1 files changed, 16 insertions, 1 deletions

diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index f72e0d1e0da8..7982bcc4d151 100644
--- a/Documentation/spi/spi-summary
+++ b/Documentation/spi/spi-summary
@@ -543,7 +543,22 @@ SPI MASTER METHODS
         queuing transfers that arrive in the meantime. When the driver is
         finished with this message, it must call
         spi_finalize_current_message() so the subsystem can issue the next
-        transfer. This may sleep.
+        message. This may sleep.
+
+    master->transfer_one(struct spi_master *master, struct spi_device *spi,
+                         struct spi_transfer *transfer)
+        The subsystem calls the driver to transfer a single transfer while
+        queuing transfers that arrive in the meantime. When the driver is
+        finished with this transfer, it must call
+        spi_finalize_current_transfer() so the subsystem can issue the next
+        transfer. This may sleep. Note: transfer_one and transfer_one_message
+        are mutually exclusive; when both are set, the generic subsystem does
+        not call your transfer_one callback.
+
+        Return values:
+        negative errno: error
+        0: transfer is finished
+        1: transfer is still in progress
 
     DEPRECATED METHODS