path: root/Documentation/spi
diff options
authorBaruch Siach <baruch@tkos.co.il>2014-01-25 22:36:14 +0200
committerMark Brown <broonie@linaro.org>2014-01-27 18:44:35 +0000
commit18cc0adb132b390d026c574deec29bf182aede51 (patch)
tree605f8c65d7d23d3b4b8a17595a905bd07992a821 /Documentation/spi
parent6e5f52674ff0756e61a8879f6232b9ac33735cba (diff)
spi: document the transfer_one spi_master callback
Signed-off-by: Baruch Siach <baruch@tkos.co.il> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'Documentation/spi')
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary
index f72e0d1e0da8..dcaad476789c 100644
--- a/Documentation/spi/spi-summary
+++ b/Documentation/spi/spi-summary
@@ -545,6 +545,21 @@ SPI MASTER METHODS
spi_finalize_current_message() so the subsystem can issue the next
transfer. 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
master->transfer(struct spi_device *spi, struct spi_message *message)