2 files changed, 80 insertions, 0 deletions

diff --git a/drivers/spi/spi-offload.c b/drivers/spi/spi-offload.c
index 43582e50e279..df5e963d5ee2 100644
--- a/drivers/spi/spi-offload.c
+++ b/drivers/spi/spi-offload.c
@@ -18,6 +18,7 @@
 
 #include <linux/cleanup.h>
 #include <linux/device.h>
+#include <linux/dmaengine.h>
 #include <linux/export.h>
 #include <linux/kref.h>
 #include <linux/list.h>
@@ -332,6 +333,75 @@ void spi_offload_trigger_disable(struct spi_offload *offload,
 }
 EXPORT_SYMBOL_GPL(spi_offload_trigger_disable);
 
+static void spi_offload_release_dma_chan(void *chan)
+{
+	dma_release_channel(chan);
+}
+
+/**
+ * devm_spi_offload_tx_stream_request_dma_chan - Get the DMA channel info for the TX stream
+ * @dev: Device for devm purposes.
+ * @offload: Offload instance
+ *
+ * This is the DMA channel that will provide data to transfers that use the
+ * %SPI_OFFLOAD_XFER_TX_STREAM offload flag.
+ *
+ * Return: Pointer to DMA channel info, or negative error code
+ */
+struct dma_chan
+*devm_spi_offload_tx_stream_request_dma_chan(struct device *dev,
+					     struct spi_offload *offload)
+{
+	struct dma_chan *chan;
+	int ret;
+
+	if (!offload->ops || !offload->ops->tx_stream_request_dma_chan)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	chan = offload->ops->tx_stream_request_dma_chan(offload);
+	if (IS_ERR(chan))
+		return chan;
+
+	ret = devm_add_action_or_reset(dev, spi_offload_release_dma_chan, chan);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(devm_spi_offload_tx_stream_request_dma_chan);
+
+/**
+ * devm_spi_offload_rx_stream_request_dma_chan - Get the DMA channel info for the RX stream
+ * @dev: Device for devm purposes.
+ * @offload: Offload instance
+ *
+ * This is the DMA channel that will receive data from transfers that use the
+ * %SPI_OFFLOAD_XFER_RX_STREAM offload flag.
+ *
+ * Return: Pointer to DMA channel info, or negative error code
+ */
+struct dma_chan
+*devm_spi_offload_rx_stream_request_dma_chan(struct device *dev,
+					     struct spi_offload *offload)
+{
+	struct dma_chan *chan;
+	int ret;
+
+	if (!offload->ops || !offload->ops->rx_stream_request_dma_chan)
+		return ERR_PTR(-EOPNOTSUPP);
+
+	chan = offload->ops->rx_stream_request_dma_chan(offload);
+	if (IS_ERR(chan))
+		return chan;
+
+	ret = devm_add_action_or_reset(dev, spi_offload_release_dma_chan, chan);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(devm_spi_offload_rx_stream_request_dma_chan);
+
 /* Triggers providers */
 
 static void spi_offload_trigger_unregister(void *data)
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index a7a4647717d4..10c365e9100a 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -31,6 +31,7 @@
 #include <linux/ptp_clock_kernel.h>
 #include <linux/sched/rt.h>
 #include <linux/slab.h>
+#include <linux/spi/offload/types.h>
 #include <linux/spi/spi.h>
 #include <linux/spi/spi-mem.h>
 #include <uapi/linux/sched/types.h>
@@ -4158,6 +4159,15 @@ static int __spi_validate(struct spi_device *spi, struct spi_message *message)
 
 		if (_spi_xfer_word_delay_update(xfer, spi))
 			return -EINVAL;
+
+		/* Make sure controller supports required offload features. */
+		if (xfer->offload_flags) {
+			if (!message->offload)
+				return -EINVAL;
+
+			if (xfer->offload_flags & ~message->offload->xfer_flags)
+				return -EINVAL;
+		}
 	}
 
 	message->status = -EINPROGRESS;