diff options
Diffstat (limited to 'include/linux/spi/spi.h')
| -rw-r--r-- | include/linux/spi/spi.h | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 68bb1c501d0..bf21ef63984 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -264,6 +264,13 @@ struct spi_master { int (*transfer)(struct spi_device *spi, struct spi_message *mesg); + /* + * Synchronous non blocking transfer function. Should guarantee + * data availability when it returns + */ + int (*transfer_sync)(struct spi_device *spi, + struct spi_message *mesg); + /* called on release() to free memory provided by spi_master */ void (*cleanup)(struct spi_device *spi); }; @@ -573,6 +580,29 @@ spi_async(struct spi_device *spi, struct spi_message *message) return spi->master->transfer(spi, message); } +/** + * spi_non_blocking_transfer - Synchronous, non blocking transfer + * @spi: device with which data will be exchanged + * @message: describes the data transfers with optional completion handlers + * Context: any (irqs may be blocked, etc) + * + * Data is guaranteed to be written or read when this function returns. + * + * Note : This may not be supported by all spi masters. + */ + +static inline int +spi_non_blocking_transfer(struct spi_device *spi, struct spi_message *message) +{ + if (unlikely(!spi->master->transfer_sync)) { + dev_err(&spi->master->dev, + "non-blocking transfers not supported\n"); + return -EIO; + } + + return spi->master->transfer_sync(spi, message); +} + /*---------------------------------------------------------------------------*/ /* All these synchronous SPI transfer routines are utilities layered |