
+ * IIO device.
  *
- * The buffer will be automatically de-allocated once the device gets destroyed.
+ * Once done using the buffer iio_dmaengine_buffer_teardown() should be used to
+ * release it.
  */
-static struct iio_buffer *devm_iio_dmaengine_buffer_alloc(struct device *dev,
-	const char *channel)
+struct iio_buffer *iio_dmaengine_buffer_setup_ext(struct device *dev,
+						  struct iio_dev *indio_dev,
+						  const char *channel,
+						  enum iio_buffer_direction dir)
 {
+	struct dma_chan *chan;
 	struct iio_buffer *buffer;
-	int ret;
 
-	buffer = iio_dmaengine_buffer_alloc(dev, channel);
-	if (IS_ERR(buffer))
-		return buffer;
+	chan = dma_request_chan(dev, channel);
+	if (IS_ERR(chan))
+		return ERR_CAST(chan);
 
-	ret = devm_add_action_or_reset(dev, __devm_iio_dmaengine_buffer_free,
-				       buffer);
-	if (ret)
-		return ERR_PTR(ret);
+	buffer = __iio_dmaengine_buffer_setup_ext(indio_dev, chan, dir);
+	if (IS_ERR(buffer))
+		dma_release_channel(chan);
 
 	return buffer;
 }
+EXPORT_SYMBOL_NS_GPL(iio_dmaengine_buffer_setup_ext, "IIO_DMAENGINE_BUFFER");
+
+static void devm_iio_dmaengine_buffer_teardown(void *buffer)
+{
+	iio_dmaengine_buffer_teardown(buffer);
+}
 
 /**
- * devm_iio_dmaengine_buffer_setup() - Setup a DMA buffer for an IIO device
- * @dev: Parent device for the buffer
+ * devm_iio_dmaengine_buffer_setup_ext() - Setup a DMA buffer for an IIO device
+ * @dev: Device for devm ownership and DMA channel consumer device
  * @indio_dev: IIO device to which to attach this buffer.
  * @channel: DMA channel name, typically "rx".
+ * @dir: Direction of buffer (in or out)
  *
  * This allocates a new IIO buffer with devm_iio_dmaengine_buffer_alloc()
  * and attaches it to an IIO device with iio_device_attach_buffer().
  * It also appends the INDIO_BUFFER_HARDWARE mode to the supported modes of the
  * IIO device.
  */
-int devm_iio_dmaengine_buffer_setup(struct device *dev,
-				    struct iio_dev *indio_dev,
-				    const char *channel)
+int devm_iio_dmaengine_buffer_setup_ext(struct device *dev,
+					struct iio_dev *indio_dev,
+					const char *channel,
+					enum iio_buffer_direction dir)
 {
 	struct iio_buffer *buffer;
 
-	buffer = devm_iio_dmaengine_buffer_alloc(indio_dev->dev.parent,
-						 channel);
+	buffer = iio_dmaengine_buffer_setup_ext(dev, indio_dev, channel, dir);
 	if (IS_ERR(buffer))
 		return PTR_ERR(buffer);
 
-	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
+	return devm_add_action_or_reset(dev, devm_iio_dmaengine_buffer_teardown,
+					buffer);
+}
+EXPORT_SYMBOL_NS_GPL(devm_iio_dmaengine_buffer_setup_ext, "IIO_DMAENGINE_BUFFER");
+
+static void devm_iio_dmaengine_buffer_free(void *buffer)
+{
+	iio_dmaengine_buffer_free(buffer);
+}
+
+/**
+ * devm_iio_dmaengine_buffer_setup_with_handle() - Setup a DMA buffer for an
+ *						   IIO device
+ * @dev: Device for devm ownership
+ * @indio_dev: IIO device to which to attach this buffer.
+ * @chan: DMA channel
+ * @dir: Direction of buffer (in or out)
+ *
+ * This allocates a new IIO buffer with devm_iio_dmaengine_buffer_alloc()
+ * and attaches it to an IIO device with iio_device_attach_buffer().
+ * It also appends the INDIO_BUFFER_HARDWARE mode to the supported modes of the
+ * IIO device.
+ *
+ * This is the same as devm_iio_dmaengine_buffer_setup_ext() except that the
+ * caller manages requesting and releasing the DMA channel handle.
+ */
+int devm_iio_dmaengine_buffer_setup_with_handle(struct device *dev,
+						struct iio_dev *indio_dev,
+						struct dma_chan *chan,
+						enum iio_buffer_direction dir)
+{
+	struct iio_buffer *buffer;
+
+	buffer = __iio_dmaengine_buffer_setup_ext(indio_dev, chan, dir);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
 
-	return iio_device_attach_buffer(indio_dev, buffer);
+	return devm_add_action_or_reset(dev, devm_iio_dmaengine_buffer_free,
+					buffer);
 }
-EXPORT_SYMBOL_GPL(devm_iio_dmaengine_buffer_setup);
+EXPORT_SYMBOL_NS_GPL(devm_iio_dmaengine_buffer_setup_with_handle,
+		     "IIO_DMAENGINE_BUFFER");
 
 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 MODULE_DESCRIPTION("DMA buffer for the IIO framework");
 MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("IIO_DMA_BUFFER");