Merge branch 'fixes-for-v3.14' of git://git.linaro.org/people/mszyprowski/linux-dma...

[cascardo/linux.git] / Documentation / spi / spi-summary

diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index f72e0d1..7982bcc 100644 (file)
--- 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